We consider interpretable topological spaces and topological groups in a p-adically closed field K. We identify a special class of "admissible topologies" with topological tameness properties like generic continuity, similar to the topology on definable subsets of K n . We show every interpretable set has at least one admissible topology, and every interpretable group has a unique admissible group topology. We then consider definable compactness (in the sense of Fornasiero) on interpretable groups. We show that an interpretable group is definably compact if and only if it has finitely satisfiable generics (fsg), generalizing an earlier result on definable groups. As a consequence, we see that fsg is a definable property in definable families of interpretable groups, and that any fsg interpretable group defined over Q p is definably isomorphic to a definable group. the subspace topology. Then D is admissible. We will see below that D is not manifold dominated (Example 6.5).
Closure propertiesRemark 4.11. Let X be a finite interpretable set with the discrete topology. Then X is strongly admissible. In fact, X is a definable manifold.In the category of topological spaces, the class of open maps is closed under composition and base change. Consequently, ifProposition 4.12. The following classes of interpretable topological spaces are closed under finite disjoint unions and finite products.1. The class of locally definable spaces.
The class of locally Euclidean spaces.3. The class of definably dominated spaces.
The class of manifold dominated spaces.5. The class of admissible spaces.
The class of strongly admissible spaces.Proof. We focus on binary disjoint unions and binary products. (The 0-ary cases are handled by Remark 4.11.)Cases ( 2) and (1) are straightforward. For (3), let X 1 , X 2 be two definably dominated spaces. Let f i : Y i → X i be a map witnessing definable domination for i = 1, 2. Up to definable homeomorphism, Y 1 ⊔ Y 2 is a definable set, and sois definably dominated. The proof for (4) is similar. Then (1) and (3) give (5), while (2) and ( 4) give (6).Say that a class C of interpretable topological spaces is "closed under subspaces" if C contains every interpretable subspace of every X ∈ C. Proposition 4.13. The following classes of interpretable topological spaces are closed under subspaces:1. The class of locally definable spaces.2. The class of definably dominated spaces.