Celestial Current Algebra from Low's Subleading Soft Theorem

Abstract

The leading soft photon theorem implies that four-dimensional scattering amplitudes are controlled by a two-dimensional (2D) $U(1)$ Kac-Moody symmetry that acts on the celestial sphere at null infinity ($\mathcal{I}$). This celestial $U(1)$ current is realized by components of the electromagnetic vector potential on the boundaries of $\mathcal{I}$. Here, we develop a parallel story for Low's subleading soft photon theorem. It gives rise to a second celestial current, which is realized by vector potential components that are subleading in the large radius expansion about the boundaries of $\mathcal{I}$. The subleading soft photon theorem is reexpressed as a celestial Ward identity for this second current, which involves novel shifts by one unit in the conformal dimension of charged operators.

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Cited by in corpus (32)

• Lectures on Celestial Amplitudes
• Holographic Symmetry Algebras for Gauge Theory and Gravity
• Celestial amplitudes and conformal soft theorems
• Symmetries of Celestial Amplitudes
• Celestial Operator Product Expansions and ${\mathrm{w}}_{1+\infty }$ Symmetry for All Spins
• Celestial Diamonds: Conformal Multiplets in Celestial CFT
• BMS Flux Algebra in Celestial Holography
• Revisiting the Conformally Soft Sector with Celestial Diamonds
• MHV Gluon Scattering Amplitudes from Celestial Current Algebras
• Holographic Chiral Algebra: Supersymmetry, Infinite Ward Identities, and EFTs
• Goldilocks Modes and the Three Scattering Bases
• On loop celestial amplitudes for gauge theory and gravity
• Relativistic partial waves for celestial amplitudes
• Non-abelian infrared divergences on the celestial sphere
• Celestial Dual Superconformal Symmetry, MHV Amplitudes and Differential Equations
• On Sugawara construction on Celestial Sphere
• Radiative phase space extensions at all orders in r for self-dual Yang-Mills and Gravity
• Conformally Soft Fermions
• Celestial Superamplitudes
• Gravitation in flat spacetime from entanglement
• Celestial Recursion
• Poincaré Constraints on Celestial Amplitudes
• Asymptotic Charges and Coherent States in QCD
• Photon Chiral Memory Effect Stored on Celestial Sphere
• The Grassmannian for Celestial Superamplitudes
• Structure of deformed $w_{1+\infty }$ symmetry and topological generalization in Celestial CFT
• Celestial IR divergences and the effective action of supertranslation modes
• A Shorter Path to Celestial Currents
• A low-energy limit of Yang-Mills theory on de Sitter space
• Celestial OPE blocks
• Charge algebra for non-abelian large gauge symmetries at $O(r)$
• The classical dynamics of gauge theories in the deep infrared