This article needs additional citations for verification. (April 2014) |
String theory |
---|
Fundamental objects |
Perturbative theory |
Non-perturbative results |
Phenomenology |
Mathematics |
In theoretical physics, type II string theory is a unified term that includes both type IIA strings and type IIB strings theories. Type II string theory accounts for two of the five consistent superstring theories in ten dimensions. Both theories have extended supersymmetry which is maximal amount of supersymmetry — namely 32 supercharges — in ten dimensions. Both theories are based on oriented closed strings. On the worldsheet, they differ only in the choice of GSO projection. They were first discovered by Michael Green and John Henry Schwarz in 1982,[1] with the terminology of type I and type II coined to classify the three string theories known at the time.[2]