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arXiv · 1905.09836

Misalignment & Co.: (Pseudo-)scalar and vector dark matter with curvature couplings

Gonzalo Alonso Álvarez·Joerg Jaeckel·Thomas Hugle
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Abstract

Motivated by their potential role as dark matter, we study the cosmological evolution of light scalar and vector fields non-minimally coupled to gravity. Our focus is on a situation where the dominant contribution to the energy density arises from the misalignment mechanism. In addition, we also discuss the possibility that dark matter is generated in a stochastic scenario or from inflationary fluctuations. Even small deviations in the non-minimal couplings from the standard scenarios lead to significant qualitative and quantitative changes. This is due to the curvature-coupling driven superhorizon evolution of the homogeneous field and the non-zero momentum modes during inflation. Both the relic density yield and the large-scale density fluctuations are affected. For the misalignment mechanism, this results in a weakening of the isocurvature constraints and opens up new viable regions of parameter space.

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Gonzalo Alonso Álvarez, Joerg Jaeckel, Thomas Hugle. 2019-05-23. Misalignment & Co.: (Pseudo-)scalar and vector dark matter with curvature couplings. https://doi.org/10.1088/1475-7516%2F2020%2F02%2F014

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