$Q \bar{Q}$ Potential from Strings in Curved Spacetime - Classical Results
Y. Kinar, E. Schreiber, J. Sonnenschein
TL;DR
The paper develops a unified classical framework in which Wilson loops are realized as string world sheets in curved spacetimes with an extra dimension, parameterized by metric functions $f(s)$ and $g(s)$. It proves a sharp confinement criterion: confinement occurs if and only if $f(0)>0$, in which case the string tension is $f(0)$, and it derives the large-$l$ behavior of the quark–antiquark potential $E(l)$ including subleading corrections. The corrections are either exponential (in a critical case) or negative-power in $l$ (in noncritical cases), with explicit constants determined by local expansions of $f$ and $g$ near the minimum or divergence of the extra dimension. The general results are then applied to a broad set of backgrounds—AdS5×S5, non-conformal D$p$-brane setups, finite-temperature YM, MQCD, rotating branes, and Polyakov’s non-critical string—recovering known results (such as Maldacena’s $E(l) o l$ behavior) and clarifying the structure and magnitude of the corrections. The work also discusses invariance under reparameterizations of the extra dimension and the distinction between even and odd string configurations, laying a foundation for future inclusion of quantum fluctuations.
Abstract
We compute the leading behaviour of the quark anti-quark potential from a generalized Nambu-Goto action associated with a curved space-time having an "extra dimension". The extra dimension can be the radial coordinate in the AdS/CFT correspondence, the Liouville field in Polyakov's approach, or an internal dimension in MQCD. In particular, we derive the condition for confinement, and in the case it occurs we find the string tension and the correction to the linear potential.
