An outstanding open question is how quantum gravity makes sense of cosmologies with timelike singularities. One promising approach to this issue is super-critical string theory. This is a theory in which there are more than ten spacetime dimensions, and time dependent backgrounds are automatically present. A particularly significant issue with this approach, however, is the presence of strong coupling phenomena in the far past. In this talk we give a general proposal for how to deal with this singular behavior: We use compactifications of the conventional 10D superstring to two dimensions as a means to generate super-critical string theories which are automatically UV complete. We give some examples of how to extract the effective worldsheet theory in systems with N = (0,2) supersymmetry. This leads to a rich class of physical and mathematical structures which are of interest in their own right. We illustrate these general points for compactifications of type I and heterotic strings on Calabi-Yau fourfolds, and F-theory on Calabi-Yau fivefolds.
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