Bimetric gravity is cosmologically viable

被引：128

作者：

Akrami, Yashar ^{[1
,2
,3
]}

Hassan, S. F. ^{[1
,2
,4
,5
]}

Koennig, Frank ^{[1
,2
,3
]}

Schmidt-May, Angnis ^{[1
,2
,6
]}

Solomon, Adam R. ^{[1
,2
,3
,7
]}

机构：

[1] KTH Royal Inst Technol, NORDITA, SE-10691 Stockholm, Sweden

[2] Stockholm Univ, SE-10691 Stockholm, Sweden

[3] Heidelberg Univ, Inst Theoret Phys, D-69120 Heidelberg, Germany

[4] Stockholm Univ, AlbaNova Univ Ctr, Dept Phys, SE-10691 Stockholm, Sweden

[5] Stockholm Univ, AlbaNova Univ Ctr, Oskar Klein Ctr, SE-10691 Stockholm, Sweden

[6] ETH, Inst Theoret Phys, CH-8093 Zurich, Switzerland

[7] Univ Cambridge, Ctr Math Sci, DAMTP, Cambridge CB3 0WA, England

来源：

PHYSICS LETTERS B | 2015年 / 748卷

基金：

瑞士国家科学基金会;

关键词：

Modified gravity; Massive gravity; Background cosmology; Cosmic acceleration; Dark energy; Bimetric gravity; Bigravity; FIELD-THEORY;

D O I：

10.1016/j.physletb.2015.06.062

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Bimetric theory describes gravitational interactions in the presence of an extra spin-2 field. Previous work has suggested that its cosmological solutions are generically plagued by instabilities. We show that by taking the Planck mass for the second metric, M-f, to be small, these instabilities can be pushed back to unobservably early times. In this limit, the theory approaches general relativity with an effective cosmological constant which is, remarkably, determined by the spin-2 interaction scale. This provides a late-time expansion history which is extremely close to Lambda CDM, but with a technically-natural value for the cosmological constant. We find M-f should be no larger than the electroweak scale in order for cosmological perturbations to be stable by big-bang nucleosynthesis. We further show that in this limit the helicity-0 mode is no longer strongly-coupled at low energy scales. (C) 2015 The Authors. Published by Elsevier B.V.

引用

页码：37 / 44

页数：8

共 81 条

[1] The nature of spacetime in bigravity: Two metrics or none? [J].