TY - JOUR

T1 - Black holes in quartic-order beyond-generalized Proca theories

AU - Kase, Ryotaro

AU - Minamitsuji, Masato

AU - Tsujikawa, Shinji

N1 - Funding Information:
We thank Ying-li Zhang for useful discussions. RK is supported by the Grant-in-Aid for Young Scientists B of the JSPS No. 17K14297 . MM is supported by FCT-Portugal through Grant No. SFRH/BPD/88299/2012 . ST is supported by the Grant-in-Aid for Scientific Research Fund of the JSPS No. 16K05359 and MEXT KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas “Cosmic Acceleration” (No. 15H05890 ). MM thanks Tokyo University of Science for kind hospitality at the early stage of this work. RK and ST appreciate CENTRA for warm hospitality at the final stage of this work.
Publisher Copyright:
© 2018 The Author(s)

PY - 2018/7/10

Y1 - 2018/7/10

N2 - The generalized Proca theories with second-order equations of motion can be healthily extended to a more general framework in which the number of propagating degrees of freedom remains unchanged. In the presence of a quartic-order nonminimal coupling to gravity arising in beyond-generalized Proca theories, the speed of gravitational waves ct on the Friedmann–Lemaître–Robertson–Walker (FLRW) cosmological background can be equal to that of light c under a certain condition. By using this condition alone, we show that the speed of gravitational waves in the vicinity of static and spherically symmetric black holes is also equivalent to c for the propagation of odd-parity perturbations along both radial and angular directions. As a by-product, the black holes arising in our beyond-generalized Proca theories are plagued by neither ghost nor Laplacian instabilities against odd-parity perturbations. We show the existence of both exact and numerical black hole solutions endowed with vector hairs induced by the quartic-order coupling.

AB - The generalized Proca theories with second-order equations of motion can be healthily extended to a more general framework in which the number of propagating degrees of freedom remains unchanged. In the presence of a quartic-order nonminimal coupling to gravity arising in beyond-generalized Proca theories, the speed of gravitational waves ct on the Friedmann–Lemaître–Robertson–Walker (FLRW) cosmological background can be equal to that of light c under a certain condition. By using this condition alone, we show that the speed of gravitational waves in the vicinity of static and spherically symmetric black holes is also equivalent to c for the propagation of odd-parity perturbations along both radial and angular directions. As a by-product, the black holes arising in our beyond-generalized Proca theories are plagued by neither ghost nor Laplacian instabilities against odd-parity perturbations. We show the existence of both exact and numerical black hole solutions endowed with vector hairs induced by the quartic-order coupling.

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U2 - 10.1016/j.physletb.2018.05.078

DO - 10.1016/j.physletb.2018.05.078

M3 - Article

AN - SCOPUS:85048528156

VL - 782

SP - 541

EP - 550

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

SN - 0370-2693

ER -