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Title P[3]内の曲線の分類と, 関連した話題 Author(s) ロビン, ハーツホーン; 石田, 正典; 佐藤, 栄一 Citation 数理解析レクチャー・ノート (1977), 2: 1-74 Issue Date 1977-03 URL http://hdl.handle.net/2433/216005 Right Type Book Textversion publisher Kyoto University

Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

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Page 1: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

Title P[3]内の曲線の分類と, 関連した話題

Author(s) ロビン, ハーツホーン; 石田, 正典; 佐藤, 栄一

Citation 数理解析レクチャー・ノート (1977), 2: 1-74

Issue Date 1977-03

URL http://hdl.handle.net/2433/216005

Right

Type Book

Textversion publisher

Kyoto University

Page 2: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

: "' D t:' / · J \ - '/ ;i\ - / 1 î I' J-

l 9771f3 JJ

Page 3: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

l~&1r.-.

§o. ~{~

I

§ i. r 6) t 6) luM'-e 6)/jjf~ / e

§ 2 . l l < "J "5' 6) ÂM/l.fo.c.a. 6) 1: 0) ~ 3 I

§3. [fciâ'-~fJ.(1c.wWeAl::;::;Li-z.0!1tJ!' 43

§ L/-. ~ ~(rv._ ~ # É 1J l ) Uuv\1-e 5 b

§ !5 . Jr3 l (f) cww~ ôJ kMrrv- 1 2 -:> l 1 -Z b 1

Page 4: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

) - ~ -i'F ~

~"' iE.:~ . 11i-1f * -.

Page 5: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

Classification of curves in ~3 and related topics

Introduction

The purpose of this seminar was to study the classification of curves

in w3, and look for applications to a) subvarieties of codimension two in

Pn, and b) vector bundles of rank two on Pn for n ~ 3. In particular,

we hoped to read the long papers of Max Noether LlO] and G. Halphen [4]

from the year 1882, to see what their results were, and find modern proofs

for them. We succeeded only partially.

Of course, curves are classified first by the numerical invariants

d=degree, and g=genus. After that, for fixed d, g, one knows from the

theory of the Chow variety or the Hilbert scheme, that the curves with

given d, g forma finite number of irreducible algebraic families.

Ideally, one would like to know which values of d and g occur, and

then the structure of the families of those curves.

Already a non-trivial problem is to determine for which ordered pairs

<d, g> there exists an irreducible non-singular curve X of degree d and

genus g • jp3 in • We spent a fair arnount of time on this question.

can summarize the results as follows.

a) We always have d > 0, g ~O.

b) If X is a plane curve 1 g ~ z-<d-1) (d-2).

c) If X does not lie in a plane, then

g ~

4<l2 - d + 1

4

1 2 4<d -1)- d + 1

- 1 -

if d even

if d odd

We

Page 6: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

Furthermore, the maximum is attained for each d, and in that case X

necessarily lies on a quadric surface.

d) If X lies on a quadric surface, then for some 0 < a < d, we

have 2

g = ad - a - d + 1, and for each such a, there is an irreducible

non-singular X.

In addition to these results, we have some information about small

values of d and g, and about curves lying on a non-singular cubic surface.

This does not yet completely answer the question of which <d, g> occur.

There are two further statements in Halphen's book, which taken with the

above would provide a complete answer, but we were not able to understand

Halphen's proof nor find a new proof of our own. They are

e) If X does not lie on a quadric surface,

then

g ~ ~(d-l)(d-2) + ~

f) If <d, g> satisfies the inequality of e), with d ~ 1 and

g ~ 0, then there exists an irreducible non-singular curve X of degree

d and genus g on a cubic surface.

The matters, along with some preliminaries and related results, occupy

the first 4 sections of the notes.

The fifth section is independent. It gives some examples of curves

which have no smooth deformation in various senses (examples due to Mumford,

Peskine and Szpiro, and Hartshorne). It still seems to be unknown whether

every reduced irreducible curve in P 3 has a smooth deformation in P3•

Sections 6 and 7 deal with the notion of liaison studied by Peskine

and Szpiro [11]. In particular, we discuss the equivalence relation on

- 2 -

Page 7: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

the· set of curves in IP 3 generated by liaison, and the connection with

3 vector bundles of rank 2 on .IP •

It is my pleasure to thank all the participants of the seminar for

their interest and support. And especially I would like to thank

M. 1'1aruyama for organizing the seminar, and 1'1. Ishida and E. Sato for

writing such clear notes from my disorganized lectures.

i o If~ 6 {)M.cl 7 If

â:t. \7683)

- 3 -

Robin Hartshorne Kyoto March 17, 1976

Page 8: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

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< De1 .. 0 .1 > ~J: f4'- t,r 7J /-~rmcJ, M.p~J. A~ -a. uuvw lao/-1)';0 CMNw X ?)<'_

~ l: fJA o;wt- 7J L. ::! )( Id: CJfl'>i-µ -( j) ~ l li :> o

< 11+· 0.2 > X -â lüU;M UUvv<.e. 'l1 ~ 'i~. 'J..O) ~.,_ ~ = P~ li. R= 1-X.(&x)

-C1ie~ t IJ , 1s LX ( él,x.) li éJ;< 0) S,;.fu P~CMAi c)wr. ( ; . e. · 'X Cü,x) = -ff (X ,&x) - ~(X, r:Jx) )

X 75< ri~~ ( ~ /f,. ) 0 t :j . Pv.. 1-t '*--1 ~.

~ 'l L ) tJ 11., 52. '/( ?)-o: lm1.R.fJ ( iM.u);.,<-~ ~, 7

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~6)%~~0)~ i'hl-Jl~t:::Rtfh 5 lJliffk') ~Ici:

lcnu.µ niTYVJMt-F /m;tettwe tJ t(J) ~ 1 f;J,

<lk{.0.3) )<.]:~ 'lLt.'l~.XOJcirJied

to-Wt g {t\: -a fu ~ l. -t 1;J '1:Yl10~ ()) 7L 1i. 'j.Jf)

~&V 'l 0113~, -f fj;Y; -5 X 6) dw.,f,,,ov- D IJ_ ~

Mv>11- :2:. Vl.1 Pi C Yl-1 <::- Z Pi<= X) ôYlfJt2 :t1-t-? ~ôll~ dz~D = ~Yl,E2. 'L..<b<"

4-

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~c/t.i_·l'fV\ -fùU /.(, = /<(_X) OJ n_ f =t o 1: J.t l. f ŒJ

~ov (f) fi (-fj == L. Vp(f) P -c1c~-t h. ~~t.,

P lâ )\ 6) i I\' -z. 6) JouJ.. 17o-i-Wt tz ~ ~ . Vp 1J: P 1 ~ )i;t. i ~ k <f) -v-~·lfM l -t 1;J 0

Z PA op 0 . 1 l -f :\:: 0 t !<'.(?<} 6) fi:*- (J) 7f., L 1 ~ ('.. cg .

oUJ l-f) == 0 . l IJ: 1;J,

<. D.et 0. 4 > UvW-e X 0 olvv-i.a ô r D1 , Di. 1:: J r L . k <D 7L -f ::f o --{ D1 - Di = tf) t: 7J G t. oJ ;)'1',f}.(:t t /;J 'l.

-:::\ . D 'L Di. 1;1: k~ ~ --z_"t; fJ 'l l! t 1 .

D, "'-DL L t.( ,t,g- 1d1 if 'r'-0 o' rv D} tz. /) 6J c~M, ~

)

~ l o4t-v: ID! 'l ~ <.

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s

Page 10: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

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~ )}!. ûJ t -3 (:2-tff~·i h 2 L.lf\'"C::3 h,

X 6J ~ drneJ F~ P /: ;l.i L i.-p lt ~ {)p Ytlo~ A..tv1ik (

t'~Jii:6'5. i/Jo->tt-19-tfk.. -;lp ~ &p ;6~·1tift6,j~'.

A p f---j A 'L L ts 'L ~ . 'YLp 0 ) = Vp lî) l à-<. Q

>1. ~ 7-"

< [lf 0. ~ > A 6) J"'-o-~or = (<l)o = I:. Ylp~J P r &.--,.J. rvi;J ~X

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< R()p o. 2 > V H0 (X.i-) 7 vJJ.i :to l~Ril 0Jo '"--' (A1)o

LJ \:>' D w~ ~~V CJI L. :t L D r-...G!J)o IJ 1;;

A E H0 Q\. ;l) ~~· ~;fl. t;l:". w')o = D fJ. ~ A1E H0(/<. t)

?j~·~atld Q

3) H0Q<, 't) ? .Al, AÎ 1 ::f 0 (::'. ~-;\ l 0)o = (d)o Z:: )>

' ,<l == À.A'

6

Page 11: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

* k ~ olvv-<Arrv<J } 'L < ~~ Ât'-'{j . \~Ml; _2-~~ \ /--<'~ 1

l"d:éJ~I~ ! J.4 / 1::;X:iAt!;)" ~O)~ t, t P,,tDp 0.1 l~t ')

/Dl"" (H0('f.rl)-~07)/~* l1Jfd, ~1 1 ) IDI

(J roj-E ~ .,1, p"-c.n 'l ~ 1-- 3 hi? ,

< ~ o. G > CMNv-e X w ~rir (}) ~{;;5 .if ?5". ~h ~ov- D 1.:ttL /D/ 01 ku!M-41/J;~pv..u. 'li°J, -z_

I

l ) ~ 'l :1 (~ ;J- ~ k.,i,;Â ~ l l ) ) 0

Sx_c,,,-,v.p}J_ O , 1 X ~ 1P Y\ l: ~ =J:-fl Io. c.wvv ..i t L . ,

1-1 -& Il?\'\ ôJ .fe;;)J/L~ t -r ho f-1 ~X Œ> t :r. H n X (-:tttlt t ~~ 9 ) liX ôJ ~é)V' -t'-&;h o ~ (j) t) 7J

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~~ ~;&,V' -(Ji ho

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1: tl ~ t ~ k-J2wt l'M<-f H0(fl'. !90)) ~ ,L-(0 (X . i )

i1, .. Jt t % *" ,J- f-J. I"' L~ 1 ~Jtf: Î 'h /H r1 X 1 a;

'7

Page 12: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

C-' è' J. V

( D.vf 0, '7 > p ~ X ôJ 1~, ~ 1?_ /.,/y.;,µ{ 1(:~

t t k t ~ . "'J- <fJ 11 t. 0 D r è ~r L -<.Mf'r 0 9 p 'l ~ t,, 'l

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.J; \V X 1- 7(/Jof!J, · ... , /J"v.1)

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Page 13: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

<lhM0.2) )(t~ J-t;_~~~

z::t'tJ'l~.

(1) J- : _kM-ep~ ~ ~ VpE/( 1~ Jil ckn(_;J2--p) == ckr-.;$ -1

@ L J- - P == ~ D- P 1 Dé rJ..- pr;, /J».-ff D} (2) ,S : ~ p~ ~ -c Thm I 0 lf 75\:'

kJ. imim>LMl~ ~ 'dp.QE:X (P==QtiYJ-z..) (2f-tL

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~ (J-r:>-Q) :::: ~052--PJ - ( I Cl} à:" 1)

~ (,J--p} "" ~ ;J--' ~, L o&m(J--P-Q) :::::. k. ;Jl - 2 .

P =-Q 0) t ~ P -2·~~/k 1 --c~ h 0 H li . 'l h if' ~1) (/--1 () 'X - P) =1t P ~ ) c clwn(J-P-Q J

- rkm (;J- - P) - / = cJ,;,,lll Y -- 2

~ 8J) > ;)' /2 ~ f~ tu pt Q Oî t ~

9

Page 14: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

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~ff D 7 P bff(O-PJ =t P ?J{! oi:;.,,J2 01!J-fti

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J 1 l 'f 1;!:. ~Â ~~ t /; ~ .

}· e. J..

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/0

Page 15: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

r;/,w.-wo V D (~ ttit i ~ ~ ~~ ~ t r l f:_ 'l

~. -lt(x.t) -8 -li. 0(0) 'L:t;t<.. (f.:J#d:: -C.'(x,i) ~ -A'(D) 'l t <.a

<-ThW\ 0.3) (~-Rocl) 1) --P, 0 (DJ - {'(D) == rÂ.eg D + / - r;J-

ii) {1(D) == {

0(k-D) ( ~)

(Cor ) rhd- k = 2 ~ - 2

P<-"'1Y+ ) Thl-h ;r 1) ~OC_k) - -ftl(k.) =- o(y_~ k +/ -1 "tJ; .?15~' li°O<) = -h..'(X.<Yx) = <J- > l,_'{J<.J == i 0(Y.,rh) = /

-;-; /;' s ~ - 1 = oU'd- /< + 1- J '" W.~ k ~ 2 <?1- - 2

Q. E. 1).

< l2e.{ O. 2) -1,.,'(D) :j:o 6)t-1 ~ov- D rt Auû'J i' <fJ 6 'lu l ! -/(,1 (D) ';:!. o Q) t ~ non-' ..-Jpec;J -z:· ï#; ~ c: ( ) ) 0

< Th~ O. L/- > ( Ctf{e'LcJ ) d#vv1AfYL D li"

fi,U-c;_J i' ~ b 'l ~if~~·

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11

Page 16: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ Dr--vO

[] 1) '1.- k

1 \ X I~ -4f1M-dt;;t..·(, --( D = r' E } r= 0). - ';~-/ 1!? L t: (f) 1it i (<f î âl

~J Op) 1~0 ( l 2]

< ~ O. q Î ~ 2 (]) ·mr:n1~ tf: X -? 1!?1

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< Rop O. 4-) ewwe_ X 1.1" ~rwét;r:i -Z'ëf;i ~ è'. ~ i) w8 E = 2 u) oliw- / t:f :=-1 iii) k =Œ - !) '= IJ ~ C/~ 0 V' J a44 [; /rv ?}" O~ - '? 4 /If 11.J o

gJfl~~

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k 1..-c r {; d~Ji ~(T'Y\ x C---7 p~-1 11 cCW1frr1Jc.J.

