27 citations · 130 across the 13 of their papers we have counts for
13 papers
The validity of separate-universe approach in transient ultra-slow-roll inflation
Rathul Nath Raveendran
We investigate the breakdown of the separate-universe approximation during transitions in transient ultra-slow-roll inflation by analyzing the evolution of the comoving curvature p…
Violation of Bell inequality from a squeezed coherent state of inflationary perturbations
Aurindam Mondal, Rathul Nath Raveendran
We investigate the quantum nature of primordial perturbations by studying the violation of Bell inequality when the initial state is taken to be a coherent state rather than the us…
Conserved cosmological perturbations in USR inflation and bouncing scenarios
Rathul Nath Raveendran
Inflationary and bouncing scenarios are two frameworks that provide the mechanism to overcome the horizon problem as well as generate the primordial perturbations. In this work, we…
Mimicking two field inflationary features with a single field
Anvy Moly Tom, Rathul Nath Raveendran
It is well known that damped superimposed oscillations at large scales in the primordial power spectrum can be generated in both single field and two field models. In single field…
Amplifying quantum discord during inflationary magnetogenesis through violation of parity
Sagarika Tripathy, Rathul Nath Raveendran, Krishnamohan Parattu +1
It is well known that, during inflation, the conformal invariance of the electromagnetic action has to be broken in order to produce magnetic fields of observed strengths today. Of…
Distinguishing cosmological models through quantum signatures of primordial perturbations
Rathul Nath Raveendran, Sumanta Chakraborty
We study the evolution of various measures of quantumness of the curvature perturbation by integrating out the inaccessible entropic fluctuations in the multi-field models of infla…
Enhanced power on small scales and evolution of quantum state of perturbations in single and two field inflationary models
Rathul Nath Raveendran, Krishnamohan Parattu, L. Sriramkumar
With the detection of gravitational waves from merging binary black holes, over the last few years, there has been a considerable interest in the literature to understand if these…
Reconstruction of potentials of the hybrid inflation in the light of primordial black hole formation
Ki-Young Choi, Su-beom Kang, Rathul Nath Raveendran
The large enhancement of the primordial power spectrum of the curvature perturbation can seed the formation of primordial black hole, that can play as a dark matter component in th…
A gauge invariant prescription to avoid -crossing instability in Galileon bounce
Rathul Nath Raveendran
We revisit the evolutions of scalar perturbations in a non-singular Galileon bounce. It is known that the second order differential equation governing the perturbations is numerica…
Viable scalar spectral tilt and tensor-to-scalar ratio in near-matter bounces
Rathul Nath Raveendran, L. Sriramkumar
In a recent work, we had constructed a model consisting of two fields---a canonical scalar field and a non-canonical ghost field---that had sourced a symmetric matter bounce scenar…
Primordial features from ekpyrotic bounces
Rathul Nath Raveendran, L. Sriramkumar
Certain features in the primordial scalar power spectrum are known to improve the fit to the cosmological data. We examine whether bouncing scenarios can remain viable if future da…
Viable tensor-to-scalar ratio in a symmetric matter bounce
Rathul Nath Raveendran, Debika Chowdhury, L. Sriramkumar
Matter bounces refer to scenarios wherein the universe contracts at early times as in a matter dominated epoch until the scale factor reaches a minimum, after which it starts expan…
Numerical evaluation of the tensor bispectrum in two field inflation
Rathul Nath Raveendran, L. Sriramkumar
We evaluate the dimensionless non-Gaussianity parameter , that characterizes the amplitude of the tensor bispectrum, numerically for a class of two field inflationar…