Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Type I Strings with F- and B-Flux

Ralph Blumenhagen, Boris Kors, Dieter Lust

TL;DR

This work analyzes Type I string compactifications with both NSNS B-field flux and world-volume F-flux on D9-branes, and extends the framework to K3 via T^4/Z_2. By developing boundary-state formalisms for fluxed D-branes and deriving generalized tadpole cancellation conditions, the authors show how fluxes alter gauge-group ranks through doubled brane wrapping and enable chiral spectra, including a concrete three-generation Standard Model–like model in four dimensions. They also construct and analyze a spectrum of six-dimensional models on T^4/Z_2 with varying fluxes, illustrating non-supersymmetric and supersymmetric possibilities and the rich phenomenological implications of flux backgrounds. The results demonstrate the viability of fluxed Type I vacua as a route to semi-realistic, intersecting-brane–dual descriptions with controlled RR tadpoles and anomaly-free spectra.

Abstract

We present non-supersymmetric toroidal compactifications of type I string theory with both constant background NSNS two-form flux and non-trivial magnetic flux on the various D9-branes. The non-vanishing B-flux admits four-dimensional models with three generations of chiral fermions in standard model like gauge groups. Additionally, we consider the orbifold T^4/Z_2, again with both kinds of background flux present, leading to non-supersymmetric as well as supersymmetric models in six dimensions. All models have T-dual descriptions as intersecting brane worlds.

Type I Strings with F- and B-Flux

TL;DR

This work analyzes Type I string compactifications with both NSNS B-field flux and world-volume F-flux on D9-branes, and extends the framework to K3 via T^4/Z_2. By developing boundary-state formalisms for fluxed D-branes and deriving generalized tadpole cancellation conditions, the authors show how fluxes alter gauge-group ranks through doubled brane wrapping and enable chiral spectra, including a concrete three-generation Standard Model–like model in four dimensions. They also construct and analyze a spectrum of six-dimensional models on T^4/Z_2 with varying fluxes, illustrating non-supersymmetric and supersymmetric possibilities and the rich phenomenological implications of flux backgrounds. The results demonstrate the viability of fluxed Type I vacua as a route to semi-realistic, intersecting-brane–dual descriptions with controlled RR tadpoles and anomaly-free spectra.

Abstract

We present non-supersymmetric toroidal compactifications of type I string theory with both constant background NSNS two-form flux and non-trivial magnetic flux on the various D9-branes. The non-vanishing B-flux admits four-dimensional models with three generations of chiral fermions in standard model like gauge groups. Additionally, we consider the orbifold T^4/Z_2, again with both kinds of background flux present, leading to non-supersymmetric as well as supersymmetric models in six dimensions. All models have T-dual descriptions as intersecting brane worlds.

Paper Structure

This paper contains 13 sections, 31 equations, 2 figures, 6 tables.

Table of Contents

  1. Introduction
  2. D-branes on a $\mathbb{T}^2$ with background fluxes
  3. Non-supersymmetric toroidal models with $B$- and $F$-flux
  4. Tadpole cancellation
  5. A three generation model
  6. Type I strings on K3 with background fluxes
  7. Tadpole cancellation
  8. Massless spectra
  9. Examples
  10. Example 1
  11. Example 2
  12. Example 3
  13. Conclusions

Figures (2)

  • Figure 1: Dual configurations
  • Figure 2: D7-brane configurations of 6D examples