J!/r>Lbeiilcl~1 ~ t.. l ) J ' ~lfe~~9;

12

Page 17: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

d(faR.-J.. ~ t t ;fi 0 lî_ <F1 t ~ f 1'h - ftt 1~,,; /-/ c

P" 4P-Vvp-/w.~"' {:C)_'î l Xr1 \-1 -ncn-~.,,rwfw, l'. f; ~ 0 ~SI~ X '?){ C~d -i' JM,.._ )( 2 2 ~ ) 1;;'.' X r, lî t:.

c ~VÛ-iJ. '( f; /;} 0

71'- t 4i - #111' H 'l r;J. -/v; fi'~ W1t.€ 0 lJ 1 ::,ç,.,y~ _,~u,,

~ IHI (J) 2~ 6f-b>• ,,J IJ c !Hi 7l'1-, 1

-z IJ (f) cl' eru..r/... />~ 1 :: ~q ;;'t Î :6 ./'(!pi-;/ {;v>J!. ô) ~ t 0

P'lo-ir-f ) Y :: JMv,. X l t ~ , X 0 J~ ;tMJ x l.èJ-:J L B_,._ = { H \ H ~~pl~ /-1 7x -A.t.

H n X ~,r<LM J: ;i.. } 'l et· < • -f 0 E:: /'(Jp ~ Ôf.J))

~ Z 6- (-fo) 0 )'.'._~ {1 { ô) I~ F L f.<-kcq !}tl<f Cf ~

Cf '. l ( (9-IP (U) lYx/!11.Î \JI

-f 1 ----7 -f-/ -f o

i' 1~$,; t ~ , P (l9JP (/ l) ô) ))77[ (J- Yi T f ('." D'x/m: {j));'<_ if,

/'j. 'r-t I f{> (;): /.Uvlyd.""' i' -Ji 1J 1' S of;_ ~ Cf :::o vt- r

-3 P(0-JP(11) '=' { =fo 1~1_1i;:i ~ -1:.;;rtfwrJ.... ~,, Bx i: At il; ~ 'L t "f/fo = o "J"* 1) f Eo ~ ((! IJ lfl)@-z" ;E;

~ 7J' 5 Bx. ( J ~Wl Â</'~ -Z" .li.. <!) ~ ~ z tJ Yi. - (" -r I ?.,'' -s ti 0

B = V Bx C::: X x lH \ f~ J~J.. Au-t -t X /1 0 X&";(

p·tO)~d.:r~ âJdi -r1brt:. 0) ~,k 7U1- n-r- I i' &; ~ :6' ; ' B 0 ;,< 7L id- n- I & ' -Z. (8 i © /H l I\ lfJ ;Y1 o/edt.&.,,,, (ÎJ Wiar-

13

Page 18: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

c it '< n- 1 ïZ 7l \Hl ~, 5 B 0 wv.Cl.dl -a,M: u t t~ 1J ~

lJ t:.. i .:ft. 1i' v'1-1 f lJ 1 >).t1...- H n x: rn::rvi-/J,y,~:r_Lv, t 1J

/;; o ~ 7.., JMv- 'f > 2 , X Cl':t',~cÂ- 15) L '3 Id- Y = X n \-( r!ly -a y 0 ~J (rd.y '.:è: &xl-1)) t L ,

Y-v ~ r1_: c" ~'/Z'& !;; X ôJ ~J~ch~ c-, ~ 0

}:: 1)

H0 (&x) -7 H0(ô\v) -7 \-1 10-xt--V)) H0(&x) ~ i. 1.-' oltAf,{ H' ((}.1f.::v>) -= ~i<. Hr-'(Wx.&>) Y-1 21 Ël5'5 -V>>O 07t=3 oL~Hr-icwxtvl)= o

'', olwv-.~H0(0y-J) S. 1 .r} c Y-v lt Cr;-vvn_p__cj;_J,_ y 'l.

Y-v 1 t 51 C' baae.. Â fli.à;,_ -& 14 7 7), ; y 1 ;J: c ~vted

Q.E.D.

<~Dp 0, '5 / X ~ ~ CJ- ôJ Cww-e D ~~/)Il_ -{ ~ D-=oL 'li~~ ':i cl >2CJ. 1-S rf/D/ id:~ evw-;h -1,' -/; & 0

f?to-irt ) v P ~ x 1::: ).-t c R-R Thtrt r~ ~ 1J {

0 (D) = ol t 1 - ~ -+ t 1 (p)

~OÙ)- p) =(o!_-t) -(- / - } T -li_' (t)- p)

{1(D)={0(1<-I)) J -fc'(D-e)=-Ci. 0Q<-DtP)

1 Lf

Page 19: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

1 i' "t; {i ,7f' dJ.. fj k = 2 ~ - )_ 1 d.J-ft D L 2 ~ t 1 (;" 0' ; k\EJJ -= {' (D-1)) = O d:, 2

~(IDl-e)={0(D-P)-I ={0(j)J-2 =~lul-1 TIHn 0, 2 d::' ~ \Dl Â-Me p~ (i.-u.. t. !J ho ·:: ; 1.;

V Ç) E: X ( ~ t1 L ~ (D - e -Q) >- 2 ~ - 1 J: , l -t_ 1 (D- P-Q) = -it,0 8<-D 1P-t0) = o ; tL0 lD-P-Q)

== ( ol - 2.) -+ 1 - i W! x_ ( 2

~(ID 1-P-<J) = ~ (Dl -2

t-1 ~ :6' .5 Thfh O. 2 ~ 'J \Dl ~ ~ Q.E.D.

<~u. o. 1 > V ~ P' 1.::-i i ;ft ~ r ;fe7L '11Y1i -

AWt~ ~ t i /,f [ ":1 'IL > 2r -H i' éYJ:fi 1-/ .r il) A. P '-' P zl' ; w P-A-~, 11.. ' P" ---7 P r.-1

1::. r h V -7 7C l V) 7J'' ~rrm--rf u,&w. l /j ,; t ôJ ?5,. ~ tx 1 h.

p,,,~)

® (1)

p 0 (_2)

15

Page 20: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

Ill LI) Ô) f ) 1:::: V 0) /~' Ç), R ~ ~ Je _).:;,,l\.Q Ô) l:. i: p /)"'Ji;

? t 1 0 J R 1 J. ll- 1 :. .r 'J f~ c i~J: -;, 7 ? o î r:: &7 Q.J 6) J:

) 1 ~ V (J),~. Q Ô) t, '2-t~ktl 12 p If' P:i ~ ('. ~ Q. (j)

ic"";70vé Apt<-~ 0 1"-- 12 J: 6 '.f {~l<f 0,.~Jf.:ü'V' -r 7J < 7J ho )<\ ' ·)'

(.. - (,

V (~ PQ)- c_ rr~ P,Qf\l

Q. t:. D.

:c.. al 'tk .. vrv>.o. 0 rarvt.~ -z" iYvU J là: if :;t; 0"/>';

e-ur.,,v..e_ X ôJ ~<!V' D ;j~· ~ ~~ OJ t '1

X c__..,, !P" 12 ~ ~ ~~ t &~ 1/ ~ L @ltl L l. ~1-UL d.. {j) ~ ~(YIA X L--7 lP3 i' H nx ,.,_ D

'l Id. h t O)iJ~·;f'J-4:1 h, 41 (_; X ~ @- {) c~

o ot.t'f'-U- J.. OJ ~()-V' -r cl -; 2@- ~ s 1 r c1t,r1h--o1... n cl rr:z..e v( ~{)-"" X L-----'l JP 3 i' H (1 X

'" j) t 1j l,t =t 0 IF '& b o

S--;:-ww-,& 0. 2 IP2 J )< CWV"l (_ 'fl.tPt·A0-.~

-( I;;.< l. t j::' l 1 ?51" ~6.e)d C~fo-n.b>-_;:(, ~ M- ,r: 1j. (}) ()~~X

-= o( 'li 1,i 'l X 0 r'.itJ 'f< [x~, x,, x,] ::> lx IJ.

16

Page 21: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

1-& ;t ~ cb.y.-u d..o; i~~~ Â~ + i' Ix =-(f)

t /j it o P"" c)( J -a_ -t~ (X) t ) , °' w l - />t o d (j) .vµ.cf

..âe-~(.Q_

0 -7 ~X --:> ôl-.JPi ~ Ô-x --7 0

1 ~ à} l 1 -z r1 x "' & iP 2 (_- et) -i" t ~ /J' s IL (0-x) ~ X( &w·)

-x(<JJP 2foO) X (f9_w1) = (, t. 0 (rJpi(-cl.)) = ù,.

-A-'(rJrr1 t-J_J) =o 1 li1(éJ-ffe·éd.J) =-/i,0(gœi{::-3-rd.V =(':rJ.t') = (ol; ') J- 1 z ?C((Jy.) = 1-Cj_;')

11,_ (X)= (ol..; 1) = i(oé-l)(cA.-2)

17

Page 22: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

2- ô.l § 0) §~li. f 3 (}) cP CD CWw.e. ô) '7J Î~. ti 1 :.~ ~

cc = {(ri)~> 3 X Y\.S. ~ c li?' l rk~ X= ol JMU4 X=â f

i?~og ~ r 1::<5~ o L6' l ::.6Ji-G~'1t-il~~t1f:-t h-:.. L.

1-J !il 1@i JJ ~ 0

~ ô) t,g ~ ~FoY\· ~ l. t 1J t . >k <f) :::.. 'l ? 1) 6) ~~(*À-_s 'l'Lh 0

1 ) lf ~ ~(?~ J:" 3 7i ~~6 \î i) ;t & < clJ ~> 1.: J.:t l . ,X 15~·~.B:i h t li) li:G~

12 'l Al·f 1) 1::. ~ t J7- 1-t <cl, ij-> f_ é( ~ cl2. i o < ~ ~ i_(cL-l)(ct.-2) t 1J: lcl o X c ~ ro3

cl.<G o/. Jl .:: 1i. fi X -7 7C.(X) 15~· 1>1.,d.1tvwl i ~ ~ ~ n.

t fJ ~ JYLojeJ<.cn--. lL ~t-:\\. /·f Ti.f...X) ,, JP1

~ 7C(X} = cl i' ~ X = (jC/rWA Tc.(X) s_ ~([1.J:f))

= ;fCol-r)(cA.-2.)" ::i.) (.: => u -i :J == i_(c/-1>(ol-2) f& > 1-J."

xr~ïftif:t-t~. P~ 1P~(N=(Ji1)) 1~ cl.:,& [? 2

-t À~ "l. lP"107 ~ 1J ~;wi-;Jtutt H ~tL-~ t t<. tf, ~ T~ r::. cl:" ') H fJJP~ X prv /J JPL (i) ~'fWl Q <J) n~ Cw'w-e

18

Page 23: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

t fJ !-;; ' &a-~ 0. 2 { 2 '& 1) ~ ::: /l(X) = i {cl-!fll-2).

J' ? -Z.. X~ JP'-c:::__.,;, lP3 ?)~·, ~ ô1 l;t{9'1 'L 1j ~ ,

~ ( :::_ "=' l) l, H~ 1-J . ; k 6) J: -) 1 ::_ JJ;'\' L l ) h 0

o) Xc_,,JP1 ='7 ~= ~Cd..-1)(cl-2)

b) X ~ \P2 =?> < f ~l - d. + 1 cl:-W-eN1

â - l Ql'-- 1 - ol + 1 cl: ad.of /.f

c) :tL 3X ,-0;t j~Cd..-1J(rÂ.-2)+~ r[-:0(3)

~ > ( tcJ-1J(J-2> h 1,2 (3)

~ X1JiQ ~ ~c_e_{~~'à'-~ho ~~C:: ~::: 1- cl-t Ào{_ -;\2.. 3_A ~ Z.,

cL) < â < [ f(ol-1)(d-2) + ~ ol~o (?) 0

- - ( ~ (cl-1)(rl-2) cle.1,2(3)

~ ~(_ ~llCR {~~ ~;j'i_,l,;. rh_J c{ ~ ~ 0) fi~ CWvv-e. ;;j\" 4.f::ri ~ 0

~ O'J 3 -5 c) , ri) 0 t~ IJ :t- 8A i' t/? ~ , ~s L c) ôJ X .?5"'

~ /,t rkc ~œ c:: it. ;1'1..lf'l rf 3 = /- d -r). ol- )..1

t l (-j- () ~ '[ 1t ~8~--Z"-'3 h 0

è( -&~!\· l,}\Kq 12. 1,r;7z 0foq1i~1<- r ? , Proble-m l . 1. V~ '> o 12 t:t L -i ~ ~ OJ

atdw.J: uvw-e fi 4.f:t i ;; '5' ,

CD !Pi!~ i â: h !;, J.e~ ol tfJ non-~M cww-e /~

19

Page 24: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~= ~(o{:-1)(ol-2) -z"

#i ;a ?Î' _; . â 14 /Éi ~ 0)

J:- 7 7J îiii Îi r ~ .

cll / 2 3 Lf- 5 6 â 0 0 1 3 6 10

Q) v rJ 1 v e t= IV 1: f.1 l ~ Tlvrvi. ~ 'J

~tw- cl (f} n&n-4-in~L ~« b''itf:ri 'ho ~ <J)

- ? 11 Fel ~ ~ fJ Z:: ~. -i S 1:: ~ 7~L J:' ') rMF e CîJ ÂM/1.,.-fa.CQ. Fe. i' Fd.. !1 Fe ::=-X lf~· n/JYl:Â/À~l.

