## Video URL

http://pirsa.org/23010110# On quantum corrections to the celestial operator product in gravity

### APA

Bittleston, R. (2023). On quantum corrections to the celestial operator product in gravity. Perimeter Institute for Theoretical Physics. http://pirsa.org/23010110

### MLA

Bittleston, Roland. On quantum corrections to the celestial operator product in gravity. Perimeter Institute for Theoretical Physics, Jan. 24, 2023, http://pirsa.org/23010110

### BibTex

@misc{ scitalks_23010110, doi = {}, url = {http://pirsa.org/23010110}, author = {Bittleston, Roland}, keywords = {Quantum Fields and Strings}, language = {en}, title = {On quantum corrections to the celestial operator product in gravity}, publisher = {Perimeter Institute for Theoretical Physics}, year = {2023}, month = {jan}, note = {Talk #23010110 see, \url{https://scitalks.ca}} }

Roland Bittleston Perimeter Institute for Theoretical Physics

## Abstract

The question of whether the holomorphic collinear singularities of graviton amplitudes define a consistent chiral algebra has garnered much recent attention. I will discuss a version of this question for infinitesimal perturbations around the self-dual sector of 4d Einstein gravity. The singularities of tree amplitudes in such perturbations do form a consistent chiral algebra. However, at loop level new poles are generated, the simplest of which are described the 1-loop effective graviton vertex. These quantum corrections violate associativity of the operator product. I will argue that this failure can be traced to an anomaly in the twistor uplift of self-dual gravity. Associativity can be restored by coupling to an unusual 4th-order gravitational axion, which cancels the anomaly by a Green-Schwarz mechanism. Alternatively, the anomaly vanishes in certain theories of self-dual gravity coupled to matter, including in self-dual supergravity.

Zoom link: https://pitp.zoom.us/j/91979544537?pwd=Ykw4Q3lRK2ZicVhCMDhlNUxFaHhlUT09