*-Trek III: The Search for Ramond-Ramond Couplings

TL;DR

This paper investigates the supergravity couplings of noncommutative D-branes to Ramond-Ramond potentials through disk amplitude calculations, incorporating Elliott's formula and comparing different formalisms.

Contribution

It provides a detailed derivation of RR couplings for noncommutative D-branes, including the all-order inclusion of Elliott's formula and a comparison with Matrix model representations.

Findings

Confirmed the inclusion of Elliott's formula to all orders in gauge fields.

Derived explicit disk amplitude expressions for RR couplings.

Compared noncommutative gauge theory results with Matrix model formulations.

Abstract

We give a detailed discussion of the disk amplitudes with one closed string insertion, which we used to construct the supergravity couplings of noncommutative D-branes to the RR potentials, given in hep-th/0104139. We prove the inclusion of Elliott's formula, the integer-valued modification of the noncommutative Chern character, to all orders in the gauge field. We also give a detailed comparison between the form of the result in which Elliott's formula is manifest, and the form expressed in Matrix model variables.