Bibliography
Total Page:16
File Type:pdf, Size:1020Kb

Load more
Recommended publications
-
Compact Topological Spaces Inspired by Combinatorial Constructions
Compact Topological Spaces Inspired By Combinatorial Constructions A thesis submitted to the School of Mathematics of the University of East Anglia in partial fulfilment of the requirements for the degree of Doctor of Philosophy Sharifa Al Mahrouqi June, 2013. c This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with the author and that any information derived there from must be in accordance with current UK Copyright Law. In addition, any quotation or extract must include full attribution. Abstract Due to Mr´owka [24], polyadic spaces are compact Hausdorff spaces that are continuous images of some power of the one point compactification αλ of a discrete space λ. It turns out that many results about polyadic spaces hold for a more general class spaces, as we shall show in this thesis. For a sequence λ = hλi : i 2 Ii of cardinals, a compact Hausdorff space X is λ-multiadic if Y it is a continuous image of αλi. It is easy to observe that a λ-multiadic i2I space is λ-polyadic, but whether the converse is true is a motivation of this dissertation. To distinguish the polyadic spaces and multiadic spaces, we consider (αλ)I Y and αλi. We investigate two cases regarding λ: if it is a successor or a i2I limit cardinal. For an inaccessible cardinal λ we clarify by an example that λ Y the polyadic space (αλ) is not an image of αλi. Beside this result we i<λ find a model of set theory using Prikry-like forcing to get an analogous result when λ is singular. -
Weak Convergence of Measures
Mathematical Surveys and Monographs Volume 234 Weak Convergence of Measures Vladimir I. Bogachev Weak Convergence of Measures Mathematical Surveys and Monographs Volume 234 Weak Convergence of Measures Vladimir I. Bogachev EDITORIAL COMMITTEE Walter Craig Natasa Sesum Robert Guralnick, Chair Benjamin Sudakov Constantin Teleman 2010 Mathematics Subject Classification. Primary 60B10, 28C15, 46G12, 60B05, 60B11, 60B12, 60B15, 60E05, 60F05, 54A20. For additional information and updates on this book, visit www.ams.org/bookpages/surv-234 Library of Congress Cataloging-in-Publication Data Names: Bogachev, V. I. (Vladimir Igorevich), 1961- author. Title: Weak convergence of measures / Vladimir I. Bogachev. Description: Providence, Rhode Island : American Mathematical Society, [2018] | Series: Mathe- matical surveys and monographs ; volume 234 | Includes bibliographical references and index. Identifiers: LCCN 2018024621 | ISBN 9781470447380 (alk. paper) Subjects: LCSH: Probabilities. | Measure theory. | Convergence. Classification: LCC QA273.43 .B64 2018 | DDC 519.2/3–dc23 LC record available at https://lccn.loc.gov/2018024621 Copying and reprinting. Individual readers of this publication, and nonprofit libraries acting for them, are permitted to make fair use of the material, such as to copy select pages for use in teaching or research. Permission is granted to quote brief passages from this publication in reviews, provided the customary acknowledgment of the source is given. Republication, systematic copying, or multiple reproduction of any material in this publication is permitted only under license from the American Mathematical Society. Requests for permission to reuse portions of AMS publication content are handled by the Copyright Clearance Center. For more information, please visit www.ams.org/publications/pubpermissions. Send requests for translation rights and licensed reprints to [email protected]. -
ON SEPARABLE SUPPORTS of BOREL MEASURES Let E
GEORGIAN MATHEMATICAL JOURNAL: Vol. 2, No. 1, 1995, 45-53 ON SEPARABLE SUPPORTS OF BOREL MEASURES A. KHARAZISHVILI Abstract. Some properties of Borel measures with separable sup- ports are considered. In particular, it is proved that any σ-finite Borel measure on a Suslin line has a separable supports and from this fact it is deduced, using the continuum hypothesis, that any Suslin line contains a Luzin subspace with the cardinality of the continuum. Let E be a topological space. We say that the space E has the pro- perty (S) if for every σ-finite Borel measure µ defined in this space there exists a separable support, i.e., a separable closed set F (µ) E such that µ(E F (µ)) = 0. ⊂ Letn us consider some examples of topological spaces having the property (S). Example 1. It is obvious that any separable topological space E has the property (S). Example 2. Let E be an arbitrary metric space whose topological weight is not measurable in a wide sense. Then according to the well-known result from the topological measure theory the space E has the property (S). Example 3. Let E be the Alexandrov compactification of some discrete topological space. Then the following statements are equivalent: a) the space E has the property (S); b) card(E) is not measurable in a wide sense. Example 4. Let E be a Hausdorff topological space. We say that E is a Luzin space if every σ-finite diffused (i.e., continuous) Borel measure defined in E is identically zero. The classical Luzin set on the real line R is a Luzin topological space (about Luzin sets see, for example, [1]). -
