Time Gauge Fixing and Hilbert Space in Quantum String Cosmology

Recently the low-energy effective string theory has been used by Gasperini and Veneziano to elaborate a very interesting scenario for the early history of the universe (“birth of the universe as quantum scattering”). Here we investigate the gauge fixing and the problem of the definition of a global time parameter for the quantum form of the model, and obtain the positive norm Hilbert space of states.