相关论文: P-term Strings and Semi-local Strings

We investigate the microphysics of supersymmetric cosmic strings. In particular we focus on the vortices admitted by N=1 supersymmetric abelian Higgs models. We find the vortex solutions and demonstrate that the two simplest supersymmetric…

In the first part of this paper I review the construction of the realistic free fermionic models, as well as current attempts to study aspects of these models in the nonperturbative framework of M- and F-theories. I discuss the recent…

The relevant characteristic features, including energy per unit length and tension, of a cosmic string carrying massless fermionic currents in the framework of the Witten model in the neutral limit are derived through quantization of the…

In this article we study in detail the supersymmetric structures that underlie the system of fermionic zero modes around a superconducting cosmic string. Particularly, we extend the analysis existing in the literature on the one dimensional…

We consider a generalization of the Nielsen-Olesen ansatz, in an abelian-Higgs model with externally coupled charge, which describes strings with twisted magnetic flux lines in the vortex core. The solution does not possess cylindrical…

In this work, the current stability is discussed for cosmic strings with the bosonic superconductivity. A non-vanishing curvature of string generally induce the quantum instability of the current-carrying particle. Its decay rates are…

We investigate the standard model in a cosmic string background and show that the electroweak symmetry is partially restored. For a range of parameters the electroweak Higgs field can wind in this region, producing an electroweak string…

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…

Detecting the parity-odd, or B-mode, polarization pattern in the cosmic microwave background radiation due to primordial gravity waves is considered to be the final observational key to confirming the inflationary paradigm. The search for…

This PhD thesis discusses the internal structure of topological defects, and branes in extra-dimensions, carrying fermionic currents. The general framework in which these objects may appear is presented in the first part while the second…

Production of domain walls and string-like solitons in the model with two real scalar fields and potential with at least one saddle point and a local maximum is considered. The model is regarded as 2-dimensional spatial slices of…

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…

In the light of the proposal of hep-th/0207195, we discuss in detail the issue of the cosmological constant, explaining how can string theory naturally predict the value which is experimentally observed, without low-energy supersymmetry.

We investigate the evolution of small perturbations around black strings and branes which are low energy solutions of string theory. For simplicity we focus attention on the zero charge case and show that there are unstable modes for a…

We analyze the physical (reduced) space of non-local theories, around the fixed points of these systems, by analyzing: i) the Hamiltonian constraints appearing in the 1+1 formulation of those theories, ii) the symplectic two form in the…

We provide a thorough exposition of recent results on the quantum stabilization of cosmic strings. Stabilization occurs through the coupling to a heavy fermion doublet in a reduced version of the standard model. The study combines the…

The space-time light-cone Hamiltonian P^- of large-N matrix models for dynamical triangulations may be viewed as that of a quantum spin chain and analysed in a mean field approximation. As N -> infinity, the properties of the groundstate as…

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…

We study the intercommuting of semilocal strings and Skyrmions, for a wide range of internal parameters, velocities and intersection angles by numerically evolving the equations of motion. We find that the collisions of strings and strings,…

We review some aspects of moduli in string theory. We argue that one should focus on {\it approximate moduli spaces}, and that there is evidence that such spaces exist non-perturbatively. We ask what it would mean for string theory to…