Anomalous dimensions of monopole operators in three-dimensional quantum electrodynamics
Silviu S. Pufu
TL;DR
The paper computes the scaling dimensions of monopole operators in three-dimensional QED with $N_f$ fermion flavors by mapping local monopole insertions to states on $S^2 \times \mathbb{R}$ and performing a $1/N_f$ expansion via the state-operator correspondence.Leading order comes from integrating out fermions in a fixed monopole background, while next-to-leading order arises from Gaussian fluctuations of the U(1) gauge field; the calculation hinges on the fermion Green's function and the gauge-field kernel in the monopole background.For the unit monopole ($n=1$), the dimension at the infrared fixed point is found to be $\text{dim} = 0.265\,N_f - 0.0383 + O(1/N_f)$, reflecting a small but nonzero $O(1)$ correction to the leading result.The analysis reveals exact UV divergence cancellations between electric and magnetic-type gauge-field fluctuations and provides a framework to assess confinement/deconfinement by comparing monopole dimensions to the spacetime dimension.The results are consistent with lattice and theoretical expectations about the critical flavor number for confinement and highlight the potential for applying similar methods to non-supersymmetric gauge theories.
Abstract
The space of local operators in three-dimensional quantum electrodynamics contains monopole operators that create $n$ units of gauge flux emanating from the insertion point. This paper uses the state-operator correspondence to calculate the anomalous dimensions of these monopole operators perturbatively to next-to-leading order in the $1/N_f$ expansion, thus improving on the existing leading order results in the literature. Here, $N_f$ is the number of two-component complex fermion flavors. The scaling dimension of the $n=1$ monopole operator is $0.265 N_f - 0.0383 + O(1/N_f)$ at the infrared conformal fixed point.
