Unravelling the quantum nature of de Sitter spacetime

De Sitter spacetime is the description most consistent with experimental data from the early and late universe but is still ill understood.

Regions in de Sitter are cloaked from an observer by a cosmological horizon, which shares many features with the horizon of a black hole. However, the interpretation of its entropy is expected to be fundamentally different from black holes.

Another peculiarity of de Sitter spacetime is that a holographic dual (a map to a unitary quantum mechanical system) is unknown.The first main question we aim to answer in this proposal is: if information escapes through the cosmological horizon, is it recoverable by studying the quantum mechanical radiation that is emitted by the horizon like recent advances suggest for black holes?

We employ recent advances in brane-world models (or double holography) and pioneer protocols of information recovery in such models beyond two dimensions.

The second main question we aim to answer in this proposal is: can we develop a complexity probe to gain insights into the two competing approaches for de Sitter holography?

We aim to develop a novel bulk complexity probe that can reproduce Krylov complexity and combine it with conventional holographic complexity to gain insights in how to complement two competing approaches for de Sitter holography.Answering these questions will lead to important breakthroughs on the quantum nature of our universe that will have important knock-on effects for future research.