Costas Kounnas

TL;DR: In this paper, the choice of a particular class of Einstein spaces for the Kahler manifold of the hidden sector leads to a vanishing cosmological constant without unnatural fine tuning, and the resulting low energy softly broken globl supersymmetry for the matter fields is the same as in the case of factorized superpotential models with a flat Kahler metric.

TL;DR: In this article, the authors prove that modular invariance and factorization ensure the presence of a massless graviton and the correct connection between spin and statistics, and also prove that the existence of the massless spin-3/2 state ensures the absence of tachyons and vanishing of the one-loop cosmological constant.

TL;DR: In this paper, the authors constructed locally supersymmetric GUTs in which radiative corrections determine all the mass scales which are hierarchically smaller than the Planck mass: m 3 2 = O (m W ) = exp ( − O (1) α t )m p, etc.

TL;DR: In this article, the structure of SU(1, 1) supergravity models is investigated, and the hierarchy problem is solved in the sense that m32 and mW are determined dynamically to be exp [-O(1)/α] × mP.

TL;DR: In this article, it was shown that certain one-loop corrections to superstring effective four-dimensional lagragians, involving non-harmonic field-dependent renormalization of gauge couplings, can be consistently written in a standard N = 1 supergravity form, preserving target-space duality.