Aspects of Large N Gauge Theory Dynamics as Seen by String Theory

TL;DR

The paper investigates how Maldacena's AdS/CFT duality informs the dynamics of large-$N$ gauge theories, including both supersymmetric and non-supersymmetric cases, by mapping gauge-theory strong coupling to semiclassical string/M-theory in AdS backgrounds. It demonstrates confinement-like behavior, monopole condensation, and a mass gap via Wilson loops and bulk brane configurations, and extends the analysis to theta-dependence and oblique confinement, higher representations, and heavy baryons through Chern-Simons couplings in AdS. The results provide nontrivial consistency checks for the duality, offering a geometric, string-theoretic picture of nonperturbative phenomena that resemble QCD-like physics at large $N$. However, the authors caution that the master-field correspondence may be regime-limited and possibly governed by phase transitions at finite $\lambda$, raising questions about the universality and continuum applicability of the dual descriptions. Overall, the work strengthens the case that large-$N$ gauge theories can be probed via string/M-theory in AdS backgrounds, yielding insights into confinement, mass gaps, and hadron structure in a controlled strong-coupling framework.

Abstract

In this paper we explore some of the features of large N supersymmetric and nonsupersymmetric gauge theories using Maldacena's duality conjectures. We shall show that the resulting strong coupling behavior of the gauge theories is consistent with our qualitative expectations of these theories. Some of these consistency checks are highly nontrivial and give additional evidence for the validity of the proposed dualities.

Figures (11)

• Figure 1: The string drops to the horizon first before spreading in the ${\bf R}^p$ direction.
• Figure 2: For $L > L_{\rm crit}$, there is no volume-minimizing D$2$ brane configuration connection the $m$-$\bar{m}$ pair
• Figure 3: For $L > L_{\rm crit}$, there is no area-minimizing string worldsheet connecting the two Wilson loops. The critical distance $L_{\rm crit}$ is determined by the size of the loop.
• Figure 4: For $0 < L < 1.3525 R_0$, the solid curve $R = R_{\rm min} {\rm cosh}(L/2R_{\rm min})$ intersects twice with the dotted line $R = R_0$, determining the minimum radius $R_{\rm min}$ of the catenoid. For $L > L_{\rm crit}$, there is no intersection, indicating that a catenoid solution does not exist.
• Figure 5: The string worldsheet connecting the Wilson loops collapses at $L = L_{\rm crit}$ and is replaced by the supergraviton exchange.