Skewness in CMB temperature fluctuations from curved cosmic (super-)strings

Daisuke Yamauchi, Yuuiti Sendouda, Chul-Moon Yoo, Keitaro Takahashi, Atsushi Naruko, Misao Sasaki

We compute the one-point probability distribution function of small-angle cosmic microwave background temperature fluctuations due to curved cosmic (super-)strings with a simple model of string network by performing Monte Carlo simulations. Taking into account of the correlation between the curvature and the velocity of string segments, there appear non-Gaussian features, specifically non-Gaussian tails and a skewness, in the one-point pdf. The obtained sample skewness for the conventional field-theoretic cosmic strings is g1 ≈ −0.14, which is consistent with the result reported by Fraisse et al. We also discuss the dependence of the pdf on the intercommuting probability. We find that the standard deviation of the Gaussian part increases and non-Gaussian features are suppressed as the intercommuting probability decreases. For sufficiently small intercommuting probability, the skewness is given by ≲ (a few) × 10−2.

Journal of Cosmology and Astroparticle Physics

05

033

10.1088/1475-7516/2010/05/033

1004.0600