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arXiv · 1109.2225

Isomorphism versus commensurability for a class of finitely presented groups

Goulnara Arzhantseva·Jean-Francois Lafont·Ashot Minasyan
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Abstract

We construct a class of finitely presented groups where the isomorphism problem is solvable but the commensurability problem is unsolvable. Conversely, we construct a class of finitely presented groups within which the commensurability problem is solvable but the isomorphism problem is unsolvable. These are first examples of such a contrastive complexity behaviour with respect to the isomorphism problem.

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Goulnara Arzhantseva, Jean-Francois Lafont, Ashot Minasyan. 2011-09-10. Isomorphism versus commensurability for a class of finitely presented groups. https://arxiv.org/abs/1109.2225

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