Related papers: Constraining the quintessential $\alpha$-attractor…
The recent local measurement of the Hubble constant based on the distance-ladder method has reached a $1.91\%$ precision, but this result is in tension with the early-universe measurements at the more than 4$\sigma$ level, bringing a crisis…
With the growing consensus on simple power law inflation models not being favored by the PLANCK observation, dynamics for the non-standard form of the inflaton potential gain significant interest in the recent past. In this paper, we…
We consider inflation in a universe with a positive cosmological constant and a nonminimally coupled scalar field, in which the field couples both quadratically and quartically to the Ricci scalar. When considered in the Einstein frame and…
In this paper we report on a major theoretical observation in cosmology. We present a concrete cosmological model for which inflation has natural beginning and natural ending. Inflation is driven by a cosine-form potential, $V(\phi)=…
We study models of modular inflation of the form expected to arise from low energy effective actions of superstring theories. We argue on general grounds that the most likely models of modular slow-roll inflation are small field models in…
It is proposed that if quantum states of space-time are coherent on null surfaces, holographic Planck-scale fluctuations of inflationary horizons dominate the formation of primordial scalar curvature perturbations. It is shown that the…
We present an inflationary model that is geodesically complete and does not suffer from the transplanckian problem. In most inflationary models, massless (conformal) scalar field fluctuations in a deSitter background gives rise to a…
We investigate warm inflation in the framework of $f(Q)$ gravity within a Friedmann-Robertson-Walker spacetime. Unlike cold inflation, where the inflaton evolves in isolation, warm inflation features continuous interaction between the…
We investigate the relaxation and decay of a particle during inflation by implementing the dynamical renormalization group. This investigation allows us to give a meaningful definition for the decay rate in an expanding universe. As a…
We perform in this work an analysis of the background dynamics for $\alpha$-attractor models in the context of loop quantum cosmology. Particular attention is given to the determination of the duration of the inflationary phase that is…
We review recent progress in string model building in both early and late time cosmology. We describe the main theoretical and phenomenological features of an entire class of inflationary models where inflation is driven by a type IIB…
In this paper, we apply reconstruction techniques to recover the potential parameters for a particular class of single-field models, the $\alpha$-attractor (supergravity) models of inflation. This also allows to derive the inflaton vacuum…
We provide a detailed study of gravitational reheating in quintessential inflation generalizing previous analyses only available for the standard case when inflation is followed by an era dominated by the energy density of radiation.…
We use a mathematical approach based on the constraints systems in order to reconstruct the equation of state and the inflationary potential for the inflaton field from the observed spectral indices for the density perturbations $n_{s}$ and…
We develop general criteria to construct unified frameworks for inflation and quintessence which employ a unique scalar field to drive both. By using such a minimal theoretical framework we avoid having to fine-tune couplings and…
We investigate theoretical and observational aspects of a warm inflation scenario driven by the $\beta$-exponential potential, which generalizes the well-known power law inflation. In such a scenario, the decay of the inflaton field into…
Inflationary paradigm has several issues, such as the pre-inflationary horizon problem or the eternal inflation. To avoid that the standard Starobinsky inflation has been extended to $R + \alpha R^n$ and $R + \alpha R^n -\delta R^{2-n}$…
Slow-roll inflation may simultaneously solve the horizon problem and generate a near scale-free fluctuation spectrum P(k). These two processes are intimately connected via the initiation and duration of the inflationary phase. But a recent…
We study in detail the recently proposed mechanism of generating superheavy Dark Matter with the mass larger than the Hubble rate at the end of inflation. A real scalar field constituting Dark Matter linearly couples to the inflaton. As a…
We investigate the entropy dynamics of de Sitter spacetime during the inflationary phase. The cosmological horizon in de Sitter spacetime, which limits the causally accessible region for an observer, exhibits thermal properties similar to a…