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Results in Algebraic Determinedness and an Extension of the Baire Property
In this work, we concern ourselves with particular topics in Polish space theory. We first consider the space A(U) of complex-analytic functions on an open set U endowed with the usual topology of uniform convergence on compact subsets. With the operations of point-wise addition and point-wise multiplication, A(U) is a Polish ring. Inspired by L. Bers' algebraic characterization of the relation of conformality, we show that the topology on A(U) is the only Polish topology for which A(U) is a Polish ring for a large class of U. This class of U includes simply connected regions, simply connected regions excluding a relatively discrete set of points, and other domains of usual interest. One thing that we deduce from this is that, even though C has many different Polish field topologies, as long as it sits inside another Polish ring with enough complex-analytic functions, it must have its usual topology. In a different direction, we show that the bounded complex-analytic functions on the unit disk admits no Polish topology for which it is a Polish ring. We also study the Lie ring structure on A(U) which turns out to be a Polish Lie ring with the usual topology. In this case, …
Date:
May 2017
Creator:
Caruvana, Christopher
System:
The UNT Digital Library
Random Variables of One Dimension
This thesis examines random variables of one dimension.
Date:
August 1958
Creator:
Casler, Burtis Griffin
System:
The UNT Digital Library
The Use of the Power Method to Find Dominant Eigenvalues of Matrices
This paper is the result of a study of the power method to find dominant eigenvalues of square matrices. It introduces ideas basic to the study and shows the development of the power method for the most well-behaved matrices possible, and it explores exactly which other types of matrices yield to the power method. The paper also discusses a type of matrix typically considered impossible for the power method, along with a modification of the power method which works for this type of matrix. It gives an overview of common extensions of the power method. The appendices contain BASIC versions of the power method and its modification.
Date:
July 1992
Creator:
Cavender, Terri A.
System:
The UNT Digital Library
Properties of Extended and Contracted Ideals
This paper presents an introduction to the theory of ideals in a ring with emphasis on ideals in a commutative ring with identity.
Date:
August 1966
Creator:
Chan, George
System:
The UNT Digital Library
The Relative Complexity of Various Classification Problems among Compact Metric Spaces
In this thesis, we discuss three main projects which are related to Polish groups and their actions on standard Borel spaces. In the first part, we show that the complexity of the classification problem of continua is Borel bireducible to a universal orbit equivalence relation induce by a Polish group on a standard Borel space. In the second part, we compare the relative complexity of various types of classification problems concerning subspaces of [0,1]^n for all natural number n. In the last chapter, we give a topological characterization theorem for the class of locally compact two-sided invariant non-Archimedean Polish groups. Using this theorem, we show the non-existence of a universal group and the existence of a surjectively universal group in the class.
Date:
May 2016
Creator:
Chang, Cheng
System:
The UNT Digital Library
Simplicial Homology
The purpose of this thesis is to construct the homology groups of a complex over an R-module. The thesis begins with hyperplanes in Euclidean n-space. Simplexes and complexes are defined, and orientations are given to each simplex of a complex. The chains of a complex are defined, and each chain is assigned a boundary. The function which assigns to each chain a boundary defines the set of r-dimensional cycles and the set of r—dimensional bounding cycles. The quotient of those two submodules is the r-dimensional homology group.
Date:
August 1973
Creator:
Chang, Chih-Chen
System:
The UNT Digital Library
Which Came First : The Measure or the Integral?
This thesis provides a development of integration from two different points of view. In Chapter I, a measure and a measurable function are defined. A theory of integration is then developed in Chapter II based on the measure. In Chapter III, the integral is introduced directly without first going through the process of defining a measure, and a measure is developed from the integral. The concluding chapter shows the equivalence of the two integrals under rather general conditions.
