Summing over all Topologies in CDT String Field Theory

Understand

By explicitly allowing for topology to change as a function of time, two-dimensional quantum gravity defined through causal dynamical triangulations gives rise to a new continuum string field theory.

• Within a matrix-model formulation we show that -- rather remarkably -- the associated sum over all genera can be performed in closed form, leading to a nonperturbative definition of CDT string field theory.
• We also obtain explicit formulas for the n-loop correlation functions.
• Our construction exhibits interesting parallels with previous, purely Euclidean treatments.