Related papers: Observational constraints on tachyon and DBI infla…
In this paper we analyze scalar gravitational perturbations on a Robertson-Walker background in the presence of multiple scalar fields that take values on a (geometrically non-trivial) field manifold during slow-roll inflation. For this…
In scalaron-Higgs inflation the Standard Model Higgs boson is non-minimally coupled to gravity and the Einstein-Hilbert action is supplemented by the quadratic scalar curvature invariant. For the quartic Higgs self-coupling $\lambda$ fixed…
We compute the 3-point correlation function for a general model of inflation driven by a single, minimally coupled scalar field. Our approach is based on the numerical evaluation of both the perturbation equations and the integrals which…
We investigate a novel scenario of cosmological inflation in a gauged $B-L$ extended minimal supersymmetric Standard Model with R-symmetry. We use a noncanonical K\"{a}hler potential and a superpotential, both preserving the R-symmetry to…
Generalized slow roll conditions and parameters are obtained for a general form of scalar-tensor theory (with no external sources), having arbitrary functions describing a nonminimal gravitational coupling F(\phi), a Kahler-like kinetic…
The slow-roll approximation to inflation is ultimately justified by the presence of inflationary attractors for the orbits of the solutions of the dynamical equations in phase space. There are many indications that the inflaton field…
One class of single-field inflationary models compatible with the recently-conjectured Swampland criteria would be those in which a Hubble slow-roll parameter $\epsilon_\text{H}$ is not the same as $\epsilon_\text{V} \sim (V'/V)^2$.…
We revisit inflation with non-canonical scalar fields by applying deformed-steepness exponential potentials. We show that the resulting scenario can lead to inflationary observables, and in particular to scalar spectral index and…
In this paper, we consider two case examples of Dirac-Born-Infeld (DBI) generalizations of canonical large-field inflation models, characterized by a reduced sound speed, $c_{S} < 1$. The reduced speed of sound lowers the tensor-scalar…
We discuss a supersymmetric version of DBI (Dirac-Born-Infeld) inflation, which is a typical inflation model in string cosmology. The supersymmetric DBI action together with a superpotential always leads to correction terms associated with…
Using the latest observational data, we constrain the inflationary dynamics and the subsequent reheating epoch. Predictions for both phases can be significantly improved by employing numerically computed results compared to the slow-roll…
We derive the general formulae for the the scalar and tensor spectral tilts to the second order for the inflationary models with non-minimally derivative coupling without taking the high friction limit. The non-minimally kinetic coupling to…
We explore the dynamics and observational predictions of the Warm Little Inflaton scenario, presently the simplest realization of warm inflation within a concrete quantum field theory construction. We consider three distinct types of scalar…
In the present paper, we aim to generalize the constant-roll inflation in the non-canonical set-up, particularly in the context of scalar Dirac-Born-Infeld (DBI) theory which has emerged to be prospective candidate for describing inflation…
A new shifted hybrid inflationary scenario is introduced which, in contrast to the older one, relies only on renormalizable superpotential terms. This scenario is automatically realized in a concrete extension of the "minimal"…
We formalize the Hubble slow-roll formalism for inflationary dynamics in Randall-Sundrum Type II braneworld cosmologies, defining Hubble slow-roll parameters which can be used along with the Hamilton-Jacobi formalism. Focussing on the…
Extensions of the Standard Model and general relativity featuring a UV fixed point can leave observable implications at accessible energies. Although mass parameters such as the Planck scale can appear through dimensional transmutation, all…
In this paper we explored in detail a phenomenological model of modified single field natural inflation in light of recent cosmological experiments, BICEP2. Our main goal is to construct an inflationary model which not only predicts the…
We revisit the status of hybrid inflation in the light of Planck and recent BICEP2 results, taking care of possible transient violations of the slow-roll conditions as the field passes from the large field to the vacuum dominated phase. The…
Precise cosmological data from WMAP and forthcoming CMB experiments motivate the study of the quantum corrections to the slowroll inflationary parameters.We find the quantum (loop) corrections to the equations of motion of the classical…