CWv0-l l'. '1 ~ -t ôJ~'",;ft;é: i h " r}_g_~ X :::: ole WJP3 = (J {::-Lf-) wFv<. ;; fY-r~ ( J-t.;-) wx = Gx (J.. f e -If) t 'J 2~-2 = ole-ff wx -

cl e C ci+ e - !.f-) &- ) z. ~ = -dz Je C ol f e -4) + 1

l' 1 ~ 0 JP\D tf (J.) Fe<. ~ 1 1 3 If

Fe (J) c~ ~d'on I 0 0 I 3 (]) J-f--11.-M (f)1ft_ IJ/o â) 2 0 1 if ~ 4- .::i r:: n 1;; 0 3 I 4- Io I i

If- 3 q I q 33 @ '(lf!VI.-~ ~(_ ~<.R. Q c lP; -g

~1'-ho G ~ r'xr' i'ifJ 1J' fPLc.[p 1x.ll?1 = ;Itf!g c;·-jo~ 0 ~&r D 6 (!/\-. b) (.:CftL. D: 4 ~;&-

~ o.,,b >o ~, 0 \~ T/vr.1. ~ ~ o._, b '1 o

1J ~ If (9- , b) 1 .è j,-1 h Yi1JY1..-~w.. CWv'V'-e c p'x 1\? 1

20

Page 25: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

75'"iftA 1 ~ o x_(f) ~ 1~ o_J:, -o..-b + 1 t 7J ~ o

r;v-~ ~o..ce 1: '.) t• <- ttf(~i'10_ < ~ L < ~~ ~ t (: i "1 • .1 J,- b = J <5J l 1 ~ = a._ - I -L'

X c:. ; J!?'x1P1 ;-,, 1P1

~~ ~\ t fJ 'J x (~ itJr dt-i1-c r IJ -90 ~:fL (~ f ~ If~ > o r.:: JA L . ~ ~ <D u.~ -1~/ii tri h 2- l ?),,,

%-:J-6' Îi. ~I:: ~) / IJ, ~ ~jW"~'- 12 t~~o <'.Thm 1 _ 2> ( HJrfl{);vl_) X~ Jb'vWl ~ ([) ewvV'l

t 1 '!;; t~ ;~rar~(c@. \) "ri (}11_-Aftd IJ ciR.rw- cl 0) ~ C<IVv<pft

~rrV' ;6~' i?tli:i 1 h, iv ol '2: ~ t 3

R~ ) D ~ 'f 6l ?1 r;;v /Jfddc,) 7J ~1»2- d 0

~()'(' l i h l =1 ' ThM 0' 2 J:" IJ D: 'W/"(J {lfti-! ~ V P,G ~ X -/L 0(D- P) ==- ~C(D)-- / { 0(D-f-O) = -h 0(J)) - 2. . c ~ 61.5"' R-R ()) 1î:t~ J= 1) ~0(D) ::::_ ol-~t/ -A0(D-P) ==- ol.-1 - ~ + 1 + i 1(D-P) { 0 (o -P-Q) = d._-2-~ +I +{.'(D-P-0) d:, 2 { 0 (D-P):=

fi, 0(p) -1 i'i-,fa(2/j:. 0-() /1o-vt,-4f-lc,;_J; -Â0{[J-f-Q)

Page 26: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

= {0(D) - .2 i'-kih 121-J D-P-Q non-~ùol 7."-bh

2c;)''' .À,l·f/f IJ-::>+1Ji"~/;;o D-P-Q nrm-~Ct.J.._

-i"<V>lh. If D-P nm-4;-edJ -t-;f; iJ75' :S D- P-Q /5,"11

* À~ 1-J«t· ll 0

D-P-Q A-p.ei<_JJ.~ { 1(D-P-Q) > o

~ { 0(k.- DtP+Q) )O

8 3 R1, --·/Rt E X i:= 2â-ri

--<IJ. Rif -- ·+ R t r\__. k -D + P+Q

3tXITT "JIÀC~ ~ , Cf t >n~~ cr: xt+ 2 JrL

~ w (P,Q)R1)---JR-t) 1 > k'+P+O-R1--"-R-1:

'l i ~ 0 t l --t-t-2 < 9r 1& 5 /cl:" k. JJ.. = ~ fS'lj- "5 3 D D 'Î IWI <f ~ 0) D l"d- V p > Q D-P-Q Î1rJY'<4perN,l

-t+2 L~ 6)l=J1-;J. <f l'J ~'.e~ è'._fj, -Z.. v't>

o&.d D = d. /j: 3 P, Q D- P-Q A,;ie~

Q.E.D. 1<..rwtwJ 1 . 3 . X 1i lPi (:; 1 ~ ;fi, 1J l l JP3 6) ?ta>t-

Ahc;J'i'/L e-wvv-e -{ D::: /-/ fJ X ~~ t 1 ~ 'l ~ T~ t 1

) 3 < o&m 1 D \ < ~ ~~ D d="; L

dv > 6 L;J' t ol= 6 ~ D =- k or X : /v;?M­dlft;c

21

Page 27: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

No 1 2 3 L/-- 5 6 '7 g q

I 2

3 Lj-

~

b

·o 0 1

1 ----

• 0 • • 0 • • • 0

·--

• • • • D

o~~ 9 Th1n 1. 2 t:: J:' 0 H n X ri61'l-4p!ÂJ

7'J Cvl/\Ne

0 F:i · f3

(0

01

ci =- 6 OJ t :S . ~ .:h ~t-9~ 6l ~ i'f ;J:iftki: L ~ l l ~ t IJ . ;71_ l::

If t 0

îhnt l, 4-. 'f -a ~ <J- ô) eww-e. D 1: X .t <fJ ~ ol ôJ WfaiJ Offe-p_ ~cr i' D 1~ .4ftd..ti/ 20 /~ nrm-A~Gwi i' ~'/Dl L 3 <:'. i ~ t. d 'L. 6 -z" ~(cl -t-2) s_ ~ < 2d.. - o( t 7J h o

~wt ) J 1 l~ -2 fJ > li' { 1(0) -::.-fi_0{f!_-D)

== 0 t 1J 1J D n1m-4p.er;,;.J. à:" , 'Z. 1~ IJi: l:: 1) d <

Page 28: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

21j._-2 Lttr"?-Z, ~(c(f2)sS\. ~/Dl>J

i'~/;)6' ~ Uiffo~d Tlvm d= 1) 3 < ~/Dl ~±cl

~., z cl> 6 1l~ l;f <l s2d-g i'-ki~6~', X t JP3 11! (::: Bx(U :: <Jx{JJ) 'l Tj ~ . y_''Jc 11 ;éwn-e. (:_ -ti 1' /f1.

7J ( ) J: -) 1::; -J i:tJ ~ d-1- . ;fa_ OJ ~ut ÂlF Cf. ~ '5 ;Z_ 1.i o

o -7 dx(2) -::> &r3(2) -7 &x (2) --?o

2.::11 r IJ ~J- 4.L~œ

o--7 H 0~x()_))--? H0( 01P,Q-)) 7 H0

((Yx(l))

.?5~'1~ Sk? 7.F H0 ( GJP3Q.)) ôJ)}z_Jtlt /0 i'{IJ) JÎ1o --z."

fJ t )1[ rj:. J]?'()) r;v-wh.J., ~o.ce. (~j_~ L. >l ;;\'t.7)"'

l-f 0 (dxC2)) <JJ 1l ·-c-Jy h ~ l'. fJttx i ~ ~ hVA-(a<-e.

i'.S''X ~i;l ~ 'l t f5l~i'-hh" ~ ~ -i' X CG1 XCG2

01 /J1 ~ F~ Â.Wl.f(!( i' QI =F (),_ ci~ 'l, X/-J ~C//M. 1.:- 1 i ;Ft. lj t J 75' s . Q 1 ~ G .i. 11 Wi..ru:LJ.l 'l i'J. \J x cQ1 rO:i. t ~ 3 ;5"'01no2 li rkr-u- Lf- 0 ~ fi'fJ' 5 ~ te fi 1i 9 4~7J u o ~) L- H0(dx (;!)) 0) >Pit li. ~ 1 I , ;\:- , 1- ..J0.t> J; /Je..~Q. t 1

) Îi, o { fJ.x~)) =

-/:..0(0x(20)) ~ 9 2D /~ n15Y'..-Af€Vl.'ol t'IJ''5 !<-!< t ~ 9 < { 0(rJ1J}.D)) :: 2d., - CfJ + 1 J- ? l. ~ < 2oi.- B

iif't4~ > h h 0

Q.E,D.

Page 29: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

::. 6) Thmt r:: J-, l ) L. rl = b t lJ. 1êi (J) 1i ~ T/vn;t

d:" 1) rf:J D"' o ) b) D = K ) c..) x: ~< ?} ? D

= r E 1 s. r i ~-1 i'l) ·f ~J:l' -Z:'~ J.i 75~', o) ri ci t. c, J: ~

i? ~ {~ /j l \ b) \)) j~{; 6 :::: ~ k = 2 ~ - 2 :r \) ~ = 4- --i"

~ h rf', X ~ !P3 rJ ôJ h. t F3 â) UJw-µ ~d'Oh l'. 1 ht o&.~x-::::2,3==-6 â=l·2,3(2+3-4)+1 =:'f

Wx = 6Lx (1) 'l fj ') 6fx(1) = Gx (D) 'li ;;\l 11'. -fl'<P> =­

{ 0(&x) = / rv DAteuJ i'/..19-D)=/v0(:-D)=o

t ') 2 IJ nh(-4f€w.f. :r , l. cl=- 6 ~ = 'f â) t\t RMt, ~ ()) J: J t~ ~OV' ~ :/:1 ? CWl/v'e 11 it+~ i ~ o C) l'J-

(~-1) E ==- k d= ') ~ E ?1éÎ, ~ !HM~ . E ri baM.. jJ~ ~ ···{1;7;6'5 Yt, \r:ol, .. >~-/ -t llH.N(

~rÂ- -c-J; 'J ~~ i1 u, i t d = 2cl- g tfJ 0 ô!l"J:,

li. 0((}.y_@)) = 9 'l /J 0 'l -:1 i". ::. ÔJ 'l :S .!)<: 1 -li,0 (<1-x<?-J)

:= 1 i'11"11-5 . Xtd: 45 G ~ .MA-{a.~ r~ i î ;tt.

ho Tfvm \. ~, X t ~t ~(Q f:c4 ~{'<..

IJ.t> ~ ~ 6J CWvv-l- 'l L. DO>~ d. 6J ~ AA1ph. ~cr -c 2. D li A-pe.C:.J 3 D r# ri!Jl'l-

~u~ ?J =t <f) l".. i f.i 'C ol '2 ~ i' 0 l= 9 ~=-/0 ~1il-J. 2) ri-Z.10 i' ol+t<~ ~ 3J.-/q Li1

25

Page 30: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

P~ ) Thrn 1. 't O)~ifef\ r IJ AiJ'·· ~(_, M<ltjw.e ..

( ~ 3 "=J ,fz_lJ ( t ;fl 1 ;f -h 0ldx (2 D)) L. I o 7-'. -;V; ') . 2 D Apeu(;J!.

J: IJ Jim. \2 t::;I ~ ~. 2..J ::::: ot. r- J -z.. cl > q cl:=. 1 'l 1 h â,J 11- 2D :=. /( W t '! -i' ! <6 ==- 2~ - :;_ j:" 1) j :=. 10

:::. :t'Lld- JP3(f)1f 0) F3 t f, (j) <..&r<µ_ ~~ 'l L

·-L.rk7f~: et+ ,a j 1d. ~ 1.. cl 2 10 07 'l ;j . X 12 ff1 (]) r.P f~

O"U) = OxlP) 'l-i;.f;J r 31~ > 't.! 2-J+. ~J 4l~ 0 -7 dx. l3) -7 &_pl3) ----?' r9-;<. (3) -7 0

0 -:> H0Cdx (3J)----'> H0(c9w3(3;) -7 H0 (Üx (3))

-~A~ fci - X c f3 , f-3 1 F> _, F/ ~è A.Wi..fli\_~ F, 4- F;'

l i h 'L . X/;~' F~ .4WL f.C/2 {::; ~ 1. ;fi_ IJ (} 2. L l)' ; .

F; l F/ IJ JÀM_~ 'l t ~ X c F;, () Fj I h fi F, I

oltruJL cr ô) ~ '(_Id. ~ <k:; o è. r o :r 9 . ~ :tt 1i

-;Y} ~«~ 1; u 0 ~) ê -h0(dxGJ) ~ 1 /i0 (&r' (3)) = 20

-i'-J! f;J ;:5' j Ji,D(<'Jx.(3)):::: -f,,D(f3x(3D)) ~ /q R.-P.. ):: ') /9 < { 0

( &x(3D)) == 3 D - ~ + 1 (3 D : nmt-4-µu.J) ~.,

L. ~ < 3 J_- / g ~ t:2_ 2. D AjJUA:J.. i- 'J 2ol < 2~-1 :r., 7- cl+/<';}

G. E. D.

26

Page 31: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

3 D ~J, 'li 1J 'L ~ Thm. d=" 1) d;;m /3DI ~ -:} 3c,{_ -i" lJ /;} (/ Tiwt I , $ (f) ~ite~ ()) tf î" i L f. J::- ) {::,

X ;J;;' p-o..k~ ,Uv~ft(_Q / ::.1. î :fL 7'J lî :h t;t." ~ 0(3 D) > 19

t J (_ j g ~ i d i '1 ;f; s cl 2- 1 2 '* iS,q'~· i' f1 h ~

) l:: rd.M:. ,i.wtf~u . .e 1::: i î -ft. 6 Ylon-~;Jw< ûu'vre

{j ol = u + b } ::: Ct. b - i - b î I CL, b t: ,fV o; fi~{.: l lî h ï5~· l s cl~ t l o ~ ;i 5 to (]) ;~@-fl:J: TlvM 1. 2,,

1. L/-, J . !:; ôlf~IID 1::- ;\ S 1:i- U 0) Id: J,::: ~ J::: ~ 01 8î t-''11

-( ~ 6 . ~ i <," 0) ;f!;; "'- Ïj_ :tz I~ L L d-f 1,) 'l

• Thm 1. 2

11 Thiat 1 . Lf-0 ~è@l

~ Thm \. 5 o~C, \j]

~7l-f o! 1 2 3 11- sr:,' 7!g q l10/11[12i13l1~l1s \ 0 1 i 1 '

, ........ . Q ~ Ui.!i/V"€_ _ 1 0 e e " • " e

11•••111111@• 0 -12:'1 ....

2'7

Page 32: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ 0il *'~oj~ -0 li . 1..;;\'t. i' .;tt dJ ~fr t ~ fti f: i ~ 7J".

t.> h t i if7- 1-i. 1 ~ 1; lJ !i Il{ (~" 1J 5 7J ( ) 2 t 1f 7ï' l --z: () Q ?)\"

tr~: 1:;.4 ,(j -t fJl)' '(; 15' t~h ;5· 5 7J ( ). i 2 -z;· /?

&~;b l:'. l -z. lÎiw. 1 . 4 6) fc 1IB. i rJ ti ~ D µv:J.

2 D Y1011-Aµuo.1 'l 1 h ~ a..ir& dh--tAor /) 1i f~

'/ C-Wvv.e OJiî+li L~~~~(;lill~'> &'! ~==5 t:;. ?Cie

'lf~,f+ft 1 9 ~' '() ,,, gJ~/\" 7 If J:' ? .

