130 ix 05 ICFA

High Energy Astro-Particle Physics

International Conference on Future Accelerators

Daegu, Korea

Roger D. BlandfordKIPAC

Stanford University

230 ix 05 ICFA

The Scope of Astro-Particle Physics

* Cosmology– Physics of the Early Universe, inflation, baryo/leptogenesis…

– Dark Matter/Dark Energy

* Physics of Extreme Environments– Neutron Stars - Pulsars, Magnetars…

– Black Holes - Quasars, Gamma-ray Bursts…

* High Energy Particles– Cosmic Rays - UHE Protons, VHE Gamma rays, UHE ’s…

– Cosmic Accelerators - Shock Fronts, Electromagnetic Inductors…

330 ix 05 ICFA

The Scope of Astro-Particle Physics

* Cosmology– Physics of the Early Universe, inflation, baryo/leptogenesis…

– Dark Matter/Dark Energy

* Physics of Extreme Environments– Neutron Stars - Pulsars, Magnetars…

– Black Holes - Quasars, Gamma-ray Bursts…

* High Energy Particles– Cosmic Rays - UHE Protons, VHE Gamma rays, UHE ’s…

– Cosmic Accelerators - Shock Fronts, Electromagnetic Inductors…

430 ix 05 ICFA

General Relativity

* General Relativity (Einstein 1915)– Singular “simple” theory of classical gravity

– G=8T

– Many, more elaborate alternatives

• Scalar tensor, bimetric, extra dimensions, PPN…

* Experimental Program– Classical tests

• Redshift, Mercury. Light deflection

– Modern tests

• Shapiro delay, gravitational radiation, EP, inverse square law...

GR/AE vindicated at level from 10-2 to 10-4!

530 ix 05 ICFA

Cosmology

* Einstein 1916– G+g=8T - Cosmological Constant

• Vacuum energy: P=-

* Friedmann 1922• a(t) is scale factor ( =1 now)

0][

][

.3

4

2

3

3

22

ad

adP

constaa

B

Const. measurescurvature =0 when flat.

630 ix 05 ICFA

Historically, was taken very seriously

* Lemaitre 1927 – Basic equations, relativistic growth of perturbations

* Eddington 1933– The universe is much bigger than particles; therefore there must a

cosmological lengthscale - -1/2

– “I would as soon think of reverting to Newtonian theory as of dropping the cosmical constant”

– “To drop the cosmical constant would knock the bottom out of space”

* Bondi 1948– CDM Universe

730 ix 05 ICFA

Simple World Models

only– r const– a ~ exp t – De Sitter Universe

* Matter only– ~ a-3

– a ~ t2/3 – Einstein - De Sitter Universe– Deceleration

* Matter plus – Singular “simple” theory – a ~ (sinh t)2/3

– CDM universe– Deceleration -> acceleration

t

13

2

a

aaj

830 ix 05 ICFA

Cosmological Observations

* Kinematical– Cannot measure time accurately

– Instead measure d(a), where

– Observe objects of known size

• eg density fluctuations – at recombination when a ~ 10-3

now

then

now

then

a

dtd

za

1

1

930 ix 05 ICFA

Microwave Background Observations

Hinshaw et al WMAP

* Measure spectrum of temperature fluctuations– Derive from scale-invariant initial conditions => inflation?

* Calculate linear size of peak; angle => distance

Universe Flat to ~ 2 percent

1030 ix 05 ICFA

Cosmological Observations

* Kinematical– Cannot measure time accurately

– Instead measure d(a), where

– Observe objects of known size

• eg density fluctuations – at recombination when a ~ 10-3

– Observe objects of known power

• eg supernovae– For a > 0.3

now

then

now

then

a

dtd

za

1

1

Perlmutter

1130 ix 05 ICFA

Cosmological Observations

* Dynamical– Newtonian physics in Universe

expanding at rate given by a(t)

– Measure CMB fluctuation spectrum

– Clusters of galaxies

– Growth of structure

• Compare with CMB

4.0B

B

MM

X-rays +Lensing

Nuclear PhysicsTegmark et al

1230 ix 05 ICFA

CDM Dynamics

* Positive perturbations grow– Gravity vs expansion– Initial conditions when a~0.001 from CMB observations– Fluctuation spectrum has “simple,” scale-free form

• Linear perturbations evolve with time according to:

– Extend into nonlinear phase using simulations– many uncertainties on short scales

03

4

3

]coth[8 t

1330 ix 05 ICFA

Standard Model of the Universe

* = const

=0.7nJm-3 =6 x 10-28 kg m-3

Equivalent to:

• 0.4 mG, 40 K, 1meV, 100, 3THz

• m ~mSUSY2/mP

• Extra dimensions…

* DM = 0.25nJm-3 Supersymmetric particle?

* = 0.05nJm-3

* Flat spatial geometry

All contemporary data consistent with CDM to 10-20%

1430 ix 05 ICFA

How do we study DE/DM at 1% level?

* What physics must we explain?

* CMB observations will improve

* Kinematic Tests– Distance to supernovae– Baryon oscillations– …

* Dynamical Tests– Weak gravitational lensing– Counting clusters of galaxies– …

* Only careful, well-planned projects will be up to the task

Eisenstein et al

In US, a task force is making choices

1530 ix 05 ICFA

Extreme Conditions

* SGR 1806-20 Magnetar Explosion Dec 27 2004

* Highly Magnetized Neutron Star in our Galaxy

* Released large fraction of magnetic energy in electromagnetic bomb– M ` 3 x 1030 kg: R ~ 10km; giant

nucleus

– B ~ 1011T, E~1041J

• ~30 BQED,

• 15MeV cyclotron energy

– E ~ 1040J in ~ 1s

– Afterglow in radio and X-rays

– Still fading

300srisetime

1630 ix 05 ICFA

Extreme Physics

* Cold nuclear matter at several times nuclear density – Many body effects dominant– Composition still unknown

• Neutrons, hyperons, quarks, strange stars…• Superconductivity, superfluidity

– M(R), cooling etc

* QED in supercritical fields– Novel, though uncontroversial effects– Largely unexplored

• Plenty of new effects!

* Ultrarelativistic shock waves, pair plasma physics– Accelerators increasingly used to perform HED experiments

1730 ix 05 ICFA

Cosmic Particle Acceleration

* Naturally occuring accelerators produce UHE CR:– E ~ ZeV = 1012 GeV

– ECM ~ PeV; Higher energy collisions on our past light cone

– I ~ 1 EA = 1018 A

* How do they work?

Shock FrontsBlack Holes

Jets

Chandra X-ray Observatory

1830 ix 05 ICFA

TeV -ray Astronomy

* H.E.S.S. (VERITAS)* Atmospheric Cerenkov

emission in stereo* Particle physics techniques* Observe up to 30 TeV* Combine with GLAST in

2007* How are GCR accelerated* Test Lorentz Invariance on cosmological scale

ASCA 1-3 keV

> 1 TeV

1930 ix 05 ICFA

Summary

* Astro-Particle Physics remains a very exciting area

* Fundamental problems – Dark Energy - astronomical observation plus pure thought– Dark Matter – below, on and above ground– Inflation - CMB polarization

* Outstanding astro-engineering puzzles – How do shocks and Zevatrons work?– What causes magnetars and gamma ray bursts to explode?– What is a neutron star?

* Tremendous discovery potential for new physics– Baryogenesis and leptogenesis– Black hole observations as tests of strong field gravitation– Strong field QED