Cosmological non-Linearities as an effective fluid

نیما چرتاب سلطانی (دانشکده فیزیک دانشگاه صنعتی شریف)

 Abstract:   The most important features of the anisotropies of the cosmic microwave background and the large scale structure observed in galaxy surveys are accurately described by linear perturbations around a homogeneous Friedmann-Robertson-Walker (FRW) background. However, with the advance of observations the study of small non-linear corrections to the long wavelength dynamics is becoming more and more relevant. In this talk, I will introduce the effective stress-energy tensor induced by the short wavelength modes. After integrating out short wavelengths, I will present an effective theory which describes a universe with long wavelength perturbations, sourced by small scale non-linearities. I will show that this leads to a renormalization of the background pressure and background density.

یکشنبه 6 تیر ماه 1395، ساعت 10:00

    دانشکده فیزیک، طبقه اول، کلاس فیزیک 4