This chapter reviews standard tools used in the analysis of horizon and black hole physics,
most notably the congruences of null geodesics crossing a horizon. Rindler, event, Killing …

We review spherical and inhomogeneous analytic solutions of the field equations of Einstein
and of scalar–tensor gravity, including Brans–Dicke theory, non-minimally (possibly …

Although the idea that there is a maximum force in nature seems untenable, we explore
whether this concept can make sense in the restricted context of black holes. We discuss …

In an accelerating universe in General Relativity there is a maximum radius above which a
shell of test particles cannot collapse, but is dispersed by the cosmic expansion. This radius …

Abstract We apply the Hawking-Hayward quasi-local energy construct to obtain in a rigorous
way the turnaround radius of cosmic structures in General Relativity. A splitting of this quasi …

We construct models of Einstein and f (R) gravity with two scalar fields, which admit
analytical solutions describing time-varying dynamical black holes. Their thermodynamics is …

The TOV equation appears as the relativistic counterpart of the classical condition for
hydrostatic equilibrium. In the present work we aim at showing that a generalised TOV …

The cuscuton was introduced in the context of cosmology as a field with infinite speed of
propagation. It has been claimed to resemble Hořava gravity in a certain limit, and it is a …

A bstract We study evolution and thermodynamics of a slow-roll transition between early and
late time de Sitter phases, both in the homogeneous case and in the presence of a black …

Classic black hole mechanics and thermodynamics are formulated for stationary black holes
with event horizons. Alternative theories of gravity of interest for cosmology contain a built-in …