1 1 Dark Energy with SNAP and other Next Generation Probes Eric Linder Berkeley Lab

2 2 Dark Energy to z > 1 New parametrization w(a)=w 0 +w a (1-a) Model independent, 2D phase space Well behaved at high z More accurate reconstruction More sensitive to data! Linder 2002 PRL; astro-ph/ Time variation w´ is a critical clue to fundamental physics. Deep surveys of galaxies and SN to z>1 Large scale structure formation CMB constraints from z lss =1100

3 3 Evolving Equation of State Linder 2002, astro-ph/ following Corasaniti & Copeland 2002 w(a) = w 0 +w a (1-a) Accurate to 3% in EOS back to z=1.7 (vs. 27% for w 1 ). Accurate to 0.2% in distance back to z lss =1100!

4 4 SN + CMB Complementarity SNAP tightly constrains dark energy models. SNAP+Planck have excellent complementarity, equal to a prior  (  M )  Frieman, Huterer, Linder, & Turner 2002 SNAP+Planck can detect time variation w´ at 99% cl (e.g. SUGRA).

5 5 Large Scale Structure Pilot Study with KAOS KAOS: Kilo-Aperture Optical Spectrometer Next generation 2dF survey Gemini South front end (8 meter) 4000 fibers, 1.5 sq.deg. FOV 400 sq.deg. area, 10 6 galaxies Linder, Colless Next generation galaxy survey: 2dF  400dF !

6 6 Cosmic Shear Test Alcock & Paczyński 1979 Transverse and radial distances are not equal, even for a sphere, because they are measured at different a(t).  z /  = H(z)  dz´/H(z´)  zz SNAP still offers the best hope to detect w´. Linder astro-ph/

7 7 KAOS+SNAP: Baryon Oscillations Standard ruler: ratio of wiggle scale to sound horizon  H(z) / (  m h 2 ) 1/2 Just like CMB – simple, linear physics Eisenstein astro-ph/ Linder astro-ph/

8 8 Growth of Structure Growth in linear perturbation theory with w´ vs. cosmological constant vs. constant w vs. constant w degenerate in CMB Linder 2002

9 9 Large Scale Structure running! Growth predicted to be very sensitive to w´ Running blind: SZ, cluster/halo counts, lensing Need full scale LSS simulations with w, w´ None exist! but in planning with C. Frenk, A. Jenkins vs. cosmological constant vs. constant w vs. constant w degenerate in CMB

10 First Simulation Results 10 7 particles L box =648 Mpc/h  M =0.3 + SUGRA DE Linear P k as Hubble LCDM Fits Jenkins mass function Agrees with Hubble FOF(b0.2) to 5% Jenkins & Linder 2003

11 Expansion History of the Universe SNAP will map the expansion history, uncovering physics just like the thermal history revealed early universe physics.

12 Present Day Inflation SNAP will map the expansion history precisely and see the transition from acceleration to deceleration.

13 Beyond Dark Energy SNAP can not only determine dark energy parameters, but test the cosmology framework – alternative gravitation, higher dimensions, etc.

14 History constrains Fate SNAP will bound the possible fate of the universe. Axion, supergravity, decaying dark energy models leading to collapse of universe have detectable w´. Collapsing universe (e.g. axion DE) Work in progress, with Kallosh, Kratochvil, Linde

15 SNAP Complements SNAP SN Ia Weak Lensing SN II Clusters Baryon Oscillations Strong Lensing Wide, Deep and Colorful 9000 times the area of Hubble Deep Field 15 sq.deg. to AB mag R=30 ; 120 epochs 300 sq.deg. to AB mag R=28

16 Next Generation Resource For Astronomers SNAP main survey will be 5000x larger (and as deep) than the biggest HST deep survey, the ACS survey Complementary to NGST: target selection for rare objects Can survey 300 sq. deg. in a year to J=28 (AB mag) Archive data distributed Guest Survey Program For Cosmologists Mapping the expansion history of the universe through the accelerating phase back into the decelerating epoch Precision determination of cosmological parameters For Fundamental Physicists Exploring the nature of dark energy Testing higher dimension theories Testing alternate theories of gravitation