相关论文: $R^2$ Gravity Effects on the Kinetic Axion Phase S…

We study sustained oscillations in two-dimensional oscillator systems driven by Rayleigh-type negative friction. In particular we investigate the influence of mismatch of the two frequencies. Further we study the influence of external noise…

We investigate the production of gravitational waves during preheating after inflation in the common case of field potentials that are asymmetric around the minimum. In particular, we study the impact of oscillons, comparatively long lived…

In construction of an inflationary model, one usually assumes that the matter sector of the gravitational action is minimally coupled to the background. It means that the matter (inflaton) part of the action is coupled with the same metric…

We investigate the $\phi^2$ inflationary model in the Bianchi-I spacetime using effective spacetime description of loop quantum cosmology to understand the issues of the resolution of initial singularity, isotropization, effect of…

We analyze a two-field inflationary model consisting of the Ricci scalar squared ($R^2$) term and the standard Higgs field non-minimally coupled to gravity in addition to the Einstein $R$ term. Detailed analysis of the power spectrum of…

We derive the quantum kinetic theory for fermions with arbitrary mass in a background electromagnetic field from the Wigner-function approach. Since spin of massive fermions is a dynamical degree of freedom, the kinetic equations with the…

Inspired by the chromo-natural inflation model of Adshead&Wyman, we reshape its scalar content to relax the tension with current observational bounds. Besides an inflaton, the setup includes a spectator sector in which an axion and SU(2)…

We study the generation of the chiral charge during axion inflation where the pseudoscalar inflaton field $\phi$ couples axially to the electromagnetic field through the term $(\beta/M_p)\phi\,\boldsymbol{E}\cdot\boldsymbol{B}$ with…

Effects due to fermion-vacuum polarization by an external static magnetic field are considered in a two-dimensional noncompact curved space with a nontrivial topology. An expression for the vacuun angular momentum is obtained. Like the…

We study the classical stability of an anisotropic space-time seeded by a spacelike, fixed norm, dynamical vector field in a vacuum-energy-dominated inflationary era. It serves as a model for breaking isotropy during the inflationary era.…

Scalar fields are widely and popularly used in cosmology in order to explain different phenomena among which, inflation and dark energy are two of the most popular ones. Specifically, in recent years, scale invariance in the gravitational…

Large field inflation is arguably the simplest and most natural variant of slow-roll inflation. Axion monodromy may be the most promising framework for realising this scenario. As one of its defining features, the long-range polynomial…

We discuss a new scenario for early cosmology when the inflationary de Sitter phase emerges dynamically. This genuine quantum effect occurs as a result of dynamics of the topologically nontrivial sectors in a strongly coupled QCD- like…

We study preheating via kinetic couplings after dilaton-axion $\alpha$-attractor inflation. We focus on E-model $\alpha$-attractor driven inflation where the inflaton is kinetically coupled to an ultralight axion. In this class of models,…

The $SL(2,\mathbb{Z})$ invariant $\alpha$-attractor models have plateau potentials with respect to the inflaton and axion fields. The potential in the axion direction is almost exactly flat during inflation, hence, the axion field remains…

We explore the evolutionary behaviors of compact objects in a modified gravitational theory with the help of structure scalars. Particularly, we consider the spherical geometry coupled with heat and radiation emitting shearing viscous…

We explore a novel cosmological model based on coupled fields in the framework of scalar tensor theories, considering the specific interplay between gravity and scalar fields. The model further extends a recent axion-dilaton system by…

We use a quantum mechanical charged particle as a test particle which probes the dynamics of force-related fields it is subject to. We allow for geodesic motion and relations involving gravitation appear. Gravitation affects quantum…

In this work we elaborate on solving the trans-Planckian censorship problem of standard slow-roll inflation by using a power-law inflationary tail generated by a scalar field with an exponential potential. We use a quantitative approach by…

Gauge-flation, non-Abelian gauge field inflation, which was introduced in arXiv:1102.1513 and analyzed more thoroughly in arXiv:1102.1932, is a model of inflation driven by non-Abelian gauge fields minimally coupled to Einstein gravity. In…