相关论文: String Theory and Cosmology

We establish the main features of homogeneous and isotropic dilaton, metric and Yang-Mills configurations in a cosmological framework. We identify a new energy exchange term between the dilaton and the Yang-Mills field which may lead to a…

String-loop effects may generate very weak matter couplings for a (massless) dilaton. We examine limits on the shift of such a dilaton toward its present equilibrium value from big-bang nucleosynthesis and the binary pulsar. On the other…

I discuss cosmological models either derived from, or inspired by, string theory or M-theory. In particular I discuss solutions in the low-energy effective theory and the role of the dilaton, moduli and antisymmetric form fields in the…

`Old' String Theory is a theory of one-dimensional extended objects, whose vibrations correspond to excitations of various target-space field modes including gravity. In these lectures I will give an introduction to low-energy Effective…

We study the effect of higher-curvature terms in the string low-energy effective actions on the cosmological solutions of the theory, up to corrections quartic in the curvatures, for the bosonic and heterotic strings as well as the type II…

We discuss some aspects of string cosmology with an emphasis on the role played by the dilaton. A cosmological scenario based on the assumption that all spatial dimensions are periodic so that winding modes play an important role is…

We establish the main features of homogeneous and isotropic dilaton, metric and Yang-Mills field configurations in a cosmological framework. Special attention is paid to the energy exchange between the dilaton and the Yang-Mills field and,…

String theory abounds with light scalar fields (the dilaton and various moduli) which create a host of observational problems, and notably some serious cosmological difficulties similar to the ones associated with the Polonyi field in the…

We study cosmological solutions to the low-energy effective action of heterotic string theory including possible leading order $\alpha'$ corrections and a potential for the dilaton. We consider the possibility that including such stringy…

An overview is presented of some cosmological aspects of string theory. Recent developments are emphasised, especially the attempts to derive inflation or alternatives to inflation from the dynamics of branes in string theory. Time…

String cosmology aims at providing a reliable description of the very early Universe in the regime where standard-model physics is no longer appropriate, and where we can safely apply the basic ingredients of superstring models such as…

In spite of its great phenomenological success, current models of scalar field-driven inflation suffer from important unresolved conceptual issues. New fundamental physics will be required to address these questions. String theory is a…

In spite of the phenomenological successes of the inflationary universe scenario, the current realizations of inflation making use of scalar fields lead to serious conceptual problems which are reviewed in this lecture. String theory may…

In spite of the phenomenological successes of the inflationary universe scenario, the current realizations of inflation making use of scalar fields lead to serious conceptual problems which are reviewed in this lecture. String theory may…

An attempt to construct a cosmological scenario directly from string theory is made. Cosmological string theory was presented by Antoniadis, Bachas, Ellis and Nanopoulos. They also expect loop effects on cosmological string theory. In this…

In string theory the coupling ``constants'' appearing in the low-energy effective Lagrangian are determined by the vacuum expectation values of some (a priori) massless scalar fields (dilaton, moduli). This naturally leads one to expect a…

Recent developments in string theory have important implications for cosmology. Topics discussed here are inflation, the cosmological constant, smoothing of cosmological singularities, and dark matter from parallel universes. Talk presented…

A qualitative analysis is presented for spatially flat, isotropic and homogeneous cosmologies derived from the string effective action when the combined effects of a dilaton, modulus, two-form potential and central charge deficit are…

It is pointed out that string-loop effects may generate matter couplings for the dilaton allowing this scalar partner of the tensorial graviton to stay massless while contributing to macroscopic gravity in a way naturally compatible with…

We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are…