## T Duality
n is an integer. Winding-mode excitations, due to a closed string
winding m times around the circular dimension, are special to string
theory. Ifdenotes the string tension (energy per unit length), the contribution
to the energy squared is T duality exchanges
these two kinds of excitations by exchanging m with n and This is part of an exact map between a Two important examples of superstring theories that are T-dual when compactified on a
circle are the IIA and IIB theories and the HE and HO theories.
These two dualities reduce the number of distinct theories from five to
three. Previous |Next |

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