相关论文: New Sources of Gravitational Waves during Inflatio…
In principle, the tensor metric (gravity-wave) perturbations that arise in inflationary models can, beyond probing the underlying inflationary model, provide information about the Universe: ionization history, presence of a cosmological…
For the first time, the possibility of generation of thermal gravitational waves from warm inflation is investigated with cosmic microwave background. Gravitons produced from the quantum fluctuations during warm inflation are found to carry…
A detection of primordial B-modes has been heralded not only as a smoking gun for the existence of inflation, but also as a way to establish the scale at which inflation took place. In this paper we critically reinvestigate the connection…
A recent paper argued that it is not possible to infer the energy scale of inflation from the amplitude of tensor fluctuations in the Cosmic Microwave Background, because the usual connection is substantially altered if there are a large…
Detecting the parity-odd, or B-mode, polarization pattern in the cosmic microwave background radiation due to primordial gravity waves is considered to be the final observational key to confirming the inflationary paradigm. The search for…
Inflationary cosmology is successful in explaining a number of outstanding cosmological issues including the flatness, the horizon and the relic issues. More spectacular is the experimental confirmation of the structure as arose from the…
We investigate small-scale signatures of the inflationary particle content. We consider the case of a light spin-2 particle sourcing primordial gravitational waves by employing an effective field theory description. Upon allowing…
The determination of the inflationary energy scale represents one of the first step towards the understanding of the early Universe physics. The (very mild) non-Gaussian signals that arise from any inflation model carry information about…
Recent theoretical results indicate that the detection of primordial gravity waves from inflation may be a hopeless task. First, foregrounds from lensing put a strict lower limit on the detectability of the B-mode polarization signal in the…
The scale of small-field inflation cannot be constrained via primordial gravitational waves through measurement of tensor-to-scalar ratio $r$. In this study, I show that if cosmic strings are produced after symmetry breaking at the end of…
We consider a novel contribution to the polarization of the Cosmic Microwave Background induced by vector and tensor modes generated by the non-linear evolution of primordial scalar perturbations. Our calculation is based on relativistic…
Inflation typically predicts a quasi scale-invariant spectrum of gravitational waves. In models of slow-roll inflation, the amplitude of such a background is too small to allow direct detection without a dedicated space-based experiment…
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…
We consider gravitational wave production due to parametric resonance at the end of inflation, or ``preheating''. This leads to large inhomogeneities which source a stochastic background of gravitational waves at scales inside the comoving…
If the inflationary phase lasted longer than the minimal period, the length scales observed today originate from modes that were smaller than the Planck length during inflation. It was recently argued that this "trans-Planckian problem" can…
We study the tilt of the primordial gravitational waves spectrum. A hint of blue tilt is shown from analyzing the BICEP2 and POLARBEAR data. Motivated by this, we explore the possibilities of blue tensor spectra from the very early universe…
We consider the impact of thermal inflation -- a short, secondary period of inflation that can arise in supersymmetric scenarios -- on the stochastic gravitational wave background. We show that while the primordial inflationary…
We investigate the tensor perturbation in the inflation model driven by a massive-scalar field in Eddington-inspired Born-Infeld gravity. For short wave-length modes, the perturbation feature is very similar to that of the usual chaotic…
The production of a stochastic background of gravitational waves is a fundamental prediction of any cosmological inflationary model. The features of such a signal encode unique information about the physics of the Early Universe and beyond,…
In this paper, we construct a bounce inflation cosmological scenario in the framework of the modified symmetric teleparallel gravity, namely f(Q) theory, and investigate the tensor perturbations therein. As is well-known, the tensor…