Cosmological implications of a dark matter self-interaction energy density

• Verfasst von: Stiele, Rainer [VerfasserIn]
• Verfasst von: Boeckel, Moritz Tillmann [VerfasserIn]
• Verfasst von: Schaffner-Bielich, Jürgen [VerfasserIn]
• Titel: Cosmological implications of a dark matter self-interaction energy density
• Verf.angabe: Rainer Stiele, Tillmann Boeckel, and Jürgen Schaffner-Bielich
• E-Jahr: 2010
• Jahr: 14 June 2010
• Umfang: 14 S.
• Fussnoten: Gesehen am 01.12.2023
• Titel Quelle: Enthalten in: Physical review / D
• Ort Quelle: [S.l.] : Soc., 1970
• Jahr Quelle: 2010
• Band/Heft Quelle: 81(2010), 12, Artikel-ID 123513, Seite 1-14
• ISSN Quelle: 1550-2368
• ISSN Quelle: 1089-4918
• DOI: doi:10.1103/PhysRevD.81.123513
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1871787416

Abstract

We investigate cosmological constraints on an energy density contribution of elastic dark matter self-interactions characterized by the mass of the exchange particle mSI and coupling constant αSI. Because of the expansion behavior in a Robertson-Walker metric we investigate self-interacting dark matter that is warm in the case of thermal relics. The scaling behavior of dark matter self-interaction energy density (ϱSI∝a−6) shows that it can be the dominant contribution (only) in the very early universe. Thus its impact on primordial nucleosynthesis is used to restrict the interaction strength mSI/√αSI, which we find to be at least as strong as the strong interaction. Furthermore we explore dark matter decoupling in a self-interaction dominated universe, which is done for the self-interacting warm dark matter as well as for collisionless cold dark matter in a two component scenario. We find that strong dark matter self-interactions do not contradict superweak inelastic interactions between self-interacting dark matter and baryonic matter (σSIDMA≪σweak) and that the natural scale of collisionless cold dark matter decoupling exceeds the weak scale (σCDMA>σweak) and depends linearly on the particle mass. Finally structure formation analysis reveals a linear growing solution during self-interaction domination (δ∝a); however, only noncosmological scales are enhanced.