We propose a variant of hybrid inflation which is applicable in a wide class of supersymmetric grand unified models. The observed temperature perturbations of cosmic background radiation can be reproduced with natural values of the parameters of the theory and a grand unification scale which is consistent with the unification of the minimal supersymmetric standard model gauge couplings as measu...

In this talk1, we propose a GUT scenario in which doublet-triplet splitting is naturally realized in SO(10) unification using the DimopoulosWilczek mechanism [4] and the realistic mass matrices of quarks and leptons are obtained in a simple way. For the neutrino sector, bi-maximal neutrino mixing angles are realized. Moreover, the generic interaction is allowed, namely, all the terms which are ...

The idea that isolated magnetic poles might exist was first advanced over a half century ago [1], and since that time extensive theoretical and experimental work on this topic has been done [2]. There is now one candidate for the detection of a monopole [3]. Monopoles have been shown to arise in gauge theories [4], and in many versions of the grand unification theories very massive monopoles ar...

A fully realistic unified theory is constructed, with SU(5) gauge symmetry and supersymmetry both broken by boundary conditions in a fifth dimension. Despite the resulting explicit breaking of SU(5) locally at a boundary of the dimension, when the size of the extra dimension is taken to be large precise predictions emerge for gauge coupling unification, αs(MZ) = 0.118± 0.003, and for Yukawa cou...

Modeling & Simulation (M&S) is used in many different fields and has made many significant contributions. As a field in its own right, there have been many advances in methodologies and technologies. In 2002 a workshop was held in Dagstuhl, Germany, to reflect on the grand challenges facing M&S. Ten years on, a series of M& S Grand Challenge activities are marking a decade of progress and are p...

Molecular characterization of the components of signalling pathways that mediate disease resistance is at last providing a unified picture of how plants fight disease.

Generalized Yang-Mills theories have a covariant derivative that employs both scalar and vector bosons. Here we show how grand unified theories of the electroweak and strong interactions can be constructed with them. In particular the SU(5) GUT can be obtained from SU(6) with SU(5)xU(1) as a maximal subgroup. The choice of maximal subgroup also determines the chiral structure of the theory. The...

Neutrino masses have been extensively studied in the context of discrete symmetries. A family permutation symmetry easily explains all neutrino oscillations and their mixing angles. However it is not obvious the embedding of such symmetry in a grand unified theory where all fermions live in the same representation. We show that it is possible to embed such a horizontal discrete symmetry in a gr...

In August of 2007 and December of 2007, North American academic researchers, industry representatives and regulators were invited to meetings in Washington and Minneapolis, respectively, with the goal of forming a Software Certification Consortium (SCC). At the first meeting, objectives were established for the consortium and a certification grand challenge was issued. At the second meeting, al...