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arXiv · 1012.5502

Improved estimation of radiated axions from cosmological axionic strings

Takashi Hiramatsu·Masahiro Kawasaki·Toyokazu Sekiguchi·Masahide Yamaguchi·Jun'ichi Yokoyama
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Abstract

Cosmological evolution of axionic string network is analyzed in terms of field-theoretic simulations in a box of 512^3 grids, which are the largest ever, using a new and more efficient identification scheme of global strings. The scaling parameter is found to be ξ=0.87 +- 0.14 in agreement with previous results. The energy spectrum is calculated precisely using a pseudo power spectrum estimator which significantly reduces the error in the mean reciprocal comoving momentum. The resultant constraint on the axion decay constant leads to f_a <= 3*10^11 GeV. We also discuss implications for the early Universe.

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Takashi Hiramatsu, Masahiro Kawasaki, Toyokazu Sekiguchi, Masahide Yamaguchi, Jun'ichi Yokoyama. 2011-06-29. Improved estimation of radiated axions from cosmological axionic strings. https://doi.org/10.1103/physrevd.83.123531

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