74 citations · 624 across the 44 of their papers we have counts for
6 papers · 1 filter
A note on oscillons: non-negligible metric fluctuations during preheating
Daniel del-Corral, Paolo Gondolo, K. Sravan Kumar +1
The dominant lattice approach to post-inflationary preheating and oscillon formation evolves an inhomogeneous inflaton field on a spatially homogeneous Friedmann-Lemaître-Robertson…
Unitary Quadratic Quantum Gravity in 4D
K. Sravan Kumar, João Marto
In quadratic gravity, with a positive Weyl squared coefficient, the extra spin-2 sector is shown to correspond to a dual inverted harmonic oscillator, instead of a ghost. Using the…
Quantum (quadratic) gravity: replacing the massive tensor ghost with an inverted harmonic oscillator-like instability
K. Sravan Kumar, João Marto
The quadratic theory of gravity is the unique renormalizable theory of quantum gravity in 4 dimensions, as proved by K. S. Stelle in 1977. Over the decades, the theory has been und…
Power-Law Inflation in n-Dimensional Fractional Scalar Field Cosmology: Observational Constraints and Dynamical Analysis
Daniel Oliveira, Seyed Rasouli, Joao Marto +1
Power-law inflation with is conceptually simple and predicts a scalar tilt compatible with CMB data, but in four-dimensional Einstein gravity it…
A new understanding of Einstein-Rosen bridges
Enrique Gaztañaga, K. Sravan Kumar, João Marto
The formulation of quantum field theory in Minkowski spacetime, which emerges from the unification of special relativity and quantum mechanics, is based on treating time as a param…
Tunnelling in Quantum Cosmology: WKB vs SWKB
Duarte Guimarães, João Marto, Paulo Vargas Moniz
This study analyses WKB and Supersymmetric WKB (SWKB) methods in a closed Friedmann-Robertson-Walker (FRW) minisuperspace model to determine whether they yield different results in…