Cosmology in the Time of Dark Energy Lecture

Cosmology in the Time of Dark Energy Lecture 2 Ignacy Sawicki CEICO, Institute of Physics, Prague ceico

Previously on… Image credit: NASA and ESA

The background is the playground SDSS/BOSS Planck (2015)

How to Test Gravity? � Newtonian gravity Closed Orbits Linear Theory: Superposition

How to Test Gravity? � General Relativity: Schwarzschild unique* spherical vacuum solution

Will (1971), Norvedt (1972) How to Test Gravity? � PPN Extension

What do we know about gravity? Baker, Psaltis, Skordis (2015)

Inhomogeneities �

The Perturbed FLRW Lightcone

Matter Power Spectrum DES (2015) Adiabatic

“Modify Gravity” �

Observables in the Late Universe

Massive Probes: Galaxy Surveys SDSS/BOSS � ~ 3 million galaxies

Correlation Function SDSS/BOSS DR 10 SDSS/BOSS

But bias

Galaxies Redistributed

Effects of Metric Fluctuations

What Counting Measures Bonvin & Durrer (2011) Physical counts Redshift-space distortions Doppler + ISW Shapiro + Shear

Relative Importance Bonvin & Durrer (2011)

Redshift-Space Distortions Kaiser (1985) Redshift space Real space

Redshift-Space Distortions Redshift space Real space SDSS/BOSS DR 10 Samushia et al. (2013)/BOSS

Planck 2018

Caveat Emptor Bose et al. (2017)

Massless Probes: Cosmic Shear

Weak Lensing Following Bernardeau, Bonvin, Vernizzi (2009) M. White

Weak Lensing Kilbinger (2014)

WL Sensitivity Kilbinger (2014)

WL: Current Status Troxel et al. (2018)

Latest Constraints on MG params

Can we remove dependence on ICs? Amendola, Kunz, Motta, Saltas, IS (2013) �

The Nearing Future

Projected DESI Expansion Rate

Measuring shear in next generation wide field cosmic shear surveys

The Takeaway �