I have a general or overview question related to charges on D- Branes lies in the K theory of Spacetime. We normally think charges of D branes lies in the Cohomology like $D_0$ branes couple to RR-1 form and so on.
The whole idea behind AdS/CFT duality (Maldacena' paper) is based on the fact that D-branes couple to RR form and it curves the spacetime. Can we think of this duality in terms of K-theory? By thinking in terms of K theory will give something new in this Holography business.