δM Formalism 

علیرضا طالبیان اشکذری (دانشکده فیزیک دانشگاه تهران)

Abstract: We study the evolution of the “non-perturbative” metric perturbations in a Bianchi background in the long-wavelength limit. By applying the gradient expansion to the equations of motion we exhibit a generalized “Separate Universe” approach to the cosmological perturbation theory. Having found this consistent separate universe picture, we introduce the δM formalism for calculating the evolution of the tensor perturbations in anisotropic inflation models in almost similar way as the so-called δN formula for the superhorizon dynamics of the curvature perturbations. Likewise its ancestor, δN formalism, this new method can substantially reduce the amount of calculations related to the evolution of the tensor modes.

یکشنبه 14 آذر ماه 1395، ساعت 15:00

    دانشکده فیزیک، تالار پرتوی