N=2 superstring
In string theory, N=2 superstring is a theory in which the worldsheet admits N=2 supersymmetry rather than N=1 supersymmetry as in the usual superstring. The target space (a term used for a generalization of space-time) is four-dimensional, but either none or two of its dimensions are time-like, i.e. it has either 4+0 or 2+2 dimensions. The spectrum consists of only one massless scalar, which describes gravitational fluctuations of self-dual gravity. The target space theory is therefore self-dual gravity, and is thought to consist no local (or propagating) degrees of freedom.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.