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Title: Partially acoustic dark matter, interacting dark radiation, and large scale structure

The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H 0 and the matter density perturbation σ 8 inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ 8 problem, while the presence of tightly coupled dark radiation ameliorates the H 0 problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experimentsmore » designed to probe the CMB and large scale structure.« less
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [1]
  1. Univ. of Maryland, College Park, MD (United States). Dept. of Physics. Maryland Center for Fundamental Physics
  2. Univ. of Maryland, College Park, MD (United States). Dept. of Physics. Maryland Center for Fundamental Physics; Univ. of California, Riverside, CA (United States). Dept. of Physics and Astronomy; Perimeter Inst., North Waterloo, ON (Canada)
  3. Florida State Univ., Tallahassee, FL (United States). Dept. of Physics
Publication Date:
Grant/Contract Number:
SC0010102; PHY-1315155; PHY-1066293
Type:
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2016; Journal Issue: 12; Journal ID: ISSN 1029-8479
Publisher:
Springer Berlin
Research Org:
Florida State Univ., Tallahassee, FL (United States); Univ. of Maryland, College Park, MD (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); National Science Foundation (NSF)
Contributing Orgs:
Univ. of California, Riverside, CA (United States); Perimeter Inst., North Waterloo, ON (Canada)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Cosmology of Theories beyond the SM; Beyond Standard Model
OSTI Identifier:
1368037

Chacko, Zackaria, Cui, Yanou, Hong, Sungwoo, Okui, Takemichi, and Tsai, Yuhsinz. Partially acoustic dark matter, interacting dark radiation, and large scale structure. United States: N. p., Web. doi:10.1007/JHEP12(2016)108.
Chacko, Zackaria, Cui, Yanou, Hong, Sungwoo, Okui, Takemichi, & Tsai, Yuhsinz. Partially acoustic dark matter, interacting dark radiation, and large scale structure. United States. doi:10.1007/JHEP12(2016)108.
Chacko, Zackaria, Cui, Yanou, Hong, Sungwoo, Okui, Takemichi, and Tsai, Yuhsinz. 2016. "Partially acoustic dark matter, interacting dark radiation, and large scale structure". United States. doi:10.1007/JHEP12(2016)108. https://www.osti.gov/servlets/purl/1368037.
@article{osti_1368037,
title = {Partially acoustic dark matter, interacting dark radiation, and large scale structure},
author = {Chacko, Zackaria and Cui, Yanou and Hong, Sungwoo and Okui, Takemichi and Tsai, Yuhsinz},
abstractNote = {The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H0 and the matter density perturbation σ8 inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ8 problem, while the presence of tightly coupled dark radiation ameliorates the H0 problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experiments designed to probe the CMB and large scale structure.},
doi = {10.1007/JHEP12(2016)108},
journal = {Journal of High Energy Physics (Online)},
number = 12,
volume = 2016,
place = {United States},
year = {2016},
month = {12}
}