Related papers: On relation between unitary gauge and gauge given …
Under the assumption that all the gauge groups in supersymmetric theories unify at the fundamental scale, the numbers and the mass scales of messenger quarks and leptons, as well as the beta-function coefficient of the sector for dynamical…
We consider extra dimensional gauge theories on an interval. We first review the derivation of the consistent boundary conditions (BC's) from the action principle. These BC's include choices that give rise to breaking of the gauge…
We investigate gauge coupling unification for F-theory respectively Type IIB orientifold constructions of SU(5) GUT theories with gauge symmetry breaking via non-trivial hypercharge flux. This flux has the non-trivial effect that it splits…
We discuss several issues regarding analyses which use loop calculations to put constraints on anomalous trilinear gauge boson couplings (TGC's). Many such analyses give far too stringent bounds. This is independent of questions of gauge…
Potentially realistic string models often contain additional abelian gauge factors besides the standard model group. The consequences of such extended gauge structure are manifold both for theory and phenomenology as I show focussing in the…
We explore vacua of the U(N) gauge model with N=2 supersymmetry recently constructed in hep-th/0409060. In addition to the vacuum previously found with unbroken U(N) gauge symmetry in which N=2 supersymmetry is partially broken to N=1, we…
We explore possibilities of gauge coupling unification in left--right symmetric models with non--minimal particle content. In addition to unification we require the absence of anomalies and sufficient proton lifetime. Numerous previously…
We investigate the divergence structure of one-loop corrections to S and T parameteres in gauge-Higgs unification. We show that these parameters are finite in five dimensions, but divergent in more than five dimensions. Remarkably, a…
We provide vector-like gauge theories which break supersymmetry dynamically.
A supersymmetric model with two copies of the Standard Model gauge groups is constructed in the gauge mediated supersymmetry breaking scenario. The supersymmetry breaking messengers are in a simple form. The Standard Model is obtained after…
In SU($N$) gauge-Higgs theories, with a single Higgs field in the fundamental representation, there exists in addition to the local gauge symmetry a global SU(2) symmetry, at $N=2$, and a global U(1) symmetry, for $N \ne 2$. We construct a…
We briefly review a construction of N=2 supersymmetric U(N) gauge model in which rigid N=2 supersymmetry is spontaneously broken to N=1. This model generalizes the abelian model considered by Antoniadis, Patouche and Taylor. We discuss the…
We consider constraints on gauge mediated supersymmetry breaking models imposed by the requirement of grand unification. In particular, we demonstrate several ways to reduce the number of parameters coming from the dynamical supersymmetry…
We extend work done previously concerning the formation of vortices in a U(1)->1 gauge theory at a first order phase transition to the symmetry breaking SU(2)xU(1)->U(1). It is shown that the collision of bubbles, appearing at the phase…
Gauge invariance is extended to allow to allow for a U(1)-SU(2) mixing term, which can cause a SU(2) deconfining transition.
By considering the constraints from nucleon decay we obtain upper limits on tan beta in generalized supersymmetric SU(5) grand unified theories with gauge-mediated supersymmetry breaking. We find that the predicted values of tan beta in…
Gauge unification is widely considered to be a desirable feature for extensions of the standard model. Unfortunately the standard model itself does not exhibit a unification of its running gauge couplings but it is required by grand unified…
In this paper we study the topological susceptibility of two-dimensional $U(N)$ gauge theories. We provide explicit expressions for the partition function and the topological susceptibility at finite lattice spacing and finite volume. We…
We investigate a supersymmetric theory with an extra U(1) gauge symmetry surviving down to low energies. The extra U(1) is assumed to originate from an E$_6$ grand unified theory (GUT). We show that if one assumes universal soft…
In these lectures I present a basic introduction to supersymmetry, especially to N=1 supersymmetric gauge theories and their renormalization, in the Wess-Zumino gauge. I also discuss the various ways supersymmetry may be broken in order to…