Geodesic
Selections on $\Psi$-spaces
Commentationes Mathematicae Universitatis Carolinae, Tome 42 (2001) no. 4, pp. 763-769 Cet article a éte moissonné depuis la source Czech Digital Mathematics Library

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We show that if $\Cal A$ is an uncountable AD (almost disjoint) family of subsets of $\omega$ then the space $\Psi(\Cal A)$ does not admit a continuous selection; moreover, if $\Cal A$ is maximal then $\Psi(\Cal A)$ does not even admit a continuous selection on pairs, answering thus questions of T. Nogura.
We show that if $\Cal A$ is an uncountable AD (almost disjoint) family of subsets of $\omega$ then the space $\Psi(\Cal A)$ does not admit a continuous selection; moreover, if $\Cal A$ is maximal then $\Psi(\Cal A)$ does not even admit a continuous selection on pairs, answering thus questions of T. Nogura.
Classification : 03E05, 54B20, 54C65
Keywords: MAD family; Vietoris topology; continuous selection 
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     title = {Selections on $\Psi$-spaces},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {763--769},
     year = {2001},
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Hrušák, M.; Szeptycki, P. J.; Tomita, A. H. Selections on $\Psi$-spaces. Commentationes Mathematicae Universitatis Carolinae, Tome 42 (2001) no. 4, pp. 763-769. http://geodesic.mathdoc.fr/item/CMUC_2001_42_4_a15/