Description
In this talk, I will discuss a stringy "post-Newtonian" expansion of string theory. At each order in 1/c², where c is the speed of light, this produces a new string theory which "remembers" the preceding string theories that appear at lower orders. The next-to-leading order (NLO) theory reduces to the Gomis-Ooguri string once a suitable "strong" foliation constraint is imposed. In general, the geometry to which these strings couple is the string 1/c² expansion of Lorentzian geometry, subject to a foliation constraint arising from the string 1/c² expansion of the string β-functions to lowest order in α'. I will showcase the expansion of closed bosonic string theory up to NNLO and make some comments on the expansion of the open string.
