A resolution of the cosmological singularity with orientifolds

• Type: Article in International Scientific Journal
• Date: 2002

Authors

Cornalba, L (Author) Other; Costa, MS (Author) FCUP; Kounnas, C (Author) Other

Journal

Title: Nuclear Physics B

Vol. 637

Pages: 378-394

ISSN: 0550-3213

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 120 Citations

Scopus - 118 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-007-AHQ

DOI: 10.1016/s0550-3213(02)00446-7

Abstract (EN): We propose a new cosmological scenario which resolves the conventional initial singularity problem. The space-time geometry has an unconventional time-like singularity on a lower-dimensional hypersurface, with localized energy density. The natural interpretation of this singularity in string theory is that of negative tension branes, for example the orientifolds of type II string theory. Space-time ends at the orientifolds, and it is divided in three regions: a contracting region with a future cosmological horizon; an intermediate region which ends at the orientifols; and an expanding region separated from the intermediate region by a past cosmological horizon. We study the geometry near the singularity of the proposed cosmological scenario in a specific string model. Using D-brane probes we confirm the interpretation of the brane singularity as an orientifold. The boundary conditions on the orientifolds and the past/future transition amplitudes are well defined. Assuming the trivial vacuum in the past, we derive a thermal spectrum in the future.

Language: English

Type (Professor's evaluation): Scientific