Scientific article
Open access

Loop corrections and graceful exit in string cosmology

Published inNuclear physics. B, vol. 552, p. 395-419
Publication date1999

We examine the effect of perturbative string loops on the cosmological pre-big-bang evolution. We study loop corrections derived from heterotic string theory compactified on a $Z_N$ orbifold and we consider the effect of the all-order loop corrections to the Kahler potential and of the corrections to gravitational couplings, including both threshold corrections and corrections due to the mixed Kahler-gravitational anomaly. We find that string loops can drive the evolution into the region of the parameter space where a graceful exit is in principle possible, and we find solutions that, in the string frame, connect smoothly the superinflationary pre-big-bang evolution to a phase where the curvature and the derivative of the dilaton are decreasing. We also find that at a critical coupling the loop corrections to the Kahler potential induce a ghost-like instability, i.e. the kinetic term of the dilaton vanishes. This is similar to what happens in Seiberg-Witten theory and signals the transition to a new regime where the light modes in the effective action are different and are related to the original ones by S-duality. In a string context, this means that we enter a D-brane dominated phase.

Citation (ISO format)
FOFFA, Stefano, MAGGIORE, Michele, STURANI, Riccardo. Loop corrections and graceful exit in string cosmology. In: Nuclear physics. B, 1999, vol. 552, p. 395–419. doi: 10.1016/S0550-3213(99)00248-5
Main files (1)
Article (Accepted version)
ISSN of the journal0550-3213

Technical informations

Creation07/07/2009 2:47:00 PM
First validation07/07/2009 2:47:00 PM
Update time03/14/2023 3:09:34 PM
Status update03/14/2023 3:09:34 PM
Last indexation10/17/2023 2:43:04 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack