# Black holes in Einstein-Gauss-Bonnet gravity with a string cloud background - High Energy Physics - Theory

Abstract: We obtain a black hole solution in the Einstein-Gauss-Bonnet theory for thestring cloud model in a five dimensional spacetime. We analyze the eventhorizons and naked singularities. Later, we compute the Hawking temperature$T {\mathrm{H}}$, the specific heat $C$, the entropy $S$, and the Helmholtzfree energy $F$ of the black hole. The entropy was computed using the Waldformulation. In addition, the quantum correction to the Wald-s entropy isconsidered for the string cloud source.We mainly explore the thermodynamical global and local stability of thesystem with vanishing or non-vanishing cosmological constant. The globalthermodynamic phase structure indicates that the Hawking-Page transition isachieved for this model. Further, we observe that there exist stable blackholes with small radii and that these regions are enlarged when choosing smallvalues of the string cloud density and of the Gauss-Bonnet parameter. Besides,the rate of evaporation for these black holes are studied, determining whetherthe evaporation time is finite or not. Then, we concentrate on the dynamicalstability of the system, studying the effective potential for s-wavespropagating on the string cloud background.

Author: Estanislao Herscovich, Martín G. Richarte

Source: https://arxiv.org/