Noncommutative manifolds from the Higgs sector of coincident D-branes

The Higgs sector of the low-energy physics of n coincident D-branes contains the necessary elements for constructing noncommutative manifolds. The coordinates orthogonal to the coincident branes, as well as their conjugate momenta, take values in the Lie algebra of the gauge group living inside the brane stack. In the limit when n -> infinity (and in the absence of orientifolds), this is the unitary Lie algebra u(infinity). Placing a smooth manifold K orthogonally to the stack of coincident D-branes, one can construct a noncommutative C*-algebra that provides a natural definition of a noncommutative partner for the manifold K.