Observational constraints on cosmic string production during brane inflation
Abstract
Overall, brane inflation is compatible with the recent analysis of the Wilkinson microwave anisotropy probe (WMAP) data. Here we explore the constraints of WMAP and the 2dF Galaxy Redshift Survey (2dFGRS) data on the various brane inflationary scenarios. Brane inflation naturally ends with the production of cosmic strings, which may provide a way to distinguish these models observationally. We argue that currently available data cannot exclude a nonnegligible contribution from cosmic strings definitively. We perform a partial statistical analysis of mixed models that include a subdominant contribution from cosmic strings. Although the data favor models without cosmic strings, we conclude that they cannot definitively rule out a cosmicstringinduced contribution of ̃10% to the observed temperature, polarization and galaxy density fluctuations. These results imply that Gμ≲1.3×10^{6}(Bλ/0.1), where λ⩽1 is a measure of the intercommutation probability of the cosmic string networks and B measures the importance of perturbations induced by cosmic strings. We argue that, conservatively, the data available currently still permit B≲0.1. Precision measurements sensitive to the Bmode polarization produced by vector density perturbation modes driven by the string network could provide evidence for these models. Accurate determinations of n_{s}(k), the scalar fluctuation index, could also distinguish among various brane inflation models.
 Publication:

Physical Review D
 Pub Date:
 July 2003
 DOI:
 10.1103/PhysRevD.68.023506
 arXiv:
 arXiv:hepth/0304188
 Bibcode:
 2003PhRvD..68b3506P
 Keywords:

 98.80.Cq;
 Particletheory and fieldtheory models of the early Universe;
 High Energy Physics  Theory;
 Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology
 EPrint:
 16 pages, 4 figures. A few errors in the computer code used to calculated CMB anistotropy from strings are fixed, resulting in a somewhat tighter bound on G\mu and an enhanced Bmode polarization. Details of the corrected errors and their implications can be found in astroph/0604141