18Hofmann, Karl
8Gabriyelyan, Saak
7Leiderman, Arkady
5Mammadov, Musa
5Tilakaratne, Chandima
2Chalebgwa, Taboka
2Hernández, Salvador
2McPhail, Carolyn
2Tkachenko, Mikhail
1Hurst, Cameron
1Itzkowitz, Gerald
1Kakol, Jerzy
1Krupski, Mikolaj
1Poguntke, D.
1Tkachuk, Vladimir
1Yost, David

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250101 Pure Mathematics
6Mathematics
5Lie group
4Pro-Lie groups
4Topological group
3Abelian topological group
3Banach space
3Exponential function
3Free locally convex space
3Free topological vector space
3Lie algebra
3Projective limit
3Quotient group
3Separable quotient problem
201 Mathematical Sciences
20199 Other Mathematical Sciences
20802 Computation Theory and Mathematics
2Compact groups
2Coproducts
2Embedding

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A continuous homomorphism of a thin set onto a fat set

- Chalebgwa, Taboka, Morris, Sidney

**Authors:**Chalebgwa, Taboka , Morris, Sidney**Date:**2022**Type:**Text , Journal article**Relation:**Bulletin of the Australian Mathematical Society Vol. 106, no. 3 (2022), p. 500-503**Full Text:**false**Reviewed:****Description:**A thin set is defined to be an uncountable dense zero-dimensional subset of measure zero and Hausdorff measure zero of an Euclidean space. A fat set is defined to be an uncountable dense path-connected subset of an Euclidean space which has full measure, that is, its complement has measure zero. While there are well-known pathological maps of a set of measure zero, such as the Cantor set, onto an interval, we show that the standard addition on

A novel approach for predicting trading signals of a stock market index

- Tilakaratne, Chandima, Mammadov, Musa, Morris, Sidney

**Authors:**Tilakaratne, Chandima , Mammadov, Musa , Morris, Sidney**Date:**2010**Type:**Text , Book chapter**Relation:**Forecasting models: Methods and applications p. 145-160**Full Text:**false**Reviewed:**

A remark on the separable quotient problem for topological groups

**Authors:**Morris, Sidney**Date:**2019**Type:**Text , Journal article**Relation:**Bulletin of the Australian Mathematical Society Vol. 100, no. 3 (Dec 2019), p. 453-457**Full Text:**false**Reviewed:****Description:**The Banach-Mazur separable quotient problem asks whether every infinite-dimensional Banach space B has a quotient space that is an infinite-dimensional separable Banach space. The question has remained open for over 80 years, although an affirmative answer is known in special cases such as when B is reflexive or even a dual of a Banach space. Very recently, it has been shown to be true for dual-like spaces. An analogous problem for topological groups is: Does every infinite-dimensional (in the topological sense) connected (Hausdorff) topological group G have a quotient topological group that is infinite dimensional and metrisable? While this is known to be true if G is the underlying topological group of an infinite-dimensional Banach space, it is shown here to be false even if G is the underlying topological group of an infinite-dimensional locally convex space. Indeed, it is shown that the free topological vector space on any countably infinite k(omega)-space is an infinite-dimensional toplogical vector space which does not have any quotient topological group that is infinite dimensional and metrisable. By contrast, the Graev free abelian topological group and the Graev free topological group on any infinite connected Tychonoff space, both of which are connected topological groups, are shown here to have the tubby torus T-omega, which is an infinite-dimensional metrisable group, as a quotient group.

A topological group observation on the Banach-Mazur separable quotient problem

- Gabriyelyan, Saak, Morris, Sidney

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2019**Type:**Text , Journal article**Relation:**Topology and Its Applications Vol. 259, no. (2019), p. 283-286**Full Text:****Reviewed:****Description:**The Separable Quotient Problem of Banach and Mazur asks if every infinite-dimensional Banach space has an infinite-dimensional separable quotient Banach space. It has remained unsolved for 85 years but has been answered in the affirmative for special cases such as reflexive Banach spaces. An affirmative answer to the Separable Quotient Problem would obviously imply that every infinite-dimensional Banach space has a quotient topological group which is separable, metrizable, and infinite-dimensional in the sense of topology. In this paper it is proved that every infinite-dimensional Banach space has as a quotient group the separable metrizable infinite-dimensional topological group, T

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2019**Type:**Text , Journal article**Relation:**Topology and Its Applications Vol. 259, no. (2019), p. 283-286**Full Text:****Reviewed:****Description:**The Separable Quotient Problem of Banach and Mazur asks if every infinite-dimensional Banach space has an infinite-dimensional separable quotient Banach space. It has remained unsolved for 85 years but has been answered in the affirmative for special cases such as reflexive Banach spaces. An affirmative answer to the Separable Quotient Problem would obviously imply that every infinite-dimensional Banach space has a quotient topological group which is separable, metrizable, and infinite-dimensional in the sense of topology. In this paper it is proved that every infinite-dimensional Banach space has as a quotient group the separable metrizable infinite-dimensional topological group, T

Advances in the theory of compact groups and pro-lie groups in the last quarter century

- Hofmann, Karl, Morris, Sidney

**Authors:**Hofmann, Karl , Morris, Sidney**Date:**2021**Type:**Text , Journal article , Review**Relation:**Axioms Vol. 10, no. 3 (2021), p.**Full Text:****Reviewed:****Description:**This article surveys the development of the theory of compact groups and pro-Lie groups, contextualizing the major achievements over 125 years and focusing on some progress in the last quarter century. It begins with developments in the 18th and 19th centuries. Next is from Hilbert’s Fifth Problem in 1900 to its solution in 1952 by Montgomery, Zippin, and Gleason and Yamabe’s important structure theorem on almost connected locally compact groups. This half century included profound contributions by Weyl and Peter, Haar, Pontryagin, van Kampen, Weil, and Iwasawa. The focus in the last quarter century has been structure theory, largely resulting from extending Lie Theory to compact groups and then to pro-Lie groups, which are projective limits of finite-dimensional Lie groups. The category of pro-Lie groups is the smallest complete category containing Lie groups and includes all compact groups, locally compact abelian groups, and connected locally compact groups. Amongst the structure theorems is that each almost connected pro-Lie group G is homeomorphic to RI × C for a suitable set I and some compact subgroup C. Finally, there is a perfect generalization to compact groups G of the age-old natural duality of the group algebra R[G] of a finite group G to its representation algebra R(G, R), via the natural duality of the topological vector space RI to the vector space R(I), for any set I, thus opening a new approach to the Hochschild-Tannaka duality of compact groups. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

**Authors:**Hofmann, Karl , Morris, Sidney**Date:**2021**Type:**Text , Journal article , Review**Relation:**Axioms Vol. 10, no. 3 (2021), p.**Full Text:****Reviewed:****Description:**This article surveys the development of the theory of compact groups and pro-Lie groups, contextualizing the major achievements over 125 years and focusing on some progress in the last quarter century. It begins with developments in the 18th and 19th centuries. Next is from Hilbert’s Fifth Problem in 1900 to its solution in 1952 by Montgomery, Zippin, and Gleason and Yamabe’s important structure theorem on almost connected locally compact groups. This half century included profound contributions by Weyl and Peter, Haar, Pontryagin, van Kampen, Weil, and Iwasawa. The focus in the last quarter century has been structure theory, largely resulting from extending Lie Theory to compact groups and then to pro-Lie groups, which are projective limits of finite-dimensional Lie groups. The category of pro-Lie groups is the smallest complete category containing Lie groups and includes all compact groups, locally compact abelian groups, and connected locally compact groups. Amongst the structure theorems is that each almost connected pro-Lie group G is homeomorphic to RI × C for a suitable set I and some compact subgroup C. Finally, there is a perfect generalization to compact groups G of the age-old natural duality of the group algebra R[G] of a finite group G to its representation algebra R(G, R), via the natural duality of the topological vector space RI to the vector space R(I), for any set I, thus opening a new approach to the Hochschild-Tannaka duality of compact groups. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

