Black holes in quartic-order beyond-generalized Proca theories

作者：Kase Ryotaro^*; Minamitsuji Masato; Tsujikawa Shinji

来源：Physics Letters B, 2018, 782: 541-550.

DOI：10.1016/j.physletb.2018.05.078

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 cton the Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological background can be equal to that of light cunder 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 cfor 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.

• 出版日期2018-7-10