Related papers: Fermionic currents flowing along extended objects
Macroscopic fundamental and Dirichlet strings have several potential instabilities: breakage, tachyon decays, and confinement by axion domain walls. We investigate the conditions under which metastable strings can exist, and we find that…
We obtain the equations of motion for cosmic strings in extensions of the 3+1 FRW model with extra dimensions. From these we derive a generalisation of the Velocity-dependent One-Scale (VOS) model for cosmic string network evolution which…
Chiral cosmic strings naturally arise in many particle physics models, in particular in supersymmetric theories with a D-term. These strings have a single fermion zero mode in the core. We derive the general equation of motion for such…
We consider the cosmology of a thick codimension 1 brane. We obtain the matching conditions leading to the cosmological evolution equations and show that when one includes matter with a pressure component along the extra dimension in the…
Topological defects are ubiquitous in condensed-matter physics but only hypothetical in the early universe. In spite of this, even an indirect evidence for one of these cosmic objects would revolutionize our vision of the cosmos. We give…
In recent years, unprecedented progress in observational cosmology has revealed a great deal of information about the formation and evolution of structures in the universe. This, in turn, has raised many challenging issues for the…
We show that the equations of motion governing the dynamics of strings in a compact internal space can be written as dispersion relations, with a local speed that depends on the velocity and curvature of the string in the large dimensions.…
The formation and evolution of cosmic string wakes in the framework of a $f(R)$ theory of gravity are investigated in this work. We consider a simple model in which baryonic matter flows past a cosmic string. We treat this problem in the…
We investigate the generic distribution of bosonic and fermionic states at all mass levels in non-supersymmetric string theories, and find that a hidden ``misaligned supersymmetry'' must always appear in the string spectrum. We show that…
In these lectures I discuss the possibility that superstrings of cosmic length might exist and be observable. I first review the original idea of cosmic strings arising as gauge theory solitons, and discuss in particular their network…
We first examine the microstructure of a cosmic string endowed with two simple Abelian currents. This microstructure depends on two state parameters. We then provide the macroscopic description of such a string and show that it depends on…
D-branes are fundamental in all scenarios where there are large extra dimensions and the string scale is much smaller than the four-dimensional Planck mass. We show that this current picture leads to a new approach to string cosmology where…
We construct branes in the plane wave background under the inclusion of fermionic boundary fields. The resulting deformed boundary conditions in the bosonic and fermionic sectors give rise to new integrable and supersymmetric branes of type…
I will briefly review the formation and evolution of cosmic superstrings, in the context of brane-world cosmological models within M-theory. These objects can play the role of cosmic strings, offering a variety of astrophysical…
Cosmic strings are linear topological defects which are hypothesized to be produced during inflation. Most searches for strings have been relying on the string's lensing of background galaxies or CMB. In this paper I obtained the solution…
The gravitational properties of cosmic strings in the Randall-Sundrum brane world scenario are investigated. Using a gauge in which the brane remains straight, the leading order corrections to the metric on the brane are determined. In…
In this work we analyze the effects produced by bosonic and fermionic constituents, including quantum corrections, in two-dimensional (2D) cosmological models. We focus on a gravitational theory related to the…
Cosmic strings provide a radically different paradigm for the formation of structure to the prevailing inflationary one. They afford some extra technical complications: for example, the calculation of the power spectrum of matter and…
The lowest order quantum corrections to the effective action arising from quantized massive fermion fields in the Randall-Sundrum background spacetime are computed. The boundary conditions and their relation with gauge invariance are…
We investigate the cosmological consequences of particle physics theories that admit stable loops of current-carrying string - vortons. In particular, we consider chiral theories where a single fermion zero mode is excited in the string…