On the non-uniform complexity of the Graph Isomorphism problem

We study the non-uniform complexity of the Graph Isomorphism (GI) and Graph Automorphism (GA) problems considering the implications of different types of polynomial time reducibilitites from these problems to sparse sets. We show that if GI (or GA) is bounded truth-table or conjunctively reducible t...

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Detalles Bibliográficos
Autores: Lozano Boixadors, Antoni|||0000-0002-3633-063X, Torán Romero, Jacobo
Tipo de recurso: informe técnico
Fecha de publicación:1992
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/368983
Acceso en línea:https://hdl.handle.net/2117/368983
Access Level:acceso abierto
Palabra clave:Computational complexity
Complexitat computacional
Àrees temàtiques de la UPC::Informàtica
Descripción
Sumario:We study the non-uniform complexity of the Graph Isomorphism (GI) and Graph Automorphism (GA) problems considering the implications of different types of polynomial time reducibilitites from these problems to sparse sets. We show that if GI (or GA) is bounded truth-table or conjunctively reducible to a sparse set, then it is in P; while if we suppose that it is truth-table reducible without restrictions to a sparse set (or, equivalently, that it belongs to P/poly) then the problem is low for MA, the class of sets with publishable proofs. With respect to nondeterministic reductions, contrasting with the fact that GI and GA belong to the class NP¿(co-NP/poly) [Schö 88], we show that if the considered problems are btt strong nondeterministically reducible to a sparse set then they are in co-NP. Some of these results are proved using graph constructions that show new properties of the GI and GA problems.