Lecturer: Prof. Tom Banks
Affiliation:University of California, Santa Cruz
and Rutgers University
Abstract:
Type 0B string theory in 1+1 dimensions is one
of a small number of exactly soluble string
models. It was always something of a
disappointment, since it does not contain black
holes, despite the fact that its low energy
effective field theory has black hole solutions. I
show how to rederive the model from the
formalism of holographic space-time. The
derivation explains a number of peculiar
features of the model: necessity for an
additional scalar in the gravitational action,
absence of a Lorentz invariant ground state, and
the absence of black holes. Despite the latter
fact, the scattering amplitudes in the model
exhibit a baby version of 't Hooft's black hole S
matrix. The HST approach shows us how to
generalize the model so that it exhibits behavior
consistent with the black hole solutions. I
suggest that the generalized models might fit
into string theory as near horizon limits of linear
dilaton black holes, making connections with
the seminal paper of CGHS. Along the way we
learn that 1+1 dimensional black holes do not
exhibit much of the interesting behavior
expected of asymptotically flat black holes in
higher dimensions.