TY - JOUR
T1 - Stable cosmological solutions in degenerate theory of gravity
AU - Kase, Ryotaro
AU - Kimura, Rampei
AU - Naruko, Atsushi
AU - Yoshida, Daisuke
N1 - Funding Information:
R. Kimura and D.Y. thank Masahide Yamaguchi for many useful comments and discussions. R. Kase and A.N. would like to thank the Yukawa Institute for Theoretical Physics at Kyoto University, where discussions during the YITP symposium YKIS2018a “General Relativity – The Next Generation” were useful to complete this work. This work was supported in part by JSPS Grant-in-Aid for Scientific Research Nos. JP17K14297 (R. Kase), JP17K14276 (R. Kimura), JP25287054 (R. Kimura) and JSPS Postdoctoral Fellowships for Research Abroad (D.Y.). A.N. is supported in part by a Japan Science and Technology Agency grant “Establishing a Consortium for the Development of Human Resources in Science and Technology”. The work of A.N. is also partly supported by the JSPS Grant-in-Aid for Scientific Research No. 16H01092.
Funding Information:
R. Kimura and D.Y. thank Masahide Yamaguchi for many useful comments and discussions. R. Kase and A.N. would like to thank the Yukawa Institute for Theoretical Physics at Kyoto University, where discussions during the YITP symposium YKIS2018a “General Relativity – The Next Generation” were useful to complete this work. This work was supported in part by JSPS Grant-in-Aid for Scientific Research Nos. JP17K14297 (R. Kase), JP17K14276 (R. Kimura), JP25287054 (R. Kimura) and JSPS Postdoctoral Fellowships for Research Abroad (D.Y.). A.N. is supported in part by a Japan Science and Technology Agency grant “Establishing a Consortium for the Development of Human Resources in Science and Technology”. The work of A.N. is also partly supported by the JSPS Grant-in-Aid for Scientific Research No. 16H01092 .
Publisher Copyright:
© 2018 The Authors
PY - 2018/8/10
Y1 - 2018/8/10
N2 - We study cosmological applications of extended vector–tensor theories, whose Lagrangians contain up to two derivatives with respect to metric and vector field. We derive background equations under the assumption of homogeneous and isotropic universe and study the nature of cosmological perturbations on top of the background. We found an example of healthy cosmological solutions in non-trivial degenerate theory of gravity for the first time, where those perturbations do not suffer from any instabilities, that is, ghost and gradient instabilities.
AB - We study cosmological applications of extended vector–tensor theories, whose Lagrangians contain up to two derivatives with respect to metric and vector field. We derive background equations under the assumption of homogeneous and isotropic universe and study the nature of cosmological perturbations on top of the background. We found an example of healthy cosmological solutions in non-trivial degenerate theory of gravity for the first time, where those perturbations do not suffer from any instabilities, that is, ghost and gradient instabilities.
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U2 - 10.1016/j.physletb.2018.07.009
DO - 10.1016/j.physletb.2018.07.009
M3 - Article
AN - SCOPUS:85051255380
SN - 0370-2693
VL - 783
SP - 320
EP - 325
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
ER -