Higher Spins Without (Anti-)de Sitter

TL;DR

This paper reviews recent advances in three-dimensional higher-spin gravity theories, exploring potential holographic dualities beyond AdS/CFT, including flat spacetimes and Carroll gravity, and discusses related algebraic structures.

Contribution

It provides a comprehensive review of higher-spin gravity in 3D, focusing on flat space holography and the role of extended ms_3 symmetries, including Carroll gravity.

Findings

Holographic duality proposals for flat spacetimes with higher-spin symmetries

Development of higher-spin ms_3 algebraic structures

Analysis of Carroll gravity within higher-spin frameworks

Abstract

Can the holographic principle be extended beyond the well known AdS/CFT correspondence? During the last couple of years there has been a substantial amount of research trying to find answers for this question. In this work we provide a review of recent developments of three-dimensional theories of gravity with higher-spin symmetries. We focus in particular on a proposed holographic duality involving asymptotically flat spacetimes and higher spin extended $\mathfrak{bms}_3$ symmetries. In addition we also discuss developments concerning relativistic and nonrelativistic higher spin algebras. As a special case Carroll gravity will be discussed in detail.