Long Range, Large Charge, Large $N$

Abstract

We study operators with large charge $j$ in the $d$-dimensional $O(N)$ model with long range interactions that decrease with the distance as $1/r^{d+s}$, where $s$ is a continuous parameter. We consider the double scaling limit of large $N$, large $j$ with $j/N=\hat{j}$ fixed, and identify the semiclassical saddle point that captures the two-point function of the large charge operators in this limit. The solution is given in terms of certain ladder conformal integrals that have recently appeared in the literature on fishnet models. We find that the scaling dimensions for general $s$ interpolate between ${\Delta }_j\sim \frac{(d-s)}{2}j$ at small $\hat{j}$ and ${\Delta }_j\sim \frac{(d+s)}{2}j$ at large $\hat{j}$, which is a qualitatively different behavior from the one found in the short range version of the $O(N)$ model. We also derive results for the structure constants and 4-point functions with two large charge and one or two finite charge operators. Using a description of the long range models as defects in a higher dimensional local free field theory, we also obtain the scaling dimensions in a complementary way, by mapping the problem to a cylinder in the presence of a chemical potential for the conserved charge.

45 pages, 10 figures

References in corpus (9)

• Feynman diagrams and the large charge expansion in $3-\epsilon$ dimensions
• The OPE meets semiclassics
• Mirror channel eigenvectors of the $d$-dimensional fishnets
• A model of persistent breaking of continuous symmetry
• Following the flow for large N and large charge
• Spinning correlators in large-charge CFTs
• Critical long-range vector model in the UV
• Long-Range Vector Models at Large N
• Boundary Conformal Field Theory at Large Charge

Cited by in corpus (4)

• The connection between nonzero density and spontaneous symmetry breaking for interacting scalars
• Gauge Invariance at Large Charge
• Sphere free energy of scalar field theories with cubic interactions
• The thermal representation of conformal ladder integrals