Related papers: Consistency Relations for Large Field Inflation: N…

We perform a combined perturbation and observational investigation of the scenario of non-minimal derivative coupling between a scalar field and curvature. First we extract the necessary condition that ensures the absence of instabilities,…

We show that non-minimal inflation, based on the phi^4 potential, may be rendered unitarity conserving and compatible with the Planck results for 4.6x10^(-3)<~r21=c2R/c1R^2<~1, if we introduce a linear contribution (c1R phi) to the frame…

We examine inflationary models in the $f(R, T)$ gravity framework where we have a conformal constant and an $RT$-mixing term apart from an R term. The RT-mixing term introduces non-minimal coupling between gravity and matter. We consider…

In this work, we show the effect of the non-minimal coupling $\xi \phi^2 R$ on the inflationary parameters by considering the single-field inflation and present the inflationary predictions of the appealing potential for the particle…

We analyze non-minimally coupled scalar field theories in metric (second-order) and Palatini (first-order) formalisms in a comparative fashion. After contrasting them in a general setup, we specialize to inflation and find that the two…

In this paper, we consider a model of tachyon with a non-minimal coupling to gravity and study its cosmological effects. Regarding inflation we will show that for a specific coupling of tachyon to gravity this model satisfies observations…

In the hope of avoiding model dependence of the cosmological observables, phenomenological parametrizations of Cosmic Inflation have recently been proposed. Typically, they are expressed in terms of two parameters associated with an…

We revisit a single field inflationary model based on Coleman-Weinberg potentials. We show that in small field Coleman-Weinberg inflation, the observed amplitude of perturbations needs an extremely small quartic coupling of the inflaton,…

We discuss the hybrid inflation model where the inflaton field is nonminimally coupled to gravity. In the Jordan frame, the potential contains $\phi^4$ term as well as terms in the original hybrid inflation model. In our model, inflation…

We revisit perturbative unitarity in scalar field inflation with a nonminimal coupling, with Higgs inflation serving as the most prominent example. Although such models are phenomenologically successful, it is critical to examine whether or…

We study the dynamics and perturbations during inflation and reheating in a multi-field model where a second scalar field $\chi$ is nonminimally coupled to the scalar curvature $(\frac12 \xi R\chi^2$). When $\xi$ is positive, the usual…

We consider models of chaotic inflation driven by the real parts of a conjugate pair of Higgs superfields involved in the spontaneous breaking of a grand unification symmetry at a scale assuming its supersymmetric value. We combine a…

The Atacama Cosmology Telescope (ACT) collaboration has reported a scalar spectral index $ n_s~=~0.9743~\pm~0.0034 $. This is substantially larger than the classical prediction of non-minimally coupled inflation models such as Higgs…

We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to $n_s = 0.9603 \pm…

We reconsider an inflationary model that inflaton field is non-minimally coupled to gravity. We study parameter space of the model up to the second ( and in some cases third ) order of the slow-roll parameters. We calculate inflation…

A model for a noncommutative scalar field coupled to gravity is proposed via an extension of the Moyal product. It is shown that there are solutions compatible with homogeneity and isotropy to first non-trivial order in the perturbation of…

We consider Supersymmetric (SUSY) and non-SUSY models of chaotic inflation based on the simplest power-law potential with exponents n=2 and 4. We propose a convenient non-minimal coupling to gravity and a non-minimal kinetic term which…

We consider a multidimensional model of the universe given as a $D$-dimensional geometry, represented by a Riemannian manifold $(M,g)$ with arbitrary signature of $g$, $M= \R\times M_1\times \cdots \times M_n$, where the $M_i$ of dimension…

We study symmetry-breaking inflation within the framework of metric-affine gravity. By introducing a non-minimal coupling, $\beta(\phi)\tilde{\cal R}$, between the Holst invariant and the inflaton, both small-field and large-field…

We discuss the structure of parametric resonance which occurs in the process of reheating after inflation with two interacting scalar fields. It is found that, for the case of a not too large coupling constant, a quasi-homogeneous part of…