Cosmic expansion histories in massive bigravity with symmetric matter coupling

Journal Article · Thu Jan 01 00:00:00 EST 2015 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2015/01/006· OSTI ID:22382044

Enander, Jonas; Mörtsell, Edvard ^[1]; Solomon, Adam R. ^[2]; Akrami, Yashar ^[3]

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1. Oskar Klein Center, Stockholm University, Albanova University Center, 106 91 Stockholm (Sweden)
2. DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Rd., Cambridge CB3 0WA (United Kingdom)
3. Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)

We study the cosmic expansion history of massive bigravity with a viable matter coupling which treats both metrics on equal footing. We derive the Friedmann equation for the effective metric through which matter couples to the two metrics, and study its solutions. For certain parameter choices, the background cosmology is identical to that of ΛCDM. More general parameters yield dynamical dark energy, which can still be in agreement with observations of the expansion history. We study specific parameter choices of interest, including minimal models, maximally-symmetric models, and a candidate partially-massless theory.

• OSTI ID: 22382044
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2015, Issue 01; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMOLOGY
COUPLING
EQUATIONS
EXPANSION
METRICS
NONLUMINOUS MATTER
SYMMETRY