Upload
eljah
View
53
Download
0
Embed Size (px)
DESCRIPTION
MASSIVE NEUTRINOS AND COSMOLOGY. ν. Sergio Pastor (IFIC). CuTAPP 2005, Ringberg Castle. Outline. Neutrinos as DM. Effect of neutrino mass on cosmological observables. Current bounds and future sensitivities. Neutrinos decoupled at T~MeV, keeping a - PowerPoint PPT Presentation
Citation preview
04/22/23
MASSIVE NEUTRINOS AND COSMOLOGY
Sergio Pastor (IFIC)
ν
CuTAPP 2005,
Ringberg Castle
Current bounds and future sensitivities
Effect of neutrino mass on cosmological observables
Outline
Neutrinos as DM
The Cosmic Neutrino Background
• Number density
• Energy density
flavor per
cm )( 112
present at3- 3
23
3
11
3(6
11
3
2 CMBγννν Tπ
)ζn)(p,Tf
π)(
pdn
nm
T
)(p,Tfπ)(
pdmp
i
ii
CMB
νν
43/42
3
322
11
4
120
7
2
Massless
Massive mν>>T
Neutrinos decoupled at T~MeV, keeping a spectrum as that of a relativistic species 1e
1T)(p,f p/T
04/22/23
Relic neutrinos influence several cosmological epochs
T < eVT ~ MeV
Formation of Large Scale Structures
LSS
Cosmic Microwave Background
CMB
Primordial
Nucleosynthesis
BBN
No flavor sensitivity Neff & mννevs νμ,τ Neff
Non-instantaneous ν decoupling (including oscillations)
3.045N eff T.Pinto et al, in preparation
Neutrinos as Dark Matter
• Neutrinos are natural DM candidates
• They stream freely until non-relativistic (collisionless phase mixing) Neutrinos are HOT Dark Matter
• First structures to be formed when Universe became matter -dominated
• Ruled out by structure formation CDM
MpceV 30
m 41
-1
ν
Neutrino Free Streaming
b, cdm
eV 46 m 1 Ω eV 93.2
mhΩ
iiν
ii
2ν
Neutrinos as Dark Matter
• Neutrinos are natural DM candidates
• They stream freely until non-relativistic (collisionless phase mixing) Neutrinos are HOT Dark Matter
• First structures to be formed when Universe became matter -dominated
• HDM ruled out by structure formation CDM
eV 46 m 1 Ω eV 93.2
mhΩ
iiν
ii
2ν
MpceV 30
m 41
-1
ν
Neutrinos as Hot Dark Matter
• Effect of Massive Neutrinos: suppression of Power at small scales
Massive Neutrinos can still be subdominant DM: limits on mν from Structure Formation (combined with other cosmological data)
CMB DATA: INCREASING PRECISION
Multipole Expansion
Angular Power SpectrumMap of CMBR temperature
Fluctuations
T
T-),T(),Δ(
Galaxy Redshift Surveys
SDSS
2dFGRS
~ 1300 M
pc
Power Spectrum of density fluctuations
Galaxy Surveys
CMB experiments
SDSS
Field of density Fluctuations
)(
)(x
x
Matter power spectrum is the Fourier transform of the
two-point correlation function
Power spectrum of density fluctuations
Bias b2(k)=Pg(k)/Pm(k)
Non-linearity
2dFGRS
kmax
SDSS
Neutrinos as Hot Dark Matter
W. Hu
• Effect of Massive Neutrinos: suppression of Power at small scales
Massive Neutrinos can still be subdominant DM: limits on mν from Structure Formation (combined with other cosmological data)
Effect of massive neutrinos on the CMB and Matter Power
