TY - JOUR
T1 - Self-interacting dark radiation
AU - Jeong, Kwang Sik
AU - Takahashi, Fuminobu
N1 - Funding Information:
F.T. thanks Tsutomu Yanagida for communication. This work was supported by Grant-in-Aid for Scientific Research (C) (No. 23540283 ) [K.S.J.], S cientific Research on Innovative Areas (No. 24111702 [F.T.], No. 21111006 [F.T.], and No. 23104008 [K.S.J. and F.T.]), Scientific Research (A) (No. 22244030 and No. 21244033 ) [F.T.], and JSPS Grant-in-Aid for Young Scientists (B) (No. 24740135 ) [F.T.], and Inoue Foundation for Science [F.T.]. This work was also supported by World Premier International Center Initiative (WPI Program) , MEXT , Japan [F.T.].
PY - 2013
Y1 - 2013
N2 - We consider a simple class of models where dark radiation has self-interactions and therefore does not free stream. Such dark radiation has no anisotropic stress (or viscosity), leaving a distinct signature on the CMB angular power spectrum. Specifically we study a possibility that hidden gauge bosons and/or chiral fermions account for the excess of the effective number of neutrino species. They have gauge interactions and remain light due to the unbroken hidden gauge symmetry, leading to δNeff≃0.29 in some case.
AB - We consider a simple class of models where dark radiation has self-interactions and therefore does not free stream. Such dark radiation has no anisotropic stress (or viscosity), leaving a distinct signature on the CMB angular power spectrum. Specifically we study a possibility that hidden gauge bosons and/or chiral fermions account for the excess of the effective number of neutrino species. They have gauge interactions and remain light due to the unbroken hidden gauge symmetry, leading to δNeff≃0.29 in some case.
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U2 - 10.1016/j.physletb.2013.07.001
DO - 10.1016/j.physletb.2013.07.001
M3 - Article
AN - SCOPUS:84880703586
SN - 0370-2693
VL - 725
SP - 134
EP - 138
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
IS - 1-3
ER -