Nondeterministic Linear-Time Tasks May Require Substantially Nonlinear Deterministic Time in the Case of Sublinear Work Space

  • Yuri Gurevich ,
  • Saharon Shelah

We develop a technique to prove time-space trade-offs and exhibit natural search problems (e.g. Log-size Clique Problem) that are solvable in linear time on polylog-space (and sometimes even log-space) nondeterministic Turing machine, but no deterministic machine (in a very general sense of this term) with sequential-access read-only input tape and work space nσ solves the problem within time n1+τ if σ + 2τ < 1/2.