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Long-lived Light Mediator to Dark Matter and Primordial Small Scale Spectrum

Zhang, Yue (2015) Long-lived Light Mediator to Dark Matter and Primordial Small Scale Spectrum. Journal of Cosmology and Astroparticle Physics, 2015 (5). Art. No. 008. ISSN 1475-7516. doi:10.1088/1475-7516/2015/05/008.

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We calculate the early universe evolution of perturbations in the dark matter energy density in the context of simple dark sector models containing a GeV scale light mediator. We consider the case that the mediator is long lived, with lifetime up to a second, and before decaying it temporarily dominates the energy density of the universe. We show that for primordial perturbations that enter the horizon around this period, the interplay between linear growth during matter domination and collisional damping can generically lead to a sharp peak in the spectrum of dark matter density perturbation. As a result, the population of the smallest DM halos gets enhanced. Possible implications of this scenario are discussed.

Item Type:Article
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Additional Information:© 2015 IOP Publishing. Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received March 11, 2015. Accepted April 15, 2015. Published May 6, 2015. We thank Sean Carroll, Clifford Cheung, Francis Yan Cyr-Racine, Hooman Davoudiasl, Jonathan Feng, Michael Graesser, Hong-Jian He, Goran Senjanovic, Tim Tait, Mark Wise, Hai-bo Yu for useful discussions and comments on the draft. This work is supported by the Gordon and Betty Moore Foundation through Grant #776 to the Caltech Moore Center for Theoretical Cosmology and Physics, and by the DOE Grant DE-FG02-92ER40701, and also by a DOE Early Career Award under Grant No. DE-SC0010255.
Group:Walter Burke Institute for Theoretical Physics, Moore Center for Theoretical Cosmology and Physics
Funding AgencyGrant Number
Gordon and Betty Moore Foundation776
Department of Energy (DOE)DE-FG02-92ER40701
Department of Energy (DOE)DE-SC0010255
Subject Keywords:power spectrum, dark matter theory, particle physics - cosmology connection, cosmological perturbation theory
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Issue or Number:5
Classification Code:PACS: 95.35.+d; 98.80.Cq
Record Number:CaltechAUTHORS:20150324-084840570
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Official Citation:Long-lived light mediator to dark matter and primordial small scale spectrum Yue Zhang JCAP05(2015)008
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:56003
Deposited By: Joy Painter
Deposited On:24 Mar 2015 16:07
Last Modified:12 Jul 2022 17:36

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