TY - JOUR

T1 - Structure formation in a string-inspired modification of the cold dark matter model

AU - Gubser, Steven S.

AU - Peebles, P. J.E.

N1 - Funding Information:
We are grateful to Neal Dalal, Glennys Farrar, David Lyth, Indrajit Mitra, and Scott Watson for useful discussions, and to Robert Brandenberger for commenting on a draft of the manuscript. The work of SSG was supported in part by the Department of Energy under Grant No. DE-FG02-91ER40671, and by the Sloan Foundation. SSG also thanks the KITP at UCSB for hospitality; his work there on this paper was supported in part by the National Science Foundation under Grant No. PHY99-07949.

PY - 2004/12

Y1 - 2004/12

N2 - Motivated in part by string theory, we consider the idea that the standard ACDM cosmological model might be modified by the effect of a long-range scalar dark matter interaction. The variant of this widely-discussed notion considered here is suggested by the Brandenberger-Vafa [R. H. Brandenberger and C. Vafa, Nucl. Phys. B316, 391 (1989).] picture for why we perceive three spatial dimensions. In this picture there may be at least two species of dark matter particles, with scalar charges such that the scalar interaction attracts particles with like sign and repels unlike signs. The net charge vanishes. Under this condition the evolution of the mass distribution in linear perturbation theory is the same as in the ACDM cosmology, and both models therefore can equally well pass the available cosmological tests. The physics can be very different on small scales, however: if the scalar interaction has the strength suggested by simple versions of the string scenario, nonlinear mass concentrations are unstable against separation into charged halos with properties unlike the standard model prediction and possibly of observational interest.

AB - Motivated in part by string theory, we consider the idea that the standard ACDM cosmological model might be modified by the effect of a long-range scalar dark matter interaction. The variant of this widely-discussed notion considered here is suggested by the Brandenberger-Vafa [R. H. Brandenberger and C. Vafa, Nucl. Phys. B316, 391 (1989).] picture for why we perceive three spatial dimensions. In this picture there may be at least two species of dark matter particles, with scalar charges such that the scalar interaction attracts particles with like sign and repels unlike signs. The net charge vanishes. Under this condition the evolution of the mass distribution in linear perturbation theory is the same as in the ACDM cosmology, and both models therefore can equally well pass the available cosmological tests. The physics can be very different on small scales, however: if the scalar interaction has the strength suggested by simple versions of the string scenario, nonlinear mass concentrations are unstable against separation into charged halos with properties unlike the standard model prediction and possibly of observational interest.

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U2 - 10.1103/PhysRevD.70.123510

DO - 10.1103/PhysRevD.70.123510

M3 - Article

AN - SCOPUS:19944432876

SN - 0556-2821

VL - 70

SP - 123510-1-123510-14

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

IS - 12

M1 - 123510

ER -