An open mapping theorem

- Gabriyelyan, Saak, Morris, Sidney

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2016**Type:**Text , Journal article**Relation:**Bulletin of the Australian Mathematical Society Vol. 94, no. 1 (2016), p. 65-69**Full Text:****Reviewed:****Description:**It is proved that any surjective morphism f : Z(k) -> K onto a locally compact group K is open for every cardinal k. This answers a question posed by Hofmann and the second author.

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2016**Type:**Text , Journal article**Relation:**Bulletin of the Australian Mathematical Society Vol. 94, no. 1 (2016), p. 65-69**Full Text:****Reviewed:****Description:**It is proved that any surjective morphism f : Z(k) -> K onto a locally compact group K is open for every cardinal k. This answers a question posed by Hofmann and the second author.

An open mapping theorem for pro-Lie groups

- Hofmann, Karl, Morris, Sidney

**Authors:**Hofmann, Karl , Morris, Sidney**Date:**2007**Type:**Text , Journal article**Relation:**Journal of the Australian Mathematical Society Vol. 83, no. 1 (2007), p. 55-77**Full Text:**false**Reviewed:****Description:**A pro-Lie group is a projective limit of finite dimensional Lie groups. It is proved that a surjective continuous group homomorphism between connected pro-Lie groups is open. In fact this remains true for almost connected pro-Lie groups where a topological group is called almost connected if the factor group modulo the identity component is compact. As consequences we get a Closed Graph Theorem and the validity of the Second Isomorphism Theorem for pro-Lie groups in the almost connected context. © 2007 Australian Mathematical Society.**Description:**C1**Description:**2003005492

Cardinalities of locally compact groups and their Stone-Čech compactifications

- Itzkowitz, Gerald, Morris, Sidney, Tkachuk, Vladimir

**Authors:**Itzkowitz, Gerald , Morris, Sidney , Tkachuk, Vladimir**Date:**2003**Type:**Text , Journal article**Relation:**Bulletin of the Australian Mathematical Society Vol. 67, no. 3 (2003), p. 353-364**Full Text:**false**Reviewed:****Description:**If G is any Hausdorff topological group and**Description:**C1**Description:**2003000377

Compact homeomorphism groups are profinite

- Hofmann, Karl, Morris, Sidney

**Authors:**Hofmann, Karl , Morris, Sidney**Type:**Text , Journal article**Relation:**Topology and its Applications Vol. , no. (), p.**Full Text:**false**Reviewed:****Description:**If the homeomorphism group H (X) of a Tychonoff space X is compact in the compact open topology, then it is a profinite topological group. © 2012.

Contributions to the structure theory of connected pro-Lie groups

- Morris, Sidney, Hofmann, Karl

**Authors:**Morris, Sidney , Hofmann, Karl**Date:**2009**Type:**Text , Journal article**Relation:**Topology Proceedings Vol. 33, no. (2009), p. 225-237**Full Text:**false**Description:**We present some recent results in the structure theory of pro-Lie groups and locally compact groups, improvements of known results, and open problems.

