Structural properties of extremal asymmetric colorings

Let Ω be a space with probability measure µ for which the notion of symmetry is defined. Given A ⊆ Ω, let ms(A) denote the supremum of µ(B) over symmetric B ⊆ A. An r-coloring of Ω is a measurable map χ : Ω → {1, . . . , r} possibly undefined on a set of measure 0. Given an r-coloring χ, let ms(Ω; χ...

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Published in:Algebra and Discrete Mathematics
Date:2003
Main Author: Verbitsky, O.
Format: Article
Language:English
Published: Інститут прикладної математики і механіки НАН України 2003
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/155696
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Journal Title:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Cite this:Structural properties of extremal asymmetric colorings / O. Verbitsky // Algebra and Discrete Mathematics. — 2003. — Vol. 2, № 4. — С. 92–117. — Бібліогр.: 12 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-155696
record_format dspace
spelling Verbitsky, O.
2019-06-17T10:52:28Z
2019-06-17T10:52:28Z
2003
Structural properties of extremal asymmetric colorings / O. Verbitsky // Algebra and Discrete Mathematics. — 2003. — Vol. 2, № 4. — С. 92–117. — Бібліогр.: 12 назв. — англ.
1726-3255
2000 Mathematics Subject Classification: 05D10.
https://nasplib.isofts.kiev.ua/handle/123456789/155696
Let Ω be a space with probability measure µ for which the notion of symmetry is defined. Given A ⊆ Ω, let ms(A) denote the supremum of µ(B) over symmetric B ⊆ A. An r-coloring of Ω is a measurable map χ : Ω → {1, . . . , r} possibly undefined on a set of measure 0. Given an r-coloring χ, let ms(Ω; χ) = max₁≤i≤r ms(χ⁻¹ (i)). With each space Ω we associate a Ramsey type number ms(Ω, r) = infχ ms(Ω; χ). We call a coloring χ congruent if the monochromatic classes χ⁻¹ (1), . . . , χ⁻¹ (r) are pairwise congruent, i.e., can be mapped onto each other by a symmetry of Ω. We define ms* (Ω, r) to be the infimum of ms(Ω; χ) over congruent χ. We prove that ms(S¹ , r) = ms* ([0, 1), r) for the unitary interval of reals considered with central symmetry, and explore some other regularity properties of extremal colorings for various spaces.
I am thankful to Yaroslav Vorobets whose insightful suggestions contributed a lot to this work. I would like also to thank Taras Banakh and Alexander Ravsky for helpful discussions and useful pointers to the literature. I especially thank Alexander Ravsky for careful proofreading of the manuscript and allowing me to announce here his Theorem 5.13.
en
Інститут прикладної математики і механіки НАН України
Algebra and Discrete Mathematics
Structural properties of extremal asymmetric colorings
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Structural properties of extremal asymmetric colorings
spellingShingle Structural properties of extremal asymmetric colorings
Verbitsky, O.
title_short Structural properties of extremal asymmetric colorings
title_full Structural properties of extremal asymmetric colorings
title_fullStr Structural properties of extremal asymmetric colorings
title_full_unstemmed Structural properties of extremal asymmetric colorings
title_sort structural properties of extremal asymmetric colorings
author Verbitsky, O.
author_facet Verbitsky, O.
publishDate 2003
language English
container_title Algebra and Discrete Mathematics
publisher Інститут прикладної математики і механіки НАН України
format Article
description Let Ω be a space with probability measure µ for which the notion of symmetry is defined. Given A ⊆ Ω, let ms(A) denote the supremum of µ(B) over symmetric B ⊆ A. An r-coloring of Ω is a measurable map χ : Ω → {1, . . . , r} possibly undefined on a set of measure 0. Given an r-coloring χ, let ms(Ω; χ) = max₁≤i≤r ms(χ⁻¹ (i)). With each space Ω we associate a Ramsey type number ms(Ω, r) = infχ ms(Ω; χ). We call a coloring χ congruent if the monochromatic classes χ⁻¹ (1), . . . , χ⁻¹ (r) are pairwise congruent, i.e., can be mapped onto each other by a symmetry of Ω. We define ms* (Ω, r) to be the infimum of ms(Ω; χ) over congruent χ. We prove that ms(S¹ , r) = ms* ([0, 1), r) for the unitary interval of reals considered with central symmetry, and explore some other regularity properties of extremal colorings for various spaces.
issn 1726-3255
url https://nasplib.isofts.kiev.ua/handle/123456789/155696
citation_txt Structural properties of extremal asymmetric colorings / O. Verbitsky // Algebra and Discrete Mathematics. — 2003. — Vol. 2, № 4. — С. 92–117. — Бібліогр.: 12 назв. — англ.
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