Mathematics Commons^™

A Note On Solid Coloring Of Pure Simplicial Complexes, Joseph O'Rourke

Computer Science: Faculty Publications

We establish a simple generalization of a known result in the plane. The simplices in any pure simplicial complex in R^d may be colored with d+1 colors so that no two simplices that share a (d-1)-facet have the same color. In R² this says that any planar map all of whose faces are triangles may be 3-colored, and in R³ it says that tetrahedra in a collection may be "solid 4-colored" so that no two glued face-to-face receive the same color.

Warped Product Einstein Metrics Over Spaces With Constant Scalar Curvature, Chenxu He, Peter Petersen, William Wylie

Mathematics - All Scholarship

In this paper we study warped product Einstein metrics over spaces with constant scalar curvature. We call such a manifold rigid if the universal cover of the base is Einstein or is isometric to a product of Einstein manifolds. When the base is three dimensional and the dimension of the fiber is greater than one we show that the space is always rigid. We also exhibit examples of solvable four dimensional Lie groups that can be used as the base space of non-rigid warped product Einstein metrics showing that the result is not true in dimension greater than three. We …

On A Generalized Time-Varying Seir Epidemic Model With Mixed Point And Distributed Time-Varying Delays And Combined Regular And Impulsive Vaccination Controls, Ravi P. Agarwal, Manuel De La Sen, Asier Ibeas, Santiago Alonso-Quesada

Mathematics and System Engineering Faculty Publications

This paper discusses a generalized time-varying SEIR propagation disease model subject to delays which potentially involves mixed regular and impulsive vaccination rules. The model takes also into account the natural population growing and the mortality associated to the disease, and the potential presence of disease endemic thresholds for both the infected and infectious population dynamics as well as the lost of immunity of newborns. The presence of outsider infectious is also considered. It is assumed that there is a finite number of time-varying distributed delays in the susceptible-infected coupling dynamics influencing the susceptible and infected differential equations. It is also …

Classification Of Generalized Hadamard Matrices H(6,3) And Quaternary Hermitian Self-Dual Codes Of Length 18, Masaaki Harada, Clement Lam, Akihiro Munemasa, Vladimir Tonchev

Department of Mathematical Sciences Publications

All generalized Hadamard matrices of order 18 over a group of order 3, H(6,3),are enumerated in two different ways: once, as class regular symmetric (6,3)-nets,or symmetric transversal designs on 54 points and 54 blocks with a group of order 3 acting semi-regularly on points and blocks, and secondly,as collections of fullweight vectors in quaternary Hermitian self-dual codes of length 18. The second enumeration is based on the classification of Hermitian self-dual [18,9] codes over GF(4), completed in this paper. It is shown that up to monomial equivalence, there are 85 generalized Hadamard matrices H(6,3), and 245 inequivalent Hermitian self-dual codes …

Graphs Of Bounded Degree And The P-Harmonic Boundary, Michael J. Puls

Publications and Research

Let p be a real number greater than one and let G be a connected graph of bounded degree. We introduce the p-harmonic boundary of G and use it to characterize the graphs G for which the constant functions are the only p-harmonic functions on G. We show that any continuous function on the p-harmonic boundary of G can be extended to a function that is p-harmonic on G. We also give some properties of this boundary that are preserved under rough-isometries. Now let Gamma be a finitely generated group. As an application of our results, we characterize the vanishing …

Global Dimension Of Ci: Compete Or Collaborate, Arden L. Bement Jr.

PPRI Digital Library

No abstract provided.

