Related papers: Inflation in Supersymmetric Cosmic String Theories
We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra…
Using an analytical model for the string network we show that the kurtosis of cosmic microwave background (CMB) temperature gradient maps is a good statistic to distinguish between the cosmic string model and inflationary models of…
We propose a variant of hybrid inflation which is applicable in a wide class of supersymmetric grand unified models. The observed temperature perturbations of cosmic background radiation can be reproduced with natural values of the…
Combination of Plank and BICEP2 data reported that tensor to scalar ratio $r\simeq 0.16$ and scalar spectral index $n_{s}\simeq 0.96$. In this short note, it is shown that chaotic inflation with quadratic potential, which perfectly accounts…
Attempts at building an unified description of the strong, weak and electromagnetic interactions usually involve several stages of spontaneous symmetry breaking. We consider the effects of such symmetry breaking during an era of primordial…
Flat directions are a generic feature of the scalar potential in supersymmetric gauge field theories. They can arise, for example, from D-terms associated with an extra abelian gauge symmetry. Even when supersymmetry is broken softly, there…
The prototype hybrid SUSY SU(5) inflation models, while well motivated from particle physics, and while allowing an acceptable inflationary phase with little or no fine tuning, are shown to have two fundamental phenomenological problems.…
In the framework of superstring compactifications with N=1 supersymmetry spontaneously broken, (by either geometrical fluxes, branes or else), we show the existence of new inflationary solutions. The time-trajectory of the scale factor of…
We discuss, in the context of a concrete supersymmetric grand unified model based on the Pati-Salam gauge group SU(4)_c x SU(2)_L x SU(2)_R, two "natural" extensions of supersymmetric hybrid inflation, which avoid the cosmological disaster…
We present a supersymmetric model where energy scales of a discrete $R$-symmetry breaking ($Z_{6R}$) and cosmic inflation are commonly attributed to the confinement scale of a hidden $Sp(2)$ strong dynamics. Apart from these, SUSY-breaking…
Local cosmic strings solutions are introduced in a model with a pseudo-anomalous U(1) gauge symmetry. Such a symmetry is present in many superstring compactification models. The coupling of those strings with the axion necessary in order to…
We propose a realization of inverted hybrid inflation scenario in the context of n=2 supersymmetric quantum cosmology. The spectrum of density fluctuations is calculated in the de Sitter regimen as a function of the gravitino and the Planck…
A single field inflation based on a supergravity model with a shift symmetry and $U(1)$ extension of the MSSM is analyzed. We show that one of the real components of the two $U(1)$ charged scalar fields plays the role of inflaton {with} an…
Attempts to connect string theory with astrophysical observation are hampered by a jargon barrier, where an intimidating profusion of orientifolds, Kahler potentials, etc. dissuades cosmologists from attempting to work out the astrophysical…
Because cosmic superstrings generically form junctions and gauge theoretic strings typically do not, junctions may provide a signature to distinguish between cosmic superstrings and gauge theoretic cosmic strings. In cosmic microwave…
No-scale supergravity and the flipped SU(5)$\times$U(1) gauge group provide an ambitious prototype string-inspired scenario for physics below the string scale, which can accommodate the Starobinsky-like inflation favoured by observation…
The theory of cosmological perturbations is the main tool which connects theories of the early universe (based on new fundamental physics such as string theory) with cosmological observations. In these lectures, I will provide an…
We study the structure of cosmic strings produced at the breaking of an anomalous U(1) gauge symmetry present in many superstring compactification models. We show that their coupling with the axion necessary in order to cancel the anomalies…
Super--inflation driven by dilaton/moduli kinetic energy is naturally realized in compactified string theory. Discussed are selected topics of recent development in string inflationary cosmology: kinematics of super-inflation, graceful exit…
Supersymmetric theories often include the non-compact directions in the field space along which the tree level potential grows only up to a certain limited value (determined by the mass scale of the theory) and then stays constant for the…