From the 1 of 7 linked papers with an AI index.
7 papers
Primordial black holes through preheating instabilities in -attractor models
Daniel del-Corral, Paolo Gondolo, K. Sravan Kumar +2
The paper investigates how primordial black holes can form during the preheating phase after α‑attractor inflation, using instability criteria and comparing the Press‑Schechter and…
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…
Scalar-Induced Gravitational Waves from self-resonant preheating in -attractor models
Daniel del-Corral, Paolo Gondolo, K. Sravan Kumar +1
After the inflationary phase, the universe enters the preheating phase, during which the inflaton field rolls down its potential and oscillates. When the potential significantly de…
Gravitational waves from primordial black hole dominance: The effect of inflaton decay rate
Daniel del-Corral, K. Sravan Kumar, João Marto
In this work, we explore primordial black holes (PBH) formation scenario during the post-inflationary preheating stage dominated by the inflaton field. We consider, in particular,…
Revisiting quantum field theory in Rindler spacetime with superselection rules
K. Sravan Kumar, João Marto
Quantum field theory (QFT) in Rindler spacetime is a gateway to understanding unitarity and information loss paradoxes in curved spacetime. Rindler coordinates map Minkowski spacet…