Baire property in product spaces


  • Constancio Hernández Universidad Autónoma Metropolitana
  • Leonardo Rodríguez Medina Universidad Autónoma Metropolitana
  • Mikhail Tkachenko Universidad Autónoma Metropolitana



Baire space, strongly Baire space, skeletal mapping, Banach-Mazur-Choquet game, paratopological group, semitopological group.


We show that if a product space $\mathit\Pi$ has countable cellularity, then a dense subspace $X$ of $\mathit\Pi$ is Baire provided that all projections of $X$ to countable subproducts of $\mathit\Pi$ are Baire. It follows that if $X_i$ is a dense Baire subspace of a product of spaces having countable $\pi$-weight, for each $i\in I$, then the product space $\prod_{i\in I} X_i$ is Baire. It is also shown that the product of precompact Baire paratopological groups is again a precompact Baire paratopological group. Finally, we focus attention on the so-called \textit{strongly Baire} spaces and prove that some Baire spaces are in fact strongly Baire.


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How to Cite

C. Hernández, L. Rodríguez Medina, and M. Tkachenko, “Baire property in product spaces”, Appl. Gen. Topol., vol. 16, no. 1, pp. 1–13, Feb. 2015.