Related papers: Brane inflation and the robustness of the Starobin…
We investigate a non-singular cosmological scenario in which uniform-rate inflation is realised on an anisotropic Shtanov-Sahni braneworld. The model naturally resolves the initial singularity resulting in an infinite number of smooth…
The 2015 Planck data release has placed tight constraints on the allowed class of inflationary models. The current data favors concave downwards inflationary potentials while offering interesting hints on possible deviations from the…
We examine some inflationary models based on modifications of gravity in the light of Planck 2015 data, such as the generalised Chaplygin inspired inflation, models based in $N=1$ supergravity and braneworld scenarios. We also show that,…
In the context of dynamical breaking of local supersymmetry (supergravity), including the Deser-Zumino super-Higgs effect, for the simple but quite representative cases of N=1, D=4 supergravity, we discuss the emergence of Starobinsky-type…
We investigate a standard minimally-coupled scalar-field inflationary scenario, which is based on a new potential, with suitably generalized plateau features, that leads to extra small tensor-to-scalar ratios. In particular, we consider a…
This thesis is dedicated to the study of inflationary scenarios based on string theory. Inflation is a brief period of accelerated expansion in the very early Universe which gives natural explanations for problems of the Standard Big Bang…
We investigate the cosmological inflation in a class of supergravity models that are generalizations of non-supersymmetric $R^2$ models. Although such models have been extensively studied recently, especially after the launch of the PLANCK…
In this lecture I will review the present status of inflation within string-based brane-world scenarios. The idea is to start from a supersymmetric configuration with two parallel static Dp-branes, and slightly break the supersymmetry…
The inflationary paradigm provides a robust description of the peculiar initial conditions which are required for the success of the Hot Big Bang model of cosmology, as well as of the recent precision measurements of temperature…
Starobinsky described an inflationary scenario in which quantum corrections to vacuum Einstein equations drive the inflation. The quantum cosmology of the model is studied by solving the Wheeler-DeWitt equation. A connection between…
We analyze various phases of inflation based on the anomaly-induced effective action of gravity (modified Starobinsky model), taking the cosmological constant Lambda and k=0, +/- 1 topologies into account. The total number of the…
We explored a parameterized slow-roll inflationary model within the $\Lambda$CDM framework, utilizing a combination of data from Planck 2018, ACT DR6, DESI DR2, and BICEP/Keck 2018 (P-ACT-LB-BK18). Additionally, we incorporated the SH0ES…
Potential slow-roll parameters are widely used in inflationary cosmology to estimate the scalar and tensor perturbation amplitudes and the scalar spectral index, although the inflationary observables are fundamentally expressed in terms of…
We point out that in the large field regime, the recently proposed superconformal D-term inflation model coincides with the Starobinsky model. In this regime, the inflaton field dominates over the Planck mass in the gravitational kinetic…
Inflationary cosmology is the leading explanation of the very early universe. Many different models of inflation have been constructed which fit current observational data. In this work theoretical and numerical methods for constraining the…
Supersymmetry is the most natural framework for physics above the TeV scale, and the corresponding framework for early-Universe cosmology, including inflation, is supergravity. No-scale supergravity emerges from generic string…
In a recent paper we showed how Starobinsky-like inflation could emerge from dilaton dynamics in brane cosmology scenarios based on string theory, in which our universe is represented as a three-brane and the effective potential acquires a…
An inflationary brane model driven by a bulk inflaton with exponential potential is proposed. We find a family of exact solutions that describe power-law inflation on the brane. These solutions enable us to derive exact solutions for metric…
Starobinsky model, which has a Ricci scalar squared term $R^{2}$ in its action, is one of the most promising inflation models from the viewpoint of Cosmic Microwave Background observations. However, it is well known that observational…
Brane inflationary universe model in the context of intermediate inflation is studied. General conditions for this model to be realizable are discussed. In the high-energy limit we describe in great details the characteristic of this model.