University of Isfahan International Journal of Group Theory 2251-7650 15 4 2026 12 01 Finite subgroups of automorphisms of free products 169 178 30123 10.22108/ijgt.2025.143507.1934 EN Ioannis Papavasileiou Independent Researcher, Athens, Greece Dionysios Syrigos Independent Researcher, Basingstoke, UK Journal Article 2024 11 26 We study finite subgroups of outer automorphisms of free products. We give upper bounds for the orders of these finite subgroups as well as bounds for the orders of individual torsion outer automorphisms under some (necessary) conditions for the free factors. Automorphisms of free products Finite subgroups Outer space of a free product https://ijgt.ui.ac.ir/article_30123_1eaa7ef72954bb817776875438c29054.pdf