High Energy Astro-Particle Physics

High Energy Astro-Particle Physics International Conference on Future Accelerators Daegu, Korea Roger D. Blandford KIPAC Stanford University 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 n’s… • Cosmic Accelerators - Shock Fronts, Electromagnetic Inductors… ICFA

General Relativity • General Relativity (Einstein 1915) • Singular “simple” theory of classical gravity • G=8pT • 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! ICFA

Cosmology B • Einstein 1916 • G+Lg=8pT - Cosmological Constant • Vacuum energy: P=-r. • Friedmann 1922 • a(t) is scale factor ( =1 now) Const. measures curvature =0 when flat. ICFA

Historically, L 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 - L-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 • LCDM Universe ICFA

Simple World Models • L only • r const • a ~ exp t • De Sitter Universe • Matter only • r ~ a-3 • a ~ t2/3 • Einstein - De Sitter Universe • Deceleration • Matter plus L • Singular “simple” theory • a ~ (sinh t)2/3 • LCDM universe • Deceleration -> acceleration t 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 ICFA

Microwave Background Observations • Measure spectrum of temperature fluctuations • Derive from scale-invariant initial conditions => inflation? • Calculate linear size of peak; angle => distance Hinshaw et al WMAP Universe Flat to ~ 2 percent 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 Perlmutter 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 Nuclear Physics Tegmark et al X-rays +Lensing ICFA

LCDM 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 ICFA

Standard Model of the Universe All contemporary data consistent with LCDM to 10-20% • rL = const =0.7nJm-3 =6 x 10-28 kg m-3 Equivalent to: • 0.4 mG, 40 K, 1meV, 100m, 3THz • mL ~mSUSY2/mP • Extra dimensions… • rDM = 0.25nJm-3 Supersymmetric particle? • rB = 0.05nJm-3 • Flat spatial geometry 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 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 300ms risetime 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 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? Black Holes Shock Fronts Jets Chandra X-ray Observatory ICFA

TeV g-ray Astronomy ASCA 1-3 keV • 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 > 1 TeV 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 ICFA

High Energy Astro-Particle Physics