Related papers: Collisions of strings with Y junctions

We show that a large class of phenomenologically viable models for gauge mediation of supersymmetry breaking based on meta-stable vacua can be realized in local Calabi-Yau compactifications of string theory.

The exact spectrum of dyons in a class of N=4 supersymmetric string theories gives us information about dyon spectrum in N=4 supersymmetric gauge theories. This in turn can be translated into prediction about the BPS spectrum of three…

We perform numerical simulations of cosmic necklaces (systems of monopoles connected to two strings each) and investigate the conditions under which monopoles annihilate. When the total monopole energy is large compared to the string…

We calculate the energy spectrum of closed strings in SU(N) gauge theories with N=2,3,4,6,8 in 2+1 dimensions to a high accuracy. We attempt to control all systematic errors, and this allows us to perform a precise comparison with different…

Topological defects are a fossil relic of early Universe phase transitions, with cosmic strings being the best motivated example. While in most cases one studies Nambu-Goto or Abelian-Higgs strings, one also expects that cosmologically…

This paper explores a recent idea of Nambu to generate hierarchies among Yukawa couplings in the context of effective supergravity and superstrings models. The Yukawa couplings are homogeneous functions of the moduli and a geometrical…

Considerable progress has been achieved recently in the observation of string breaking within non-Abelian Higgs models, by use of multi-channel methods allowing for broken string states. Similarly, in pure gauge theory this approach has…

This is a report on our newly proposed model of dynamical supersymmetry breaking with some details of the analysis involved. The model in the simplest version has only a chiral superfield (multiplet), with a strong four-superfield…

We consider the metric perturbations around a stationary rotating Nambu-Goto string in Minkowski spacetime. By solving the linearized Einstein equations, we study the effects of azimuthal frame-dragging around the rotation axis and linear…

This report presents some studies of the gauge/string theory correspondence, a deep relation that is possible to establish between quantum field theories with local gauge symmetry and superstring theories including gravity. In its original…

At the classical level we study open bosonic strings. A generic description of string self-interactions localized at string ends is given. Self-interactions are characterized by two dimensionless coupling constants. The model is rewritten…

We study the classical cosmic string solution in a theory with dynamical $U(1)$ symmetry breaking. We calculate the energy per unit length of the string and compare it to that obtained in a model with a fundamental Higgs. We find that the…

We investigate the space-time picture of string evolution and hadron production in a fully string-based model for high energy collisions involving heavy ions. We find that although the density strings is quite large at the time of…

We revisit the classical dynamics of fundamental strings in BTZ black holes with NSNS flux. We analyse probe strings in the black hole background and determine their classical energy using a Nambu-Goto action. Three-dimensional gravity has…

The number of cosmic strings in the observable universe is relevant in determining the probability of detecting such cosmic defects through their gravitational signatures. In particular, we refer to the observation of gravitational lensing…

Linear perturbations for a one parameter family of stationary, closed Nambu-Goto strings winding around a flat torus in the five-dimensional Schwarzschild spacetime have been studied. It has been shown that this problem is solvable in the…

The intersection of string theory with cosmology is unavoidable in the early universe, and its exploration may shine light on both fields. In this thesis, three papers at this intersection are presented and reviewed, with the aim of…

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…

Starting from the Nambu-Goto bosonic string, a four dimensional superstring model is constructed using the equivalence of one boson to two Majorana-Weyl fermions. The conditions of anomaly cancellation in a 'heterotic' string theory lead to…

The mechanism of dynamical chiral symmetry breaking is studied in the Abelian version of the gauged Nambu-Jona-Lasinio model in four dimensions. The most interesting feature of the gauged Nambu-Jona-Lasinio model is the appearance of…