相关论文: $R^2$ inflation to probe non-perturbative quantum …
We present a unified treatment of cosmic inflation within the framework of Myrzakulov Gravity, exploring its realization in three different formalisms: metric (curvature-based), teleparallel (torsion-based), and symmetric teleparallel…
$R+R^2$ Supergravity is known to be equivalent to standard Supergravity coupled to two chiral supermultiples with a no-scale K\"ahler potential. Within this framework, that can accomodate vanishing vacuum energy and spontaneous…
We generalize the notion of constant-roll inflation earlier introduced in General Relativity (GR) and $f(R)$ gravity to inflationary models in more general scalar-tensor gravity. A number of novel exact analytic solutions for a FLRW…
Recently, the idea of taking ensemble average over gravity models has been introduced. Based on this idea, we study the ensemble average over (effectively) all the gravity models (constructed from Ricci scalar) dubbing the name…
We discuss another approach regarding the inflation from the R^2 theory of gravity originally proposed by Starobinski. A non-singular early cosmology is proposed, where, adding a nonlinear electrodynamics Lagrangian to the high-order…
This paper investigates a scale-invariant inflationary model characterized by a scalar field non-minimally coupled to gravity and a curvature term quadratic in the Ricci scalar. The model's dynamic is analyzed using a full numerical…
We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…
We propose a predictive $SO(10)$ Grand Unified Theory (GUT) framework for cosmic inflation in the Palatini $\mathcal{R}^2$ formulation of gravity. In this model, a GUT Higgs field both drives inflation and induces intermediate-scale…
We classify the metric-affine theories of gravitation, in which the metric and the connections are treated as independent variables, by use of several constraints on the connections. Assuming the Einstein-Hilbert action, we find that the…
In the framework of $F(\mathcal{R},\tilde{\mathcal{R}})$ Einstein-Cartan gravity with an action depending both of the Ricci scalar and the so-called Holst-invariant curvature we consider models that include cubic terms of the latter in the…
We explore a broad class of three-parameter inflationary models, called the $\Lambda$-inflation, and its observational predictions: high abundance of cosmic gravitational waves consistent with the Harrison-Zel'dovich spectrum of primordial…
A sizeable tensor-to-scalar ratio, such as recently claimed by BICEP2, would imply a scale of inflation at the typical scale of supersymmetric grand unification. This could be an accident, or strong support for supersymmetric theories.…
We show, within the single-field inflationary paradigm, that a linear non-minimal interaction $\xi\,M_P\,\phi\,R$ between the inflaton field $\phi$ and the Ricci scalar $R$ can result in successful inflation that concludes with an efficient…
In this paper, we study the cosmological inflation phenomenon in symmergent gravity theory. Symmergent gravity is a novel framework which merges gravity and the standard model (SM) so that the gravity emerges from the matter loops and…
Superstring/M-theory is the theory of quantum gravity that can provide the UV-completion to viable inflation models. We modify the Starobinsky inflation model by adding the Bel-Robinson tensor $T^{\mu\nu\lambda\rho}$ squared term proposed…
A new model of nonlinear electrodynamics with dimensional parameters $\beta$ and $\gamma$ is proposed. The principles of causality and unitarity are studied. We show that a singularity of the electric field at the origin of charges is…
We consider the UV-protected inflation, where the inflaton potential is obtained by quantum (one-loop) breaking of a global symmetry into a discrete symmetry. In this model, all coupling scales are sub-Planckian. This is achieved by…
In the framework of classical scale invariance, we consider quadratic gravity in the Palatini formalism and investigate the inflationary predictions of the theory. Our model corresponds to a two-field scalar-tensor theory, that involves the…
We discuss non-minimal quadratic inflation in supersymmetric (SUSY) and non-SUSY models which entails a linear coupling of the inflaton to gravity. Imposing a lower bound on the parameter cR, involved in the coupling between the inflaton…
We propose a novel mechanism for enhancing the primordial gravitational waves without significantly affecting the curvature perturbations produced during inflation. This is achieved due to non-linear sourcing of resonantly amplified scalar…