Density character of subgroups of topological groups

- Leiderman, Arkady, Morris, Sidney, Tkachenko, Mikhail

**Authors:**Leiderman, Arkady , Morris, Sidney , Tkachenko, Mikhail**Date:**2017**Type:**Text , Journal article**Relation:**Transactions of the American Mathematical Society Vol. 369, no. 8 (2017), p. 5645-5664**Full Text:****Reviewed:****Description:**We give a complete characterization of subgroups of separable topological groups. Then we show that the following conditions are equivalent for an omega-narrow topological group G: (i) G is homeomorphic to a subspace of a separable regular space; (ii) G is topologically isomorphic to a subgroup of a separable topological group; (iii) G is topologically isomorphic to a closed subgroup of a separable path-connected, locally path-connected topological group. A pro-Lie group is a projective limit of finite-dimensional Lie groups. We prove here that an almost connected pro-Lie group is separable if and only if its weight is not greater than the cardinality c of the continuum. It is deduced from this that an almost connected pro-Lie group is separable if and only if it is homeomorphic to a subspace of a separable Hausdorff space. It is also proved that a locally compact (even feathered) topological group G which is a subgroup of a separable Hausdorff topological group is separable, but the conclusion is false if it is assumed only that G is homeomorphic to a subspace of a separable Tychonoff space. We show that every precompact (abelian) topological group of weight less than or equal to c is topologically isomorphic to a closed subgroup of a separable pseudocompact (abelian) group of weight c. This result implies that there is a wealth of closed non-separable subgroups of separable pseudocompact groups. An example is also presented under the Continuum Hypothesis of a separable countably compact abelian group which contains a non-separable closed subgroup.

**Authors:**Leiderman, Arkady , Morris, Sidney , Tkachenko, Mikhail**Date:**2017**Type:**Text , Journal article**Relation:**Transactions of the American Mathematical Society Vol. 369, no. 8 (2017), p. 5645-5664**Full Text:****Reviewed:****Description:**We give a complete characterization of subgroups of separable topological groups. Then we show that the following conditions are equivalent for an omega-narrow topological group G: (i) G is homeomorphic to a subspace of a separable regular space; (ii) G is topologically isomorphic to a subgroup of a separable topological group; (iii) G is topologically isomorphic to a closed subgroup of a separable path-connected, locally path-connected topological group. A pro-Lie group is a projective limit of finite-dimensional Lie groups. We prove here that an almost connected pro-Lie group is separable if and only if its weight is not greater than the cardinality c of the continuum. It is deduced from this that an almost connected pro-Lie group is separable if and only if it is homeomorphic to a subspace of a separable Hausdorff space. It is also proved that a locally compact (even feathered) topological group G which is a subgroup of a separable Hausdorff topological group is separable, but the conclusion is false if it is assumed only that G is homeomorphic to a subspace of a separable Tychonoff space. We show that every precompact (abelian) topological group of weight less than or equal to c is topologically isomorphic to a closed subgroup of a separable pseudocompact (abelian) group of weight c. This result implies that there is a wealth of closed non-separable subgroups of separable pseudocompact groups. An example is also presented under the Continuum Hypothesis of a separable countably compact abelian group which contains a non-separable closed subgroup.

Editors' cut : Managing scholarly journals in mathematics and IT

- Hofmann, Karl, Morris, Sidney

**Authors:**Hofmann, Karl , Morris, Sidney**Date:**2005**Type:**Text , Journal article**Relation:**Journal of Research and Practice in Information Technology Vol. 37, no. 4 (2005), p. 299-309**Full Text:**false**Reviewed:****Description:**The first version of this essay was jointly delivered by the authors as a colloquium lecture at the University of Ballarat on 24 November, 2004. A second, expanded and illustrated version was published in German in the Mitteilungen der Deutschen Mathematikervereinigung early in 2005. Because of the very positive feedback, the authors decided it would be useful to publish a version in English in a computing journal. The purpose of the essay is to provide advice and information to authors of articles about publishing in scholarly journals from an editor's perspective. Of particular importance are remarks about etiquette.**Description:**C1

Effectiveness of using quantified intermarket influence for predicting trading signals of stock markets

- Tilakaratne, Chandima, Mammadov, Musa, Morris, Sidney

**Authors:**Tilakaratne, Chandima , Mammadov, Musa , Morris, Sidney**Date:**2007**Type:**Text , Conference paper**Relation:**Paper presented at Data Mining and Analytics 2007: Sixth Australasian Data Mining Conference, AusDM 2007 Vol. 70, p. 171-179**Full Text:****Reviewed:**