@) rti'lij <1)~1 E.~ ~

X f? ~ 5 <J) ewvv-e. D ~ rle.;ru '7 ôJ olv-t/Jôr

t i li R-1< J:' 1) le 0( D) = 7 -t- / - s --f liYD) -c ;fi & ~\" -li,1(D)

= -t. 0(](-D) IJ, ch_~(k.-D)::: 1 1§..11' T~1 1. 2;} :5. D

NeNj WltApk i"-#i Îl 1-f D ! t /JfUc<.J --c cb ~ ïJ 5 /i (D) = / 'l 7J 1

) -li, 0(D) = 4 'l 7J ~ o

[) 4 CWvipi.: ~ V p, Q E.X ~o(.P-P--O)~-fto(0)-2

B ~tb) :-fi,'(D-P) =-/t,1(D-P-G)

"'P,QEX

~ 3 R E-X R=-\<'.--D i"VP,OEX {

0(R)= -{C>(P-tR) =~ 0(P-tQtR)=I

'l '2 3 i' j<f: X ~ fr-- L ~ 'l ~ {

0 (R) = 1 ~ X: 'Î~o-viJ 7-"/J () Yp & )Z ft,0Cl<iP) =- 1 ~ X : lvt;wJt.fti-1., --z,"lJ l J

2B

Page 33: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

i.0(R-tP+Q)=I ~ X ~ ~~~,,1 <-''nt J

ewvw. X t$'" -tv:i!ThJ ~ 3 ~or D ~d/)=3 4!DI>\

t , -z X 15~' ~ 5" t5) ewvv--e (j) t ~ X iJJ..3 ~ <."

b;:!z (~· 11j,o; ~or /) dej D = 7 /J ~ ~ -c 7J < 'X ?S'" 1N:.?ô7''J i' (J 1t :11. tf /<€: X ~ -) 1- <-fi 1. -i'

D ~ i< - !< 'l cJ;, 11 li' D f* dt~ 7 -i" ~ aw.;h 'l

lJ h 0 i ~ (,''f J1~1 t ~ t; (j) "bi;,3 f/'flJ, -t 1 ( ) c.wvv-e ;S\",{}Jl i h ~' t") ;)' ('._ \G'J1@-Z:'~ h.

g"P i, 6. ~ ~ OJ -/;,,i,JrmJ i'~( J ut1wt

ef~'t+:f.:t 1 ho Jt'~ X t [llf 11'1 -z:· X= f, · f;. · F; cow-µ ~d..ôn ('.'. i;h,lfJ:"() 0

f2i_.,t ) Wp = (j~ S-)

W F, =- (J {_-3)

WF:i fl = 0 (--1)

W X = (J (\)

'L fJ ') 2 ~ - 2 = J . 2 . 2. =- 'i? ;i:- 1J ~ = s X 7.5' ,,

NaoriJ -z"i>~rf 3 P,0; i< AJ ~/P+G-/-R\ Li R-R r'J ~0 (PfQ-/-Q)=3-!i-r-1-+{0(1<-P-G-!<)

> 2 r., 7- ~0 (~-P-Q-R) > 3 i lJ1? '5 [P'f ())

~ ~~ t '1r;ku- H,; Hl, Hj -z''#

Page 34: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

t::. P J G 1 R -ai 1' t 6) l)''',.f+ ifi i ~ o iP = H 1 n j-1, n \-h si

P ~ o / p r 1; 1P1 c r, -F. · F, == x ::: if<. (J ~ 1@ . r , z. 'f- IJ 1/i_;_~ô""-J -( 7J l 1 o

Q. E. D.

30

Page 35: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ 2 l l ~ -:::> lp ôJ .MA-f~œ (j) _t OJ GWVv-e4

1. 1'1.UM..-4WcrulM. rk0 ~(_Q_ _t ô) uuwe.

Q ~ lP3 15) rirJïv,,;...:;...rf{l/I, ~~ AwL-fu-e l. L Q

J:. 0) i !\" -i ô) n lfh.-AhgJM. ~~ c.ww-e 1/;il~1

f.J ~ 'L 1'5 ;L .?. Q ~ U?'x IP' -c· 1> ~ J5' .5 p,\. Q = z <jl J'.'. ~ L. (1, o)

/j: lP/ = JP17C]x'r ô) dv.M (0, 1) l'i if~::: iAxJP1 (J) ~

'li h 0 (X li IP1 6) !i4;t 6),•?.,)

1) -i!{fe~ ciwvitn D <>~· (o., b) ~ R'c Q (2-

/i i h 'l i .Q 'l ' R ::: D . JP1 > ô b == D . il?,' > 0

2) Dt:: (û, b) lf\" ÛAV'/Â- B D, > o O· E > o

V E :f 0 4~ ~iY/. 'l /J 1J ?j\'' DJ_ =- ). o..b } E =-

(Cl) b) o..'> o, b1,? o t i 1J t D·E =- a.b 1 +be/

J-) 7- D: OM<th ~ O., b >o 3) -.\\\~ t::: 1), ~ a....r6- Dl w Â-a_u_ rtiJ -i J;

1t ( f Di -+ Il. 1-J ~ !Mtt;d l 7j 6 ?j" (1 ) !) <t ~ aayl.( -(,' (1, 0) ( 0, 1) { J -n ü k f,,;.;t ·z." S iJ ;f _;

(}. J b > 0 <J) t. :3 ( ()_ / b) ( 1 /iN!/v'j M>-;~ (,,, ~ h 0

Ll J: -& l Y.. '!!; 6 'L

(y..,, b) .a,,, -1{e~ ~o'L 11{ 7 ~ o..,b >o (Cl.? b) ;?j\'' CIAM-ph ~ (0, b) 1-i''' ~ U#t~ ~ o., b > 0

31

Page 36: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

(0, b) b > 0 6J ..vW-~ ~ü"°L IJ i /\"l D =­

~ 1t:tjxJJ?1 O)f~alêUh('.5'; Vw.~ trJ-hOltd.. t."'=.t

b ==- r oJ 'L =t t.·11 -t ~ "!;;., J.t l i' (o., b) E:- 1~ c Q 05'"

n0>1.-4-Wtrk'- /Jvi.ed.,.cJJ-l Gwl!V'e "t 'â <!..>' GJ {j © C<. )) ) o

Q) Cl.=-o, b::.I GD â.= 1, b=o ô)lif';ft.;?,-z.''"t~,

Ca.-) b) (~'th lt!J;t-~ uvvv-e Xli HE(i,1)

t''75' 5 dr;,8 X = a_ -r b <-" t 6 o - J) ~ 11- ~ t~

.v/,/-e~ ~&'L {J(:cjtL 2fl.(D)-2:::-[)·{JJ-tl<)

--c iJJ ') k ~ - 2 H é:(:2,-2) 0"7>' 3

l~ -2 -= GL(_D-2) + b(ll-2)

.:: 2a..b - 2CL -2b

J:- 7 'L ~ = CL b - û. - b t I -(jy IJ o

2 ~ -z," J -a_ F L ~ f}if 6) d- d7 ~;( 1@ t. 5f<. k'J l df ';.

/,, Qtb=ol. à:'J b=cl-a

~ ::: a..(rl- a.) - a_ - (cl -Cl) + 1 = cul. - 0.1 - J_ t /

f'tJ':S cl:~ô)i~,g a.=<1- -(jlt-1~ ~2

-ol+/ r;L: ode{ w ~6 ll = dî_t -z;":fd1@ d~-r- -al t I 'l'. 4

h,

2. rr(._k( {,(J/li!. J: n c.ww-e..

X ~ .\P3 {fJ Fdu:-c C&ne ~ l, ~ ÔJ ~ 0

~ ~ r ::_ t z_ b4w- ""fJ L- t:: t 0; ~ F 'é'. 1 9 o

32

Page 37: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

,) c, F I~ 11/J}\-~il/\.

AM-{u.u t (j ~ • t 1,,

kéow u...f t-:2 J: 'J L~.ti .:\'t.

1.1 /I; /

ewwe. ~ Co t <li« o

X~() -aitlJ.tJ

0 ~/M-~ -c· cwi:

· t 1.J 'l , c OJ'lA.è, l'.: 7J ? ;;f-:' I X ~ 0 ?.5' > H { 2

;uc;"<ch'w. t ~ 'l, . ~~ tJ H l OJ ~ 'l 1i ~.

Î3f~I~ F '5' ~ c()'Yl-Ù -" d) /~ m(}..r -a ;,.,..k i ;. L if t ~ :fi. ra. U?~~.t& 0>~111i =t? • NH4, = &Ho) <O""'Uc rJ =- ~!< d:b~! t·~ 6 lf' s

[:" - Co = X - {o'( ~ \/{__(){).))

J r i '

loYV<-G

t, -z.. "F .'.:::' \P ~© &~J) "IL r !P1 i Col.=- -2 -c'

1;~ 0

lP' <l}f:i! 6J,~, 0) fibre i 1- l. i ~ 'l -f z.=O _, Co· f "° 1

P,'c, F = ~Ef) ïZ "i' Q. o) (i Co 1-...J-f -C---'-o

(O. l) (1- + -c+rt :1 *- ('. u !,} t L L t ----JP'

33

Page 38: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

lr4:,~. 0) -ejf-vlr-e_ ~M. D a-~ F (~ :ZtL 2fa_(DJ

- 2 = D ·(D+I<} i'-f; 6 2 t °& 1î1u1- k ~ f J<) J:-7 o

k = a.Co t b f t J;· lt If [) =- f Oî t '!

-2 = .Y·(ltCot(_b+l)f) ::: Cl a= -2

D==-f 'l1hc -2= C.·(-C 0 tbf)= 2tb b=-'t

,i:";. '- k= -2Cc-L/-f

~µt~ H-= a_Co + h f /-1 · Co = O t ') H·f == l J:- '.>

J::'.) t.. H =- Co -f2f

b -.2CL =O

Cl -= 1

!) D ::: QCc + b f 'l- th l ~ D Vw_~ -t{~ ~ 5 li D=- f Zlt D· f >o ~ CL)o_,

D = Co ~ 1.2 t;J: D · Co > o ~ -2 Q -1- b ?': o .1 J:. ) L

/) ::: f ) c 0 ~ t:. {l (;(_ > 0 .) b ~ 2 Cl

if D = QCo + hf t i ~ l ~ 0 ~,& 7J- ; 1t'

D·f )O J: IJ a;>o D Co >o J:- 1) b-2et.>o

3) b ::: CL Co -t b -f <$'", U ? ~ r:;vw..,,& ~

/j: ~ 7)' ~"\12 ().

C1Mm. Co + 3 f 1-J: ~ (ÂM>'~

Page 39: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

f'1<>-r7 + ) c 0 + 3 f :0 H T f --[_ H t + t

ba.<U p~ ~ -t'-;h ?6' 5 Co+ 3f =t PC14.12

p~ ~ --(-f; h 0 fi/W.. ô)::: ,!t Q_ Mftvtc.:;&, 1 h .2. '(_

1-;l:, - lJ (1) 1~,J\~· F- Lo (2 °ii;h If H c," Mf~ i'1 ltfl

/) 'l t Co O),~, ·("th ;fi_ fi f -L' MfW'~ i' '5. 'h " 11A_.15) i'5,âJ ~ IW-w'cf~ 1i ~ 1~2~/-j_ F-Co aJf.t1t H lèt ~

.4.e..-f vAcVle --T ;\'t -z -Ji· 'J } Co

6) t :~, p lt p i ~ > 7J. ()

3-f 'l- Co ffJ d/v.MrYL Do

'l Co t 1. :\'? _; TJ ( J H t P ~ JÉl G t ff'J oiV.--l4M [>,

C .!:" , l- 412-f evw.h "1 ;\L ~ o

) ). J: 7-" U.M>rc (rj: ~il a~ 1 t_

/2 0

Do

p Co -*1----~l-l--

f

H

1-/ = Co + l { , -Ç (~ bOM. !~ f-w- CD + 3 f /-j: ~ a-w.~ -ci> la -'f' .s a.> o _, b > 2C<. (}) t '3_

°'-Co --f b -f (1 -wNj û-Mp--& --t'1J ~" O/,'A~ ( ::_

id: h ~14' 'L~ -îJ -it (J 'L

e D = Ct. Co -+ h f 1 è ;Z.t L

D : (µMp-& ~ {) : ~ evvv-th- t;;;=; (). > o ) b >2l<--

35

Page 40: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

X~ JP3 (i) p-~ c~ 'l L 0 ~ 't 0) ~ t

i ~ 0

C t X (:: i i1t h non-MM.~ ~ t... i J.i t ~

64..e. 1. 0 ~ C m t s. C(;J: F 6) Gw\/V'l 'l ~ ),_

s:tz. c E(o.,b) r t:ttrr c· c~ ==-2a.-t-b= o .'. 2 a.::: b 'C 7J 1) C n... a H -i .. C !;î: cow<µ_ ~&v. X·Fc.. ÛUe- 2. 0 E C (f) L ~ ( .;_ (Ct. _, b) 'l l ~ t '1

C nO'h.-~~ -c,"/hh?.f'.5 C·Co = -2o_+b :=:- 1

.'. b"" 2Q+/ C =. lLCo + Q.o..+1) f C 6) ~

{j d:=:- ( · /--/;::. 2C<_ 1- I ~ (/- {j:

2~-2 ==- C·((.+l<.) ~ (Cl.Co+ 0-o. + l)f) ·(C0-.-2)Co -+QQ-3) f) = ~2 0..(0..-2) t CL(2a-3) + (2a-rl)(o.-2) = -2a.1+ q..ez.. -t 2a.""- Ja...+ 2a..i-+C<.-Lf-a..-2

= 2.0...,l.-2Q-2

.1.- 'J @- = 0-:i. - CL

i<Mrltuvf<. G {L(JYI.-~~ rp-o.ct.M_ ~CQ_ c JP~ -{ ( E (()..1 b) 0) t "3 cJ... == et+ b ~ .::: ()., b -

(). - b t / -( 1> , 0. /)"' b == û + I (J) t ':! ol = 20.. + 1

~ "" a_ (li.+ 1) - Cl. - (o._ -t !) + I == Û. i._ C\. J:'., 7..,

36

Page 41: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

cgv-0-Ad..'c li91U. 1::.i '};li_ h YL&it-~~ ~

CD ~ ~ "6'" <o(; ~ > /J. _; non -AWir. pa.du.c. 4wi..fa.c.e (:::. 1 ~ *-,? ?t.&n-4#...rfM. ~ -z_"

~ } ~ l/~' <.d) 'j. > Îj h 'ê (J) -1'4ft1 ~ :! t 1~-.