Spaces Not Distinguishing Convergences of Real-Valued Functions
Topology and its Applications 112 (2001) 13–40 Spaces not distinguishing convergences of real-valued functions Lev Bukovský a, Ireneusz Recław b, Miroslav Repický c,∗ a Department of Computer Science, University of P.J. Šafárik, Jesenná 5, 041 54 Košice, Slovakia b Institute of Mathematics, University of Gda´nsk, Wita Stwosa 57, 80952 Gda´nsk, Poland c Mathematical Institute, Slovak Academy of Sciences, Jesenná 5, 041 54 Košice, Slovakia Received 6 March 1998; received in revised form 7 September 1999 Abstract In [Topology Appl. 41 (1991) 25] we have introduced the notion of a wQN-space as a space in which for every sequence of continuous functions pointwisely converging to 0 there is a subsequence quasi-normally converging to 0. In the present paper we continue this investigation and generalize some concepts touched there. The content is a variety of notions and relationships among them. The result is another scale in the investigation of smallness and the question is how this scale fits with other known scales and whether all relations in it are proper. 2001 Elsevier Science B.V. All rights reserved. Keywords: mQN-space; Σ-space; wQN-space; QN-space; QN-space; ΣQN-space; wΣQN-space; Weak distributivity of a family of sets AMS classification: 54G99; 54C30 0. Introduction In [6] we have introduced the notion of a wQN-space as a space in which for every sequence of continuous functions pointwisely converging to 0 there is a subsequence quasi- normally converging to 0, i.e., the wQN-space does not distinguish pointwise and quasi- normal convergence. The motivation for introducing this notion comes from the theory of thin sets of trigonometric series and actually our knowledge about wQN-spaces was used in [5]. -
Cardinal Invariants of the Continuum — a Survey
Cardinal invariants of the continuum — A survey J¨org Brendle∗ The Graduate School of Science and Technology Kobe University Rokko–dai 1–1, Nada–ku Kobe 657–8501, Japan [email protected] February 3, 2004 Abstract These are expanded notes of a series of two lectures given at the meeting on axiomatic set theory at Ky¯otoUniversity in November 2000. The lectures were intended to survey the state of the art of the theory of cardinal invariants of the continuum, and focused on the interplay between iterated forcing theory and car- dinal invariants, as well as on important open problems. To round off the present written account of this survey, we also include sections on ZFC–inequalities be- tween cardinal invariants, and on applications outside of set theory. However, due to the sheer size of the area, proofs had to be mostly left out. While being more comprehensive than the original talks, the personal flavor of the latter is preserved in the notes. Some of the material included was presented in talks at other conferences. ∗Supported by Grant–in–Aid for Scientific Research (C)(2)12640124, Japan Society for the Promotion of Science 1 1 What are cardinal invariants? We plan to look at certain basic features of the real line R from the point of view of combinatorial set theory. For our purposes, it is convenient to work with the Cantor space 2ω or the Baire space ωω instead of R itself. Here we put, as usual, 2 = {0, 1} ω = N = {0, 1, 2, 3, ...} = the natural numbers 2ω = the set of functions from ω to 2 ωω = the set of functions from ω to ω. -
Residual Measures in Locally Compact Spaces
CORE Metadata, citation and similar papers at core.ac.uk Provided by Elsevier - Publisher Connector Topology and its Applications 108 (2000) 253–265 Residual measures in locally compact spaces Ondrejˇ Zindulka Department of Mathematics, Faculty of Civil Engineering, Czech Technical University, Thákurova 7, 160 00 Prague 6, Czech Republic Received 23 November 1998; received in revised form 21 May 1999 Abstract A σ -finite diffused Borel measure in a topological space is called residual if each nowhere dense set has measure zero. If the measure is also fully supported, then it is called normal. Results on the influence of Martin’s Axiom and the Continuum Hypothesis on the existence of residual and normal measures in locally compact spaces are obtained. A connection with L-spaces is established. 2000 Elsevier Science B.V. All rights reserved. Keywords: Borel measure; Residual measure; Normal measure; Jordan measure; Meager set; L-space; Martin’s Axiom; Continuum Hypothesis AMS classification: 28C15; 03E50 1. Introduction A σ -finite diffused Borel measure in a topological space is called residual if each nowhere dense set has measure zero. The Lebesgue measure in the real line that is provided with the density topology provides a nice example of a residual measure: The topology and measure are nicely related—a set is nowhere dense iff it is meager iff it is closed and discrete iff it is of outer measure zero. Other nice examples are provided by Stone spaces of measurable algebras: Spaces that are extremally disconnected and compact and are inhabited by a finite measure which zero sets are exactly those that are nowhere dense. -