Spectra
Max Tegmark
www.hep.upenn.edu/~max/
Cosmological bounds on neutrino mass(es)
A unique cosmological bound on mν DOES NOT exist !Different analyses have found upper bounds on neutrino masses, since they depend on
• The assumed cosmological model: number of parameters (problem of parameter degeneracies)
• The combination of cosmological data used
Cosmological Parameters: example
SDSS Coll, PRD 69 (2004) 103501
Cosmological Data
• CMB Temperature: WMAP plus data from other experiments at large multipoles (CBI, ACBAR, VSA…)
• CMB Polarization: WMAP
• Large Scale Structure:
* Galaxy Clustering (2dF,SDSS)
* Bias (Galaxy, …): Amplitude of the Matter P(k) (SDSS,σ8)
* Lyman-α forest: independent measurement of power on small scales
• Priors on parameters from other data: SNIa (Ωm), HST (h), …
3 degenerate massive neutrinos Σmν = 3m0
Neutrino masses in 3-neutrino schemes
eV
From present evidences of atmospheric and solar neutrino oscillations
atmatm
solar
solar
eV 0.009 m
eV 0.05m
2sun
2atm
eV
m0
Absolute mass scale searches
Cosmology < 0.42-2.0 eV
Neutrinoless double beta decay
< 0.3-1.6 eVi
ieiee mUm 2
Tritium decay < 2.3 eV
i
im~
2/1
22
iiei mUm
e
Cosmological bounds on neutrino mass since 2003
390280640 . . .
Bound on Σmν (eV) at 95% CL
Data used
Ichikawa, Fukugita & KawasakiPRD 71 (2005) 043001
2.0 WMAP
SDSS Coll.PRD 69 (2004) 103501
1.7 WMAP, SDSS
HannestadJCAP 0305 (2003) 004
1.01 WMAP, other CMB, 2dF, HST
Crotty, Lesgourgues & SPPRD 69 (2004) 123007
1.0 [0.6] WMAP, other CMB, 2dF, SDSS [HST,SN]
Barger. Marfatia & TregrePLB 595 (2004) 55
0.75 WMAP, other CMB, 2dF, SDSS, HST
WMAP Coll.ApJ Suppl 148 (2003) 175
0.7
WMAP, other CMB,2dF (bias,galaxy clustering), Ly-α, HST
Fogli et al.PRD 70 (2004) 113003
0.47WMAP, other CMB, 2dF, SDSS (Ly-α),HST
Seljak et al.PRD (2005) [astro-ph/0407372]
0.42WMAP, SDSS (bias, galaxy clustering, Ly-α)
Neutrino masses in 3-neutrino schemes
Fig from Strumia & Vissani, hep-ph/0503246
CMB + galaxy clustering
+ HST, SNI-a [σ8]
+ Ly-α [bias]
Global analysis: oscillations + tritium decay + 02 + Cosmology
Fogli et al., PRD 70 (2004) 113003
CMB + 2dF
390280640 . . .
Bound on Σmν (eV) at 95% CL
Data used
Ichikawa, Fukugita & KawasakiPRD 71 (2005) 043001
2.0 WMAP
SDSS Coll.PRD 69 (2004) 103501
1.7 WMAP, SDSS
HannestadJCAP 0305 (2003) 004
1.01 WMAP, other CMB, 2dF, HST
Crotty, Lesgourgues & SPPRD 69 (2004) 123007
1.0 [0.6] WMAP, other CMB, 2dF, SDSS [HST,SN]
Barger. Marfatia & TregrePLB 595 (2004) 55
0.75 WMAP, other CMB, 2dF, SDSS, HST
WMAP Coll.ApJ Suppl 148 (2003) 175
0.7
WMAP, other CMB,2dF (bias,galaxy clustering), Ly-α, HST
Fogli et al.PRD 70 (2004) 113003
0.47WMAP, other CMB, 2dF, SDSS (Ly-α),HST
Seljak et al.PRD (2005) [astro-ph/0407372]
0.42WMAP, SDSS (bias, galaxy clustering, Ly-α)
Allen, Smith & BridleMNRAS 346 (2003) 593
WMAP, other CMB, 2dF, X-ray galaxy cluster
390280640 . . .
