String theory and cosmology

String Theory and Cosmology

We discuss the main cosmological implications of considering string-loop eeects and a potential for the dilaton in the lowest order string eeective action. Our framework is based on the eeective model arising from regarding homogeneous and isotropic dilaton, metric and Yang-Mills eld conngurations. The issues of innation, entropy crisis and the Polonyi problem as well as the problem of the cosm...

Lectures on string theory and cosmology

In these lectures I review recent attempts to apply string theory to cosmology, including string cosmology and various models of brane cosmology. In addition, the review includes an introduction to inflation as well as a discussion of transplanckian signatures. I also provide a critical discussion of the possible role of holography. The material is based on lectures given in January 2004 at the...

DEVELOPMENT IN STRING THEORY

The string theory is a fast moving subject, both physics wise and in the respect of mathematics. In order to keep up with the discipline it is important to move with new ideas which are being stressed. Here I wish to give extracts from new papers of ideas which I have recently found interesting. There are six papers which are involved: I ."Strings formulated directly in 4 dimensions " A. N...

Anthropic reasoning and typicality in multiverse cosmology and string theory

Anthropic arguments in multiverse cosmology and string theory rely on the weak anthropic principle (WAP). We show that the principle is fundamentally ambiguous. It can be formulated in one of two ways, which we refer to as WAP1 and WAP2. We show that WAP2, the version most commonly used in anthropic reasoning, makes no physical predictions unless supplemented by a further assumption of “typical...

String Cosmology