Using the Non-Abelian Batalin-Vilkovisky formalism introduced recently, we present a generalization of the Yang-Mills gauge transformations , to include antisymmetric tensor fields as gauge bosons. The Freedman-Townsend transformation for the two-form gauge field is automatically recovered. New characteristic classes involving this two-form field and the Yang-Mills one-form field are derived. W...

We review the prototype model of a grand unified theory on the orbifold S/Z2 and discuss topics related to the choice of boundary conditions; the dynamical rearrangement of gauge symmetry and the equivalence classes of BCs. We explore a family unification scenario by orbifolding.

The coupling of chiral fermions to gravity makes use only of the selfdual SU(2) subalgebra of the (complexified) SO(3, 1) algebra. It is possible to identify the antiselfdual subalgebra with the SU(2)L isospin group that appears in the Standard Model, or with its right-handed counterpart SU(2)R that appears in some extensions. Based on this observation, we describe a form of unification of the ...

It was recently suggested that the reported anomalies in Rb and R, can be interpreted as the effect of a heavy vector boson that couples to quarks and is universally decoupled from leptons. We examine how an extra gauge boson with this property can arise from supersting derived models. In a specific three generation model we show that the U( ~)B__L symmetry combines with the horizontal flavor s...

In discussing the construction of a consistent theory of quantum gravity unified with the gauge interactions we are naturally led to a string theory. We review its properties and the five consistent supersymmetric string theories in ten dimensions. We finally discuss the evidence that these theories are actually special limits of a unique 11-dimensional theory, called M-theory, and a recent con...

We make a numerical study of gauge and Yukawa unification in super-symmetric grand unified models and examine the quantitative implications of fermion mass ansätze at the grand unified scale. Integrating the renor

In a series of papers, we pointed out that an anomalous U(1)A gauge symmetry naturally solves various problems in grand unified theories (GUTs) and that a horizontal gauge symmetry, SU(2)H or SU(3)H , not only realizes the unification of three generation quarks and leptons in fewer multiplets but also solves the supersymmetric flavor problem. In this paper, we examine the possibility that the H...

We minimally extend the Standard Model field content by adding new vector-like fermions at TeV scale to allow gauge coupling unification a realistic scale. embed model into $SU(5)$ grand unified theory that is asymptotically safe and features an interacting fixed point for coupling. There are no Landau poles of $U(1)$ Higgs couplings. Gauge, Yukawa couplings retraced from matched those rescaled...

We compute the full set of weak-scale gauge and Yukawa threshold corrections in the minimal supersymmetric standard model, including all finite (non-logarithmic) corrections, which we show to be important. We use our results to examine the effects of unification-scale threshold corrections in the minimal and missing-doublet SU(5) models. We work in the context of a unified mass spectrum, with s...

Three aspects of supersymmetric theories are discussed: electroweak symmetry breaking, the issues of flavor, and gauge unification. The heavy top quark plays an important, sometimes dominant, role in each case. Additional symmetries lead to extensions of the standard model which can provide an understanding for many of the outstanding problems of particle physics. A broken supersymmetric extens...