)J()'ho

3. }lffYL-~F wk .4M,ft..~ J: Ô) ~ JP2

;), _; 6 1'~, R/ · - -1

p, -& t'0 3 / t_- ®#î_t 1_:fi

< I b / 7)1" - 7 0) (~ .1: {:. lj. ( ) J:' ) f .è t h ' >l L L

~M. ~ { C C : cJ-ù.. ewwe. 7 Pi/ ··· 1 p,}

1: à=- '} ./)_~J lttti-.f

JPJ. ~ lf3

~ ft; 1} /Àna.y 0) ~ t F t_ t ~ (f F lt 11.m.­

Ah-~ ~ ~ce. i'1)h.

[

fit:: ~ ~ d~coJ4 ci(j'UJ 'fdJ l L t J 'L ';\' ' i /{ (., 0) lW7!,-~M_ AIA/i.. f<.u. c JP .3 (;t .

2 ôJ J-) 1: Lê {(,lî .SAL ~

~if BR lt N~ If) ~ F()1,M,(J / 9 17 'I-f 111"'- f/2G

F 1 ntJ>t-Affi;uJ.M ~ ~\.e t t 'h t 1

F ft__ IP:l. d) 6 I~~' R / - - 0

/ R ~ bk- "'-f L t_ f_ OJ t t ~ ; ;n..; ï5' .s R:c. F ô:- 7L7 i' ..1. e1 - - · eb ~

/ / /

37

Page 42: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

pa,4ÙJ l ~ t 1L .-5 o 1 E L Jl 1 * 1[f <D P / - --; P 6 tZ: i i-~ (1 k e, t* P.: <n ~~ t1i5 o 1~ 1,

e~:::-1} ,le,'=o, e1.e;' =-o <1 ,'ti), t?.t_, LU ~o

6 H = ~fM-~ M-~ = 3}_ - t; el

k-:::: (J-(<i-'-1-)-=:: &(-1) {è ~t.t-t;ft li" {,

k = cevn&-rvt,cJ ~IYL "" -3}_ + :Z e.:. ,:::.1

D = o.,,f - 2 Dt' e~ r_ th t ~ o&d- D = D· H ==- 30- - L. b\ .

2~ -2 = D -(p -~) = a. (a-J) - L. hdbl'-1) ;r V ~ D = ~ = ~ (a_-1)(a.-2) - Z 1.b~ (b,'-t)

ü D ~ _vff~ lit,; 'l:,!zO>=---; OJ

±~-5 i)"'~ fJ c

<D D = e~ !Y [ D-e,, 20

D· 1- >o 2) D ~pie "i' lti;fL rf

D·J.. = ()_ >O D -e~ = b,· > o

b2 ::: 0.,1

- L. be > 0

38

Page 43: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~~ ~~ ~ (~JI) ' \:L O.è 1" \ i < ).L Q~ 1 \L. bt\

l =- \) ... , 6 ) CLè = I I:'. ~- (1 (f

\2- b~ \2 < 6 \:Lb!\ a1 > b( z· ~;li_ ti L. b,· < Vl ()... 'l 7J h.

3) H = 3 .Q - .L. e~ 1~ '"V'V"'J ~ ... /;,l _i_ - e,

21- - e 1 - e, - e) - e If 3 .X - 2 e1 - el. - e.3 - e '+ - e,- - e6

1-J Î'll} ~ ,~ -{j; h 0

Applicd:O'V\ cl ~ ~ L~ l'i ôi F 12i

j ;ft)~ 'flfJYl-A#i~ Wu;_~ Cww-e (j) 'J/1~d,

jhwA ('J.

~ =- f Col-1)(cl-2) + ~ = f&!--1)(cl-2)

;); rl =. 0 (Wtod. ~) i,(. ol = 1. 2 ( mod3)

t ?J 1) ' ~ Ill :fR. t: {~ ~ ~ ~ (:: t. h C-ww-e. Jf";J'f ifi i h 0

6

P-i~ ) D = al - fi b2 e2 l L t: 'l "1 d,

= 30. - Ibl·, ~:::: i(Q,-~(o..-2.) - zd b"(b"-1) ·'( i , f;. '5~· 'f4 ~ ~ f2 of... (2-J1 L "2 o..._, b'J · ..

1 D6 e

~~ 1R tt<i ·fV;?5' l t::.810) ~ OJl'x.*-11@ !-st~ -z. ;11- J:-). J. ·f ().., ! -{-vf- Lis. L.. ~ :Lb~ = 30...- d... J:- IJ

39

Page 44: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~= dC0--1)(a.-2) + l(3ct-cl) -_i :L b~1

2-:l'Lv'"IJ::.L~tsh0tà b,=-··--=-b6 ô)l1o ;r, 2-iût::

7-~t 6 ~j: {@ li

~;:::. ~(0.-1)~-2) + ~ 0o..-cl) -1i (.}ec-ci).,_

= J.. 0.1 _ i. o... + 1 t 3- a... _ _g_ _ ;?__a....,_ + 0 .. .1.J.. _ oC .2. 2 2- 2 'f :;2. /2

=- --' ri' -+ o...ol - ol'- - oL + I 4 2 12 2

2- ~ 'i' C<. 1? 7}J ~~ :S t:J.;jt If Ut= d_ IJ) t ~ ~J;:_ --z·, :Îc ti> ~

:il j: {@ (;). a - - _1 oL i. + c1._2 - d} - ol + I <l - 4- l 12. 2

d.,'--Jri+2 2 - 6 -l-3 - (r}_ -1 )(r;l-2) 2 - 6 -t- 3

t, c. ri=o (MoJ3) <Dt'1

â ~ ~ (oi.-1)(c:,{_-2) -t ~ dv = 1, 2 (14tocl 3) 6) '(_~

~ { f (ol-i)(cl-2)

t lâ 1,J 0 2- ()Jj!._A_ ~ ~ 1:Î ~ 1:: t ~ ; t (~

CD d._ = o (J'rt-oJ. 3) 6J 'é ~

J._, = 3 M (_ m > o ~) 'l~ 117.i ;;y· 11t.H =

3 ml- - vt-t z:_e~ 1t ~ Mvtr&- i' ~ tJ:.

3() ~t) - 6 W.. = 3 M =cl (, , ~ (J.

L/-O

Page 45: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ = i (3Yrt-1)(3 rn-1) - 6 · i_ ltt(/'l'l-1)

=: fGm-1)~rn.-2) - ~fC3»t-1)(3»t-2.)-2}

= : (of.-t)(ol-2) -t ~ @ d., = 1 (»t-ool 3) 6) t_ 3

d = 3 m. -t 1 t:!1t h ?J·" 31 - 2. e-: ~ ~11-21- - e1 - e:i.. - e.3 - e..'1- no~ 1~ J: 1

)

(rit-1) (3t- 2 Q~) + (21- e1 -e1 -e3 -e4-) + (21. - e, -e2-e5"-e6)

= (} Vil+ 1) J'_ - (wt + 1)(21 -t é:'2) - jll,l(e~ -tf'.4- té'. s + f s)

(j ~ aw.pÀ- i' cÛpz (j:

3(3M.+1) - 2(\t\'\.ti) - 4-Wl = 3WL+ l

~t

d- == ±. 3W\.(31'Vl-1> - 2 - i(~+'> m - +· i 1M-cm-1> = i_ · 3 Wt(3Wl-I) - \IV\. (3WL- I)

= ~·3\'V\.(3Wl-1)

= -t (cl-1)(c{_-2)

® cl= 2 ÜvtoJ 3) (J) t =li

cl= 3 »L -t 1 t. l 1-t ,61)~'

l')t (3t-z:e~) + {Jl - e1 - e:i. - e3 - e<t)

=(3m+2).f -(m.+1)(e1 -r ei i e3 + e1.1-) - wi.(es- -reb)

lt ~ (JVW.p-f.e ?,' ~ ( ;j:

L/-1

Page 46: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

3(3vrt+2) - 4-('Wl-+1) -:im. = 3 m + 2 = c(

tt:_ ~ ~ ~ (3m+ 1)(3 M) - 4-· j (Wt+I) Yv\ - 2, d rn(m-1)

= ~ (3 /'Yl +1) (3 m.)

= ..L (çl-l)(cl-2) 6

Q,E.D.

:i,t rl= 1,2,'I- (2/(JZ.,fd-~(§i~!(df-J-.

L/-2

Page 47: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

X t JP3 <5) ~ -u.~ GWl/V'{, ~ JP1 -z·· de~ cl '(_ -f la l. :i ' ;}2. û) J'Lo µd.M ~ !t 1- ,t.; 0

Ro~ (1) !P3 (J) ~ H -z; X(\ H ;f ?to 3 ,~

~Cl/L 1 ol am OJ l. l. 7J h t ô) lf~·if.}A -t t,; 0

P-w~ C2) f m ~ ~ ~ ,t P, O t;Jz 0) à:) 7J t ôJ 15,.-

4fr i~o P,o ~fID~4M _,t 1;1Xt P,Q -r; mwét;­~~ I i"~ti ~. 1. 01t!"!ôJ1~ -z"iJC-i>; llr;"

~cvilz 3. 1. U) ~ (2)

R~ ) (1) ~ l2) 1~ tiA :ç J5'.

(2) ::9(\)

-Ç ~ X X. X -LX G"tCl<W (1 '3) JJ w

P; o "(P,0 êi~L_t) L'. iif ~t ~ 'l Ili\ -f =:;'if)_ 12x-t L X * JP' ~·75, _; 1 1 ::i 'l

.îz_ /,; )( IJ) ,~J~~ r!J(~@o ~ ? L f 1()) (J ô jJZft_, I / 1: 1)

JiM lw-1 = l r c Xx '>(X I(M f -t .,,.dùmtl IYlap X >< X -7 I~ f 0 rw-tÂ- t i 1ci t -1 .

r ~ v (_--J-,,.1,_,,.tJ 1J. Â_,? ::1.,,1,_ 'Cf;;, Z\1~.

(2) à:: '} ' 117>? 1 (:jt l (_ r _:L) ~ f Ô) {1bre li ~tt â ~ ki ê 2 -;_; t; /;; ZJ' !, f ([) ~ (J 2 -[' 1.i h

1./-3

Page 48: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

2-l7l'"tt?l5'~. T = { .1. E.q(l,3)1 #l,tnX\ )3 (

t<t,<t dkm-1 <\ J:,, z.{Hp/am.e,3-1_ H:>_l_} 6))1_7L rt 2 J.'J. f. L t_-b"·, l Y JL~ T H :3? 1 iJ â

µ~ (-/ 1f·'if-ft_ th . H //' )1°µÂ0 (/) 6)4f1t12 )fti t 1 .:. t 1 t 8 A :s -'?'.

Q. l::: .D. ~~ (3) .~. A~ IP'-c X 6)f±)[ 6) nun.+

1~ P (j) fa,.-..;eJ ~ -tp t/ A 12 it i- > 7J: t O! ~'"lÎf ~ -f 1;; 0

~ 3. 2. (__J~) G)75'f>Î1T-t1J c ~ Xr;J:~y. --z:·;t6tc17o

;l/dz, 3' 5. "./ (2-) ='? (3)

11-z ~ ) {)) -Z:' 7J c ) t -th '(_ . ;;VJ ~ r- > 2 7), .. ~ , 1

li y_ ;... ·c-t -"'' -z_ <JJ 4-U.cw:i 11 r 1&-id. Â.P.-ccuwt t ;J 1ri •

0

Lf-lf

J', z, xxx ffi ~

;J f~ (f,Q) t:).q l

p, Q ~ ~ t kuz. _R. fi .t 4 'j.. {f) ;(f: <!) '"' 0 ~ ,,,_ j;; 0

~~1: 0 'l tp~{i;:!f

Œi H ô%1.~'l. tL~ lf'" H 1 ~ 1 ~ ~ 7j 11 :tz Id'-",

Page 49: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ fJ p1 E:'X !~)1l ê 0 'L p' Œ [email protected] XôJ

~f.J 1J rt r- 1 r;._ -r::. Y.-/i, !J iJ' s ~ rJ" H 1:: î 1: tfi. .t? tf Ji s

111 " :i:- , c_ tp t ia f;J: -tl ~ i'1t A -t~ :!? f.>. 1t: If)

~ c.,f 1J X OJ ,~, R 6J 1;~Wl +R t I~ r I!f ~ -,:· tp g ·V-"

i-0 t i:b ~ ?S~'. A ; t 1f01 f., ·t ié :fJ J,i t 1 1il t r<- r if- H ( :;_ { 1- ;te 6 :_ r r.: lj '6 • X ~ [P1 c" Yi 1;; li' ; . ~ OJ 'd: ) 7J R fî#i~~{@ L 15' ~ 1) 1~ Ji r l. t-, z. ~J. 7j R "t' -+p. 1~ A -a ûil h. :__;1>c t 1J mlfe4,!l:J5' > x 0 i /\;' 1- {)

1111N~ ,~·dJ ~~ ~ t-J A ê ~-Jv· ~ t ( ~ ?j_ h • l ;( l '"i' (}) .f" ~~ ~ -:1 :.n. ~ :-_ '(_ 7}" ;IJ 6' 1$ 0

fÀ op 3. 'f. cl 'fl == 0 (]) l'..- '1 (3 l (J- J\ 1/ ~~ /j_ ( l o

~) A 1J' ; 0 rojecA..'~ ~ ~ ::l ~ r X 0 1 /\'--CôJ1~,i' -'1.4J L.!J!d. c1 f<=-o 0ii{"J.. t1

? -t .A.e.~ 1nec.1, 13.'1;, s ::. :h 1~ i 1) f~ !J t 1.

Q, E .D.

