Abstract

I will revisit and extend near-BPS decoupling limits of type II superstring theories and M-theory. These limits generalize the well-known non-relativistic limit of a charged BPS particle. Consequently, non-Lorentzian geometries naturally occur as curved target space geometries, which I will present along with their appearance in worldsheet and worldvolume probe actions. These non-Lorentzian geometries are characterized by tangent space symmetries that follow from Inönü-Wigner contractions of the M-theory superalgebra, and include Newton-Cartan geometry and generalizations. I will discuss the duality web that unifies these decoupling limits and show how it connects different corners such as Matrix theories, non-relativistic string theory, and non-relativistic M-theory. Furthermore, I will exhibit how tensionless string theory, novel Carrollian string theories and Spin Matrix limits of AdS/CFT arise in the duality web.