Related papers: Unfolding Geometric Unification in M-Theory
We present a six-dimensional T^2/Z_2 orbifold model which arises as an intermediate step in the compactification of the heterotic string to the MSSM. The orbifold contains two pairs of inequivalent fixed points, with unbroken local gauge…
Among $T^7/\Gamma$ orbifold compactifications of $M$-theory, we examine models containing the particle physics Standard Model in four-dimensional spacetimes, which appear as fixed subspaces of the ten-dimensional spacetimes at each end of…
We study a grand unified SU(5)xSU(5)' model supplemented by D2 parity. The D2 greatly reduces the number of parameters and is important for phenomenology. The model, we present, has various novel and interesting properties. Because of the…
The subject of this thesis are various ways to construct four-dimensional quantum field theories from string theory. In a first part we study the generation of a supersymmetric Yang-Mills theory, coupled to an adjoint chiral superfield,…
In flux compactifications of M-theory a superpotential is generated whose explicit form depends on the structure group of the 7-dimensional internal manifold. In this note, we discuss superpotentials for the structure groups: G_2, SU(3) or…
New S-dualities in a scale invariant N=2 gauge theory with SU(2) x SU(2) gauge group are derived from embeddings of the theory in two different larger asymptotically free theories. The true coupling space of the scale invariant theory is a…
We present a model based on the gauge group SU(2)$_L\times$SU(2)$_R\times$SU(4)$_C$ with gauge couplings that are found to be unified at a scale $M_G$ near the string unification scale. The model breaks to the minimal supersymmetric…
We deconstruct the non-supersymmetric SU(5) breaking by discrete symmetry on the space-time $M^4\times S^1$ and $M^4\times S^1/(Z_2\times Z_2')$ in the Higgs mechanism deconstruction scenario. And we explain the subtle point on how to…
We investigate a 5D SU(6) grand gauge-Higgs unification model compactified on an orbifold S^1/Z_2. Ordinary quarks and leptons, together with right-handed neutrinos, are just accommodated into a minimal set of representations of the gauge…
A class of abelian fibered Calabi-Yau threefolds X_{m,n} is shown yield SU(2) structure, in addition to the standard SU(3) holonomy. Compactification of type II string theory on a manifold in this class give a 4D effective supergravity…
We study the dynamics of M-theory on G2 holonomy manifolds, and consider in detail the manifolds realized as the quotient of the spin bundle over S^3 by discrete groups. We analyse, in particular, the class of quotients where the triality…
We present the first example of a grand unified theory (GUT) with a modular symmetry interpreted as a family symmetry. The theory is based on supersymmetric $SU(5)$ in 6d, where the two extra dimensions are compactified on a…
We show that a new GUT scenario we proposed indicates that heterotic M-theory is one of the most interesting possibility to describe our world because of the two features in the scenario. The first feature is that E_6 unified group plays an…
We discuss the possible applications of string theory for the construction of generalizations of the $SU(3)\times SU(2)\times U(1)$ standard model of strong and electroweak interactions. This includes an investigation of effective $d=4$…
The Pentagon Model is an explicit supersymmetric extension of the Standard Model, which involves a new strongly-interacting SU(5) gauge theory at TeV-scale energies. We discuss embeddings of the Pentagon Model into string theory,…
We examine unification of gauge couplings in four dimensional renormalizable gauge theories inspired by the latticized (deconstructed) SM or MSSM in five dimensions. The models are based on replicated gauge groups, spontaneously broken to…
We construct and analyze an $SU(6)\times SU(2)$ GUT. The model is k=1 string embedable in the sense that we employ only chiral representations allowed at the k=1 level of the associated Ka\v{c}-Moody Algebra. Both cases $SU(6)\times…
We study manifolds arising as spaces of sections of complex manifolds fibering over the projective line with normal bundle of each section isomorphic to several copies of O(k). Such manifolds provide a natural setting for certain integrable…
The interpretation of the apparent unification of gauge couplings within supersymmetric theories depends on uncertainties induced through heavy particle thresholds. While in standard grand unified theories these effects can be estimated…
We present a field theoretical model unifying grand unified theory (GUT) and brane world scenario. As a concrete example, we consider $SU(5)$ GUT in 4+1 dimensions where our 3+1 dimensional spacetime spontaneously arises on five domain…