Information-Preserving Structures: A General Framework For Quantum Zero-Error Information, Robin Blume-Kohout, Hui Khoon Ng, David Poulin, Lorenza Viola

Dartmouth Scholarship

Quantum systems carry information. Quantum theory supports at least two distinct kinds of information (classical and quantum), and a variety of different ways to encode and preserve information in physical systems. A system’s ability to carry information is constrained and defined by the noise in its dynamics. This paper introduces an operational framework, using information-preserving structures, to classify all the kinds of information that can be perfectly (i.e., with zero error) preserved by quantum dynamics. We prove that every perfectly preserved code has the same structure as a matrix algebra, and that preserved information can always be corrected. We …

Some Results For Integral Inclusions Of Volterra Type In Banach Spaces, Ravi P. Agarwal, Mouffak Benchohra, Juan Jose Nieto, Abdelghani Ouahab

Mathematics and System Engineering Faculty Publications

We first present several existence results and compactness of solutions set for the following Volterra type integral inclusions of the form: y(t) ∈ ∫0 t a(t-s)[Ay(s)+F(s,y(s)) ]ds,a.e.t ∈ J, where J=[ 0,b ], A is the infinitesimal generator of an integral resolvent family on a separable Banach space E, and F is a set-valued map. Then the Filippov's theorem and a Filippov-Waewski result are proved.

Quantitative Stability And Optimality Conditions In Convex Semi-Infinite And Infinite Programming, M J. Cánovas, M A. Lopez, Boris S. Mordukhovich, J Parra

Mathematics Research Reports

This paper concerns parameterized convex infinite (or semi-infinite) inequality systems whose decision variables run over general infinite-dimensional Banach (resp. finite-dimensional) spaces and that are indexed by an arbitrary fixed set T. Parameter perturbations on the right-hand side of the inequalities are measurable and bounded, and thus the natural parameter space is loo(T). Based on advanced variational analysis, we derive a precise formula for computing the exact Lipschitzian bound of the feasible solution map, which involves only the system data, and then show that this exact bound agrees with the coderivative norm of the aforementioned mapping. On one hand, in this …

Solving A Generalized Heron Problem By Means Of Convex Analysis, Boris S. Mordukhovich, Nguyen Mau Nam, Juan Salinas Jr

Mathematics Research Reports

The classical Heron problem states: on a given straight line in the plane, find a point C such that the sum of the distances from C to the given points A and B is minimal. This problem can be solved using standard geometry or differential calculus. In the light of modern convex analysis, we are able to investigate more general versions of this problem. In this paper we propose and solve the following problem: on a given nonempty closed convex subset of IR!, find a point such that the sum of the distances from that point to n given nonempty …

Positive Solutions Of Singular Complementary Lidstone Boundary Value Problems, Ravi P. Agarwal, Donal O'Regan, Svatoslav Staněk

Mathematics and System Engineering Faculty Publications

We investigate the existence of positive solutions of singular problem (-1)mx(2m+1) = f(t, x,⋯, x(2m)), x (0) = 0, x(2i-1) (0) = x(2i-1) (T) = 0, 1 ≤ i ≤ m. Here, m ≥ 1 and the Carathéodory function f (t, x0,⋯, x2m) may be singular in all its space variables x0,⋯, x2m. The results are proved by regularization and sequential techniques. In limit processes, the Vitali convergence theorem is used.

Burkholder Integrals, Morrey's Problem And Quasiconformal Mappings, Kari Astala, Tadeusz Iwaniec, Istvan Prause, Eero Saksman

Mathematics - All Scholarship

Inspired by Morrey's Problem (on rank-one convex functionals) and the Burkholder integrals (of his martingale theory) we find that the Burkholder functionals B_p, p > 2, are quasiconcave, when tested on deformations of identity f in Id+C_o^inifinty (omega) with Bp (Df(x)) > 0 pointwise, or equivalently, deformations such that abs[Df]² < (p/(p-2))J_f. In particular, this holds in explicit neighbourhoods of the identity map. Among the many immediate consequences, this gives the strongest possible L^p-estimates for the gradient of a principal solution to the Beltrami equation f_z = mu(z)f_z , for any p in …

Invariant And Coinvariant Spaces For The Algebra Of Symmetric Polynomials In Non-Commuting Variables, Francois Bergeron, Aaron Lauve

Mathematics and Statistics: Faculty Publications and Other Works

We analyze the structure of the algebra K⟨x⟩Sn of symmetric polynomials in non-commuting variables in so far as it relates to K[x]Sn, its commutative counterpart. Using the "place-action" of the symmetric group, we are able to realize the latter as the invariant polynomials inside the former. We discover a tensor product decomposition of K⟨x⟩Sn analogous to the classical theorems of Chevalley, Shephard-Todd on finite reflection groups.

