Static Patch Holography

Establish a holographic duality in de Sitter spacetime by proving that the semiclassical gravity description of the region inside a holographic screen S is fully captured by a quantum theory living on S.

Background

Motivated by the covariant entropy bound and thermodynamic properties of cosmological horizons, static patch holography posits that an observer’s causal patch is encoded on a screen located at or near the cosmological horizon. The conjecture aims to provide a concrete non-AdS holographic framework for cosmology.

References

Conjecture [Static patch holography] The semiclassical gravity description of the region inside a holographic screen $\mathcal{S}$ is dual to a quantum theory defined on $\mathcal{S}$.

— Information-theoretic constraints in quantum gravity and cosmology  (2510.15787 - Franken, 17 Oct 2025) in Chapter: Static patch holography, Section: A holographic description of de Sitter spacetime?

Understanding this more general duality is an important open problem.

— Interpolating between single and double trace $T\bar T$ by moving LST into the bulk  (2609.10823 - Chu et al., 9 Sep 2026) in Section 1, Introduction