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

Tensor Renormalization Group Study of Step-Scaling Function in the CP(1) Model with a $\theta$ Term

30 Jul 2026, 14:40

20m

Margaret Brent B (Adele H. Stamp Student Union)

Contributed talk Theoretical developments and applications beyond the Standard Model Theoretical developments and applications beyond the SM

Speaker

Hayato Aizawa (University of Tsukuba)

Description

The step-scaling function (SSF) is a non-perturbative tool to determine the running coupling in lattice gauge theory.
The tensor renormalization group (TRG), which is free from the sign problem, allows us calculate the SSF in the CP(1) model with a $\theta$ term. We first study the $\theta = 0$ case to validate the calculation of the SSF with the TRG method comparing our results with the previous Monte Carlo ones.
We then extend the analysis to the $\theta = \pi$ case, where the running coupling obtained with the SSF indicates the existence of a infrared conformality.