Date:
June 1966
Creator:
Chapman, John Barnes
System:
The UNT Digital Library
Invertible Ideals and the Strong Two-Generator Property in Some Polynomial Subrings
Let K be any field and Q be the rationals. Define K^1[X] = {f(X) e K[X]| the coefficient of X in f(X) is zero} and Q^1β[X] = {f(X) e Q[X]| the coefficent of β1(X) in the binomial expansion of f(X) is zero}, where {β1(X)}^∞ i=0 are the well-known binomial polynomials. In this work, I establish the following results: K^1[X] and Q^1β[X] are one-dimensional, Noetherian, non-Prüfer domains with the two-generator property on ideals. Using the unique factorization structure of the overrings K[X] and Q[X], the nonprincipal ideal structures of both rings are characterized, and from this characterization, necessary and sufficient conditions are found for a nonprincipal ideal to be invertible. The nonprincipal invertible ideals are then characterized in terms of the coefficients of the generators, and an explicit formula for the inverse of any proper invertible ideal is found. Finally, the class groups of both rings are shown to be torsion free abelian groups. Let n be any nonnegative integer. Results similar to the above are found in the generalizations of these two rings, K^n[X] and q^nβ[X], where the coefficients on the first n nonconstant basis elements are zero. For the domains K^1[X] and Q^1β[X], the property of strong two-generation is …
Date:
May 1987
Creator:
Chapman, Scott T. (Scott Thomas)
System:
The UNT Digital Library
Results on Non-Club Isomorphic Aronszajn Trees
In this dissertation we prove some results about the existence of families of Aronszajn trees on successors of regular cardinals which are pairwise not club isomorphic. The history of this topic begins with a theorem of Gaifman and Specker in the 1960s which asserts the existence from ZFC of many pairwise not isomorphic Aronszajn trees. Since that result was proven, the focus has turned to comparing Aronszajn trees with respect to isomorphisms on a club of levels, instead of on the entire tree. In the 1980s Abraham and Shelah proved that the Proper Forcing Axiom implies that any two Aronszajn trees on the first uncountable cardinal are club isomorphic. This theorem was generalized to higher cardinals in recent work of Krueger. Abraham and Shelah also proved that the opposite holds under diamond principles. In this dissertation we address the existence of pairwise not club isomorphic Aronszajn trees on higher cardinals from a variety of cardinal arithmetic and diamond principle assumptions. For example, on the successor of a regular cardinal, assuming GCH and the diamond principle on the critical cofinality, there exists a large collection of special Aronszajn trees such that any two of them do not contain club isomorphic subtrees.
Date:
August 2020
Creator:
Chavez, Jose
System:
The UNT Digital Library
Extensions of Modules
This thesis discusses groups, modules, the module of homomorphisms, and extension of modules.
Date:
August 1967
Creator:
Chen, Paulina Tsui-Chu
System:
The UNT Digital Library
Thermodynamical Formalism
Thermodynamical formalism is a relatively recent area of pure mathematics owing a lot to some classical notions of thermodynamics. On this thesis we state and prove some of the main results in the area of thermodynamical formalism. The first chapter is an introduction to ergodic theory. Some of the main theorems are proved and there is also a quite thorough study of the topology that arises in Borel probability measure spaces. In the second chapter we introduce the notions of topological pressure and measure theoretic entropy and we state and prove two very important theorems, Shannon-McMillan-Breiman theorem and the Variational Principle. Distance expanding maps and their connection with the calculation of topological pressure cover the third chapter. The fourth chapter introduces Gibbs states and the very important Perron-Frobenius Operator. The fifth chapter establishes the connection between pressure and geometry. Topological pressure is used in the calculation of Hausdorff dimensions. Finally the sixth chapter introduces the notion of conformal measures.
Date:
August 2004
Creator:
Chousionis, Vasileios
System:
The UNT Digital Library
Prime Ideals in Commutative Rings
This thesis is a study of some properties of prime ideals in commutative rings with unity.
Date:
August 1970
Creator:
Clayton, Marlene H.
System:
The UNT Digital Library
Topological Spaces, Filters and Nets
Explores topological spaces, filters, and nets with definitions and examples.
Date:
January 1966
Creator:
Cline, Jerry Edward
System:
The UNT Digital Library
Descriptive Set Theory and Measure Theory in Locally Compact and Non-locally Compact Groups
In this thesis we study descriptive-set-theoretic and measure-theoretic properties of Polish groups, with a thematic emphasis on the contrast between groups which are locally compact and those which are not. The work is divided into three major sections. In the first, working jointly with Robert Kallman, we resolve a conjecture of Gleason regarding the Polish topologization of abstract groups of homeomorphisms. We show that Gleason's conjecture is false, and its conclusion is only true when the hypotheses are considerably strengthened. Along the way we discover a new automatic continuity result for a class of functions which behave like but are distinct from functions of Baire class 1. In the second section we consider the descriptive complexity of those subsets of the permutation group S? which arise naturally from the classical Levy-Steinitz series rearrangement theorem. We show that for any conditionally convergent series of vectors in Euclidean space, the sets of permutations which make the series diverge, and diverge properly, are ?03-complete. In the last section we study the phenomenon of Haar null sets a la Christensen, and the closely related notion of openly Haar null sets. We identify and correct a minor error in the proof of Mycielski that a …
Date:
May 2013
Creator:
Cohen, Michael Patrick
System:
The UNT Digital Library
Dynamics, Thermodynamic formalism and Perturbations of Transcendental Entire Functions of Finite Singular Type
In this dissertation, we study the dynamics, fractal geometry and the topology of the Julia set of functions in the family H which is a set in the class S, the Speiser class of entire transcendental functions which have only finitely many singular values. One can think of a function from H as a generalized expanding function from the cosh family. We shall build a version of thermodynamic formalism for functions in H and we shall show among others, the existence and uniqueness of a conformal measure. Then we prove a Bowen's type formula, i.e. we show that the Hausdorff dimension of the set of returning points, is the unique zero of the pressure function. We shall also study conjugacies in the family H, perturbation of functions in the family and related dynamical properties. We define Perron-Frobenius operators for some functions naturally associated with functions in the family H and then, using fundamental properties of these operators, we shall prove the important result that the Hausdorff dimension of the subset of returning points depends analytically on the parameter taken from a small open subset of the n-dimensional parameter space.