**Authors:**Tilakaratne, Chandima , Mammadov, Musa , Morris, Sidney**Date:**2007**Type:**Text , Conference paper**Relation:**Paper presented at Data Mining and Analytics 2007: Sixth Australasian Data Mining Conference, AusDM 2007 Vol. 70, p. 171-179**Full Text:****Reviewed:**

Embedding into free topological vector spaces on compact metrizable spaces

- Gabriyelyan, Saak, Morris, Sidney

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2018**Type:**Text , Journal article**Relation:**Topology and its Applications Vol. 233, no. (2018), p. 33-43**Full Text:**false**Reviewed:****Description:**For a Tychonoff space X, let V(X) be the free topological vector space over X. Denote by I, G, Q and Sk the closed unit interval, the Cantor space, the Hilbert cube Q=IN and the k-dimensional unit sphere for k

Embedding of the free abelian topological group A (X ⊕ X) into A (X)

- Krupski, Mikolaj, Leiderman, Arkady, Morris, Sidney

**Authors:**Krupski, Mikolaj , Leiderman, Arkady , Morris, Sidney**Date:**2019**Type:**Text , Journal article**Relation:**Mathematika Vol. 65, no. 3 (2019), p. 708-718**Full Text:**false**Reviewed:****Description:**We consider the following question: for which metrizable separable spaces X does the free abelian topological group A (X ⊕ X) isomorphically embed into A (X). While for many natural spaces X such an embedding exists, our main result shows that if X is a Cook continuum or X is a rigid Bernstein set, then A(X ⊕ X) does not embed into A(X) as a topological subgroup. The analogous statement is true for the free boolean group B (X).**Description:**We consider the following question: for which metrizable separable spaces X does the free abelian topological group A (X

Embeddings of free topological vector spaces

- Leiderman, Arkady, Morris, Sidney

**Authors:**Leiderman, Arkady , Morris, Sidney**Date:**2020**Type:**Text , Journal article**Relation:**Bulletin of the Australian Mathematical Society Vol. 101, no. 2 (2020), p. 311-324**Full Text:**false**Reviewed:****Description:**It is proved that the free topological vector space contains an isomorphic copy of the free topological vector space for every finite-dimensional cube , thereby answering an open question in the literature. We show that this result cannot be extended from the closed unit interval to general metrisable spaces. Indeed, we prove that the free topological vector space does not even have a vector subspace isomorphic as a topological vector space to , where is a Cook continuum, which is a one-dimensional compact metric space. This is also shown to be the case for a rigid Bernstein set, which is a zero-dimensional subspace of the real line. © 2019 Australian Mathematical Publishing Association Inc..

Free subspaces of free locally convex spaces

- Gabriyelyan, Saak, Morris, Sidney

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2018**Type:**Text , Journal article**Relation:**Journal of Function Spaces Vol. 2018, no. (2018), p. 1-5**Full Text:****Reviewed:****Description:**Abstract If X and Y are Tychonoff spaces, let and be the free locally convex space over and , respectively. For general and , the question of whether can be embedded as a topological vector subspace of is difficult. The best results in the literature are that if can be embedded as a topological vector subspace of , where , then is a countable-dimensional compact metrizable space. Further, if is a finite-dimensional compact metrizable space, then can be embedded as a topological vector subspace of . In this paper, it is proved that can be embedded in as a topological vector subspace if is a disjoint union of a countable number of finite-dimensional locally compact separable metrizable spaces. This is the case if It is also shown that if and denote the Cantor space and the Hilbert cube , respectively, then (i) is embedded in if and only if is a zero-dimensional metrizable compact space; (ii) is embedded in if and only if is a metrizable compact space.**Description:**If

