Constraints on anharmonic corrections of fuzzy dark matter

• Published in: The journal of high energy physics 2018-08, Vol.2018 (8), p.1-22, Article 73
• Main Authors: Cembranos, J. A. R., Maroto, A. L., Núñez Jareño, S. J., Villarrubia-Rojo, H.
• Format: Article
• Language: English
• Subjects: Anharmonicity; Beyond Standard Model; Classical and Quantum Gravitation; Cold dark matter; Constraint modelling; Cosmology; Cosmology of Theories beyond the SM; Dark matter; Elementary Particles; High energy physics; Large scale structure of the universe; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; String Theory
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP08(2018)073

A bstract The cold dark matter (CDM) scenario has proved successful in cosmology. However, we lack a fundamental understanding of its microscopic nature. Moreover, the apparent disagreement between CDM predictions and subgalactic-structure observations has prompted the debate about its behaviour at small scales. These problems could be alleviated if the dark matter is composed of ultralight fields m ∼ 10 −22 eV, usually known as fuzzy dark matter (FDM). Some specific models, with axion-like potentials, have been thoroughly studied and are collectively referred to as ultralight axions (ULAs) or axion-like particles (ALPs). In this work we consider anharmonic corrections to the mass term coming from a repulsive quartic self-interaction. Whenever this anharmonic term dominates, the field behaves as radiation instead of cold matter, modifying the time of matter-radiation equality. Additionally, even for high masses, i.e. masses that reproduce the cold matter behaviour, the presence of anharmonic terms introduce a cut-off in the matter power spectrum through its contribution to the sound speed. We analyze the model and derive constraints using a modified version of class and comparing with CMB and large-scale structure data.