2019/04/30 by Aldo Riello
Physics and Astronomy · #Black Holes and Theoretical Physics #Boundary value problem #Diffeomorphism #Formalism (music) #Gauge theory #General covariance #Homogeneous space #Invariant (physics) #Noether's theorem #Noncommutative and Quantum Gravity Theories #Quantum Chromodynamics and Particle Interactions #Spacetime #Symmetry group #hep-th
paper · pdf · doi:10.1007/jhep05(2020)125
Published version: Major improvements in the exposition, and new results on the relationship with the Ashtekar-Streubel phase space. 14 pages + appendices
openalex created_date 2019/04/25 · arxiv created 2020/05/04 · openalex publication_date 2020/05/26 · arxiv updated 2020/06/24 · openalex updated_date 2026/08/05
A bstract Infinite sets of asymptotic soft-charges were recently shown to be related to new symmetries of the S -matrix, spurring a large amount of research on this and related questions. Notwithstanding, the raison-d’être of these soft-charges rests on less firm ground, insofar as their known derivations through generalized Noether procedures tend to rely on the fixing of (gauge-breaking) boundary conditions rather than on manifestly gauge- invariant computations. In this article, we show that a geometrical framework anchored in the space of field configurations singles out the known leading-order soft charges in gauge theories. Our framework unifies the treatment of finite and infinite regions, and thus it explains why the infinite enhancement of the symmetry group is a property of asymptotic null infinity and should not be expected to hold within finite regions, where at most a finite number of physical charges — corresponding to the reducibility parameters of the quasi-local field configuration — is singled out. As a bonus, our formalism also suggests a simple proposal for the origin of magnetic-type charges at asymptotic infinity based on spacetime (Lorentz) covariance rather than electromagnetic duality.