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2018**Type:**Text , Journal article**Relation:**Journal of Function Spaces Vol. 2018, no. (2018), p. 1-5**Full Text:****Reviewed:****Description:**Abstract If X and Y are Tychonoff spaces, let and be the free locally convex space over and , respectively. For general and , the question of whether can be embedded as a topological vector subspace of is difficult. The best results in the literature are that if can be embedded as a topological vector subspace of , where , then is a countable-dimensional compact metrizable space. Further, if is a finite-dimensional compact metrizable space, then can be embedded as a topological vector subspace of . In this paper, it is proved that can be embedded in as a topological vector subspace if is a disjoint union of a countable number of finite-dimensional locally compact separable metrizable spaces. This is the case if It is also shown that if and denote the Cantor space and the Hilbert cube , respectively, then (i) is embedded in if and only if is a zero-dimensional metrizable compact space; (ii) is embedded in if and only if is a metrizable compact space.**Description:**If

Free topological vector spaces

- Gabriyelyan, Saak, Morris, Sidney

**Authors:**Gabriyelyan, Saak , Morris, Sidney**Date:**2017**Type:**Text , Journal article**Relation:**Topology and its Applications Vol. 223, no. (2017), p. 30-49**Full Text:**false**Reviewed:****Description:**In this paper the free topological vector space V(X) over a Tychonoff space X is defined and studied. It is proved that V(X) is a kω-space if and only if X is a kω-space. If X is infinite, then V(X) contains a closed vector subspace which is topologically isomorphic to V(N). It is proved that for X a k-space, the free topological vector space V(X) is locally convex if and only if X is discrete and countable. The free topological vector space V(X) is shown to be metrizable if and only if X is finite if and only if V(X) is locally compact. Further, V(X) is a cosmic space if and only if X is a cosmic space if and only if the free locally convex space L(X) on X is a cosmic space. If a sequential (for example, metrizable) space Y is such that the free locally convex space L(Y) embeds as a subspace of V(X), then Y is a discrete space. It is proved that V(X) is a barreled topological vector space if and only if X is discrete. This result is applied to free locally convex spaces L(X) over a Tychonoff space X by showing that: (1) L(X) is quasibarreled if and only if L(X) is barreled if and only if X is discrete, and (2) L(X) is a Baire space if and only if X is finite. © 2017 Elsevier B.V.

Hilbert 13: Are there are any genuine continuous multivariate real-valued functions?

**Authors:**Morris, Sidney**Date:**2021**Type:**Text , Journal article**Relation:**Bulletin of the American Mathematical Society Vol. 58, no. 1 (2021), p. 107-118**Full Text:**false**Reviewed:****Description:**This article begins with a provocative question: Are there any genuine continuous multivariate real-valued functions? This may seem to be a silly question, but it is in essence what David Hilbert asked as one of the 23 problems he posed at the second International Congress of Mathematicians, held in Paris in 1900. These problems guided a large portion of the research in mathematics of the 20th century. Hilbert’s 13th problem conjectured that there exists a continuous function (Formula presented), where (Formula presented), which cannot be expressed in terms of composition and addition of continuous functions from ℝ2 → ℝ, that is, as composition and addition of continuous real-valued functions of two variables. It took over 50 years to prove that Hilbert’s conjecture is false. This article discusses the solution. © 2021. American Mathematical Society.

Identifying and distinguishing various varieties of abelian topological groups

- McPhail, Carolyn, Morris, Sidney

**Authors:**McPhail, Carolyn , Morris, Sidney**Date:**2008**Type:**Text , Journal article**Relation:**Dissertationes Mathematicae Vol. , no. 458 (2008), p.**Full Text:**false**Reviewed:****Description:**A variety of topological groups is a class of (not necessarily Hausdorff) topological groups closed under the operations of forming subgroups, quotient groups and arbitrary products. The variety of topological groups generated by a class of topological groups is the smallest variety containing the class. In this paper methods are presented to distinguish a number of significant varieties of abelian topological groups, including the varieties generated by (i) the class of all locally compact abelian groups; (ii) the class of all k(w)-groups; (iii) the class of all sigma-compact groups; and (iv) the free abelian topological group on [0, 1]. In all cases, hierarchical containments are determined.

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