Related papers: A note on supergravity inflation in braneworld
We show the effects of supersymmetric higher derivative terms on inflation models in supergravity. The results show that such terms generically modify the effective kinetic coefficient of the inflaton during inflation if the cut off scale…
In this paper we reconsider the supersymmetric hybrid inflation in the context of the braneworld scenario . The observational bounds are satisfied with an inflationary energy scale $\mu\simeq 4\times 10^{-4}M_p$, without any fine-tuning of…
In this paper, we analyze the early-time inflation in a scalar-tensor theory of gravity where the scalar field is minimally coupled with the Gauss-Bonnet four dimensional topological invariant. The theory belongs to a class of Horndeski…
It is investigated the reconstruction during the slow-roll inflation in the most general class of scalar-torsion theories whose Lagrangian density is an arbitrary function $f(T,\phi)$ of the torsion scalar $T$ of teleparallel gravity and…
Quintessential inflation--in which a single scalar field plays the role of the inflaton and quintessence--from a sum of exponentials potential V = A (exp{5 phi}+exp{sqrt{2} phi}) or V = A (exp{5 phi}+exp{phi}) or a cosh potential V = 2A…
In the light of the Planck 2015 results, we update simple inflationary models based on the quadratic, quartic, Higgs and Coleman-Weinberg potentials in the context of the Randall-Sundrum brane-world cosmology. Brane-world cosmological…
Models of inflationary cosmology based on spontaneous symmetry breaking typically suffer from the shortcoming that the symmetry breaking scale is driven to nearly the Planck scale by observational constraints. In this paper we investigate…
Recent observations from the Atacama Cosmology Telescope (ACT) indicate a moderate upward shift in the scalar spectral index $n_s$ compared to Planck $2018$, thereby placing tighter constraints on inflationary scenarios. Motivated by these…
In this article we motivate and review the embedding of the gravitationally enhanced friction mechanism in supergravity. The very interesting feature is that inflationary models which utilize this mechanism drive inflation for a wider range…
A new modified string-inspired modular invariant supergravity model is proposed and is applied to realize the slow roll inflation in Einstein frame. Because inflation deals with Planck scale physics, the dilaton can be a strong candidate…
We study the supergravity hybrid inflation model of Ref.[1] in the presence of a modulus field. The eta-problem is solved by a shift symmetry for the inflaton, which protects the inflaton mass even in the presence of the modulus field.…
We reconsider the problems of cosmological inflation in effective supergravity theories. A singlet field in a hidden sector is demonstrated to yield an acceptable inflationary potential, without fine tuning. In the simplest such model, the…
We study early universe with a particular form of F(T) Telleparallel gravity theory, in which inflation is driven by a scalar field. To ensure slow rollover, two different potentials are chosen in a manner, such that they remain almost flat…
In these lectures, after a short introduction to cosmology, we discuss the supergravity embedding of higher curvature models of inflation. The supergravity description of such models is presented for the two different formulations of…
In this paper my prime objective is to explain the generation of large tensor-to-scalar ratio from the single field sub-Planckian inflationary paradigm within Randall Sundrum (RS) single braneworld scenario in a model independent fashion.…
In this work, I intend to show a possible candidate of inflaton potential $V(\phi)$ in a scenario of a brane world defined by a pair of branes (RS-I).
We study D-brane inflation in a warped conifold background that includes brane-position dependent corrections for the nonperturbative superpotential. Instead of stabilizing the volume modulus chi at instantaneous minima of the potential and…
We revisit a single-field new inflation model based on a discrete R symmetry. Interestingly, the inflaton dynamics naturally leads to a heavy gravitino of mass m_3/2 = O(1-100) TeV, which is consistent with the standard-model like Higgs…
Inflationary $\alpha$-attractor models in supergravity, which provide excellent fits to the latest observational data, are based on the Poincare disk hyperbolic geometry. We refine these models by constructing Kahler potentials with…
Non-supersymmetric brane world scenarios in string theory display perturbative instabilities that usually involve run-away potentials for scalar moduli fields. We investigate in the framework of intersecting brane worlds whether the leading…