Change search
ReferencesLink to record
Permanent link

Direct link
Higuchi ghosts and gradient instabilities in bimetric gravity
KTH. Ruprecht-Karls-Universität Heidelberg, Germany.
2015 (English)In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 91, no 10, 104019Article in journal (Refereed) Published
Abstract [en]

Bimetric gravity theories allow for many different types of cosmological solutions, but not all of them are theoretically allowed. In this work we discuss the conditions to satisfy the Higuchi bound and to avoid gradient instabilities in the scalar sector at the linear level. We find that in expanding universes the ratio of the scale factors of the reference and observable metric has to increase at all times. This automatically implies a ghost-free helicity-2 and helicity-0 sector and enforces a phantom dark energy. Furthermore, the condition for the absence of gradient instabilities in the scalar sector will be analyzed. Finally, we discuss whether cosmological solutions can exist, including exotic evolutions like bouncing cosmologies, in which both the Higuchi ghost and scalar instabilities are absent at all times.

Place, publisher, year, edition, pages
American Physical Society , 2015. Vol. 91, no 10, 104019
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:kth:diva-177763DOI: 10.1103/PhysRevD.91.104019ISI: 000354979300005ScopusID: 2-s2.0-84934880974OAI: diva2:874974

QC 20151130

Available from: 2015-11-30 Created: 2015-11-25 Last updated: 2015-11-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus
By organisation
In the same journal
Physical Review D
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 5 hits
ReferencesLink to record
Permanent link

Direct link