Related papers: The Dark Universe after Reheating in String Inflat…
We study the motion of a BPS D3-brane in the NS5-brane ring background. The radion field becomes tachyonic in this geometrical set up. We investigate the potential of this geometrical tachyon in the cosmological scenario for inflation as…
We describe a simple and efficient mechanism by which very heavy particles are copiously created from a primordial inflationary epoch. It works for scalar fields which are massless or very light during inflation and acquire a large mass…
A new mechanism for producing axion dark matter is proposed. By invoking low-scale inflation and a kinetic mixing between the axion and the inflaton, it is shown that the axion is driven to a field point slightly displaced from the…
In a recent paper, Liddle and Urena-Lopez suggested that to have a unified model of inflation and dark matter is imperative to have a proper reheating process where part of the inflaton field remains. In this paper I propose a model where…
A compelling way to address the inflationary period is via the warm inflation scenario, where the interaction of the inflaton field with other degrees of freedom affects its dynamics in such a way that slow-roll inflation is maintained by…
In this note, we refine the racetrack inflation model constructed in arXiv:hep-th/0406230 by including the open string modulus. This modulus encodes the embedding of our braneworld inside some Calabi-Yau throat. We argue that in generic…
It is quite possible that the reheat temperature of the universe is extremely low close to the scale of Big Bang nucleosynthesis, i.e. $T_{R}\sim 1-10$ MeV. At such low reheat temperatures generating matter anti-matter asymmetry and…
A scenario in which primeval black holes (PBHs) form at the end of an extended inflationary period is capable of producing, via Hawking radiation, the observed entropy, as well as the observed dark matter density in the form of Planck mass…
Superheavy dark matter has been attractive as a candidate of particle dark matter. We propose a ``natural" particle model, in which the dark matter serves as the inflaton in natural inflation, while decaying to high-energy particles at…
We study reheating after the end of inflation in models where the inflaton is the superpartner of goldstino and is charged under a gauged $U(1)$ R-symmetry. We consider two classes of models -- one is small field characterized by an almost…
Reheating after inflation occurs due to particle production by the oscillating inflaton field. In this paper we describe the perturbative approach to reheating, and then concentrate on effects beyond the perturbation theory. They are…
We present a novel perspective on the role of inflation in the production of Dark Matter (DM). Specifically, we explore the DM production during Warm Inflation via ultraviolet Freeze-In (WIFI). We demonstrate that in a Warm Inflation (WI)…
Using renormalization-group flow and cosmological constraints on inflation models, we exploit a unique connection between cosmological inflation and the dynamical mass of dark-matter particles in the luminogenesis model, a unification model…
An interesting result in particle astrophysics is the recent detection of an unexplained 3.5 keV line from galaxy clusters. A promising model, which can explain the morphology of the signal and its non-observation in dwarf spheroidal…
It is quite plausible that the mass of the dark matter particle increases significantly after its freeze-out, due to a scalar field rolling to large values. We describe a realization of this scenario in the context of thermal inflation…
We investigate the production of dark matter from curvature perturbations produced during inflation or in standard cosmology, for example during first order phase transitions. Perturbations break Weyl flatness of the…
The thermal inflation is the most plausible mechanism that solves the cosmological moduli problem naturally. We discuss relic abundance of superheavy particle $X$ in the presence of the thermal inflation assuming that its lifetime is longer…
We present an inflationary scenario based on a phenomenologically viable model with direct gauge mediation of low-scale supersymmetry breaking. Inflation can occur in the supersymmetry-breaking hidden sector. Although the reheating…
Towards the end of brane inflation, the brane pair annihilation produces massive closed strings. The transfer of this energy to Standard Model (SM) open string modes depends on where the SM branes and the brane annihilation are located: in…
Sterile neutrinos offer a minimal and testable explanation for dark matter (DM), with their radiative decay actively searched for in X-ray observations. We show that cold sterile neutrino DM can be efficiently produced during reheating from…