Title
Time-space lower bounds for satisfiability
Abstract
We establish the first polynomial time-space lower bounds for satisfiability on general models of computation. We show that for any constant c less than the golden ratio there exists a positive constant d such that no deterministic random-access Turing machine can solve satisfiability in time nc and space nd, where d approaches 1 when c does. On conondeterministic instead of deterministic machines, we prove the same for any constant c less than &2radic;.Our lower bounds apply to nondeterministic linear time and almost all natural NP-complete problems known. In fact, they even apply to the class of languages that can be solved on a nondeterministic machine in linear time and space n1/c.Our proofs follow the paradigm of indirect diagonalization. We also use that paradigm to prove time-space lower bounds for languages higher up in the polynomial-time hierarchy.
Year
DOI
Venue
2005
10.1145/1101821.1101822
J. ACM
Keywords
Field
DocType
constant c,nondeterministic machine,deterministic random-access Turing machine,polynomial time-space,time nc,time-space lower bounds,space nd,deterministic machine,linear time,space n1,lower bound,complexity of satisfiability,Time-space lower bound
Discrete mathematics,Time space,Combinatorics,Existential quantification,Polynomial,Computer science,Satisfiability,Golden ratio,Model of computation
Journal
Volume
Issue
ISSN
52
6
0004-5411
Citations 
PageRank 
References 
30
1.01
19
Authors
4
Name
Order
Citations
PageRank
Lance Fortnow12788352.32
Richard J. Lipton264121796.57
Dieter van Melkebeek348732.80
Anastasios Viglas419715.97