Black holes in the presence of dark energy

TL;DR

This paper reviews the theoretical interactions between dark energy and black holes, exploring accretion processes, effects on black hole mass, and potential violations of thermodynamics, highlighting novel phenomena in black hole physics influenced by dark energy.

Contribution

It provides a comprehensive analysis of dark energy's effects on black holes, including mass decrease with phantom energy and thermodynamic law violations, expanding understanding of black hole-dark energy interactions.

Findings

Black hole mass decreases when accreting phantom energy.

Dark energy can cause violations of classical thermodynamic laws.

Potential signals may escape from beneath the black hole horizon.

Abstract

The new, rapidly developing field of theoretical research --- studies of dark energy interacting with black holes (and, in particular, accreting onto black holes) --- is reviewed. The term `dark energy' is meant to cover a wide range of field theory models, as well as perfect fluids with various equations of state, including cosmological dark energy. Various accretion models are analyzed in terms of the simplest test field approximation or by allowing back reaction on the black-hole metric. The behavior of various types of dark energy in the vicinity of Schwarzschild and electrically charged black holes is examined. Nontrivial effects due to the presence of dark energy in the black hole vicinity are discussed. In particular, a physical explanation is given of why the black hole mass decreases when phantom energy is being accreted, a process in which the basic energy conditions of the famous theorem of nondecreasing horizon area in classical black holes are violated. The theoretical possibility of a signal escaping from beneath the black hole event horizon is discussed for a number of dark energy models. Finally, the violation of the laws of thermodynamics by black holes in the presence of noncanonical fields is considered.