Branes, Calibrations and Supergravity
Jerome P. Gauntlett
TL;DR
The notes develop a geometrical program to build supergravity solutions for branes wrapping calibrated cycles in special-holonomy manifolds, focusing on D=11 theory. They show how to use worldvolume calibrations and a chain of consistent Kaluza–Klein reductions, notably to D=7 SO(5) gauged supergravity, to construct near-horizon AdS geometries and their uplifts to 11D. Concrete results include wrapped fivebranes on SLAG 3-cycles yielding AdS4×H^3/Γ and RG-flow solutions, as well as wrapped membranes and D3-branes via higher-dimensional gauged supergravities; these provide new AdS/CFT examples and insights into dual field theories. The work emphasizes a unifying, geometrical approach via calibrations and G-structures to analyze supersymmetry, fluxes, and the structure of normal bundles across multiple brane configurations.
Abstract
These notes are based on lectures given at the Clay School on Geometry and String Theory, Isaac Newton Institute, Cambridge, 25 March - 19 April 2002. They attempt to provide an elementary and somewhat self contained discussion of the construction of supergravity solutions describing branes wrapping calibrated cycles, emphasising the geometrical aspects and focusing on D=11 supergravity. Following a discussion of the role of special holonomy backgrounds in D=11 supergravity, the basic membrane and fivebrane solutions are reviewed and the connection with the AdS/CFT correspondence is made. The world-volume description of branes is introduced and used to argue that branes wrapping calibrated cycles in special holonomy manifolds preserve supersymmetry. The corresponding supergravity solutions are constructed first in an auxiliary gauged supergravity theory which is obtained via Kaluza-Klein reduction.
