Related papers: Gravitational Waves from Abelian Gauge Fields and …
The relic gravitational wave background due to tensor linear perturbations generated during Higgs inflation is computed. Both the Standard Model and a well-motivated phenomenological completion (that accounts for all the experimentally…
As potential candidates of dark matter, primordial black holes (PBHs) are within the core scopes of various astronomical observations. In light of the explosive development of gravitational wave (GW) and radio astronomy, we thoroughly…
Even though one could already constrain different models in cosmology and Beyond Standard Model physics using CMB data, these models remained unconstrained at shorter wavelength scales, and knowledge of new physics at higher energy scales…
In the present work, we have studied the spectrum of the primordial gravitational waves due to magnetic instability in the presence of neutrino asymmetry. The magnetic instability generates a helical magnetic field on a large scale. The…
We compute the stochastic gravitational wave background generated by cosmic superstrings using a semi-analytical velocity-dependent model to describe their dynamics. We show that heavier string types may leave distinctive signatures on the…
We investigate how perturbative reheating after inflation modifies the primordial gravitational wave (GW) spectrum generated by cosmological phase transitions. Within a specific inflationary setup, we show that the thermodynamic quantities…
Assuming that inflation is followed by a phase where the energy density of the Universe is dominated by a component with a general equation of state, we evaluate the spectrum of primordial gravitational waves induced in the…
Parametric resonance in a single-field inflationary model with a periodic structure on the potential gives rise to curvature perturbations with large amplitudes on small scales, which could result in observable primordial black holes (PBHs)…
Primordial Black Holes (PBH) could be the cold dark matter of the universe. They could have arisen from large (order one) curvature fluctuations produced during inflation that reentered the horizon in the radiation era. At reentry, these…
Gravitational waves induced by large primordial curvature fluctuations may result in a sizable stochastic gravitational wave background. Interestingly, curvature fluctuations are gradually generated by initial isocurvature fluctuations,…
Supersolid inflation is a class of inflationary theories that simultaneously breaks time and space reparameterization invariance during inflation, with distinctive features for the dynamics of cosmological fluctuations. We investigate…
After inflation, a period of preheating may have produced a stochastic background of high frequency gravitational waves (GWs) that would persist until today. The nature of the inflaton's coupling to Standard Model or other fields is…
The detection of a primordial stochastic gravitational wave background has the potential to reveal unprecedented insights into the early universe, and possibly into the dynamics of inflation. Generically, UV-complete inflationary models…
Gravitational Wave Astronomy is becoming a reality as Earth-based interferometric gravitational-wave detectors reach the design sensitivities and move towards advanced configurations that may lead to gravitational-wave detections in the…
Gravitational waves provide a unique window into gravity, cosmology, and high-energy physics, enabling the exploration of fundamental phenomena across a wide range of scales. This review presents a coherent and pedagogical framework that…
Ultra-light primordial black holes, with masses $m_\mathrm{PBH}<10^9\mathrm{g}$, evaporate before big-bang nucleosynthesis and can therefore not be directly constrained. They can however be so abundant that they dominate the universe…
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…
We dedicate this thesis to the study of signatures coming from the primordial epochs of the universe. We will focus in particular on Primordial Black Holes (PBHs), which may be formed from perturbations generated during inflation and might…
We investigate the stochastic gravitational wave background produced by primordial black hole binaries during their early inspiral stage while accreting high-density radiation surrounding them in the early universe. We first show that the…
We calculate the spectrum of gravitational waves originated from strongly first order electroweak phase transition in the extended Higgs model with a real singlet field. In order to calculate the bubble nucleation rate, we perform a…