# Exploring the duality of gravity and gauge theory

Newswise – The gauge/gravity duality states that gravity and quantum spacetime emerge from a quantum gauge theory, which lives on the boundary between the two theories. Over the past 25 years, this duality, with concrete examples discovered by string theory, has revolutionized our understanding of systems ranging from black holes to matter composed of strongly interacting quantum particles exhibiting complex networks of entanglement. In this thematic collection, the journal *EPJ C* presents a collection of articles reviewing the latest advances in the fundamental understanding of this duality and its revolutionary applications.

Our current understanding of gravity is centered on the relativistic descriptions of spacetime first proposed by Einstein. Meanwhile, gauge theory describes how the matter fields of elementary quantum particles – including electrons and quarks – interact with each other via forces, mediated by the exchange of gauge bosons – in this case, respectively photons and gluons. While the two theories seem to be governed by completely different sets of rules, the concept of gauge/gravity duality shows how crucial the intrinsic connections between them are in explaining the fundamental nature of the universe.

Articles in this thematic collection include topics such as the principles of reconstructing Einstein’s description of spacetime from double gauge theory, and how they led to recent breakthroughs in solving information paradoxes of black holes. They also explain how quantum error correction and complexity play a fundamental role in the emergence of gravity, as well as current experimental advances in quantum simulations of gauge/gravity duality.

Additionally, the Topical Collection includes papers that apply these concepts to model the behavior of matter in neutron stars: stellar remnants that have not gained enough mass to collapse into black holes; how hydrodynamics emerge from many-body interactions; and also calculate how the strong force affects the properties of the muon.

By doing this, *EPJ C* hopes to provide a proper foundation on these broad topics, which can be easily grasped and developed by physicists working in a wide range of specialized fields, such as gravity, condensed matter physics, and quantum information theory.

All the articles of this EPJ C Topical Collection are available in free access on https://link.springer.com/journal/10052/topicalCollection/AC_3d94bcea405c66ce446bcd7d86407944. For more information, read the editorial by Ayan Mukhopadhyay.

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**Reference:** Ayan Mukhopadhyay. New frontiers of holographic duality. EUR. Phys. JC 82, 877 (2022). https://doi.org/10.1140/epjc/s10052-022-10838-4