Data: 24.10.2023

Chandra Shekhar Saraf (CAMK Warsaw)

Testing cosmological models through cross-correlation between CMB lensing and large scale structure.

Streszczenie:
The well established standard ΛCDM model of cosmology suffers from several challenges and disparities like the nature of dark matter and dark energy, accelerated expansion of the Universe and tensions in cosmological parameters derived from different observations. These shortcomings have raised questions on the validity of the ΛCDM model and led to increased interests towards alternative models of cosmology (dark energy models and Modified Gravity theories). The effect of gravitational lensing of the cosmic microwave background (CMB) provides a unique opportunity to obtain a picture of the gravitational potential of the large-scale structure of the Universe at very high redshifts. Cross-correlation of the gravitational potential with other tracers of the large-scale structure at known redshifts allows tracing the evolution of the structure and testing cosmological models. In this talk we will present the studies of systematics that can bias our inferences of cosmological parameters from cross-correlation measurements.

Bio:
I am PhD student the Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences. My research focuses on testing different cosmological models using cross-correlation between Cosmic Microwave Background (CMB) lensing and tracers of large-scale structures, like galaxies and quasars. I am interested in mitigation of systematics on testing cosmological models with upcoming large-scale structure surveys like Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), Dark Energy Spectroscopic instrument (DESI), Euclid, etc. My other research interests include:
-> understanding the effects and observational signatures of different theories of gravity at astrophysical scales,
-> optimal reconstruction of CMB lensing potential from future CMB polarisation and temperature data,
-> clustering of galaxies and the effects of Redshift Space Distortions,
-> inhomogeneous models of cosmology and their observational significance.
In addition, I am a Junior Assistant in LSST and a member in CMB Bharat consortium.