Global Structures from the Infrared
Michele Del Zotto, Iñaki García Etxebarria
TL;DR
The paper develops a field-theoretic route to determine the global form of 4d and higher-dimensional QFTs by deriving a symmetry TFT from infrared Coulomb-phase data. It shows that the allowed flux sectors and line operators organize into a bulk BF-type theory in one higher dimension, whose boundary data reproduce the observed 1-form defect groups and centers for various theories, including non-Lagrangian Argyres-Douglas theories. The approach reproduces known results from geometric engineering and extends them to a purely field-theoretic setting, with consistent generalizations to 6d and 5d theories. This provides a unifying framework connecting IR Coulomb dynamics, anomaly inflow, and global structure, and points toward richer symmetry TFTs and higher-form/ non-invertible structures to explore in future work.
Abstract
Quantum field theories with identical local dynamics can admit different choices of global structure, leading to different partition functions and spectra of extended operators. Such choices can be reformulated in terms of a topological field theory in one dimension higher, the symmetry TFT. In this paper we show that this TFT can be reconstructed from a careful analysis of the infrared Coulomb-like phases. In particular, the TFT matches between the UV and the IR. This provides a purely field theoretical counterpart of several recent results obtained via geometric engineering in various string/M/F theory setups for theories in four and five dimensions that we confirm and extend.
