Friday, January 18, 2013
Giant Graviton Geometry
David Berenstein has written a fresh new paper on the geometry of giant gravitons. Essentially, he begins by studying N=4 SYM and a Z/2 orbifold, building giant graviton states with their collective coordinates, attaching strings to them and computing the energies of the strings as functions of the collective coordinates. At the end of the computations it is found that the contribution to the mass of the strings stretched between the giants (at one loop order in the field theory) is a distance squared in the collective coordinate geometry.
The procedure makes contact with the D-brane description, where one can associate the masses to the Higgs mechanism associated to breaking an enhanced gauge symmetry of coincident D-branes down to a diagonal group when the branes are separated. This Higgsed gauge symmetry is the emergent gauge symmetry, realized in terms of collective coordinates of D-branes.