Related papers: Cosmic Superstrings Revisited
The scattering and capture of right-handed neutrinos by an Abelian cosmic string in the SO(10) grand unification model are considered. The scattering cross-section of neutrinos per unit length due to the interaction with the gauge and Higgs…
String cosmology aims at providing a reliable description of the very early Universe in the regime where standard-model physics is no longer appropriate, and where we can safely apply the basic ingredients of superstring models such as…
Superstring theory predicts the existence of relic metastable particles whose average lifetime is longer than the age of the universe and which could, in principle, be good dark matter candidates. At the same time, these states would be…
I address the issue of spacetime dimensionality within Kaluza-Klein theories and theories with large extra dimensions. I review the arguments explaining the dimensionality of the universe, within the framework of string gas cosmology and…
Cosmic strings represent an attractive source of gravitational waves (GWs) from the early Universe. However, numerical computation of the GW signal from cosmic strings requires the evaluation of complicated integral and sum expressions,…
I report on recent numerical simulations of the simplest field theory with cosmic string solutions, the Abelian Higgs model. We find that random networks of string quickly converge to a scaling solution in which the network scale length…
This text is a review of aspects of supergravity theories that are relevant in superstring cosmology. In particular, it considers the possibilities and restrictions for `uplifting terms', i.e. methods to produce de Sitter vacua. We…
Cusps of cosmic strings emit strong beams of high-frequency gravitational waves (GW). As a consequence of these beams, the stochastic ensemble of gravitational waves generated by a cosmological network of oscillating loops is strongly non…
Cosmic super-strings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic super-string loops, and…
I use a combination of state-of-the-art numerical simulations and analytic modelling to discuss the scaling properties of cosmic defect networks, including superstrings. Particular attention is given to the role of extra degrees of freedom…
We investigate the cosmological and astrophysical constraints on superconducting cosmic strings (SCSs). SCS loops emit strong bursts of electromagnetic waves, which might affect various cosmological and astrophysical observations. We take…
In string gas cosmology, extra dimensions are stabilised by a gas of strings. In the matter-dominated era, competition between matter pushing the extra dimensions to expand and the string gas pulling them back can lead to oscillations of…
Thermalized fireballs should be created by cusp events on superconducting cosmic strings. This simple notion allows to reliably estimate particle emission from the cusps in a given background magnetic field. With plausible assumptions about…
We present projected constraints on the cosmic string tension, $G\mu/c^2$, that could be achieved by future gravitational wave detection experiments and express our results as semi-analytic relations of the form $G\mu(\Omega_{\rm…
Cosmology motivated by string theory has been studied extensively in the recent literature. String theory is promising because it has interesting features such as unifying gravity, electromagnetic, weak and strong nuclear forces. However,…
I describe our understanding of physics near the planck length, in particular the great progress of the last four years in string theory. Superstring theory, and a recent extension called M theory, are leading candidates for a quantum…
Motivated by recent developments in superstring theory in the cosmological context, we examine a field theory which contains string networks with 3-way junctions. We perform numerical simulations of this model, identify the length scales of…
If the Universe underwent a cosmic phase transition, it may have left behind a network of cosmic strings. When these strings arise from the breaking of a gauge symmetry, their decay produces a significant stochastic background of…
Predicting signatures of string theory on cosmological observables is not sufficient. Often the observable effects string theory may impact upon the cosmological arena may equally be predicted by features of inflationary physics. The…
We calculate the gravitational radiation emitted by an infinite cosmic string with two oppositely moving wave-trains, in the small amplitude approximation. After comparing our result to the previously studied cases we extend the results to…