Subgroups of direct products closely approximated by direct sums

Maria V. Ferrer, Salvador Hernandez, Dmitri Shakhmatov

Let $I$ be an infinite set, $\{G_i:i\in I\}$ be a family of (topological) groups and $G={\prod }_{i\in I}{G}_i$ be its direct product. For $J\subseteq I$, $p_{J}: G\to \prod_{j\in J} G…