Where the sign of the metric makes a difference
Abstract
The groups Pin(n,m) and Pin(m,n) are not isomorphic, and the obstruction classes to their respective bundles are different. It follows that for nonorientable superstring theories the contributions to a Polyakov path integral from surfaces with positive metric are different from the contributions from those with negative metrics.
- Publication:
-
Physical Review Letters
- Pub Date:
- April 1988
- DOI:
- 10.1103/PhysRevLett.60.1599
- Bibcode:
- 1988PhRvL..60.1599C
- Keywords:
-
- 02.40.+m;
- 11.17.+y