Coupling the Superstring to a D-Brane Ramond-Ramond Background

TL;DR

This paper introduces a novel method for coupling type II superstrings to D-brane Ramond-Ramond backgrounds within the RNS formalism, avoiding the use of RR vertex operators by leveraging mixing between closed and open string excitations.

Contribution

It presents an alternative approach to coupling superstrings to RR backgrounds, based on mixing of string excitations rather than vertex operator insertion.

Findings

Demonstrates a new coupling mechanism in the RNS formalism.

Provides a framework for analyzing RR backgrounds without vertex operators.

Enhances understanding of string-D-brane interactions in RR backgrounds.

Abstract

We propose a new approach for coupling the type II superstring to the Ramond-Ramond background of D-branes in the RNS formalism, alternative to introducing RR vertex operators. It is based on the mixing between Ramond-Ramond p-form excitations in the closed string spectrum and transversally polarized excitations in the open string spectrum.