Observational constraints on cosmic string production during brane inflation

Apr, 2003
16 pages
Published in:
  • Phys.Rev.D 68 (2003) 023506,
  • Phys.Rev.D 73 (2006) 089904 (erratum)
e-Print:

Citations per year

200320092015202120250510152025
Abstract: (arXiv)
Overall, brane inflation is compatible with the recent analysis of the WMAP data. Here we explore the constraints of WMAP and 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 non-negligible contribution from cosmic strings definitively. We perform a partial statistical analysis of mixed models that include a sub-dominant contribution from cosmic strings. Although the data favor models without cosmic strings, we conclude that they cannot definitively rule out a cosmic-string-induced contribution of 10\sim 10 % to the observed temperature, polarization and galaxy density fluctuations. These results imply that Gμ3.5×107(λ/0.25)B/0.1G\mu \lesssim 3.5\times 10^{-7}(\lambda/0.25)\sqrt{B/0.1}, where λ\lambda is a dimensionless parameter related to the interstring distance, and BB measures the importance of perturbations induced by cosmic strings. We argue that, conservatively, the data available currently still permit B0.1B\lesssim 0.1. Precision measurements sensitive to the B-mode polarization produced by vector density perturbation modes driven by the string network could provide evidence for these models. Accurate determinations of ns(k)n_s(k), the scalar fluctuation index, could also distinguish among various brane inflation models.
Note:
  • 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 B-mode polarization. Details of the corrected errors and their implications can be found in astro-ph/0604141
  • 98.80.Cq
  • astrophysics: string
  • inflation
  • membrane model
  • cosmic background radiation
  • cosmic radiation: polarization
  • statistical analysis
  • perturbation: adiabatic
  • numerical calculations: interpretation of experiments