Abstract Details
| Name: Kanhaiya Lal Pandey Affiliation: NCRA-TIFR Pune Conference ID: ASI2015_838 Title : Reionization constraints on primordial magnetic fields Authors and Co-Authors : Tirthankar Roy Choudhury (National Centre for Radio Astrophysics-TIFR, Pune, India) Shiv K Sethi (Raman Research Institute, Bangalore, India) Andrea Ferrara (Scuola Normale Superiore, Pisa, Italy) Abstract Type : Oral Abstract Category : General Relativity and Cosmology Abstract : Search of magnetic fields in the IGM is one of the major goals for many upcoming projects such as LOFAR, MWA and SKA. The role of these magnetic fields as the likely seed field for the magnetic fields observed inside galaxies and cluster of galaxies, as well as the fact that the IGM magnetic field might trace and regulate structure formation in the early Universe, makes it considerably important. Primordial magnetic fields leave their signature on a range of cosmological processes and observables such as Faraday rotation of CMB polarization plane, weaklensing signals and Ly-alpha effective opacity etc. These fields can generate density perturbations in addition to the LCDM model in the post-recombination epoch. The matter power spectrum of these density perturbations dominates the standard LCDM matter power spectrum at small scales (k ~ 1–10 h/Mpc). This additional power can cause early formation of structures (e.g., galaxies) which consequently cause early reionization of the IGM. As of today, the main observational constraints on reionization come from the CMB polarization data (e.g., those from the WMAP and Planck experiments) and the quasar absorption spectra at z >= 5.5. Detailed models which are able to match these and a variety of other observations predict the reionization to be process extended over 6 < z < 15. It has been shown that the presence of magnetic fields can affect the reionization history and alter the HI signal from epoch of reionization. In this work, we extend available detailed models of reionization by including magnetic fields and carry out a detailed mutliparameter MCMC analysis to compare with available data sets. The main goal is to check the level of constraints one can put on the primordial magnetic field using existing constraints on reionization. As a result of this analysis we get one of the strongest upper bound on primordial magnetic field strength. |