Related papers: Three-Family Grand Unification in String Theory
I discuss several aspects of strings as unified theories. After recalling the difficulties of the simplest supersymmetric grand unification schemes I emphasize the distinct features of string unification. An important role in constraining…
The E6 grand unified theory is an attractive candidate intermediate theory between the standard model and string theory. However, only one E6 grand unified model with three generations and at least one adjoint Higgs field has been derived…
Recently it has been proposed that, in the framework of quantum field theory, both the Standard Model gauge and Yukawa interactions arise from a single gauge interaction in higher dimensions with supersymmetry. This leads to the unification…
We review our recent proposals to dimensionally regularize the light-cone gauge string field theory.
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 review the status of low-scale string theories and large extra-dimensions. After an overview on different string realizations, we discuss some of the main important problems and we summarize present bounds on the size of possible…
We describe a supersymmetric Grand Unified Theory based on the gauge group $\SU(5)^3$, or $\SO(10)^3$, invariant under the interchange of any~SU(5), or~SO(10), with each family multiplet transforming non trivially under one different…
Some mysterious features of the strong interactions become easily understood if our usual QCD with N=3 is `close to' SU(oo) and if the latter theory is confining. N=oo theories are theoretically simpler; in particular there has been much…
After reviewing the general structure of supersymmetric intersecting brane world models, we discuss the issue of stringy gauge coupling unification for a natural class of MSSM-like models.
Together with some positive features, such as the constrained hypercharge assignments, grandunification models typically have some unwelcome aspects, mostly associated with the rich and peculiarly selected matter content. I discuss some…
Thermodynamical aspects of string theory are reviewed and discussed.
We study the possibility of complete family unification in higher-dimensional space-time. Three families of matters in SU(5) grand unified theory are derived from a single bulk multiplet of SU(N) gauge group (N >= 9) in the framework of…
In this paper the $c=1$ string theory is studied from the point of view of topological field theories. Calculations are done for arbitrary genus. A change in the prescription is proposed, which reproduces the results of the $1/x^2$ deformed…
After briefly reviewing basic concepts of perturbative string theory, we explain in simple terms some of the new findings that created excitement among the string physicists. These developments include non-perturbative dualities and a…
In the framework of the four dimensional heterotic superstring with free fermions we discuss the rank eight and/or sixteen Grand Unified String Theories (GUST) which contain the SU(3)_H - gauge family symmetry. We explicitly investigate the…
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…
Equations which define classical configurations of strings in $R^3$ are presented in a simple form. General properties as well as particular classes of solutions of these equations are considered.
The aim of these notes is to give recent developments in string theory. In particular, we discuss the string spectrums, compactifications, brane physics and dualities.
Some of the supersymmetric nonlinear sigma models on exceptional groups (E7 or E8) are known to yield almost minimal necessary content of matter fields for phenomenological model building, including three chiral families and a Higgs…
After a review of some topics concerning the phenomenological applications of perturbative string theory, I discuss to what extent all of it is affected by the recent developements in string dualities.