Related papers: Brane Inflation and the Overshoot Problem
We study a two-parameter family of exactly solvable inflation models with variable sound speed, and derive a corresponding exact expression for the spectrum of curvature perturbations. We generalize this expression to the slow roll case,…
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…
Braneworld inflation on the resolved warped deformed conifold is represented by the dynamics of a D3-brane probe with the world volume of a brane spanning the large dimensions of the observable Universe. This model was recently proposed as…
We study a possible amplification mechanism for the curvature perturbations generated during inflation by a Dirac-Born-Infeld (DBI) inflaton in the presence of a sharp feature in the warp factor. The large growth resulting in the scalar…
According to a Barrow's solution for the scale factor of the universe, the main properties of the tachyon inflation model in the framework of RSII braneworld are studied. Within this framework the basic slow-roll parameters are calculated…
We investigate inflation in Randall-Sundrum type II brane scenario with closed Friedman-Robertson-Walker (FRW) brane. We consider only power-law potentials of the scalar field and wide range of powers and parameters for them. For our models…
We present a new type of brane inflation motivated by multi-kink solitonic solutions of a scalar field in five dimensions. In the thin brane limit, we analyze a non-static configuration in which the distance between two parallel domain…
We discuss supergravity inflation in braneworld cosmology for the class of potentials $V(\phi)=\alpha \phi^n\rm{exp}(-\beta^m \phi^m)$ with $m=1,~2$. These minimal SUGRA models evade the $\eta$ problem due to a broken shift symmetry and can…
We study the evolution of scalar curvature perturbations in a brane-world inflation model in a 5D Anti-de Sitter spacetime. The inflaton perturbations are confined to a 4D brane but they are coupled to the 5D bulk metric perturbations. We…
We consider issues related to tachyonic inflation with exponential potential. We find exact solution of evolution equations in the slow roll limit in FRW cosmology. We also carry out similar analysis in case of Brane assisted tachyonic…
In addition to generating the appropriate perturbation power spectrum, an inflationary scenario must take into account the need for inflation to end subsequently. In the context of single-field inflation models where inflation ends by…
We study slow-roll inflation on a three-brane in a five-dimensional bulk where the effects of energy loss from the brane due to graviton emission is included in a self-consistent manner. We explicitly derive the form of the energy loss term…
In conventional scenario of thermal inflation, the requirement that the reheating temperature must be larger than the temperature of the nucleosynthesis puts a lower bound on the mass of the inflaton field. At the same time, the mass of the…
In this article we study a constant-roll inflationary model in the context of the DGP brane-world cosmology caused by a quintessence scalar field. We determine an analytical solution for the Friedman equation coupled to the equation of…
We review a viable alternative scenario of the inflationary universe in the context of the Randall-Sundrum (RS) braneworld. In this scenario, the dynamics of a 5-dimensional scalar field, which we call a bulk scalar field, plays the central…
Randall and Sundrum have proposed that we live on a brane embedded in 5-dimensional anti-deSitter space, as a solution to the hierarchy problem. We examine the possibility of using a scalar field in the 5-D bulk as the inflaton, and show…
Penrose [1] has emphasized how the initial big bang singularity requires a special low entropy state. We address how recent brane cosmological schemes address this problem and whether they offer any apparent resolution. Pushing the start…
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…
The conceptual problems of the standard slow-roll inflationary scenario include the Trans-Planckian Censorship Conjecture issue, which severely restricts the tensor-to-scalar ratio in the standard minimally coupled scalar field inflation.…
We demonstrate an inflationary solution to the cosmological horizon problem during the Hagedorn regime in the early universe. Here the observable universe is confined to three spatial dimensions (a three-brane) embedded in higher…