The bound depends on the number of neutrinos
• Example: in the 3+1 scenario, there are 4 neutrinos (including thermalized sterile)
• Calculate the bounds with Nν > 3
Abazajian 2002, di Bari 2002
Hannestad JCAP 0305 (2003) 004
(also Elgarøy & Lahav, JCAP 0304 (2003) 004)
3 ν4 ν
5 ν
Hannestad
95% CL
WMAP + Other CMB + 2dF + HST + SN-Ia
Σmν and Neff degeneracy
(0 eV,3)
(0 eV,7)
(2.25 eV,7)(0 eV,3)
(0 eV,7)
(2.25 eV,7)
Analysis with Σmν and Neff free
Hannestad & Raffelt, JCAP 0404 (2004) 008
Crotty, Lesgourgues & SP, PRD 69 (2004) 123007
2σ upper bound on Σmν (eV)
WMAP + ACBAR + SDSS + 2dF Previous + priors (HST + SN-Ia)
Non-thermal relic neutrinos
The spectrum could be distorted after neutrino decoupling
Example: decay of a
light scalar after BBN
Cuoco, Lesgourgues, Mangano & SP, astro-ph/0502465
Thermal FD spectrum
Distortion from decay
CMB + LSS data still compatible with large deviations from a thermal neutrino spectrum (degeneracy NT distortion – Neff)
* Better expectations for future CMB + LSS data, but model degeneracy NT- Neff remains
/T p
Future sensitivities to Σmν
• Next CMB data from WMAP and PLANCK (+ other CMB experiments on large l’s) temperature and polarization spectra
• SDSS galaxy survey: 106 galaxies (250,000 for 2dF)
• Fisher matrix analysis: expected sensitivities assuming a fiducial cosmological model
• Forecast analysis for
WMAP and ΩΛ=0 models Hu et al, PRL 80 (1998) 5255
Sensitivity to
With current best-fit values
eV 0.1N
hΩ 0.65 Σm
0.82m
νν
eV0.37 Σm
Recent update: Lesgourgues, SP & Perotto, PRD 70 (2004) 045016
Fiducial cosmological model:(Ωbh2 , Ωmh2 , h , ns , τ, Σmν ) = (0.0245 , 0.148 , 0.70 , 0.98 , 0.12, Σmν )
PLANCK+SDSS
Lesgourgues, SP & Perotto, PRD 70 (2004) 045016
Ideal CMB+40xSDSS
Σm detectable at 2σ if larger than
0.21 eV (PLANCK+SDSS)
0.13 eV (CMBpol+SDSS)
Σm Σm
Fiducial value
2 sensitivity
Future sensitivities to Σmν: new ideas
galaxy weak lensing and CMB lensing
no bias uncertaintysmall scales in linear regime
makes CMB sensitive to much smaller masses
Future sensitivities to Σmν: new ideas
galaxy weak lensing and CMB lensing
sensitivity of future weak lensing survey(4000º)2 to mν
σ(mν) ~ 0.1 eV
Abazajian & DodelsonPRL 91 (2003) 041301
sensitivity of CMB(primary + lensing) to mν
σ(mν) = 0.15 eV (Planck)
σ(mν) = 0.044 eV (CMBpol)
Kaplinghat, Knox & SongPRL 91 (2003) 241301
Neutrino masses in 3-neutrino schemes
Fig from Strumia & Vissani, hep-ph/0503246
CMB + galaxy clustering
+ HST, SNI-a [σ8]
+ Ly-α [bias]
PLANCK + SDSS
CMBpol + SDSS
CMBpol (including CMB lensing)
KATRIN
Bounds on the sum of neutrino masses from CMB + 2dFGRS or SDSS, and other
cosmological data (best Σmν<0.42 eV, conservative Σmν<1 eV)
Conclusions
Sub-eV sensitivity in the next future (0.1-0.2 eV and better) Test degenerate
mass region and eventually the IH case
ν
Cosmological observables efficiently constrain some properties of (relic) neutrinos