Related papers: Gravity Waves from Tachyonic Preheating after Hybr…
We revisit the framework of axion-like inflation in view of the possibility that the coupling of the inflaton to a non-Abelian topological charge density could lead to the generation of a rapidly thermalizing heat bath. Both dispersive…
We describe the challenges and pathways when probing inflaton as dark matter with the stochastic gravitational waves (GWs) signal generated during the (p)reheating. Such scenarios are of utmost interest when no other interaction between the…
We study the stochastic background of gravitational waves which accompany the sudden freeze-out of dark matter triggered by a cosmological first order phase transition that endows dark matter with mass. We consider models that produce the…
We consider the 3-pt function (i.e. the bispectrum or non-Gaussianity) for stochastic backgrounds of gravitational waves. We estimate the amplitude of this signal for the primordial inflationary background, gravitational waves generated…
Reheating after inflation can proceed even if the inflaton couples to Standard Model (SM) particles only gravitationally. However, particle production during the transition between de-Sitter expansion and a decelerating Universe is rather…
In this paper, we investigate chiral gravitational wave (GW) signals generated from inflation to reheating, driven by a parity-violating (PV) term coupled to the inflaton. During inflation, the PV term reduces the sound horizon for…
We investigate the inhomogeneous inflation, in which the space exponentially expands with inhomogeneities, and its cosmological perturbations. The inhomogeneous inflation is realized by introducing scalar fields with spacelike gradients…
We investigate the production of primordial black holes and gravitational waves in composite hybrid inflation. Starting from an effective chiral Lagrangian with a dilaton and pions, we identify inflation occurring due to the walking…
Cosmological B-L breaking is a natural and testable mechanism to generate the initial conditions of the hot early universe. If B-L is broken at the grand unification scale, the false vacuum phase drives hybrid inflation, ending in tachyonic…
We study gravitational waves generated during the inflationary epoch in presence of a decaying cosmological parameter on a 5D geometrical background which is Riemann flat. Two examples are considered, one with a constant cosmological…
The super-inflationary phase is predicted by the Loop Quantum Cosmology. In this paper we study the creation of gravitational waves during this phase. We consider the inverse volume corrections to the equation for the tensor modes and…
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 deviates from a parabolic shape at its minimum, these…
In this paper we study the behaviour of gravitational wave background (GWB) generated during inflation in the environment of the noncommutative field approach. From this approach we derive out one additive term, and then we find that the…
Although inflationary models generically predict a flat spectrum of gravitational waves, we point out a general process that produces a sharply peaked spectrum of gravitational radiation. This process is generic for inflationary models with…
Recently, pulsar timing array (PTA) collaborations, including NANOGrav, have reported evidence of a stochastic gravitational wave background within the nHz frequency range.\ It can be interpreted by gravitational waves from preheating era.…
We discuss gravitational waves from merging binaries using a Newtonian approach with some inputs from the Post-Newtonian formalism. We show that it is possible to understand the key features of the signal using fundamental physics and also…
We show that in multi-stage axion monodromy inflation an interruption near the end of the penultimate stage can lead to a spike in the gravitational wave background. These gravitational waves are in the frequency range and with an amplitude…
We consider the primordial gravity wave background produced by inflation. We compute the small anisotropy produced by the primordial scalar fluctuations.
Anisotropies in the cosmic microwave background radiation due to gravity waves are investigated. An initial spectrum of gravity waves may have been induced during an epoch of inflation. We study the propagation of such a spectrum in a…
A direct detection of primordial gravitational waves is the ultimate probe for any inflation model. While current CMB bounds predict the generic scale-invariant gravitational wave spectrum from slow-roll inflation to be below the reach of…