Showing papers by "Micha Berkooz published in 1995"
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TL;DR: It is shown that string theory has two generic types of domain walls which could be the seeds for inflation, and it is argued that modular physics provides a very robust model of inflation.
Abstract: An exploratory study of the cosmology of moduli in string theory Moduli are argued to be natural inflaton fields and lead to a robust inflationary cosmology in which inflation takes place at the top of domain walls The amplitude of microwave background fluctuations constrains the dynamics responsible for inflation to take place at a higher scale than supersymmetry breaking Models explaining this difference in scales and also preventing the dilaton from running to infinity are proposed The problem of dilaton domination of the energy density of the universe is not resolved
161 citations
TL;DR: It is shown that in a postinflationary universe minima of the effective potential with a negative cosmological constant are not stationary points of the classical equations of scalar field cosmology, which implies that supersymmetry must be broken in any sensible inflationary cosmology.
Abstract: We review scenarios that have been proposed to solve the cosmological problem caused by moduli in string theory, the postmodern Polonyi problem (PPP). In particular, we discuss the difficulties encountered by the apparently ``trivial'' solution of this problem, in which moduli masses are assumed to arise from nonperturbative, SUSY-preserving, dynamics at a scale higher than that of SUSY breaking. This suggests a powerful cosmological vacuum selection principle in superstring theory. However, we argue that if one eschews the possibility of cancellations between different exponentials of the inverse string coupling, the mechanism described above cannot stabilize the dilaton. Thus, even if supersymmetric dynamics gives mass to the other moduli in string theory, the dilaton mass must be generated by SUSY breaking, and dilaton domination of the energy density of the Universe cannot be avoided. We conclude that the only proposal for solving the PPP that works is the intermediate scale inflation scenario of Randall and Thomas. However, we point out that all extant models have ignored unavoidably large inhomogeneities in the cosmological moduli density at very early times, and speculate that the effects associated with nonlinear gravitational collapse of these inhomogeneities may serve as an efficient mechanism for converting moduli into ordinary matter. As an important by-product of this investigation we show that in a postinflationary universe minima of the effective potential with a negative cosmological constant are not stationary points of the classical equations of scalar field cosmology. Instead, such points lead to catastrophic gravitational collapse of that part of the Universe which is attracted to them. Thus postinflationary cosmology dynamically chooses non-negative values of the cosmological constant. This implies that supersymmetry must be broken in any sensible inflationary cosmology. We suggest that further study of the cosmology of moduli will lead to additional important insight about cosmology, SUSY breaking, and the choice of the vacuum in superstring theory.
107 citations
TL;DR: In this article, a dualization of SU (2 k ) SUSY gauge theory with an antisymmetric tensor, n F fundamentals and n F anti-fundamentals is proposed.
91 citations
TL;DR: In this paper, a dualization of the SU(2k)-Susy gauge theory with antisymmetric tensors and anti-fundamentals has been proposed, by expanding the theory into an equivalent description with two gauge groups and then performing known duality tranformations on each gauge group separately.
Abstract: We suggest a dual to an $SU(2k)$ Susy gauge theory containing an antisymmetric tensor, $
f$ fundamentals and $
fb$ anti-fundamentals. This is done by expanding the theory into an equivalent description with two gauge groups and then performing known duality tranformations on each gauge group separately. Chiral operators, mass perturbations and flat directions are discussed.
21 citations
TL;DR: The first evidence of electric-magnetic duality outside the chiral ring was given in this article, where the authors matched a few non chiral operators in the electric and magnetic descriptions of SQCD.
Abstract: We match a few non chiral operators in the electric and magnetic descriptions of SQCD, suggesting the first evidence of electric-magnetic duality outside the chiral ring. Algebraically, these non chiral operators are a module of the chiral ring. Physically, the suggested correspondence essentially transforms certain electric gauge invariant composites containing the electric field strength into magnetic matter composites.