相关论文: Reheating and Cosmic String Production

We study the formation of cosmic strings by confining a stochastic magnetic field into flux tubes in a numerical simulation. We use overdamped evolution in a potential that is minimized when the flux through each face in the simulation…

We reconsider the formation of (global) cosmic strings during and after preheating by calculating the dynamics of a scalar field on both two- and three- dimensional lattices. We have found that there is little differences between the…

In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3-anti-D3-brane inflationary scenario in superstring theory requires no more than a moderate tuning. The cosmic string tension is very sensitive to…

We point out some of the outstanding challenges for embedding inflationary cosmology within string theory studying the process of reheating for models where the inflaton is a closed string mode parameterising the size of an internal cycle…

We propose an alternative scenario to cosmic inflation for producing the initial seeds of cosmic structures. The cosmological fluctuations are generated by thermal fluctuation of the energy density of the ideal string gas in three compact…

We investigate the constraints of slow-roll inflation on the string worldsheet. A general gravity-matter set-up is used in which the worldsheet consists of an abstract CFT coupled to a 3+1 dimensional non-linear sigma model. The empirical…

Production of spin 1/2 fermions and gravitinos by the standard mechanism of amplification of quantum fluctuations during the dilaton-driven inflation phase in models of string cosmology is highly suppressed. Constraints on string cosmology…

Variation of the 4-D string cosmology action with dynamical torsion and massless dilatons lead to an expression of torsion in terms of massless dilatons in the case of de Sitter inflation.The solution is approximated according to the COBE…

For suitable cosmological backgrounds, thermal fluctuations of a gas of strings can generate a scale-invariant spectrum of cosmological fluctuations without requiring a phase of inflationary expansion. We highlight the key points of this…

This is a short review on strings in curved spacetimes. We start by recalling the classical and quantum string behaviour in singular plane waves backgrounds. We then report on the string behaviour in cosmological spacetimes (FRW, de Sitter,…

We present a superstring-inspired version of D-term inflation which does not lead to cosmic string formation and appears to satisfy the current CMB constraints. It differs from minimal D-term inflation by a second pair of charged…

This paper explores the phenomenon of particle creation associated with cosmic strings in de Sitter spacetime, a model that represents the universe exponential expansion. We examine how the presence of cosmic strings in a de Sitter…

Brane inflation is a specific realization of the inflationary universe scenario in the early universe within the brane world framework in string theory. The naturalness and robustness of this realistic scenario is explained. Its predictions…

We show that a moduli space of the form predicted by string theory, lifted by supersymmetry breaking, gives rise to successful inflation for large regions of parameter space without any modification or fine tuning. This natural realization…

We estimate the stochastic gravitational wave spectrum emitted from a network of cosmic strings in which the latter are effectively stable against breaking by monopole pair creation. The monopoles are produced at a higher scale from an…

We have built a supersymmetric SO(10) model consistent with cosmological observations. The model gives rise to a false vacuum hybrid inflationary scenario which solves the monopole problem. We argue that this type of inflationary scenario…

The "central" region of moduli space of M- and string theories is where the string coupling is about unity and the volume of compact dimensions is about the string volume. Here we argue that in this region the non-perturbative potential…

The scale of small-field inflation cannot be constrained via primordial gravitational waves through measurement of tensor-to-scalar ratio $r$. In this study, I show that if cosmic strings are produced after symmetry breaking at the end of…

We investigate the nucleation of circular cosmic strings in models of generalized inflationary universes with an accelerating scale factor. We consider toy cosmological models of a smooth inflationary exit and transition into a flat…

We analyze all individual cosmic strings of various lengths in a large ensemble of the global cosmic string networks in the post-inflationary scenario, obtained from numerical simulations on a discrete lattice with $N^3 = 4096^3$. A strong…