future events

Constraints on fundamental constants with CMB data

TYPEAstrophysics Seminar
Speaker:Eloisa Menegoni
Organizer:Alessandra Mastrobuono-Battisti
Time:11:30 - 12:30
Location:Lidow 620

In this talk I will explain how  we can use the CMB radiation data  in order to constrain variations of fundamental constants of physics. There is ample experimental evidence showing that fundamental couplings run with energy, and many particle physics and cosmology models suggest that they should also roll with time. I will show how a time varying fine structure constant can leave an imprint on CMB anisotropies by changing the time of recombination and the size of the acoustic horizon at photon-electron decoupling.  The constraints on the cosmological parameters are given by performing a Monte Carlo Markov of Chain (MCMC) analysis using WMAP-5 years and Planck data and I will show the results. I also consider the possibility of an early dark energy (EDE) component and its implications for fundamental couplings. The presence of a scalar field at recombination (at redshift z=1100) could induce variations in the fine structure constant at early times and at the same time could describe the evolution of the dark energy component. I used a modified  CAMB code for early dark energy including the variations of the fine structure constant, and, in order to constrain the cosmological parameters I perform a MCMC analysis  using WMAP-7 years data and HST data.  Finally, I will show the ability of future weak lensing surveys, as those expected from the Euclid satellite experiment, to constrain variation in fundamental constants.