A monotone planar circuit (MPC) is a Boolean circuit that can be
embedded in a plane, and that has only AND and OR
gates. Yang showed that the one-input-face
monotone planar circuit value problem (MPCVP) is in NC^2, and
Limaye et. al. improved the bound to ... more >>>

We show that for all functions $t(n) \geq n$, every multitape Turing machine running in time $t$ can be simulated in space only $O(\sqrt{t \log t})$. This is a substantial improvement over Hopcroft, Paul, and Valiant's simulation of time $t$ in $O(t/\log t)$ space from 50 years ago [FOCS 1975, ... more >>>

We explore new directions in simulating complex computations with low space, building on the work of Williams [STOC'25] and Cook-Mertz [STOC'24, SICOMP'25]. We define and study a strengthened version of the parallel external memory model, in which there are $P$ processors each with private internal memory $M$, all of which ... more >>>