[ ~ / /8qo J X! d~A c~"µ ?t{1Yl-MVL~M ~ 'l L ,.J2 t ..z. ([) J: (J} ~()./\. ~ r=~;J2 i1fd. lt6)'l1 c),~~o ,15 l'd-";f< d) P/[oM è ~[4~ -f o

p,_oM Clf-) ~1t CD ~Vif- P) ~ ~J-1

Page 50: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

@ ;Jl- P 1~ b~ ld !'f4f:-fj( l. ~ ~~/211'~, P G X .ï5'"/l}it.1 ~ t -1 , / < 'v'A < 'f- 1 /2 }:-! L l.. p \ J - .. 1 PA E X i'

1) ~(J--P,-·---P,o) =~tY-A ;_) J - p, - · - - B tJ: lMe ;~ t 14 t ï1 () Q

'l ~~ f:_ 1 -:fç,â) 7.if4i1i 1 "1 0

~~ cl fi_ = p > 0 6) i ~ (lf-l .:1''"~ :à_ 1 h .?f"( -) l.5' ;!? 15' 5 7.i li '

© (if) =='?> (2) J.)~-u ~;?. t~i- X y \P3

U)'l~ J-== /Hl t.'"h-f11i"(4) O)fl1t~1itL A=- 2

0) ~~ ~®[-fi t:h 11" 3 p ) Q , J- - p - Q : ~ !~ f-.u_ t,1ho ::.~rt P,Q 1@h ~ t X 6)~tJ 1J rt P) Q i'ôJ 1_1t 'ti ~jt_·c.:4- I f:," 11-Z''"i? ~ _: '(. ~fi; l l. l 1 /5 • t ) l (2.) 75"' (1 J._ h 0

Th~ 3. S, CÂ~) X ti 1P 11 1~1i 1 i~ ?11J>l-~~ ~ 'l-f,? l-=! {3) l5'"J.t 'l JL l.ti" )<. ('J.:,}1_

6) l 1 -r;h 7f' -z--~ ~ 0 [13]

i) X=-IP 1

Il) cL { = 2

X = C~c.. c ll?2. 'ef.=X2

d-1 =- 0

Page 51: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

{

X= t f c Ji\3 '<} == -t /j\_

~ = --e-r 0.:f~ti~i (j: ::z rtib ~ "f ,f(-z"'-;Y; J,) 7)\". .: ô) C<-v'VV'Jl (;}: JP3 -z· !"J

~~ ~ i(f;~o ~0-tY+ ) cJ., i :=. 0 7J ~ if i) ;)•"() ;\ ~ ïf !:,

d { ::: p > 0 t_ i ,Q 0 Èif ~fi (j M\f Q) fi ~ X ~ .lP' UJ~ 1& t" 1t/ff 7J ? , JP2

::::> Al.2 6. ~1z OJ J: 7 (: t J,; o

1) A IJ- X-t?/;Ù-0 6) p~ d ~ 2J t. L A ~ x t. s 1·r tA :t 1 w / tA + x-~ 3) O ~X

~

A

@ RtcJi H~ X ) y "&' YLOft--~L VWvv'-e. --t ~ X -7 'Y

] k (X)/ k &') lf~· MfAJ,e_ t 7J 6 J: 7 7J htn;~ 'l j "1 o X ::;i P ! ; 11 L 7-- -f{P) ôJ ~Vv;f.@

If 7

Page 52: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

,~ ()_ 15~· p OJ ww/~d /Mcw~ -t (~J.1L -f*U = a__tJ- -+ l,~ ~ , cc:~ c :i!-f ~ t :t , t > I -( ii ~ /J" { f'J P , .. 4J

/> / 'j ûJ t ':f ~ /l.4J '{_ L 1 ? 0 1. dl t.

~if~t'

~~x -2 =- (d.tg-F) (2~y -2)-+ :L (er -1) P6X

( ,(.@ l ep = rvr ( ~11()-t- / )

?)~·~ IJ il. J o

Tlim (i)~Jti~1~t '(~ 0

,\t A k 5 ;i-~ 1\ <D

ro~4 ·~,f 1'.JJ t X ~ '4-C14M # (3> J" ~ ~ 1cvi Ji,. '-.. -Ji .? , t là .t s f< Cxi ::::> '{{(y) - -5 o ?J, s 1.<!X? 1\ (j) r o ~ ~ ~ :Z. ~ r x ----7 100

(J X-Cùû4 O),\t,.!J-?f (-;\: ~~J_ ·( H~ <Di\~ J: 1)

2~-2 :::::L(ep-1) - 2cl fEX(l.z-~ Pt-A

P~ X n :k~ P=fA C.f<il 7- 2p~;li~ J.- Jo ) -:::. (Cr -1! -t- Cr+1-t"+

1+ -· - ) p Cr t o

:X ==- a.+ -t

Page 53: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

2~-2 == z:rn - 2o1...

1) ol = 2.. P r~ Vir A t X 2) d-= Z P rt -t 1 if A ~ X

1) (Î) 'L ~ 2 ~ - 2 = 2 d- = 0 ,> cl= 2 X: ~ 2) ôJ 'l ~ 2 ~ - 2 = o{- 1 - 2 o(_ t 'J 2 ~ -t ol -:=o !

~ = 0 ) J_:::. / X = iPI Q. E.0.

~o._ 3. 6. JP3 ? X -8_ ~ ~ rh;rw-cL ô) non~ uvvw. 'l L X {-). {.) lJ 7J h ~r-F r::. ti" 'if*-4 ut: t /.J 0 ~ 0) t 1 rît > * {0.,-3) iJ) If fJ-1:-M) li rtŒYL/3-jU-wj i'~ /;;. P~) FI'/\= \j.nm.!-1/ 'l~,~ Fw

/Jp-€--w.1 t 1ii~ ~ 0 7 ~ ~ fi°(k-fM) > 0

J" , L. X ôJ +~ ~m. A -i' Fit\ -+ A "-" k ~ ~ t O"'J 11'"# ft-t 0 • ~ OJ J.- 7 7J A ~ - ? \Il Jt 1 Jj •

-1 -z. X ~ .lP2 -(j, ~ii' .5 \Hl ~ P 1" D (]) '{(])3,t

t- ®#,~J: 1:.;J <) J- ) ?J tef)lJ~·4-f:t -t i5. ex= ~ l kl

Page 54: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~lk-D) 'l"*< 'l

cfMr.. 1 k. - D l = -{ 0 (K - D) - l

= { 0(D) - cl-t â- - l -1

?_ 2-cl+â- (-fi_0 (D)'t._4-)

J, ~v:' o{V,,, !KI = d'. - \ j:- 'J

o( ~(i-1) -(2-d.-r'i) = cl-3, -- -· I ~t_ f> =- ~IF~I- ~IF111-D\ t-~<. 'l~~1:!0 ~('._/~~I~-t;hli {j~D( ~.f~ho

© 1=" ~~ ,X7Pt_M;.ffA t-lï3'l 0 ~ -ft,0(E)-{0(f-P) < { 0(f+A)-{0(Ç+A-P) ~ 1

:_\ L D =:. p, + --. -t Po<_ t i l:J 'L 1 WI. L ~~ -3)

i- 1) 2fh L. cl-J .:_ ~t.."~ t Os 1 ~ c;(-3 (2.

~-:\L L E~ é FIM --{. E~ :7 P,-'---/ Pc· / Et_~ P.:+1 1 ·-·, Pot 't. ts j t G.l ~~;tt.A t ~. ~~ t=-2)., if ~ t-i' 1- < \'V\ <'..' i; ~ '4-r-1kv L ',; -- -..1 LIM ~ L1 il D ==- iP. 1 Rj, Lin D =-~fi ... P'f-{, - - - - / L.R. fl D = {P.ü-1) P12} ) L,e.+1 /) J) :=. - - .. ::::- L/-}\ Il D = ri> 'l

IJ ~ ~ J (_' 'l ) z E~ =- l1 u ---V Lw. 'l -;):,' (T If J: l 1 L

1. -=- 2.1. + ' li > n" L ~ lt\-1 -t ~ ~ ~f1Plz--,IC0!.o4 L !! · - -> Lw- ~ L, n D =- ~p,, g_ ( , Li fl D =- [ f;/ 171- i - - - -) L_,e_ (]/) =- ~&-,, Pi.e r ) L_,e_+, () t) = !Pz..e-r,r

1

.to

Page 55: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

L.t+i (l D:::: ---- = l.,,. 11]) = ~ t.fJ; .i:- 7 (.:: "t? -z: Ec' = L , u · · · u Lw. 'l 't· r t If ~ ( 1 ~ ~ :l'i l ~

k- IF~l - ~IF!!\ -81 == 1

~ \F~-l~l - ~/Fm - fi-Pi/ = 1

~JF10-P,-·-·-Pot__,l-uL/~-ri-----Pc(.)I = 1

~ ïÎ L -z. cl)' 11 $ = ol,,.,.. /Fw.1-~ IFw.-DI > ol- 2 - ··JI ~ ~ c< "i' i, ~ -".)' s T ) "] ( ;t jf@j D t ) "2. c9-x:(VVI)

/~ ')J{Tf!. .Aj~

Q.E.D. ~ ~ô)~a_3.6. lf"~

!~ t fi '51f'I X = Fi · Fe t. t;,, 'é ri=2e r.dx = <Jx &-Lf- -r 2 --r e) = c9-x ~ -2) z:· ()Jx ft Affwd i' ~ 'J IM = !i_ (of.-tf-) -z," lY-x(M) -4jU-c;;.J c4~o .

Thm 3. ri. (C~) Xti P Œl de~ ol ~ ~ ff) '11cm-4#irk CWvW. -z:·. ( )

;f 1 6 ~r ,KM'-€ r..: t -1 i n 1 ( 1 'l i ~ r: g S: ~i - oL + 1 ~ ol ~ o ( Wl od. 2 )

· i 5 d~I -oé t I :{ d_:::. / (moo<. .2)

tl

Page 56: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

Re4) F111 = lx n Vt'\ 1-11 r. "à)·< , {tE L 1-1 1t

p3 6) 4-r--/M'l-€. ~ 0 è'. ::I f; ;;> D,, D = p, + · -·i Poi.

-i' R_,·-·,Pol O)l'."073::>{~-W~lli.::;JutOJ(?'l~o

s t11 = 4 F~ - ~ (Pw. - )) ) t ~· < • x. ([) <:: ~

s"" 2. 2wi + 1

1: -e·;J _; r== o; .. "J::il"\ l2J.tl :::i El" E Ff\\ ,.!_t,

Ev- 7 p,_,--·_, Pv- > Cr~ Pr+1, .. ·.) P~ 'llJ ~ =ê: ôPV~ ~.

~.::!\. (i 1r ( r+1

~ ( f w. - L. P~·) - k hl'\ - L P~) ~ \ i -=..t ~=- \

for- Y' ::: o · -· ) w-, /

~ t 0 7\: t ~ tJJ z" div" \-W1 - L (F~- D) > .:2.WL.+ 1

Fm -D = F~-1 12 ~it t~ l

~ Ff'-1 = ~ F1 t 2-.Gol"F{- ~ ~-1) il\ ~~l l'-'-

> 3 +~2{<.tl .

= \IV\ (f'l-1. + 1)

Gae. f. © cl=- O (!'1.oJ.2) IJ)'( ~ W..=iécl-J.) r t ~ '( ~o... 3. b t \) Üx('M) !t ')?!frt.-t1-(J€d

J:", z R-R .r 1J -/_ 0((JxCW>!) =- 111ct - d- -t ! --.. I -?j --t_ 0 (62;x(W1))-/ = ~~ 2. f\'\Qvtt-\) - --- ··]

I, JI d:" 1J Mol-~+ 1 7 Wl(Wl.+ 2) + 1 Wll"

1 <1--2) ~1-fÀ j;;uf

Page 57: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ rlCrJ-2)- ~+ \ L_ ~(cl-1J(olt2) t-1 ~.t.. ~ 1)

~ < ~(o('--4-ct-t4-) = tl.-ol._+ 1

Gue. 2. @ cf._= ( &cod.2) IJ) t ~ V\1= }irJ.-1) 'lt Îcl 'C ~'°" ?. 6 J:" ~ 0<C\MJ (t n(j)t-A~CÂ.J t ) 7.. i(- R J.- ~ /,/ ((Jy({:A)) = wo<. - ~ t 1 - - · T

- 75 -/,_, 0(CJy_l.!{_t\) )- 1 =- ~ FI" / 01. ( 141 + l) - - . TI.

1, 1[ J:°9 VV\o\_-~t 1 ) \11(11\+2) f- / Ml~

i ( ol- 'J ~ {f'A -t ;11_ ri' ~ of_(~ - 1) - ~ f 1 > l (_cl-1) (rA-3)-+ 1

.l.

d- < J (o{l.-q.o{_ +3) - o<_ ;r -of-+ I Q.E .D.

~~ CM-€_ 1 , {a,4..L 2 l :t'$~ ô)hY 1>if--::;ôJft- kFh\ == Vl\(Wl.-+ 2 ) O)t~-z" d > !>

(t'-1)fJ.ll 0

D -? J__x.C2) -3> e1P3(2) -7 8x(_2) -::i 0

(2 :Zi L .»x:acl '9 1 \

o -7 H0(tdx9l) -7 H0(<Yp<?l) -7> H0(!JxC2l) ~~~~'l

Page 58: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ H0 (fJJP3Q.))-=- /0 1

ol&w, /-( 0 (61-x &->) = ~ t 1J H0(dxl2J) "::\= o :;...;h.rt X ?f,,·ii J jv-~ ~f.c.e 1.:-i° ~ :\\-h ~ l. ~ ~ ~71 1 h

0

Hd~ r-;t :;z 0) cr) t 2-ll,"':· -z u 15 0

1 ~ S -f (pl-1 >(d-2) fJ > tf cit? c{ ~ J­O) 1ZOh.-~~M ~ X c. P1 -i' n-=>

1 6J ev.k ~Le 1::_~~~1;; =ê <f) lf'''/(J. fi 1 ~' __J

:::. O)ip ~O) ~;\~ IJ 4~/~-Z:' ~ ~ .:5'" >7z ô) ~wvk /!' ; .Œ l

ut l -c =t ':i(J) ~ A-wt.P,~ r;t 1/Jjn-~F 'l rt 'l :\l'L?J- t i 11'/ JJ'" ~ ~ ~ r Jf" t1 ?5' h.

~cvvk X t ~ â- ~J. <D

11..(frl.-~~a//._ ~ c. .JP3 -(,' 11&>!-~i:vt eul-t,c,

.MM,{ccu_ 1 :~ ~ ~ lJ L i h /:'.: â > ~ (ol - 7)

I HES *JG 112~ 11

IJ) fl~/rt'Vh 11

~~ w-14 ~y~ ~dcM 1:::.rht..

