Group isomorphism problem

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

In abstract algebra, the group isomorphism problem is the decision problem of determining whether two given finite group presentations present isomorphic groups.

The isomorphism problem was identified by Max Dehn in 1911 as one of three fundamental decision problems in group theory; the other two being the word problem and the conjugacy problem. All three problems are undecidable: there does not exist a computer algorithm that correctly solves every instance of the isomorphism problem, or of the other two problems, regardless of how much time is allowed for the algorithm to run.[why?]


  • Magnus, Wilhelm; Abraham Karrass; Donald Solitar (1976). Combinatorial group theory. Presentations of groups in terms of generators and relations. Dover Publications. p. 24. ISBN 0-486-63281-4.
  • Johnson, D.L. (1990). Presentations of groups. Cambridge University Press. p. 49. ISBN 0-521-37203-8.
  • Dehn, Max (1911). "Über unendliche diskontinuierliche Gruppen". Math. Ann. 71: 116–144. doi:10.1007/BF01456932.