Related papers: Shining on an Orbifold
Models with classical scale symmetry, which feature radiative symmetry breaking, generically lead to a supercooled first-order phase transition in the early Universe resulting in a strong gravitational-wave signal, potentially observable by…
It has recently shown that in supersymmetric left-right models with automatic R-parity conservation, the theory below the $W_R$ scale is given by MSSM with massive neutrinos and a pair of doubly charged superfields with masses in the 100…
Supersymmetry, a new symmetry that relates bosons and fermions in particle physics, still escapes observation. Search for supersymmetry is one of the main aims of the Large Hadron Collider. The other possible manifestation of supersymmetry…
Supersymmetric Gauge-Higgs Unification is a well-motivated new physics scenario, both in heterotic model building and from the perspective of higher-dimensional Grand Unified Theories. When combined with radion mediated supersymmetry…
We present a simple general framework for realistic models of supersymmetry breaking driven by anomaly mediation. We consider a 5-dimensional "brane universe" where the visible and hidden sectors are localized on different branes, and the…
The particle spectrum of the supersymmetric extension of the standard model with a gauge singlet is studied. Soft supersymmetry breaking terms are explicitly chosen to be non-universal according to orbifold string theory. they depend on…
In this thesis we analyze the problem of symmetry breaking in models with extra dimensions compactified on orbifolds. In the first chapter we briefly review the main symmetry breaking mechanisms peculiar of extra dimensions such as the…
If there are multiple hidden sectors which independently break supersymmetry, then the spectrum will contain multiple goldstini. In this paper, we explore the possibility that the visible sector might also break supersymmetry, giving rise…
We consider the problem of supersymmetry and electroweak breaking in a 5d theory compactified on an $S^{1}/Z_{2}$ orbifold, where the extra dimension may be large or small. We consider the case of a supersymmetry breaking 4d brane located…
We study some cosmological consequences of the five dimensional, two brane Randall-Sundrum scenario. We integrate over the extra dimensions and in four dimensions the action reduces to that of scalar tensor gravity. The radius of the…
We construct supersymmetric gauge theories with new mechanisms of dynamical supersymmetry breaking. The models have flat directions at the classical level, and different mechanisms lift these flat directions in different regions of the…
String theory and supersymmetry are theoretical ideas that go beyond the standard model of particle physics and show promise for unifying all forces. After a brief introduction to supersymmetry, we discuss the prospects for its experimental…
We describe a simple class of supersymmetric gauge theories that can act as supersymmetry-breaking sectors for gauge-mediated supersymmetry breaking. The models have a local supersymmetry-breaking minimum along a direction in field space…
Some old and new ideas on symmetry breaking, based on the presence of extra dimensions that have been the subject of a very fast development and intensive studies during the last years, will be presented in these lectures. Special attention…
In the context of a toy model we discuss the phenomenon of colliding five-branes, with two of the extra space dimensions compactified on tori. In one of the branes (hidden world) the torus is magnetised. Assuming opposite-tension branes, we…
Here I briefly discuss why supersymmetry is considered a leading candidate of physics beyond the standard model. I also highlight the salient features of different supersymmetry breaking models. A few other symmetries, broken or intact,…
The phenomenological implications of the M-theory limit in which supersymmetry is broken by the F-terms of five-brane moduli is investigated. In particular we calculate the supersymmetric spectrum subject to constraints of correct…
A mechanism of supersymmetry breaking in two or four-dimensions is given, in which the breaking is related to the Fermat's last theorem. It is shown that supersymmetry is exact at some irrational number points in parameter space, while it…
Gauge symmetry breaking by boundary conditions on a manifold is known to be equivalent to Wilson-line breaking through a background gauge field, and is therefore spontaneous. These equivalent pictures are related by a non-periodic gauge…
We study the cosmology of perturbative heterotic superstring theory during the radiation-like era for semi-realistic backgrounds with initial $\N=1$ supersymmetry. This analysis is valid for times after the Hagedorn era (or alternatively…