X ~ ~ ~ UJ ?1o-Yt-~~wt ~ 1.: 11rm-~rîwt.. A.MAjcu .. .e F f.>i

l ::l1t, (_ t ) ~ '(.. 1 h. l , /}?_ O} t) , 2.) Œ> 'l "t, ) 75' -( ~ ~ 0

1) F li X x ./P1 /~ b,'r~~ 2) X2 < 4- °J +) -{ t{ .,q 11. X ;&' JP'- ô)

Page 59: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

lL ~ ~ -z:_· â--= 1 Ô) '( =3: _JJ

. { 2 -z; X ?J, .. ~ ~ i n/7>1.-~7.fwi. ~è. ~

F'C pi (::'.~ ~ *- ê l) iS. '(_ -t"' l ~ AWL--fo,c.e (-J

~hi.J 1,' -fi IJ.f 5 Ct) f* ~ =-o J;<9~ Ji· 2 11 f~tJ- t).

o/;_J-x =cl r 1 J.) ('.'._ W-x = X·(X-1- W-F) CUF:::.éfi=tO t:"7>~ _s 2~ -2 =- x1

- o1._, x2 = ol+2j.-2 j t o 7J; r1 X2 < 4-~ -t !:,- -5'?) ;

o{,f2~-2 < 4-~+-> ol-7 < 2~

~-, 2. i 2 1 (cl -1)

Page 60: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ Lf- A/m,~ MoVMdt'erc ~ Î~ fs iJ_ ( ) CW1;1fe .

r t I\'' 7.. ü) /,JMc~ ewvv-e (J 'Ylon -4htF ewvv-e ôJ 4-;uud c CtA.R. -t"b '8 1' ..J 'L 1 ) ) fii1 IU! '8 ~ "!- fJ o

: 6'J Ftl!rn l ~ / c l -z. IP3 0 Wt.P.dv..~ ~ced ôWv1Ae

-i 6) & if'I r1 ~ ~, ~ '/ JJ' ., 'Z'. u 1J. 1 J if~" 1 =à- ·J" ~ O)'ft~ -z.' · O> §.'19y

~ ~ Â ~ ~ 'l ,i)''"z" -'.f ~o

~ 4 . / . JP3 Œ) rr()rt llJlclcecl CWvV-e. -C

Mn~ fd- +db ~:f#~ 7j_ t 1 t o;x~·{};ri i lii.

~r .,,e 2 o ! ~ c · s::: i [!:, '4, 'i, w-]

0 J.~o~~ t41J I ~ I = < :X: / x ~ / lj.,_, z.z..,,e - ia wL >

('.'._ -t .-5 ~ .Jl ()) 'l .::! y= ~Oj s / I c:: p3 L t ~ l ..-Ù<-ff y = i :X.=-~ = 0 } = JP 1 c lP3 -z,". i tê y lt. -VlM-fudo{ C~~ ~::(~, l. 11 lJ ( J. rk~ j = 2

7.-" 1i h ~~' Po,_ 1f :#. ~ t -) 0 y (f) f/,'/ ~ p/p l)?IU,J, 1 ;J.

-,f ~i'.9yl'AJ) -== c{ rt + 1 - Pa. i"t ~ J5'' ol == 2 ·t n lf" i 7i 7t 6) '(_ '1

o -? k ~) 'f<[x, ~J z, w-J)\ -7 H 0WyfllV-:> o i 4 ~ o li_ ~ -z· (Sir\, ~ l :Z. ~ t ~-"'t'.cf &ï- .Aptl,~ t l -z._ (J) b~ Œ

Page 61: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

:X. 1 .~11-1 X~ w-i\-l.. x.~,W-11-3 __ . X 2:.1.-1 w-Yl-...l IN.1 1 .J )

1:1- ~ 11-1) i z:.V\-2w I ~ 23 h-J w-~ - ' ' I 1;J w-yt-/

Z:11. ~i'\-1W- 2'.:h-~w-'- --- w" ) .J J )

L 'l~ ~ J5' .5 (S/:r ))'\ (J) ~/<. ft.JJ- .)_ -+ YI. i nt 1 = 2 Y1 i 1 +1

~., c_ P0- = - )_ -;t.vt rk{()'VM1.~~ rcJ: J,, > Po_

~1ff.? ;>),·- of.efW- 2 15) non-~~M Cw'-vW. /1 iP 2 Ô)

CCtn<.(;. ~'X rj ?t&rt-~r-ltvl.. o-v-a~'c ~au.. .l: if)~';!? 5 1 ( ) .=: ~fi~~ L ?J' ,(+ fi L 7J. iJ

0

o c OYkc 0 t ~ . R = o -t SxM ... ~ âJ -1 = o 6) :t~ ë1 " . /,._ - .-," "\' 1_ 0 - ..4.;t-eùa/'-Ar,J"- t,.. - '<Jo

0 = @~If< OJ L ".\ fi ::: -1 -( j_ = / (}) #}, § 1 2 fip-l -

u4 i ~~o

.1 > 2 (J) 'l 1 ~if) ~ph. (J M11ov-t/c fld ~,,;â_IYM 'f2:fij f; lJ: ( J ~ '{ ?)~· ~ 7f' h o

~ 4. 2 . ( S;;wi-15' ) f 3 Ô) M-riA.uz ol

11iYf ~ ~ -( .MrlMY-i/. flcVt 4t/VV(lD: -u~ ~ t. f: !;; ( ) =t 0) y 't lP' c JP3 ô) ~rw- 4- r5)

Page 62: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

'flfirl.-.AM..ptvt-~ L. L 1._ ~ IP 2 t Y (J) - ,~, -c~;p-?

ku ri~. YuJ..~*1.~'l ol=s -ci'>?lV !{ ô) 7s (;} -~~ (è y,) Y; i ~ 'l l 1'. y_-::j_

il (Y, u Yi)= Po-(Y,)+ P0c(Y,)+t!(y,nYi.)-1

Po. =- Po. (Y) -+ Po..{),) -+ 1 - I =3-tO+/-)

:: 3

l ~ ~ 1)" § 1 0)0 ~~:t<_ ]- ~.:ft If:\? -1' 1j ~ 7 1: ~ 4-

<f) ?1tm-~~ Curvv'-e. 0) ~ (d: 0, 1 ) 2 ) 6

6) t ) ,.-~ 7.5' i' i ~ _,, _; y u )__ /~ .Mn~ ftcJt ~~ ~#t.1 () 2- r.>J~'h·f 'ho

~pie_ 11-. 3. c H(Mflforol) ~d-"vvurk..~ ~~ i' /.Vl1Urtrif{ µ ~ a tt ~ l) t. q;i

Il . 1. Il X -t;. ' ,,., tf ;vn-&!Wit'â- VW\JV'.e. e. 'l/1711-.41,,.._~/Vi. ~

'l L P ~ 10)-? 6),ff, t f 18 t ~ p OJ --focd ~~ C9p 14t.O) ~J R 2 f< -(-i? ~ YL 1~J.1L R ::> Wlp

clJ h ~ 61 t~;Z::t L J.LVt t L 7.. Id. )( 'l{S/ L' Culw.e X /

i X ~ X1 ;y· p >;<.4~ -z" i-oir>"M~ p C).ife1

6 ,f, 1 p' 'l t.. t:. t 1 Opr == R t fJ l;i t. 0) ;y·if} ii t 1o o

Page 63: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

_:_. 6) l =i

o --7 ()x 1 -7 -f-i1 tJ>, -;;, +* 6x / rJ-x' -7 o Sl

é9p/R

"!i;if ~ (f~ 6' ~ ~ ) (~

P0- (X) = P<>- éf, l-+ _j_(Gp/p.) t.;$ > ('. lJ b 0

X ~ oÂ.dJw.d ncm-,M-,..~<M.. ~ ~ ~L2 P ~ X <f) 1,f, 'Yl >o 1 0-vt.?'1- --t ~ é'.9-p ~

wrn.f ~f! /CVL~ '[_ J ~ o )i (f) ~ ~ ~. tY\ -+ i<--ttl -t ... -+ f< -t:Ylt 1

(j) ~ -y..e_A ,4-ftld \T ( ~ g_q L R =- ~ -t V+ !M.pVl t

1-i < r. R 1-J: ~d i 1 1J . >'z. it 1.: r ~ ;Wnch;.-.o ewwe.

?i: Xv t t <. ~ è: c-t Go ~ 2 -t; t ~ ~ L -Z

o4w- v ~ 1- ôJ 1'~ t.s' rt ~Ji. ~ 'l. Po.. ( Xv ) = ~ -t i Yl -1 - i

t-.1-?o V~V1

6)c~ X--7Xv;X.-7Xv' (.:' i}tl L XïT '{_ X171 lt ~1R 1 ~ -1 11 ~~ ïJ (). ~ 1.: ~c)t

?J.Fl~ Xv- -7 X"' ?5' .• ii?;fi ri· X OJ ~~ q--

15~· ti ') X --7 Xv ô J, 0'- i. X -7 XIT'

Page 64: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

l-lJ ~ /)"' ~ ~ 2 "f-' 15' S X OJ a..de-m01--~ f;J:-1) P~(@o

+, "2-11{07 vr.:J-:1 c~11~1@()) ~. ~)IÂ~ V\,··: Vr l5'""(0, z \114 Ve (c=- 1,--·,Y) -('i;:/1_1f XIJ '<:'.

Xq' (;!. ~d ~ 'l L t ~~ -;,· iJ < 7J 6 o T = lr/l.tl.44 (n / t) 'l "Ji \ t If dwn T = t (Yl- t) -z;· -Y,~ ,

X :::. 1." î1 ~ 1~!;;. } = ~ 't. i ;fi ti 4 T = !}j +" , l.. 11 ~ +-1i -k ~ <., t;ll li

~ T > 3 P°'- - 3 = 3 ('J + 2vt - 1 - 6-) - 3

::_ ô) c ~ °&i;; V 1::)-:t L Xq (;l: ~ fi µf_ ~~ ~=tf2/j() _: '( lY'~)~ *o

<1? c, < rt ~ol PcJV~~ W ~Jt~9 !Jk6-* 'l L 71t;?<_ô)~6jf75~-~ & o

Tbn Lf. 4-. ( /'vl. Ç~ ) X ~ A3 @ ~d. 7J: ~ '(_ 11cJ t ~ y. /'J: ~ j!J q~~ ~ =t?,

66

Page 65: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

~ t p1 .1:. :) U.uweA f1) .e.:~ 1::. .., " ï

~ Y ~ 1;! p3 1: ~ 'I - ·J: X., <!) J.,ou,J.. .u.As ~ l"'

Wedd.e.J. """i'~ k t~ K. 1j " t 4 l • 4 y, 'I' ~

;t.~ 5. 1.

t. 1 ;I , }: •. 0 2 .., fJ) -!J_,(!f e :J!i r ~ 1;: t j •

y t Y ' 1-J. *:~ f1) i.f:/1~ JJ;(,-fi é ~ t: 4 " • ( L~ e J.W.. ·c y., y'J

::; 0 )

2. 2 .,, "' cJ.<A11..to.U!.-O ( ~ J J.e J. c,m,..; onJJÂ t: :f'!t ç_ /j ")

H1 , l·h fjr Ji 1) Y U Y 1 ~ H 1 /\ H ~ ( S ~ 'C L 1: J •

~~ S. 2. Y~ y' t. rJ UA/lAl'tA Y. ( = y) y 2 .... ; '

;: "' ~ ,. ~ 1 1t IOJ i'1 ~J.J {~ r- ;li ? •

H 'I . y f iiwui..._,;.B..11. 11.e..l.u.c..e. J ~ 'L. 1' ~ o Y "I

~.. rviWl t. I[ t r ~ 'C, e~.-< ~ t9q_ ~ ·L &J c- &;. à

il' .; f. 'il 1~ tt tr.- l -C. Ps 0> 2 ? " M !!Il® ·H., H,, é. t 3

H H 'f. "- H ""-'"''• !'..., ,() ~=YVY' t.;; "0 1>"-1: I I

191 Y = P' t. f 3 • Q \: t 0 2 :l i.!IJ JÏll t L . Y ·f.. ( o, 1) ~-.

61

Page 66: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

( ç; k ( Xo, X,, X2, x.,JJ , 0 0) ~ 1· 0> i:t:_ ~ 1 'T" T IL- LQ ~

( lC a )(. - ')(, )( 3) t 1 ~ 0 :'. O> ~ '2J ~: $Jt e 1 : ;If L , ;,t !;( e ~

(âl ~.!'. ~ ~ ;\; f ( <\ I Q ~,, G ly ) /J''" #.fi t î . Q fl He

:: YvZ ( He•~ f.ô-··~c!1J ~ e ;;Zd!Jtlu) t. t;i 'J, Z r;J (e,e-1)

iJl0 Q.0 ~ 7: $,~ 0 1!1~(1:-ft.0 Q.OJ (e,e-•J f9,/q

~ z 1:. tf ·l ( e- 1 :z: oJ r3 tf) e. :,Â_ dh.W He q·.(.j..(t

l , 0 0 He= Z V Y E ~if, il • ( ;: ~ 11 H0(P~ tlp1(eJ) ~

H0 ( Q, <941 (eJ) __, o J: 'J 9JI ;, tJ\ ) t < 1-;: e- 1 .> o {ï b,

t 'J z J;t '

4-" ~ !i.J '/ r ;J:J~ rJ.. 11) i.MaJ.M.cAJ,.R.u. hAll"- SIM.~

cwwe t. ;J: 3 • 't ., ~ ~.t "> +.ï 1( l :~ f::- ~ e ;J.. lll1 ffll H,, th

6\ Ji 3 • ( rJ.:f-1 :; e. ) :

H1 <)Ha~ Yvy' î.. Y' /1. ifwi_.Wv:t.f.o. >Wh-si'M~

~ \- If' ..,. Y \::. y' l"J. ~-wtl.S .J/. î- h 3 ,

~it llfl) ..9 = { H : ~ e Il) tl!J tln j H 2 Y j t f 3 •

x=iJt:L Y~~t.l"'î .Mln.r°1'1~.'(ok.E ......... ""- * 1 1f : X ~ )< t. L J> = 1T J) @ (9 X' (- lî- (''()) t if 3 t

cto...:.... : .J 1.t ~cJ. ~ .,; : x '--? r"' t:

· lit.~ 3 c 5~ ~ r~~)

62

Page 67: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

i<x) ,;i rN0 ""'"-so.«~ ,o.,J,..v~. ~ d) ~:vr.t

'I p"' "> ~ .lf IÎ!l H, , H~ t/•" ;g. ,(j_ L 1 >< 1 H 1 · ) H, ~ ,,,.,,_

s~ Üv.n_J.,.,..~ ~ j! t, !.lb) ~ 0

- /.Î "ln rr-'(YJ

1 ;I ..il... Sn oc.. ( 1t J 1 ~ jâ] ~ (" , Ti 0 (;] [· fi l>.A. I~ 2 .~. Ji à :: t -r .;...(,t;, .-....... -

li 'Î " o H.; ~ JT( X AH.:)

J:: OJ 1-li '.{__ e z dt 1 /J' .. tr .. t ~.K °' J: :> 'J. & 4#1 ti·· h ;} o

19• I • 4'A70 - s°WI s-J.M- inM..lu.dk'.. ~ Y t _iE !l lx 0.,, (). l

l:J"" /À'. E ~ 1 J: j r: 13-îi. Î à 0

ll(f $ ll!J i~J"H.; . ( ~· ~ 1, z) <!.l

)Â. t;i. 1t 11..: î·· H' (\ 1-h. = y V y I Î"' 1, ;} 0 't. 0) ~ -:. ') J;. ) {1

-& l.!f i! ;f.:i 1 H,, 1-f,_ 1: t:'"' J: :> 1~ t .,, î. t y'11 iJ *~ î- ili,

t-.. t i. rf." y 1: rJ../lAL c..v.J,.,:.c. u..vv>-e ~ 1 ~ • o.,= 2

a.,='f t. L , H1= 11'v1i' ( ïl'. ~'1-J. ~.fi'li7), HA •~i1 L.

