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arXiv · 0901.1106

Bose-Einstein Condensation of Dark Matter Axions

P. Sikivie·Q. Yang
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Abstract

We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.

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P. Sikivie, Q. Yang. 2009-09-02. Bose-Einstein Condensation of Dark Matter Axions. https://doi.org/10.1103/physrevlett.103.111301

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