1 / 37

Complementary Probes of Dark Energy

Complementary Probes of Dark Energy. Josh Frieman. Snowmass 2001. The History of 20 th Century Cosmology is littered with `detections’ of  which later evaporated. Man (and woman) cannot live by Supernovae alone. The implications of Dark Energy are so profound that

caron
Download Presentation

Complementary Probes of Dark Energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Complementary Probes of Dark Energy JoshFrieman Snowmass 2001

  2. The History of 20th Century Cosmology is littered • with `detections’ of  which later evaporated. • Man (and woman) cannot live by Supernovae alone. • The implications of Dark Energy are so profound that • the SNe Ia results must be confirmed/extended by • multiple independent methods with: * different systematic errors • * different cosmological parameter degeneracies • The Cosmic Microwave Background is not a panacea: • it has limited sensitivity to Dark Energy.

  3. Key Issues • Is there Dark Energy? • Will the SNe results hold up? • What is the nature of the Dark Energy? • Is it  or something else? • How does w = pX/X evolve? • Dark Energy dynamics  Theory

  4. Physical Effects of Dark Energy Dark Energy affects expansion rate of the Universe: Huterer & Turner Dark Energy may also interact: long-range forces Carroll

  5. Physical Observables: probing DE • 1. Luminosity distance vs. redshift: dL(z) m(z) • Standard candles: SNe Ia • 2. Angular diameter distance vs. z: dA(z) • Alcock-Paczynski test: Ly-alpha forest; redshift correlations • 3. Number counts vs. redshift: N(M,z) • probes: • *Comoving Volume element dV/dzd • *Growth rate of density perturbations (z) • Counts of galaxy halos and of clusters; QSO lensing

  6. Comoving Distance: r(z) =  dx/H(x) In a flat Universe: Luminosity Distance: dL(z) = r(z)(1+z) Angular diameter Distance: dA(z) = r(z)/(1+z) Comoving Volume Element: dV/dzd = r2(z)/H(z)

  7. Sensitivity to Dark Energy equation of state Volume element Comoving distance Huterer & Turner

  8. Warning Constraint contours depend on priors assumed for other cosmological parameters Conclusions depend on projected state of knowledge/ignorance

  9. Goliath, etal

  10. Projected SNAP Sensitivity to DE Equation of State

  11. SNAP Sensitivity to Varying DE Equation of State w = w0 + w1z + ...

  12. Angular Diameter Distance Transverse extent Angular size Intrinsically isotropic clustering: radial and transverse sizes are equal Hui, Stebbins, Burles

  13. Lyman-alpha forest: absorbing gas along LOS to distant Quasars Clustering along line of sight Cross-correlations between nearby lines of sight

  14. Sloan Digital Sky Survey Projected constraints from redshift space clustering of 100,000 Luminous Red Galaxies (z ~ 0.4) Matsubara & Szalay

  15. CMB Anisotropy: Angular diameter Distance to last Scattering surface Peak Multipole

  16. Evolution of Angular clustering as probe of Angular diameter Cooray, Hu, Huterer, Joffre

  17. Volume Element as a function of w Dark Energy  More volume at moderate redshift

  18. Counting Galaxy Dark Matter Halos with the DEEP Redshift Survey 10,000 galaxies at z ~ 1 with measured linewidths (rotation speeds) NB: must probe Dark matter- dominated regions Newman & Davis Huterer & Turner

  19. Growth of Density Perturbations Flat, matter-dominated  Open or w > -1 Holder

  20. Counting Clusters of Galaxies Sunyaev Zel’dovich effect X-ray emission from cluster gas Weak Lensing Simulations: growth factor

  21. Detection Mass thresholds Haiman, Holder, Mohr

  22. Weak Lensing: Optical Multi-band Surveys of Varying Depth R ~ 25 (SDSS South) R ~ 27.5 R ~ 30 Joffre, Frieman

  23. Expected Cluster Counts in a Deep, wide Sunyaev Zel’dovich Survey Holder, Carlstrom, etal

  24. Constraints from a 4000 sq. deg. SZE Survey Mlim = 2.5 x 1014 h-1 Msun Holder, Haiman, Mohr

  25. Weak Lensing:Number Cts of Background Galaxies 10 7 Number (per .5 mags) 5 10 3 10 1 10 Points: HDF Curve: extrapolation From SDSS luminosity Function w/o mergers 16 18 20 22 24 26 28 Mag

  26. Weak Lensing S/N > 5 for aperture mass Assume NFW Profiles Conservative on Number counts R ~ 25 (SDSS South) R ~ 27.5 R ~ 30

  27. Abell 3667 z = 0.05 Joffre, etal

  28. SDSS R=27.5 R=30 WL Detected Clusters dn/dz per sq.deg. 100 dn/dz per sq. deg. 10 1 .5 1 1.5 2 2.5 3 z

  29. Number of Clusters detected above Threshold Here, 8 = 1 (will marginalize over) R ~ 27.5; 20,000 sq. deg. (co-added LSST or 1-year wide-field SNAP) R ~ 30; 16 sq. deg. (nominal SNAP in SNe mode) R ~ 25, 200 sq. deg (SDSS south)

  30. Projected Constraints From Cluster Weak Lensing Large sky coverage is critical SNe

  31. Cluster Weak Lensing: • Bring in Da Noise, • Bring in Da Funk • (account for: • projection effects • Fuzziness in Mass limit, also variations in NFW concentration parameter) Note: there is more information to be used than N(z)

  32. Weak Lensing: Large-scale shear Convergence Power Spectrum 1000 sq. deg. to R ~ 27 Huterer

  33. Projected Constraints From Cosmic Shear 1000 sq.deg. R ~ 27 Caveat: systematics in low S/N regime

  34. Clusters, shear halos

  35. Conclusions Multiple probes of Dark Energy, including SNe, should mature over the next 5-10 years Independent confirmation of Dark Energy is within sight Good prospects for independent constraints on the nature of the Dark Energy, with varying systematics and nearly `orthogonal’ parameter degeneracies

More Related