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arXiv · 2607.18853

The isomorphism problem for random generalized Baumslag-Solitar groups with many edges

Dario Ascari·Alessandra Caraceni
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Abstract

The isomorphism problem for generalized Baumslag-Solitar (GBS) groups is a long-standing open problem. We prove that, in the random model considered here, a GBS graph with many edges is flexible with high probability. Since the isomorphism problem is decidable for flexible GBS graphs, this gives a high-probability decidability result for random GBS groups in this regime.

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Dario Ascari, Alessandra Caraceni. 2026-07-21. The isomorphism problem for random generalized Baumslag-Solitar groups with many edges. https://arxiv.org/abs/2607.18853

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