Goldstern's principle of the Lebesgue measure and Hausdorff measures

Speaker(s)

Tatsuya Goto

Affiliation

Institut für Diskrete Mathematik und Geometrie, Technische Universität Wien

Language of the talk

English

Date

Nov. 13, 2026, 4:15 p.m.

Seminar

Topology and Set Theory Seminar

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We study Goldstern's principle concerning unions of monotone increasing families of null sets indexed by elements of Baire space. M. Goldstern proved in 1993 that such an analytic family has a null union in the sense of Lebesgue measure. We prove that the coanalytic version is also true and that the version ignoring the definability condition is independent from ZFC. We also study the Hausdorff measure version of this principle.

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