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Title: Universe without dark energy: Cosmic acceleration from dark matter-baryon interactions

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1366335
Grant/Contract Number:
SC0007968
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 95; Journal Issue: 12; Related Information: CHORUS Timestamp: 2017-06-23 22:11:37; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Berezhiani, Lasha, Khoury, Justin, and Wang, Junpu. Universe without dark energy: Cosmic acceleration from dark matter-baryon interactions. United States: N. p., 2017. Web. doi:10.1103/PhysRevD.95.123530.
Berezhiani, Lasha, Khoury, Justin, & Wang, Junpu. Universe without dark energy: Cosmic acceleration from dark matter-baryon interactions. United States. doi:10.1103/PhysRevD.95.123530.
Berezhiani, Lasha, Khoury, Justin, and Wang, Junpu. Fri . "Universe without dark energy: Cosmic acceleration from dark matter-baryon interactions". United States. doi:10.1103/PhysRevD.95.123530.
@article{osti_1366335,
title = {Universe without dark energy: Cosmic acceleration from dark matter-baryon interactions},
author = {Berezhiani, Lasha and Khoury, Justin and Wang, Junpu},
abstractNote = {},
doi = {10.1103/PhysRevD.95.123530},
journal = {Physical Review D},
number = 12,
volume = 95,
place = {United States},
year = {Fri Jun 23 00:00:00 EDT 2017},
month = {Fri Jun 23 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 23, 2018
Publisher's Accepted Manuscript

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

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  • The similar cosmological abundances observed for visible and dark matter suggest a common origin for both. By viewing the dark matter density as a dark-sector asymmetry, mirroring the situation in the visible sector, we show that the visible and dark matter asymmetries may have arisen simultaneously through a first-order phase transition in the early universe. The dark asymmetry can then be equal and opposite to the usual visible matter asymmetry, leading to a universe that is symmetric with respect to a generalised baryon number. We present both a general structure, and a precisely defined example of a viable model ofmore » this type. In that example, the dark matter is ''atomic'' as well as asymmetric, and various cosmological and astrophysical constraints are derived. Testable consequences for colliders include a Z' boson that couples through the B−L charge to the visible sector, but also decays invisibly to dark sector particles. The additional scalar particles in the theory can mix with the standard Higgs boson and provide other striking signatures.« less
  • The similar cosmological abundances observed for visible and dark matter suggest a common origin for both. By viewing the dark matter density as a dark-sector asymmetry, mirroring the situation in the visible sector, we show that the visible and dark matter asymmetries may have arisen simultaneously through a first-order phase transition in the early universe. The additional scalar particles in the theory can mix with the standard Higgs boson and provide other striking signatures.
  • We elaborate on the proposal that the observed acceleration of the Universe is the result of the backreaction of cosmological perturbations, rather than the effect of a negative-pressure dark energy fluid or a modification of general relativity. Through the effective Friedmann equations describing an inhomogeneous Universe after smoothing, we demonstrate that acceleration in our local Hubble patch is possible even if fluid elements do not individually undergo accelerated expansion. This invalidates the no-go theorem that there can be no acceleration in our local Hubble patch if the Universe only contains irrotational dust. We then study perturbatively the time behavior ofmore » general-relativistic cosmological perturbations, applying, where possible, the renormalization group to regularize the dynamics. We show that an instability occurs in the perturbative expansion involving sub-Hubble modes, which indicates that acceleration in our Hubble patch may originate from the backreaction of cosmological perturbations on observable scales.« less
  • A cosmic scenario with gravitationally induced particle creation is proposed. In this model the Universe evolves from an early to a late time de Sitter era, with the recent accelerating phase driven only by the negative creation pressure associated with the cold dark matter component. The model can be interpreted as an attempt to reduce the so-called cosmic sector (dark matter plus dark energy) and relate the two cosmic accelerating phases (early and late time de Sitter expansions). A detailed thermodynamic analysis including possible quantum corrections is also carried out. For a very wide range of the free parameters, itmore » is found that the model presents the expected behavior of an ordinary macroscopic system in the sense that it approaches thermodynamic equilibrium in the long run (i.e., as it nears the second de Sitter phase). Moreover, an upper bound is found for the Gibbons–Hawking temperature of the primordial de Sitter phase. Finally, when confronted with the recent observational data, the current 'quasi'-de Sitter era, as predicted by the model, is seen to pass very comfortably the cosmic background tests.« less
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