When the universe is treated as a quantum system, it is described by a wave function. This
wave function is a function not only of the matter fields, but also of spacetime. The no …

The aim of this work is to review the tunnelling method as an alternative description of the
quantum radiation from black holes and cosmological horizons. The method is first …

A bstract We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled
with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves …

A bstract We study some aspects of the de Sitter version of Jackiw-Teitelboim gravity.
Though we do not have propagating gravitons, we have a boundary mode when we …

A bstract We study the semi-classical thermodynamics of two-dimensional de Sitter space
(dS 2) in Jackiw-Teitelboim (JT) gravity coupled to conformal matter. We extend the quasi …

A bstract In three-dimensional de Sitter space classical black holes do not exist, and the
Schwarzschild-de Sitter solution instead describes a conical defect with a single …

Dark energy cosmology is considered in a modified Gauss-Bonnet (GB) model of gravity
where an arbitrary function of the GB invariant, f (G), is added to the general relativity action …

In asymptotically flat (AF) space, the extreme Reissner-Nordstrøm (RN) black hole is
distinguished by its coldness (vanishing Hawking temperature) and its supersymmetry. We …

A bstract The entropy of a de Sitter horizon was derived long ago by Gibbons and Hawking
via a gravitational partition function. Since there is no boundary at which to define the …

We consider the thermodynamics of rotating and charged asymptotically de Sitter (dS) black
holes. Using Hamiltonian perturbation-theory techniques, we derive three different first-law …