Résumé. Nous analysons la structure de l'algèbre K⟨x⟩Sn des polynômes symétriques en des variables non-commutatives pour obtenir des analogues des résultats classiques concernant la structure de l'anneau K[x]Sn des polynômes symétriques en des variables …

Generalized Twisted Quantum Doubles And The Mckay Correspondence, Christopher D. Goff, Geoffrey Mason

College of the Pacific Faculty Articles

We consider a class of quasiHopf algebras which we call generalized twisted quantum doubles. They are abelian extensions H=C[G¯]∗⋈C[G] (G is a finite group, G¯ a homomorphic image, and * denotes the dual algebra), possibly twisted by a 3-cocycle, and are a natural generalization of the twisted quantum double construction of Dijkgraaf, Pasquier and Roche. We show that if G is a subgroup of SU₂(C) then H exhibits an orbifold McKay Correspondence: certain fusion rules of H define a graph with connected components indexed by conjugacy classes of G¯, each connected component being an extended affine Diagram of …

Feedback Control Of A Bioinspired Plate-Beam System, Cody W. Ray, Belinda A. Batten, John R. Singler

Mathematics and Statistics Faculty Research & Creative Works

In this paper we present a model for a plate-beam system to represent a bioinspired flexible wing. Using a Galerkin based finite element approximation to the system, we compute functional gains that can be used for sensor placement and show that a piezoceramic actuator on the beam can be used for camber control

Stability Of Roots Of Polynomials Under Linear Combinations Of Derivatives, Branko Ćurgus, Vania Mascioni

Mathematics Faculty Publications

Let T=α ₀ I+α ₁ D+⋅⋅⋅+α _n D ⁿ , where D is the differentiation operator and α0≠0 , and let f be a square-free polynomial with large minimum root separation. We prove that the roots of Tf are close to the roots of f translated by −α ₁/α ₀.

Rademacher-Type Formulas For Restricted Partition And Overpartition Functions, Andrew Sills

Department of Mathematical Sciences Faculty Publications

A collection of Hardy-Ramanujan-Rademacher type formulas for restricted partition and overpartition functions is presented, framed by several biographical anecdotes.

Voices, Echoes, And Narratives: Multidimensional Experiences Of Three Teachers Immersed In Ethnomathematical Encounters In Morocco, Mekyah Q. Mcqueen, Stanley F. H. Shaheed, Curtis V. Goings, Iman C. Chahine

Middle-Secondary Education and Instructional Technology Faculty Publications

No abstract provided.

How Is It That One Particular Statement Appeared Rather Than Another?: Opening A Different Space For Different Statements About Urban Mathematics Education, David W. Stinson

Middle-Secondary Education and Instructional Technology Faculty Publications

In this editorial, the author applies Michel Foucault's concept of "discursive formations" to examine fictions, fantasies, and power relationships in mathematics education research.

Sums Of Evenly Spaced Binomial Coefficients, Arthur T. Benjamin, Bob Chen '10, Kimberly Kindred

All HMC Faculty Publications and Research

We provide a combinatorial proof of a formula for the sum of evenly spaced binomial coefficients. This identity, along with a generalization, are proved by counting weighted walks on a graph.

Slider-Pinning Rigidity: A Maxwell-Laman-Type Theorem, Ileana Streinu, Louis Theran

Computer Science: Faculty Publications

We define and study slider-pinning rigidity, giving a complete combinatorial characterization. This is done via direction-slider networks, which are a generalization of Whiteley’s direction networks.

