Time evolution in string field theory and T-duality.

摘要

The time evolution operator (Schrödinger functional) of quantum field theory can be expressed in terms of first quantisedudparticles moving on S1/Z2. We give a graphical derivation of this that generalises to second quantised string theory. T-dualityudthen relates evolution through time t with evolution through 1/t and an interchange of string fields and backgrounds.