Related papers: Moduli inflation in five-dimensional supergravity …
Inflationary potentials are investigated for specific models in type IIB string theory via flux compactification. As concrete models, we investigate several cases where the internal spaces are weighted projective spaces. The models we…
We consider supersymmetric inflation with the hybrid-type potential. In the absence of the symmetry that forbids Hubble-induced mass terms, the inflaton mass will be as large as the Hubble scale during inflation. We consider gravitational…
The eta problem is one of the most significant obstacles to building a successful inflationary model in string theory. Planck mass suppressed corrections to the inflaton potential generally lead to inflaton masses of order the Hubble scale…
An exploratory study of the cosmology of moduli in string theory. Moduli are argued to be natural inflaton fields and lead to a robust inflationary cosmology in which inflation takes place at the top of domain walls. The amplitude of…
New inflationary solutions to the Einstein equation are explicitly constructed in a simple five-dimensional model with an orbifold extra dimension $S^1/Z_2$. We consider inflation caused by cosmological constants for the five-dimensional…
Cosmological inflation gives a natural answer for a variety of cosmological questions, including the horizon problem, the flatness problem, and others. However, inflation yields new questions relating to the flatness of the inflaton…
Models of cosmic inflation suggest that our universe underwent an early phase of accelerated expansion, driven by the dynamics of one or more scalar fields. Inflationary models make specific, quantitative predictions for several observable…
We present uniform rate inflation in a modified $f(T, \mathcal{T}) $ gravity. It is found that early inflation can be realized even with a scalar field field with a quadratic potential and a negative cosmological constant. We construct…
Thermal inflation, a brief low energy inflation after the primordial inflation, resolves the moduli problem in the context of supersymmetric cosmology. In the thermal inflation scenario, the primordial power spectrum is modestly redshifted…
In this article, we review how strong dynamics can be efficiently employed as a viable alternative to study the mechanism of cosmic inflation. We examine single-field inflation in which the inflaton emerges as a bound state stemming from…
We show that multi-field inflationary models with negligible turning in field space during inflation can lead to an effective sourcing of adiabatic from entropic perturbations {\it after} the end of inflation. We illustrate this general…
Recent detection of $B$-mode polarization induced from tensor perturbations by the BICEP2 experiment implies so-called large field inflation, where an inflaton field takes super-Planckian expectation value during inflation, at a high energy…
We investigate whether inflation in the early universe can be induced by an extra component of a five-dimensional ${\rm U(1)}$ gauge field in the Randall-Sundrum warped spacetime or not. We show that an effective potential obtained by…
It was recently proposed that five-dimensional inflation can relate the causal size of the observable universe to the present weakness of gravitational interactions by blowing up an extra compact dimension from the microscopic fundamental…
We study a supergravity model of inflation essentially depending on one parameter which can be identified with the slope of the potential at the origin. In this type of models the inflaton rolls at high energy from negative values and a…
A Lorentz violating vector "{\ae}ther" field in five dimensional spacetime can give rise to an inflation model in which the eta problem can be avoided. By identifying the inflaton field with the moduli field describing the radius of the…
Models of cosmological inflation resembling the Starobinsky R + R^2 model emerge naturally among the effective potentials derived from no-scale SU(N,1)/SU(N) x U(1) supergravity when N > 1. We display several examples in the SU(2,1)/SU(2) x…
The theory of inflation will be investigated as well as supersymmetry breaking in the context of supergravity, incorporating the target-space duality and the non-perturbative gaugino condensation in the hidden sector. The inflation and…
In this paper, we investigate a scenario of variable gravity and apply it to the unified description of inflation and late time cosmic acceleration dubbed quintessential inflation. The scalar field called "cosmon" which in this model…
The early universe according to the big bang and the grand unified theories is discussed. The shortcomings of big bang are summarized together with their resolution by inflationary cosmology. Inflation, the subsequent oscillation and decay…