Brane plus Bulk Supersymmetry in Ten Dimensions

TL;DR

This paper develops a generalized supergravity framework for Type IIA/IIB string theories, introduces new bulk and brane actions, and explores 8-brane solutions, including their role in string theory and implications for quantization.

Contribution

It presents a new bulk action for supergravity that couples to supersymmetric branes and analyzes 8-brane solutions within this framework, advancing understanding of brane dynamics in string theory.

Findings

Derived a new bulk supergravity action compatible with branes.

Constructed a BPS 8-brane solution satisfying jump conditions.

Established quantization conditions for mass and cosmological constant.

Abstract

We discuss a generalized form of IIA/IIB supergravity depending on all R-R potentials C^(p) (p=0,1,...,9) as the effective field theory of Type IIA/IIB superstring theory. For the IIA case we explicitly break this R-R democracy to either p<=3 or p>=5 which allows us to write a new bulk action that can be coupled to N=1 supersymmetric brane actions. The case of 8-branes is studied in detail using the new bulk & brane action. The supersymmetric negative tension branes without matter excitations can be viewed as orientifolds in the effective action. These D8-branes and O8-planes are fundamental in Type I' string theory. A BPS 8-brane solution is given which satisfies the jump conditions on the wall. As an application of our results we derive a quantization of the mass parameter and the cosmological constant in string units.