Related papers: String Gas Baryogenesis
The relation between shapes of cosmic string and baryon number violation is investigated. If there exist fermionic zero modes on the string, using bosonization technique, it is possible to obtain the effective action which describes the…
Based on a mechanism originally suggested for causal fermion systems, the present paper paves the way for a rigorous treatment of baryogenesis in the language of differential geometry and global analysis. Moreover, a formula for the rate of…
In spite of the phenomenological successes of the inflationary universe scenario, the current realizations of inflation making use of scalar fields lead to serious conceptual problems which are reviewed in this lecture. String theory may…
A scenario for the generation of the baryon asymmetry in the early Universe is proposed in which cosmic string loops, predicted by theories where the baryon and/or lepton numbers are gauged symmetries, collapse during the friction dominated…
Spontaneous and closely related to it gravitational baryogenesis are critically analyzed. It is shown that the coupling of the curvature scalar to baryonic current, which induces nonzero baryonic asymmetry of the universe, simultaneously…
If cosmic strings are present at the electroweak phase transition, they can act as seeds on which bubbles of true vacuum nucleate. We explore the nature of such a phase transition, in particular the wall velocity and thickness of the…
General features of spontaneous baryogenesis are studied. The relation between the time derivative of the (pseudo)goldstone field and the baryonic chemical potential is revisited. It is shown that this relation essentially depends upon the…
If stable electroweak strings are copiously produced during the electroweak phase transition, they may contribute significantly to the presently observed baryon to entropy ratio of the universe. This analysis establishes the feasibility of…
Brane gas cosmology is a scenario inspired by string theory which proposes a simple resolution to the initial singularity problem and gives a dynamical explanation for the number of spatial dimensions of our universe. In this work we have…
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…
We investigate cosmological aspects of spontaneous baryogenesis driven by a scalar field, and present general constraints that are independent of the particle physics model. The relevant constraints are obtained by studying the backreaction…
String gas cosmology is an approach towards studying the effects of superstring theory on early universe cosmology which is based on new symmetries and new degrees of freedom of string theory. Within this context, it appears possible to…
We study a baryogenesis mechanism operating in the context of hyperextended inflation and making use of a coupling between the scalar field and a standard model global current, such as B or B-L. The method is efficient at temperatures at…
Recently it has been shown that string gas cosmology, an alternative model of the very early universe which does not involve a period of cosmological inflation, can give rise to an almost scale invariant spectrum of metric perturbations.…
Grand unified theories can admit cosmic strings with fermion zero modes. Such zero modes result in the string being current-carrying and the formation of stable remnants, vortons. However, the string zero modes do not automaticall survive…
String Gas Cosmology is a model of the evolution of the very early universe based on fundamental principles and key new degrees of freedom of string theory which are different from those of point particle field theories. In String Gas…
A review is attempted of physical motivations, theoretical and phenomenological aspects, as well as outstanding problems, of the pre-big bang scenario in string cosmology.
We describe different electroweak strings with axionic content, including non-topological configurations calculated numerically, and show their possible influence on baryogenesis indicating that they may constitute a mechanism competitive…
Progress in early Universe cosmology, including strings, extra dimensions, inflation, phase transitions, and baryogenesis, is reviewed.
We present a new mechanism of spontaneous baryogenesis. Usually such mechanisms require a derivative coupling between a scalar field and baryon current. In our model, the scalar field instead derivatively couples to a current associated…