Abstract Details
| Name: Abir Sarkar Affiliation: Raman Research Institute Conference ID: ASI2015_647 Title : How Late can the Dark Matter form in our universe? Authors and Co-Authors : 1) Subinoy Das Indian Institute of Astrophysics Bangalore,India 2) Shiv.K.Sethi Raman Research Institute Bangalore, India Abstract Type : Poster Abstract Category : General Relativity and Cosmology Abstract : We put constraints on the epoch of dark matter formation for the case of certain non-wimp candidate where dark matter appears in between the epoch of Big Bang Nucleosynthesis and matter radiation equality. In such class of models, matter power spectra gets a strong suppression even towards linear scale, if dark matter is formed considerably close to the epoch of matter radiation equality and thus subject to strong constraints from linear power spectra measurement from SDSS and Lyman- alpha data. Unlike the case of warm dark matter, where mainly mass of the dark matter particle controls the suppression scale, in "Late forming dark matter" scenario, it is the redshift of dark matter formation which determines the free streaming scale in power spectra. We use SDSS and lyman- alpha data to directly nd the latest epoch of dark matter formation in our universe. If all the observed dark matter is late forming, we find lower bound on redshift of dark matter formation z_f > 1.08*10^5 at 99.73 % C.L from the SDSS data and z_f > 9* 10^5, at the same C.L, from the Lyman- alpha data. If only a fraction of the dark matter is late forming then we find tentative evidence of the presence of LFDM from the Lyman- alpha data. Upcoming data from SDSSIII/Boss will allow us to explore this issue in more detail. |