Greybody factor and power spectra of the Hawking radiation in the 4D Einstein–Gauss–Bonnet de-Sitter gravity

Abstract

A novel 4D Einstein–Gauss–Bonnet gravity was recently formulated by Glavan and Lin [Phys. Rev. Lett. 124, 081301 (2020)]. Although this theory may run into trouble at the level of action or equations of motion, the spherically symmetric black hole solution, which can be successfully reproduced in those consistent theories of 4D EGB gravity, is still meaningful and worthy of study. In this paper, we investigate Hawking radiation in the spacetime containing such a de Sitter black hole. Both the greybody factor and the power spectra of the Hawking radiation of the massless scalar are studied numerically for the full range of various parameters, including the GB coupling constant $$\alpha $$ α , the cosmological constant $$\Lambda $$ Λ and the coupling constant related to the scalar filed $$\xi $$ ξ . In particular, we find a negative $$\alpha $$ α leads to a larger greybody factor than that of a $$\alpha \ge 0$$ α ≥ 0 . While, for the power spectra of the Hawking radiation the situation is quite the opposite. The reason is that the temperature of the black hole would be very high when $$\alpha <0$$ α < 0 . Actually, we observe that the temperature would be arbitrarily high when $$\alpha $$ α approaches to the lower bound.

The correspondence between shadow and test field in a four-dimensional charged Einstein–Gauss–Bonnet black hole

“…Its specific values are calculated and listed in Table 1. As described in [80][81][82], α cannot be too negative, because the metric function may not be real inside the event horizon when α is too negative. The observational constraints on the coupling parameter α was found in [84].…”

Holographic superconductors in 4D Einstein-Gauss-Bonnet gravity

“…Interestingly, the solution of the same form has been presented in the conformal anomaly inspired gravity [40,41]. Along this line, the Einstein-Gauss-Bonnet gravity in the 4D spacetime has been explored extensively on various aspects, including the exact solutions [42][43][44][45][46][47][48][49][50][51][52][53][54][55], the quasinormal modes and stability [56][57][58][59][60][61][62][63][64][65][66][67], the observable shadows [68][69][70][71][72][73], the geodesics and gravitational lensing [74][75][76][77][78], and the thermodynamics and cosmic censorship conjecture [79][80][81][82][83][84][85][86].…”

Collapsing dust thin shells in Einstein–Gauss–Bonnet gravity

“…As a result of that proposal, the solution has regained widespread attention, and various properties of the 4D EGB solutions were considered within a short period time. For example, gravitational collapse was considered in [3], the generalization of the original solution [1] was studied in [4][5][6][7][8], black hole thermaldynamics was investigated in [9,10], gravitational lensing and shadow were considered in [5,6,[11][12][13], quasinormal modes and stability were showed in [14][15][16], the electromagnetic radiation properties of thin accretion disk around black hole were explored in [17], while the Hawking radiation and black hole evaporation were showed in [18,19] respectively. As research progresses, the validity of 4D EGB gravity is being questioned [20][21][22][23][24][25][26][27].…”