Bounds on cosmic strings from WMAP and SDSS

We find the constraints from Wilkinson microwave anisotropy probe (WMAP) and Sloan digital sky survey (SDSS) data on the fraction of cosmological fluctuations sourced by local cosmic strings using a Markov Chain Monte Carlo (MCMC) analysis. In addition to varying the usual 6 cosmological parameters and the string tension (mu), we also varied the amount of small-scale structure on the strings. Our results indicate that cosmic strings can account for up to 7 (14)% of the total power of the microwave anisotropy at 68 (95)% confidence level. The corresponding bound on the string mass per unit length, within our string model, is G mu < 3.4(5)x10(-7) at 68 (95)% C.L. We also calculate the B-type polarization spectra sourced by cosmic strings and discuss the prospects of their detection.