Analytic solutions of scalar perturbations induced by scalar perturbations
نویسندگان
چکیده
We study scalar perturbations induced by through the non-linear interaction appearing at second order in perturbations. derive analytic solutions of a perfect fluid. In particular, we consider radiation-dominated era and matter-dominated era. With solutions, also discuss power spectra
منابع مشابه
Scalar Perturbations and Conformal Transformation
The non-minimal coupling of gravity to a scalar field can be transformed into a minimal coupling through a conformal transformation. We show how to connect the results of a perturbation calculation, performed around a Friedmann-Robertson-Walker background solution, before and after the conformal transformation. We work in the synchronous gauge, but we discuss the implications of employing other...
متن کاملGravitational Wave Spectrum Induced by Primordial Scalar Perturbations
We derive the complete spectrum of gravitational waves induced by primordial scalar perturbations ranging over all observable wavelengths. This scalar-induced contribution can be computed directly from the observed scalar perturbations and general relativity and is, in this sense, independent of the cosmological model for generating the perturbations. The spectrum is scale-invariant on small sc...
متن کاملNonlinear perturbations of cosmological scalar fields
We present a covariant formalism for studying nonlinear perturbations of scalar fields. In particular, we consider the case of two scalar fields and introduce the notion of adiabatic and isocurvature covectors. We obtain differential equations governing the evolution of these two covectors, as well as the evolution equation for the covector associated with the curvature perturbation. The form o...
متن کاملScalar perturbations in Randall-Sundrum braneworld cosmology
We study the evolution of scalar perturbations in the radiation-dominated era of Randall-Sundrum braneworld cosmology by numerically solving the coupled bulk and brane master wave equations. We find that density perturbations with wavelengths less than a critical value (set by the bulk curvature length) are amplified during horizon re-entry. Conversely, we explicitly confirm from simulations th...
متن کاملAffleck-Dine Scalar Dynamics and Isocurvature Perturbations
We consider the evolution of the Affleck-Dine scalar during D-term and Fterm inflation and solve the combined slow-roll equations of motion. We show that for a typical case, where both the Affleck-Dine scalar and inflaton initially have large values, in D-term inflation the Affleck-Dine scalar is driven to a fixed value, with only a very slight dependence on the number of e-foldings. As a resul...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Cosmology and Astroparticle Physics
سال: 2021
ISSN: ['1475-7516', '1475-7508']
DOI: https://doi.org/10.1088/1475-7516/2021/03/013