Lydia Außenhofer

On the Mackey topology on abelian topological groups

For a locally convex vector space  (V,\tau) there exists a finest locally convex vector space topology \mu  such that the topological dual spaces (V,\tau)' and (V,\mu)' coincide algebraically. This topology is called Mackey topology.
If (V,\tau) is a metrizable locally convex vector space, then \tau is the Mackey topology.
In 1995 Chasco, Martín Peinador and Tarieladze asked the following question: Given a locally quasi-convex group (G,\tau), does there exist a finest locally quasi-convex group topology \mu on G such that the character groups (G,\tau)^\wedge and (G,\mu)^\wedge coincide?
In case such a topology exists, it is called the Mackey topology for (G,\tau).
In this talk we give  examples of topological  groups which
– have a Mackey topology,
– do not have a Mackey topology,
and we characterize in the class of bounded abelian groups all locally quasi-convex group topologies which are Mackey.