Date:
May 2005
Creator:
Coiculescu, Ion
System:
The UNT Digital Library
Fundamentals of Partially Ordered Sets
Gives the basic definitions and theorems of similar partially ordered sets; studies finite partially ordered sets, including the problem of combinatorial analysis; and includes the ideas of complete, dense, and continuous partially ordered sets, including proofs.
Date:
August 1968
Creator:
Compton, Lewis W.
System:
The UNT Digital Library
The Order Topology on a Linearly Ordered Set
The purpose of this paper is to investigate from two viewpoints an order-induced topology on a set X.
Date:
June 1970
Creator:
Congleton, Carol A.
System:
The UNT Digital Library
Rings of Continuous Functions
The purpose of this paper is to examine properties of the ring C(X) of all complex or real-valued continuous functions on an arbitrary topological space X.
Date:
August 1971
Creator:
Connell, Carolyn
System:
The UNT Digital Library
Compact Topological Spaces
The purpose of this paper is to investigate some properties of compact topological spaces and to relate these concepts to the separation properties.
Date:
June 1964
Creator:
Conway, Thomas M.
System:
The UNT Digital Library
A Comparison of Velocities Computed by Two-Dimensional Potential Theory and Velocities Measured in the Vicinity of an Airfoil
In treating the motion of a fluid mathematically, it is convenient to make some simplifying assumptions. The assumptions which are made will be justifiable if they save long and laborious computations in practical problems, and if the predicted results agree closely enough with experimental results for practical use. In dealing with the flow of air about an airfoil, at subsonic speeds, the fluid will be considered as a homogeneous, incompressible, inviscid fluid.
Date:
June 1947
Creator:
Copp, George
System:
The UNT Digital Library
Properties of Limit Functions
The purpose of this paper is to investigate properties of functions which are limits of functions with prescribed properties. Chapter II asks the question "Does a function which is the limit of a sequence of functions each of which is endowed with a certain property necessarily have that property?"
Date:
December 1972
Creator:
Coppin, Anthony M.
System:
The UNT Digital Library
Mechanization of Aircraft Performance
The purpose of this paper is to describe the mechanization of the basic equations of motion for the performance and maneuver characteristics of an airplane with some simplifications which render solutions more practicable. The results of a study made to program these equations for calculation by the IBM MODEL 650 digital computer are presented as well as the steps to be taken in using this method of calculation.
Date:
1956
Creator:
Cotten, Frances Patterson
System:
The UNT Digital Library
Abelian Group Actions and Hypersmooth Equivalence Relations
We show that any Borel action on a standard Borel space of a group which is topologically isomorphic to the sum of a countable abelian group with a countable sum of lines and circles induces an orbit equivalence relation which is hypersmooth. We also show that any Borel action of a second countable locally compact abelian group on a standard Borel space induces an orbit equivalence relation which is essentially hyperfinite, generalizing a result of Gao and Jackson for the countable abelian groups.
Date:
May 2019
Creator:
Cotton, Michael R.
System:
The UNT Digital Library
Applications of a Model-Theoretic Approach to Borel Equivalence Relations
The study of Borel equivalence relations on Polish spaces has become a major area of focus within descriptive set theory. Primarily, work in this area has been carried out using the standard methods of descriptive set theory. In this work, however, we develop a model-theoretic framework suitable for the study of Borel equivalence relations, introducing a class of objects we call Borel structurings. We then use these structurings to examine conditions under which marker sets for Borel equivalence relations can be concluded to exist or not exist, as well as investigating to what extent the Compactness Theorem from first-order logic continues to hold for Borel structurings.
Date:
August 2019
Creator:
Craft, Colin N.
System:
The UNT Digital Library