Cosmological implications of a dark matter self-interaction energy density

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.123513· OSTI ID:21408047

Stiele, Rainer ^[1]; Boeckel, Tillmann; Schaffner-Bielich, Juergen ^[1]

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1. Institute for Theoretical Physics, Heidelberg University, Philosophenweg 16, D-69120 Heidelberg (Germany)

We investigate cosmological constraints on an energy density contribution of elastic dark matter self-interactions characterized by the mass of the exchange particle m{sub SI} and coupling constant {alpha}{sub SI}. 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 ({rho}{sub SI{proportional_to}}a{sup -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 m{sub SI}/{radical}({alpha}{sub SI}), 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 ({sigma}{sub A}{sup SIDM}<<{sigma}{sub weak}) and that the natural scale of collisionless cold dark matter decoupling exceeds the weak scale ({sigma}{sub A}{sup CDM}>{sigma}{sub weak}) and depends linearly on the particle mass. Finally structure formation analysis reveals a linear growing solution during self-interaction domination ({delta}{proportional_to}a); however, only noncosmological scales are enhanced.

• OSTI ID: 21408047
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 12; Other Information: DOI: 10.1103/PhysRevD.81.123513; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BARYONS
COSMOLOGICAL MODELS
COUPLING CONSTANTS
DECOUPLING
ENERGY DENSITY
EXPANSION
MASS
MATHEMATICAL SOLUTIONS
METRICS
NONLUMINOUS MATTER
NUCLEOSYNTHESIS
SCALING
STRONG INTERACTIONS
UNIVERSE
BASIC INTERACTIONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
INTERACTIONS
MATHEMATICAL MODELS
MATTER
SYNTHESIS