English

A note on tameness of families having bounded variation

General Topology 2016-12-20 v5 Functional Analysis

Abstract

We show that for arbitrary linearly ordered set XX any bounded family of (not necessarily, continuous) real valued functions on XX with bounded total variation does not contain independent sequences. We obtain generalized Helly's sequential compactness type theorems. One of the theorems asserts that for every compact metric space (Y,d)(Y,d) the compact space BVr(X,Y)BV_r(X,Y) of all functions XYX \to Y with variation r\leq r is sequentially compact in the pointwise topology. Another Helly type theorem shows that the compact space M+(X,Y)M_+(X,Y) of all order preserving maps XYX \to Y is sequentially compact where YY is a compact metrizable partially ordered space in the sense of Nachbin.

Keywords

Cite

@article{arxiv.1412.1515,
  title  = {A note on tameness of families having bounded variation},
  author = {Michael Megrelishvili},
  journal= {arXiv preprint arXiv:1412.1515},
  year   = {2016}
}

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11 pages