Arxiv:1904.03642V2
Kantorovich problems and conditional measures depending on a parameter Vladimir I. Bogacheva,b,1, Ilya I. Malofeeva a Department of Mechanics and Mathematics, Moscow State University, 119991 Moscow, Russia b National Research University Higher School of Economics, Moscow, Russia Abstract. We study measurable dependence of measures on a parameter in the following two classical problems: constructing conditional measures and the Kan- torovich optimal transportation. For parametric families of measures and mappings we prove the existence of conditional measures measurably depending on the pa- rameter. A particular emphasis is made on the Borel measurability (which cannot be always achieved). Our second main result gives sufficient conditions for the Borel measurability of optimal transports and transportation costs with respect to a parameter in the case where marginal measures and cost functions depend on a parameter. As a corollary we obtain the Borel measurability with respect to the parameter for disintegrations of optimal plans. Finally, we show that the Skorohod parametrization of measures by mappings can be also made measurable with respect to a parameter. Keywords: Kantorovich problem, conditional measure, weak convergence, mea- surable dependence on a parameter, Skorohod representation AMS MSC 2010: 28C15, 60G57, 46G12 1. Introduction We recall that, given two probability spaces (X, BX ,µ) and (Y, BY , ν) and a non- negative BX ⊗ BY -measurable function h on X × Y (called a cost function), the associated Kantorovich problem is to find the infimum of the integral Ih(σ) := h dσ Z over all probability measures σ on B ⊗ B with projections µ and ν on the factors. arXiv:1904.03642v2 [math.FA] 3 Jul 2019 X Y This infimum is denoted by Kh(µ, ν) and called the transportation cost for h, µ, ν. -
Regular and Irregular Measures on Groups and Dyadic Spaces
Pacific Journal of Mathematics REGULAR AND IRREGULAR MEASURES ON GROUPS AND DYADIC SPACES HAROLD L. PETERSON,JR. Vol. 28, No. 1 March 1969 PACIFIC JOURNAL OF MATHEMATICS Vol. 28, No. 1, 1969 REGULAR AND IRREGULAR MEASURES ON GROUPS AND DYADIC SPACES H. LEROY PETERSON It is generally known that if I is a <7-compact metric space, then every Borel measure on X is regular. It is not difficult to prove a slightly stronger result, namely that the same conclusion holds if X is a Hausdorff space in which every open subset is σ-compact (1.6 below). The converse is not generally true, even for compact Hausdorff spaces; a counter-example appears here under IV. 1. However, it will be shown in § II that every nondegenerate Borel measure on a nondiscrete locally compact group is regular if and only if the group is cr-compact and metrizable. A similar theorem, proved in § III, holds for dyadic spaces: every Borel measure on such a space is regular if and only if the space is metric. The result for groups depends on two structure theorems which are proved here: every nonmetrizable compact connected group contains a nonmetrizable connected Abelian subgroup (11.10), and every nonmetrizable locally compact group contains a nonmetrizable compact totally disconnected subgroup (11.11). In § III, it seems that the separable case requires special attention: a theorem is proved which has as a corollary that every separable dyadic space is a continuous image of {0,1}C (III.3 and III.4), and one lemma (III.6) uses a weakened version of the continuum hypothesis. -
Supercompact Spaces
Topology and its Applications 13 (1982) 21-32 21 North-Holland Publishing Company SUPERCOMPACT SPACES Eric van DOUWEN Institute for Medicine and Mathematics, Ohio University, Athens, OH 45701, USA Jan van MILL Wiskundig Seminarium; Vrije Uniuersueit; Amsterdam, The Netherlands Received 16 November 1976 Revised 16 May 1980 We prove the following theorem: Let Y be a Hausdorff space which is the continuous image of a supercompaet Hausdorff space, and let K be a countably infinite subset of Y. Then (a) at least one cluster point of K is the limit of a nontrivial convergent sequence in Y (not necessarily in K), and (b) at most countably many cluster points of K are not the limit of some nontrivial sequence in Y. This theorem implies that spaces like (3N and (3N\N are not supercompact. Moreover we will give an example of a separable first countable compact Hausdorff space which is not supercompact. AMS Subj. Class. (1980): 54030 supercompact network Cantor tree 1. Introduction A family ff of subsets of a space X is a subbase for the closed subsets of X, or a closed subbase for short, if {(t{U fJ': fJ'e ~}: ~ a collection of finite subfamilies of 9'} is precisely the family of closed subsets of X. By Alexander's subbase lemma a space is compact if and only if it has a closed subbase ~very centered (=any finite subfamily has nonempty intersection) subfamily of which has nonempty intersection. In [15], de Groot defined a space to be supercompact if it has a closed subbase every linked (=any subfamily with at most two members has nonempty intersection) subfamily of which has nonempty intersection. -
