We use our model of the small scale structure on cosmic strings to develop further the result of Siemens, Olum, and Vilenkin that the gravitational radiation length scale on cosmic strings is smaller than the previously assumed ΓGμt. We discuss some of the properties of cosmic string loops at this cutoff scale, and we argue that recent network simulations point to two populations of cosmic stri...

We investigate large-angle anisotropies in the cosmic microwave radiation background which are induced by cosmic strings. We numerically evolve a string network from a redshift Z=100 to the present day and we use this data to generate a full-sky temperature map using sophisticated Green's function methods. Based on a limited number of realizations, we have compared the results of our simulation...

We have searched the 1st-year WMAP W-Band CMB anisotropy map for evidence of cosmic strings. We have set a limit of δ = 8πGμ/c < 8.2× 10 at 95% CL for statistical search for a significant number of strings in the map. We also have set a limit using the uniform distribution of strings model in the WMAP data with δ = 8πGμ/c < 7.34 × 10 at 95% CL. And the pattern search technique we developed here...

We study the effect of free streaming in a universe with cosmic strings with timevarying tension as well as with constant tension. Although current cosmological observations suggest that fluctuation seeded by cosmic strings cannot be the primary source of cosmic density fluctuation, some contributions from them are still allowed. Since cosmic strings actively produce isocurvature fluctuation, t...

We study Dirac-Born-Infeld type effective field theory of a complex tachyon and U(1)×U(1) gauge fields describing a D3D̄3 system. Classical solutions of straight global and local DFstrings with quantized vorticity are found and are classified into two types by the asymptotic behavior of the tachyon amplitude. For sufficiently large radial distances, one has linearlygrowing tachyon amplitude and ...