Realistic model for SU(5) grand unification

A grand unified model based on SU(5) and supersymmetry is presented. Pairs of superfields belonging to 15 and 15* representations are newly introduced, while gauge coupling unification is satisfied. Improper mass relations in the minimal model between charged leptons and d-type quarks are corrected. Neutrinos have non-vanishing masses, with large angles for generation mixings of the leptons being compatible with the small angles of the quarks. Constraints from proton decay are relaxed. A new source for lepton number generation in the early universe is provided.Comment: 9 page

Transversality of the logarithmic divergences in the Classical Finite Temperature SU(N) Self-Energy

We show that the logarithmic divergences that appear in the classical approximation of the finite temperature SU(N) self-energy are transverse. We use the Ward identities in linear gauges and the fact that the superficial degree of divergence d of a classical diagram only depends on the number of loops l via d=2-l. We comment on the relevance of this result to the construction of a low-energy effective theory beyond HTLs.Comment: 5 pages, 1 figure, REVTE

O(d,d,Z) Transformations as Automorphisms of the Operator Algebra

We implement the O(d,d,Z) transformations of T-duality as automorphisms of the operator algebras of Conformal Field Theories. This extends these transformations to arbitrary field configurations in the deformation class.Comment: 9 pages, Plain Te