Higher Spin Holography in Curved Spaces

A consistent theory of quantum gravity has long been sought by theoretical physicists, unifying the two major branches of modern physicsEinstein`s General Relativity and Quantum Field Theory. String Theory is currently the best candidate for such a theory, although many aspects of String Theory remain poorly understood; the gravitational sector of the theory is particularly mysterious. One of the main advances in String Theory in the last twenty years has been a concrete realization of the idea that quantum gravity is holographic, or equivalent to a non-gravitational theory in fewer dimensions. Higher Spin Gravity can be thought of as a limit of String Theory in which the theory simplifies drastically. Thus, by understanding Higher Spin Gravity, we can increase our knowledge of String Theory. In particular, we hope to gain understanding of the gravitational sector of String Theory and the role of enhanced symmetries, especially as they pertain to solving the problems arising in na\"{i}ve quantizations of gravity, including the presence and resolution of singularities, such as those occurring in black holes. Additionally, theories of Higher Spin Gravity admit particularly simple holographic descriptions in terms of dual (almost) free field theories, and are thus useful for understanding the underlying mechanism of the holographic principle. The field of research of this project is String Theory and Higher Spin Gravity. The research team aims to construct consistent theories of higher spins in curved spacetimes and analyze the properties of these theories. The curved backgrounds which we wish to study are important, not just in their own right as novel geometries, but because they often arise in the holographic study of condensed matter systems and other systems with less than maximal symmetry. In this framework, we aim to work on novel curved backgrounds, building consistent higher spin theories of gravity admitting holographic duals. Following the construction of such theories, the research team will analyze their properties, including the properties of black holes in these backgrounds. Europe has long been strongly associated with the study of Higher Spin Gravity, and the program of studying higher spin holography in novel curved spacetimes was conceived and initiated at the Institute for Theoretical Physics in Vienna by a collaboration including the principal investigator. Thus, it is advantageous to the state of theoretical physics in Austria and Europe as a whole to continue this role as a leader in the study of higher spins and holography, and we aim to continue the fruitful collaborations that have led to the development of this field.

A consistent theory of quantum gravity has long been sought by theoretical physicists, unifying the two major branches of modern physicsEinsteins General Relativity and Quantum Field Theory. String Theory is currently the best candidate for such a theory, although many aspects of String Theory remain poorly understood; the gravitational sector of the theory is particularly mysterious. One of the main advances in String Theory in the last twenty years has been a concrete realization of the idea that quantum gravity is holographic, or equivalent to a non-gravitational theory in fewer dimensions.Higher Spin Gravity can be thought of as a limit of String Theory in which the theory simplifies drastically. Thus, by better understanding Higher Spin Gravity, we have increased our knowledge of String Theory. We focused on gravitational theories that admit holographic duals amenable to powerful tools for increasing our understanding, such as higher spin theories and their (almost) free dual field theories, as well as theories with holographic duals admitting a bootstrap program.The field of research of this project is String Theory and Higher Spin Gravity. The research team constructed consistent theories of higher spins in novel spacetimes and analyzed the properties of these theories. The backgrounds which we studied are important, not just in their own right as novel geometries, but because they often arise in the holographic study of condensed matter systems and other systems with less than maximal symmetry.In this framework, we worked on novel curved backgrounds, building consistent higher spin theories of gravity admitting holographic duals. Following the construction of such theories, the research team analyzed their properties, including the properties of black holes in these backgrounds. In the particular case of asymptotically flat space, the research team also developed the BMS bootstrap program, an important step to solving the theory entirely, and the first construction of a non-conformal bootstrap program.Europe has long been strongly associated with the study of Higher Spin Gravity, and the program of studying higher spin holography in novel spacetimes was conceived and initiated at the Institute for Theoretical Physics in Vienna by a collaboration including the principal investigator. During the course of the project, the role of Austria was cemented as a leader in the study of higher spins and holography, and the fruitful collaborations that led to the development of this field were continued and expanded.