D-branes on orbifolds with discrete torsion and topological obstruction

Jan, 2000
15 pages
Published in:
  • JHEP 05 (2000) 006
e-Print:
Report number:
  • CALT-68-2260,
  • CITUSC-00-008

Citations per year

20002006201220182023051015
Abstract:
We find the orbifold analog of the topological relation recently found by Freed and Witten which restricts the allowed D-brane configurations of Type II vacua with a topologically non-trivial flat BB-field. The result relies in Douglas proposal -- which we derive from worldsheet consistency conditions -- of embedding projective representations on open string Chan-Paton factors when considering orbifolds with discrete torsion. The orbifold action on open strings gives a natural definition of the algebraic K-theory group -- using twisted cross products -- responsible for measuring Ramond-Ramond charges in orbifolds with discrete torsion. We show that the correspondence between fractional branes and Ramond-Ramond fields follows in an interesting fashion from the way that discrete torsion is implemented on open and closed strings.
  • string model
  • string: closed
  • string: open
  • membrane model: D-brane
  • orbifold
  • torsion: discrete
  • topology
  • K-theory