Abstract Details

Name: Abir Sarkar
Affiliation: Raman Research Institute
Conference ID: ASI2017_496
Title : The effects of non-standard dark matter on CMB spectral distortion
Authors and Co-Authors : 1) Shiv K Sethi , Raman Research Institute 2) Subinoy Das, Indian Institute of Astrophysics
Abstract Type : Oral
Abstract Category : General Relativity and Cosmology
Abstract : Currently active research is going on worldwide to understand the nature of dark matter. Here an attempt is made to reveal the nature of it by studying its effects on the spectral distortion in the CMB, an unique probe of the thermal history of the universe. In the early universe, energy is dissipated into the photon-baryon plasma due to Silk Damping which heats up the baryons. This eventually deviates the photon spectrum from its pure blackbody nature. The amount of heat dissipated and thus the deviation is dependent on the transfer function of the dipole component of the CMB, which is sensitive to the nature of dark matter. In this work, along with the standard cold dark matter we have considered a handful of other dark matter models. For each of these models, we have studied the evolution of the heating rate of the photon-baryon plasma and calculated the Compton y-parameter. We have found that not only the y-parameter is different for different dark matter models but also, given the sensitivity, those are expected to be measured and distinguished by the forthcoming PIXIE-like experiments. We also provide a physical explanation of the nature of distortion that can be expected at different epochs of the thermal history of the universe and argue that only the intermediate scales of the transfer function contribute in the spectral distortion.