Organizers: James Cline (McGill University), Robert Brandenberger (Brown University), Steve Giddings (University of California, Santa Barbara), Brian Greene (Columbia University), Rob Myers (Perimeter Institute), Gordon Semenoff (University of British Columbia).
Because of the aforementioned advances, issues in string cosmology have attracted the attention of string theorists who would not otherwise have attempted to address cosmology, as well as field theorists whose expertise is more on the cosmological issues themselves. Although the main focus of the proposed workshop will be on the mathematical and string theoretic aspects of the subject, it is worthwhile to have input from people in the second group, since the ultimate aim is still to make a connection with observable physics. The purpose of the workshop is therefore to provide an opportunity to discuss the current problems and issues in string cosmology, both at the technical level and at a more conceptual level.
To this end, we are proposing a 5-Day Workshop which will begin by providing overviews of the latest progress in areas of string cosmology, followed by forums to discuss its key problems. The topics and outstanding questions which seem most urgent at present are:
* string theory in time-dependent backgrounds
* identification of the appropriate observables for defining the theory
* time-dependent orbifolds
* AdS/CFT constructions of cosmological string backgrounds * dynamics of tachyon condensation
* consistency of string theory with deSitter space; alternative ways to get an accelerating universe from string theory
* resolution of spacelike (cosmological) singularities by string theory
* the proposed dS/CFT correspondence; does deSitter space have a finite number of degrees of freedom?
* inflation from string moduli or D-brane interactions
* string theoretic effects on inflationary perturbations
* can noncommutative geometry play a role in the early universe?
One of the goals of the proposed workshop is to try to move closer to having a set of tools or a framework within which one might hope to carry out more rigorous calculations. Despite the remarkable surge of interest amongst both string theorists and cosmologists in exploring the potential overlap of these two fields, and the variety of new ideas which have been generated, the field is still in its infancy and it requires refinement and clarification of the methodology.
The above choice of topics reflects the most important string theoretic issues that emerged from our very successful workshop on string cosmology at the Aspen Center for Physics, in August and September of 2002. The Aspen meeting had a larger phenomenological component than the one presently being proposed, so the proposed BIRS workshop will be complementary.
One measure of the importance of this workshop is the quality of people who have agreed in principle to participate, as enumerated below. They include many of the most highly recognized researchers in modern string theory and early universe cosmology. We are confident that the dialog which occurs at this meeting will positively influence the development of this rapidly progressing field of mathematical physics.
Given the rapid pace of evolution in this interdisciplinary field between mathematical physics and cosmology, the time is right to provide a forum to summarize the different paradigms of string cosmology, to clearly formulate the outstanding challenges, and to outline the most promising avenues to address them. The organizers have in mind to produce a document which will summarize the outcome of this discussion. As of now, no such written account exists which coherently defines the field of string cosmology, and the time is right to create such a reference. The experts in the field who attend the workshop will be asked to contribute. Several publishers have already expressed interest in this idea.