New solutions with accelerated expansion in string theory
  We present concrete solutions with accelerated expansion in string theory,
requiring a small, tractable list of stress energy sources. We explain how this
construction (and others in progress) evades previous no go theorems for simple
accelerating solutions. Our solutions respect an approximate scaling symmetry
and realize discrete sequences of values for the equation of state, including
one with an accumulation point at w=-1 and another accumulating near w=-1/3
from below. In another class of models, a density of defects generates scaling
solutions with accelerated expansion. We briefly discuss potential applications
to dark energy phenomenology, and to holography for cosmology.
