Comment on the stability of the Yukawa couplings and the cosmological problems of intersecting brane models

Abstract

In string theory, stabilization of moduli fields and their cosmological implications have been discussed by many authors. In this paper we do not consider conventional modulus, nor relative distance between two branes. We focus our attention to a relative position of three intersecting branes. Surprisingly, there had been no phenomonological argument on the stabilization of such moduli. We will show that the area of the corresponding triangle is not a free parameter, but an effective potential is generated from conventional loop corrections in the low energy effective theory. Of course, the stabilization does not induce any serious problem, because one is allowed to modify other parameters of the model to adjust the Yukawa couplings. Then the stabilization puts a constraint that is a different nature from the ones that have been discussed before. We also discuss cosmological problems and show a simple idea that can solve the problem.