Related papers: Anisotropic Power Law Inflation from Rolling Tachy…
In this talk we will discuss how inflation can be embedded within a minimal extension of the Standard Model where the inflaton carries the Standard Model charges. There is no need of an ad-hoc scalar field to be introduced in order to…
The apparent alignment of the cosmic microwave background multipoles on large scales challenges the standard cosmological model. Scalar field inflation is isotropic and cannot account for the observed alignment. We explore the imprints, a…
We construct an inflation model with inflaton non-minimally coupled to gravity on a warped DGP brane. Using an exponential potential, we calculate scalar power spectrum, spectral index and the running of the spectral index. We show that for…
The boundary state associated with the rolling tachyon solution on an unstable D-brane contains a part that decays exponentially in the asymptotic past and the asymptotic future, but it also contains other parts which either remain constant…
The evolution of slow--roll inflation in a five--dimensional brane world model with two boundary branes and bulk scalar field is studied. Assuming that the inflationary scale is below the brane tension, we can employ the moduli space…
We study the inflationary scenario in the Tsallis entropy-based cosmology. The Friedmann equations in this setup can be derived by using the first law of thermodynamics. To derive the relations of the power spectra of the scalar and tensor…
We investigate brane-antibrane inflation in a warped deformed conifold background that includes contributions to the potential arising from imaginary anti-self-dual (IASD) fluxes including the term with irrational scaling dimension…
We consider a cosmological scenario within the KKLT framework for moduli stabilization in string theory. The universal open string tachyon of decaying non-BPS D-brane configurations is proposed to drive eternal topological inflation.…
In the context of (4+d)-dimensional general relativity, we propose an inflationary scenario wherein 3 spatial dimensions grow large, while d extra dimensions remain small. Our model requires that a self-interacting d-form acquire a vacuum…
We propose a novel {\it k}-Gauss-Bonnet inflationary model, in which a kinetic term of scalar field is allowed to non-minimally couple to the Gauss-Bonnet topological invariant in the absence of a potential of scalar field. As a result,…
We study power law inflation (PLI) with a monomial potential and find a novel exact solution. It is well known that conventional PLI with exponential potential is inconsistent with the Planck data. Unlike the standard PLI, present model…
We discuss the gravitational waves (GW) in the context of vector inflation. We derive the action for tensor perturbations and find that tachyonic instabilities are present in most (but not all) of the inflationary models with large fields.…
We show how we can implement chaotic inflation in the context of supergravity by conveniently selecting the functional form of a strong enough non-minimal coupling between the inflaton and the Ricci scalar curvature. The procedure can be…
The gravitational baryogensis may not generate a sufficient baryon asymmetry in the standard thermal history of the Universe when we take into account the gravitino problem. Hence it has been suggested that anisotropy of the Universe can…
In a previous work we showed that large nongaussianities and nonscale-invariant distortions in the CMB power spectrum can be generated in hybrid inflation models, due to the contributions of the tachyon (waterfall) field to the second order…
We study D-brane dynamics in the gravity dual background of ODp theories using the effective action on the worldvolume of the brane. We explore the similarities of the system with the rolling tachyon, including the exponential decrease of…
By considering the Friedmann equations emerging from the entropy-area law of black hole thermodynamics in the context of the generalized uncertainty principle, we study tachyon inflation in the early universe. The presence of a minimal…
We propose a geometrical model of brane inflation where inflation is driven by the flux generated by opposing brane charges and terminated by the collision of the branes, with charge annihilation. We assume the collision process is…
Upper bounds on the energy scale at the end of inflation in the Randall-Sundrum type II braneworld scenario are derived. The analysis is made exact by introducing new parameters that represent extensions of the Hubble flow parameters. Only…
We study classes of inflation models driven by antisymmetric tensor field, with minimal and nonminimal couplings to gravity, that address known issues of such models considered in the past. First we show that with a different choice of the…