Cosmological horizons, Noether charges and entropy

Understand

It has recently been shown that, in the vicinity of their event horizons, black holes exhibit an infinite-dimensional symmetry.

• This symmetry captures relevant physical information about the black hole, and in particular about its thermodynamics.
• Here, we show that the same holds in a cosmological setup.
• More precisely, we show that around the de Sitter cosmological horizon, an infinite set of diffeomorphisms preserving a sensible set of boundary conditions emerges.