H,f\ H,: (1fn H,) V ·("lf'f) H•J 0 îlrü\, ~ YV J, ( Jl •i Jl;,..,.)

l"' J, ~ 0) \- YI l'i.~ i1 0

;:. h <!' !.> ;~ "> r .. ~.a t. J; 2., ~ D

{ pl 0) (AAAN'e. j / ~ 1J. t- ? I' J 4.;;l I~ ~ ~ 6- ~

lî. 0 1:. h I':.. ~ ~ .Io ' li L- .l>'> .1: .) o

63

Page 68: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

L M (y) .k{,.. ~ ( G:I H0( ~F'(oJ) -7 $ Ji 0

( OyCiJJ)] 1162. VéZ

( Q;. © H'( J yloJ)) 0

M tYJ 1~ ~~,,..cl... O. S -~ •

{4. -;t. 0 l.l 1;: i:t 1- Ml'IJ 17 rJ. R .1:. f~ ~,

~if s .s y , y · ~ r3 0) CUNl'l • >1. ~ ~ Y~Y

I

fJ: ; J, ~ ~ ~ )A iJ." '$, ::J ( >J:.. t ~ -; •

M (y•) : MlYJ (f'1)

{ê.. l MlY} (t"J 1~ MlYJ 0 ~ c· ~ ')

MCYJ' = 1-ttMIL ( HlYJ, k)

!l.J! 0 til ~ 1;1. du;: t -i: • il: ·r i;;t..Jf 0 ~ !!: • 1~ ·1 ~ i-t. ". 1

-f,· ;, :) 0

~ 5.b d..i...1<.MtY) i:: MW) '> ~ ( = mwx

{ 1r 1 Mv t- o ~ ~ ·f IJ 1 Mv =Io o ~ ) 1d. ~ 1-

:+ i. .

# 'I 1) Y "' c.mnti~ ~t;t.m. ~ Hl Y J::. O

{jl)

J;. ')

(t:,t y: H,olh)

Iy = l © 1 = '"'' "'~

H'(1yl1.>J)= o.

Page 69: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

. (Ù.) .Q,i(o..cÂ; 4Q~~

J. '.) , fi •. 0) ~i;t V t. if L

H' (:Iy( PJ).: 0 0

Il= 0 1: ~, k'(Oy<vJ)

= Q .i: ') i..' (Iyl111J= 1 • v = i:...; h0( or•<•i)

= k0 l Oylll}: 4 ~-, '1.0 ( Iylll} = 0 (·: y ~ ~ l; pl""""-

f;t. ;;i ") o ~ 1~ 11°( Or•< 11) ~ H 0 ( tlyl•d 1 o 0 ~. e.

~(l7;(1l)=O D l) >2. r:.1i L H0 (0pa(l>J) ·c H0

(·0ylbJJ)

là H0( OFu1) ( IW>f· · H '( Oy lll)) . I~ J: ') ~ ~ ::- oh 3 0)

\- H0( ()r• ll>J) -'J li"( Oy (VI)-:> 0 0

::. 0 (V~2) 0

~t!. 5. 7.

'it.~ r ~ .

1

V

H' ( Y, F 60 wv)

J: , Z H' ( Iy tuJ)

\.tif ~)

2., f: y'-'J Y 1:_ .ç~ ~~ ~ f>1;Wy1 =

Hefltt dy ( f.Oy ', Wy}.

Page 70: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

Y"- z ( .:, e y V 2 = H ... f) f-lb)

~ :X.. 0) ~<Ut .4..t~(.L b•" ch 3 0

O ~ t.iz (4- a..- LJ --'> Oy 11 z ___,, Oy -7 0

~ë) y, :;!!; 0) ~Jç{ j"r l\;o.> s~f €. Iy, Iz t 1 ~

-0 -il I~ :Zyl\ Iz Oyv z ~ Oy ___,, 0 •

- ~, I~ Hrrm ( Oz: Ûy112 J ... éP, J • Iynrz ~ -- Oyvz, , y Il 7 1 ;I <.o1t1ph:ti. ~c.iwi. 1- j., ;!) "' î·· Wyvz

= eyvl (ll.-tb-4) a ;l;)._1;: H°"'o (OA Ôyuz:} yvz •

= H OVl1 ( Oz, Wy 11 2 ( 4- a. - bJ) =- W:z ( 4- Q. - b).

\tl: *)

M (YJ-=- ( M(z.J)' ! &t BJJ 7 "1. rf J: •• •

K(Y) = ~ [ <fl ·H 0( "yvz cu1) -'J © H 0

( Gy(v1J] v~z ~~z

= Ken [cf> H' ( Wz (4-o.- bt-VIJ -4 © H' ( ÔytJz(uJJ] 11 V ( ~ ~{ ® H~( Oy112 (o.-tl.-'1--vl) ~ © H0

( Oz(o.-d-q-vJJ] . ~

" (H!ZJ (0.-tb-<1-J )' (ta:~) ~~ s.r. lfJ i-, dll ~l. Y, ( Ya) 0 ;J: j_t t ~t

~ "t -cl1, p, ( ~. ch, P .. J t l y, vy,.= Ha.n Hb

l:. 1 ~ 0 ~ ., ~ :,):_., :2 ? 0) Rf]ift A:: ""'" ~ "3 •

ch = o.L- d,

P1"-lo.b( 0.-1-b-.q.J-+ d, ( o.tb- ~o + P,

Page 71: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

lJl) BR.zou. t V) ~ t

1 Îl~Rî·!'3o

1 Î"" ·~ l ~ "-t~ .1: 3 1;: im• y I;: #L HCYJ., ~ "t.

1t it" i t!. ~ if. 11 ~ -~ 1- th 3 ~ ;:. °' ~ t:: # L

2.., 0 r~:i1··t> 3 ..

L) .;...o._~ ( ~ J 1;1. {P[ /J'

;:: J\. 1::.., " "l ;,t 1) ~jf :6''" J;, 3 ~

!t_:î!l ( ApQty. Go.e.to.., P.s.o~nc - Szt•i-o) y Ir p1., ~ t 1 3

y~ f <="> y: pwjJ1.c-t1·ve (ol...u. Mo.c.~o-q. ~ MlYJ=O

,jB_ L Y n ~! ûlacJl ( I7 ( Ç ~ = kll<o, x,, '><,, XJJ) \':. 1 J

S!J:y 6•· pv~~ ColillA - l'<o.~""'d

~ · ~t.~ ( Slz7 )r = 2 ç=) H~ ·( SfryJ"' o

Page 72: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

\. d-'\. I~ ;jt 0) i.ruJ_ t.0k~~ 0) llllca.<it ~t.e. V'~

~ 1 < 3.

S/.Iy~ $ 1-to(Oy(1>J)~fl'<Shv)-7 0 l.lE-Z I' ,

Il M (Y)

~ tr ~ E t:. p3 ..1:: 0 l".,,..J. 2. 6J v.11.c..tor 1:>1 ... .,d le t. L,

H0

(c) 0 "i.. s 1-. 1t L ( sJ. ( i:: "> 3i ! '* ~.) tr w.rwe. '/

! !l ~ 3 ~, v.u.to 1- l>IMld le. E t. M (Y) 'C OJ I~ {~ ê flil"\"

J:. j 0

}:! ~ : H0 (n "' ;;[, s 1;:.# t tsJij 11 ;K 6) ! .> 1~ !!{_~ J •

f .., t ~ .J. ;t: 1 o.il-!M.t ~3 { U.ll i.>. 1: J~ · L,

ô0>.. l'D o~ 0; E 1 v,,_ • -Ji. f!î•l 0 b"""- 1: t:t t -r l UA., or') "' 7t..

t}\, 'à.>. tr ;J;. t ~ • ~)(_1~ ;:_ oi ( fJ\, 'h) (Il>.) 1:: Ji L î

P3 0 subsc,hci"'e. if.· ~~ ;l ~. lSJo"' c.o~ ,,_ 2 I··

if, ~ Ili , Y .1r ~ Ufl».rA.L. ~d w.. 1- ~ ~ o

4 ~ S. 9. .1:. "' E , S J ·)! ( = lSJo : à!J J'ti.. ) I~ j1 l

M(YJ Z ® 11'( E(c.-ci}) 0

( tlil. l c,f-1~ C1 (E) V6Z.

-C- h ' H 1t p1 oi 1! f OO lfJ ro.t10>1r;. l .e.111ivo..lv.ce c.lru:s t.

1 3 )

\.tl Bf:I) s

""Kc~<I>-<. Il. , ~

Page 73: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

1·· ;t;, ~ "' 6

~~ E ~ .'l

li.010olo~iwl the.oty J: '} K 1<1 ·t.,.;.,. b!Mldl{!. V

.i: ') E ~ E(-c,J , t..t ·~ K"' Ori(-(,).

t,t_1~ MlY) - Col<.&/\. ( E!! H0

( Oi'alvJJ - ~ H'( OycviJ)

= ·@H'(Iylvll = @·H'(E(vJ) - $ l-l 1 (FCi>-C1JJ v ~ v

~ 5. 10.

( tt **)

H'(El.ill 111 :t ·.s 1.:it·L ,

MlYJ = ® H' ( tl!Jl) [.f- c,) Uto :Z

Q1, i,_ t .!ff.it·>:. ~ ~ o S.:€ H0 (ECll.:JJ (L=J.2) 1~71l

~ y, = .2 ( y, =(s.-J.) ,,, 9~ y, ~ y,_

y ( .;_ p1) I~ 1-:f ·L , Iy ~ 1. 0 ~ ~ 1

~:t'. ., 4, 1"1' ~ ~"'1 J ~ ~ J-4° îl'" M -:!

Page 74: Title P[3]内の曲線の分類と, 関連した話題 Issue Date URL http ......Furthermore, the maximum is attained for each d, and in that case X necessarily lies on a quadric surface

( E H0( Iy(l'IJ)) t:. t 3 t J St.oA.to..<R H', li" ( ·L ~ 1~T-1t:1 3

stAA.t<--UL) r:. i:t l H 'f\ li"= Y v x r- Ji.~, Y, 'X 1;t I

~, ·1·1}~.

(t.t 9fl) """"'~[If] ~,.t.

(~ s.11. °' tflil~)

"*"" û, ~ 0

.... 0 ~ DpJ(- C1-ll.J----+ ~ (-.Q..J _s_, 7 Iy,---;,.. Cl .

(§, c,lE.l"'- c, 1-1 '"f H 1êl- ~>f- OO . ., 1-a-t-10 .. c..I ..tt11ivale•t

dc..s:;. ., ..1:. '> ~~ J:. 'J t ~ k. ~., >" 1:: 74"l ï(Iy, (f"))

0) 7L s ', s" ..s·· .:&.tt l \. 1-1 '" H .. = y, V l<, ,.. "> 3.. { H'

H" Il 'l k '1: "- s: s" 1:jf t\:- 1 3 ~13JOO ) IJ'~ Y1}: x, li

eA..o' ... i> 3 • - is .(Io( 4 d; 4Jl'i,""4M~ :

0 --7"' ( c, - l J 1 ·-1- I" ) ~ · E ( -1, - c. , -t 1vo J ---? Iy ( f'4 J -;)- Ci ~ ! 1

t 1 s', $'• ( (,, H0 (Iy, (f'IJ)) 1~ ~ 1::. t J H" ( E (-J,-<,-tl"'l)

11) '3l, s', s'' '1'.. ~ :;>, .. ~ S ~ k[ Xo, x,, )(>._, Xl] -'!i. J ivo.O..o.J.

Y4 U L, p31:: 0:> c.oherRAt-1- sk.w.:f g. 1~ }:t L, J;('PJ

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References

1. Bertini, Interna ad alcuni problemi •.. Atti Ace. Sei. Torino 1§. (1890)

2. Castelnuovo, G., Sui multipli di una serie lineare di gruppi di punti appartenente ad una curva algebrica. Rend. Circ. Mat. Palerme l (1893)

3. Enriques, F. and Chisini, O., Courbes et fonctions algébriques d'une variable. Paris, Gauthier-Villars (1926)

4. Halphen, G., Mémoire sur la classification des courbes gauches algébriques. J. éc. polyt. ~ (1882) 1-200

5. Hartshorne, R., Residues and Duality. Springer Lecture Notes 20 (1966)

6. Hartshorne, R., Curves with high self-intersection on algebraic surfaces. Publ. Math. IRES 36 (1969) 111-125

7. Kleiman, S. 1., Geometry on Grassmannians and applications to splitting bundles and smoothing cycles. Publ. Math. IRES].§_ (1969) 281-298

8. Manin, Yu. I., Cubic ferros. Algebra, Geometry Arithmetic. North-Rolland, Amsterdam (1974)

9. Mumford, D., Pathologies IV. Amer. J. Math. 97 (1975) 847-849

10. NRether, M., Zur Grundlegung der Theorie der algebraischen Raumcurven. Kon. Ak. Wiss. Berlin (1883)

11. Peskine, C. and Szpiro, L., Liaison des variétés algébriques, I. Invent. Math. 1§. (1974) 271-302

12. Saint-Donat, B., On Petri's analysis of the linear system of quadrics through a canonical curve. Math. Ann. 206 (1973) 157-175

13. Samuel, P., Old and new results on algebraic curves, Tata Inst. Lecture Notes

14. Schaps, M., Non-singular deforrnations of space curves, using determinantal schernes, Thesis, Harvard Univ. (1972)

15. Serre, J. -P., Groupes algébriques et corps de classes. Hermann, Paris (1959)

16. Severi, F., Vorlesungen liber algebraische Geometrie (tr. E. LHffler) Leipzig (1921)

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