The 43rd International Symposium on Lattice Field Theory (Lattice 2026)

Scaling and cutoff effects of the topological susceptibility with gradient flow in $SU(3)$ Yang--Mills theory on the lattice

Not scheduled

20m

University of Maryland, College Park

Poster presentation Theoretical developments and applications beyond the Standard Model

Speakers

Alessandro Conigli Fernando Pérez Panadero (IFT-UAM/CSIC) Pietro Butti (Quantum Theory Center, IMADA and D-IAS, University of Southern Denmark)

Description

The computation of the topological susceptibility in lattice gauge theory requires a smoothing procedure for the gluonic topological charge, with cooling and gradient flow being the most commonly adopted approaches. While cooling is computationally cheaper, gradient flow admits a Symanzik expansion that is easier to compute and allows for a clean identification of leading order cutoff effects.
We study these effects in pure SU(3) Yang--Mills theory using ensembles generated with different gauge actions at lattice spacings ranging from 0.04 fm to 0.12 fm. By combining different levels of improvement for the flow kernel with several discretisations of the topological charge operator, we study the contributions to lattice artefacts arising from the action, flow, and observable, aiming to disentangle their respective effects. We present preliminary results on the scaling of the topological susceptibility and the effectiveness of improvement strategies.