PIRSA:22010082

Video URL

https://pirsa.org/22010082

Cosmology and astrophysics from small scales

Pandey, S. (2022). Cosmology and astrophysics from small scales . Perimeter Institute for Theoretical Physics. https://pirsa.org/22010082

Pandey, Shivam. Cosmology and astrophysics from small scales . Perimeter Institute for Theoretical Physics, Jan. 14, 2022, https://pirsa.org/22010082 

          @misc{ scivideos_PIRSA:22010082,
            doi = {10.48660/22010082},
            url = {https://pirsa.org/22010082},
            author = {Pandey, Shivam},
            keywords = {Cosmology},
            language = {en},
            title = {Cosmology and astrophysics from small scales },
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2022},
            month = {jan},
            note = {PIRSA:22010082 see, \url{https://scivideos.org/pirsa/22010082}}
          }

Shivam Pandey University of Pennsylvania

Talk numberPIRSA:22010082
DOI10.48660/22010082
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

Complex and poorly understood astrophysics impacts our ability to constrain cosmological and astrophysical models from the large scale structure. Two major sources of systematic errors are galaxy biasing (non-linear mapping between dark matter and galaxies) and baryonic feedback (impact of supernovae or AGN on LSS). In the first part of my talk, I will describe a hybrid perturbation theory model of galaxy biasing and show its validation at sub-percent accuracy. I will then describe the cosmological constraints obtained using this model on the measurements from the first three years of observations of the Dark Energy Survey (DES). In the second part of my talk, I will describe tomographic measurements and analysis of the cross-correlations between thermal Sunyaev-Zel'dovich (tSZ) effect and gravitational lensing. Using data from ACT, Planck, and DES, we obtain the highest significance (20 sigma) measurements to-date and use them to constrain models for the pressure profiles of halos across a wide range of halo mass and redshift. We find evidence for reduced pressure in low mass halos, consistent with predictions for the effects of increased feedback from AGN. Lastly, we also comment on application of this study to the sigma8 tension and hydrostatic mass bias as inferred from the cluster count analysis.