On Generalizations of Dyadic Spaces
Acta Universitatis Carolinae. Mathematica et Physica Marian Turzański On generalizations of dyadic spaces Acta Universitatis Carolinae. Mathematica et Physica, Vol. 30 (1989), No. 2, 153--159 Persistent URL: http://dml.cz/dmlcz/701809 Terms of use: © Univerzita Karlova v Praze, 1989 Institute of Mathematics of the Academy of Sciences of the Czech Republic provides access to digitized documents strictly for personal use. Each copy of any part of this document must contain these Terms of use. This paper has been digitized, optimized for electronic delivery and stamped with digital signature within the project DML-CZ: The Czech Digital Mathematics Library http://project.dml.cz 1989 ACTA UNIVERSITATIS CAROLINAE—MATHEMATICA ET PHYSICA VOL. 30. NO. 2 On Generalizations of Dyadic Spaces M. TURZANSKI Katowice*) Received 15 March 1989 The class of dyadic compact spaces (the continuous images of generalized Cantor discontinua) which is a natural generalization of the class of compact metric spaces and which is the smallest class containing the class of compact metric spaces closed with respect to cartesian products and continuous images was introduced by P. S. Alexandroff [1] in 1936. This class has a lot of nice properties and is the subject of many papers. In the 70-es a new aproach concerning the theory of dyadic spaces appeared. A. V. Arhangelskii in [2] introduced the class of dantian spaces and the class of thick spaces and put the question "is each dantian space dyadic?" It was proved later by L. B. Sapiro [9] that the answer is no. In 1970 S. Mrowka [7] introduced the class of polyadic spaces; the continuous images of the products of the one point compactifications of the discrete spaces, and in 1985 M. -
A Note on the $ Luc-$ Compactification of Locally Compact Groups
A NOTE ON THE LUC-COMPACTIFICATION OF LOCALLY COMPACT GROUPS SAFOURA JAFAR-ZADEH Abstract. Let G be a locally compact non-compact topological group. We show that Gluc (G∗) is an F-space if and only if G is a discrete group. 1. Introduction Let G be a Hausdorff locally compact group and Cb(G) denote the Banach space of bounded continuous functions on G with the uniform norm. An element f in Cb(G) is called left uniformly continuous if g 7→ lgf, where lgf(x)= f(gx) is a continuous map from G to Cb(G). Let LUC(G) denote the Banach space of left uniformly continuous functions with the uniform norm. It can be seen that Cc(G) the space of continuous compactly supported functions on G is a subspace of LUC(G). The dual space of LUC(G), LUC(G)∗, with the following Arens-type product forms a Banach algebra: < m.n, f >=< m, nf > and < nf, g >=< n,lg(f) >, where m, n ∈ LUC(G)∗, f ∈ LUC(G) and g ∈ G. In fact this product is an extension to LUC(G)∗ of the convolution product on M(G). The luc-compactification of a locally compact group G, denoted by Gluc can be regarded as a generalization to locally compact groups, of the familiar Stone-Cech compactification for discrete groups. As a topological space, Gluc is the Gelfand spectrum of the unital commutative C∗−algebra of left uniformly continuous func- tions on G, i.e., LUC(G) = C(Gluc). The restriction of the product on LUC(G)∗ arXiv:1401.4775v1 [math.FA] 20 Jan 2014 to the subset Gluc of LUC(G)∗ turns Gluc into a semigroup. -
On Countably Compact Topologies on Compact Groups and on Dyadic Compacta
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector TOPOLOGY AND ITS APPLICATIONS ELSEVIER Topology and its Applications 57 (1994) 163-181 On countably compact topologies on compact groups and on dyadic compacta A.V. Arhangel’skii a,b a Department of Mathematics, Moscow State Vniversiiy, Moscow 119899, Russia ’ Department of Mathematics, Ohio University, Athens, OH, USA (Received 11 December 1992; revised 14 January 1993,6 September 1993) Abstract In this paper we apply certain classical results of S. Mazur, J. Keisler, A. Tarski and N.Th. Varopoulos to the theory of countably compact topological groups. For example, under a mild restriction on the cardinality of a compact group G, it is proved that there is no strictly stronger countably compact group topology on G. If f is a one-to-one continuous mapping of a countably compact topological group of countable tightness onto a compact Hausdorff space X, then X is metrizable. If a countably compact topological group of countable tightness acts continuously and transitively on a compact Hausdorff space X, then X is metrizable. Among the questions left unsettled is this: Let f be a sequentially continuous homomor- phism of a compact topological group G onto a topological group H. Is then H countably compact? Equivalently, is then H totally bounded? Under Martin’s axiom this question is answered positively. Key words: Countably compact group; Totally bounded group; Quotient mapping; Sequen- tially continuous mapping; Ulam measurable cardinal; Sequential cardinal AMS (MOS) Subj. Class.: 54AQ.5, 2OK45, 22CO5 In terminology we follow [1,7,8].