RT Journal Article T1 Mackey topology on locally convex spaces and on locally quasi-convex groups. Similarities and historical remarks A1 Martin Peinador, E. A1 Taieladze, V. AB A counterpart of the Mackey–Arens Theorem for the class of locally quasi-convex topological Abelian groups (LQC-groups) was initiated in Chasco et al. (Stud Math 132(3):257–284, 1999). Several authors have been interested in the problems posed there and have done clarifying contributions, although the main question of that source remains open. Some differences between the Mackey Theory for locally convex spaces and for locally quasi-convex groups, stem from the following fact: The supremum of all compatible locally quasi-convex topologies for a topological abelian group G may not coincide with the topology of uniform convergence on the weak quasi-convex compact subsets of the dual groupG∧. Thus, a substantial part of the classical Mackey–Arens Theorem cannot be generalized to LQC-groups. Furthermore, the mentioned fact gives rise to a grading in the property of “being a Mackey group”, as defined and thoroughly studied in Díaz Nieto and Martín-Peinador (Proceedings in Mathematics and Statistics 80:119–144, 2014). At present it is not known—and this is the main open question—if the supremum of all the compatible locally quasi-convex topologies on a topological group is in fact a compatible topology. In the present paper we do a sort of historical review on the Mackey Theory, and we compare it in the two settings of locally convex spaces and of locally quasi-convex groups. We point out some general questions which are still open, under the name of Problems. PB Springer-Verlag Italia SN 15787303 YR 2016 FD 2016 LK https://hdl.handle.net/20.500.14352/24648 UL https://hdl.handle.net/20.500.14352/24648 LA eng NO Ministerio de Economía y Competitividad (MINECO) NO Shota Rustaveli National Science Foundation DS Docta Complutense RD 9 abr 2025