Studying 3D O(N) Surface CFT on the Fuzzy Sphere
Abstract
Boundary conformal field theory (BCFT) provides a universal framework for critical phenomena in the presence of boundaries. We determine BCFT data for the normal and ordinary boundary universality classes of the -dimensional boundaries of the -dimensional and Wilson-Fisher fixed points, realized microscopically by a bilayer Heisenberg model on the fuzzy sphere. Using the fuzzy-sphere state-operator correspondence, we obtain boundary operator spectra, identify low-lying boundary primary operators, extract operator-product-expansion (OPE) data, and estimate the boundary central charges for both boundary conditions. For the normal boundary condition, the universal amplitudes and extracted from one- and two-point functions agree quantitatively with Monte Carlo benchmarks where available. For both and , we find a positive extraordinary-log exponent , providing independent microscopic evidence for extraordinary-log boundary criticality. Our results extend fuzzy-sphere BCFT spectroscopy beyond the Ising universality class to continuous symmetry.
Cite
@article{arxiv.2604.21091,
title = {Studying 3D O(N) Surface CFT on the Fuzzy Sphere},
author = {Jiechao Feng and Taige Wang},
journal= {arXiv preprint arXiv:2604.21091},
year = {2026}
}
Comments
10 pages, 7 figures