More on analytic bootstrap for O(N) models
Parijat Dey, Apratim Kaviraj, Kallol Sen
TL;DR
This work extends analytic bootstrap methods to $O(N)$-symmetric CFTs by incorporating trace, antisymmetric-traceless, and symmetric-traceless exchanges in the OPE, and analyzes the resulting large-spin double-twist operators.It derives detailed expressions for the anomalous dimensions $ abla(n,bell)$ in terms of minimal-twist exchanges from stress-tensor, current, singlet, and symmetric-traceless scalars, including the $n$-dependence for all representations ($I,A,S$) and the special case $n=0$, where an exact match with the $oldsymbol{ε}$-expansion is found.The leading large-spin, large-twist behavior is shown to be governed by the universal scaling $ abla(n,bell) icommod{n^{2y}}{ ield}$ with $y$ determined by the exchanged operator’s twist, and the coefficients are expressed in closed form in terms of $N$, $Δ_phi$, and the minimal-twist data. A concrete holographic example for $N=2$ demonstrates consistency between bulk gravitational/gauge interactions in AdS$_5$ and the boundary CFT anomalous dimensions, supporting the validity of the analytic bootstrap results and providing a bridge to holography for $O(N)$ vector theories.
Abstract
This note is an extension of a recent work on the analytical bootstrapping of $O(N)$ models. An additonal feature of the $O(N)$ model is that the OPE contains trace and antisymmetric operators apart from the symmetric-traceless objects appearing in the OPE of the singlet sector. This in addition to the stress tensor $(T_{μν})$ and the $φ_iφ^i$ scalar, we also have other minimal twist operators as the spin-1 current $J_μ$ and the symmetric-traceless scalar in the case of $O(N)$. We determine the effect of these additional objects on the anomalous dimensions of the corresponding trace, symmetric-traceless and antisymmetric operators in the large spin sector of the $O(N)$ model, in the limit when the spin is much larger than the twist. As an observation, we also verified that the leading order results for the large spin sector from the $ε-$expansion are an exact match with our $n=0$ case. A plausible holographic setup for the special case when $N=2$ is also mentioned which mimics the calculation in the CFT.
