Date:
24. May 2013 - 11:30
Speaker:
Guillermo Ballesteros (Geneva)
Effective perfect fluids in cosmoloy
A perfect fluid can be described as a derivatively coupled theory whose
precise structure is determined by the fluid’s symmetries. This is an
effective theory of three scalar fields that represent the comoving
coordinates of the fluid. I will discuss how to use this framework in
cosmological perturbation theory. The longitudinal modes of fluids are
associated to adiabatic perturbations, while the transverse modes mix
with the vector metric perturbations ensuring the conservation of
vorticity.