The Gini Index And Measures Of Inequality, Frank A. Farris

Mathematics and Computer Science

The Gini index is a summary statistic that measures how fairly a resource is distributed in a population; income is a primary example. In addition to a self-contained presentation of the Gini index, we give two equivalent ways to interpret this summary statistic: first in terms of the percentile level of the person who earns the average dollar, and second in terms of how the lower of two randomly chosen incomes compares, on average, to mean income.

The Cohomology Of Modules Over A Complete Intersection Ring, Jesse Burke

Department of Mathematics: Dissertations, Theses, and Student Research

We investigate the cohomology of modules over commutative complete intersection rings. The first main result is that if M is an arbitrary module over a complete intersection ring R, and if one even self-extension module of M vanishes then M has finite projective dimension. The second main result gives a new proof of the fact that the support variety of a Cohen-Macaulay module whose completion is indecomposable is projectively connected.

Closed-Range Composition Operators On A2 And The Bloch Space, John R. Akeroyd, Pratibha G. Ghatage, Maria Tjani

Mathematics and Statistics Faculty Publications

For any analytic self-map φ of {z : |z| < 1} we give four separate conditions, each of which is necessary and sufficient for the composition operator Cφ to be closed-range on the Bloch space B . Among these conditions are some that appear in the literature, where we provide new proofs. We further show that if Cφ is closed-range on the Bergman space A2 , then it is closed-range on B , but that the converse of this fails with a vengeance. Our analysis involves an extension of the Julia-Carathéodory Theorem.

The Hopf-Laplace Equation, Jan Cristina, Tadeusz Iwaniec, Leonid V. Kovalev, Jani Onninen

Mathematics - All Scholarship

The central theme in this paper is the Hopf-Laplace equation, which represents stationary solutions with respect to the inner variation of the Dirichlet integral. Among such solutions are harmonic maps. Nevertheless, minimization of the Dirichlet energy among homeomorphisms often leads to nonharmonic solutions. We investigate the Hopf-Laplace equation for a certain class of topologically well behaved mappings which are almost homeomorphisms, called Hopf deformations. We establish Lipschitz continuity of Hopf deformations, the best possible regularity one can get. Thus in particular we show that the minimal-energy deformations are Lipschitz continuous, a result of considerable interest in the theory of minimal …

Building Graphs From Colored Trees, Rachel M. Esselstein, Peter Winkler

Dartmouth Scholarship

We will explore the computational complexity of satisfying certain sets of neighborhood conditions in graphs with various properties. More precisely, fix a radius $\rho$ and let $N(G)$ be the set of isomorphism classes of $\rho$-neighborhoods of vertices of $G$ where $G$ is a graph whose vertices are colored (not necessarily properly) by colors from a fixed finite palette. The root of the neighborhood will be the unique vertex at the "center" of the graph. Given a set S of colored graphs with a unique root, when is there a graph G with N (G) = S? Or N (G) ⊂ …

Fixed Point Theorems For Ws-Compact Mappings In Banach Spaces, Ravi P. Agarwal, Donal O'Regan, Mohamed-Aziz Taoudi

Mathematics and System Engineering Faculty Publications

We present new fixed point theorems for ws-compact operators. Our fixed point results are obtained under Sadovskii, Leray-Schauder, Rothe, Altman, Petryshyn, and Furi-Pera type conditions. An example is given to show the usefulness and the applicability of our results.

Rethinking Geometrical Exactness, Marco Panza

MPP Published Research

A crucial concern of early modern geometry was fixing appropriate norms for deciding whether some objects, procedures, or arguments should or should not be allowed into it. According to Bos, this is the exactness concern. I argue that Descartes’s way of responding to this concern was to suggest an appropriate conservative extension of Euclid’s plane geometry (EPG). In Section 2, I outline the exactness concern as, I think, it appeared to Descartes. In Section 3, I account for Descartes’s views on exactness and for his attitude towards the most common sorts of constructions in classical geometry. I also explain in …

Breathing Fresh Air Into The Philosophy Of Mathematics, Marco Panza

MPP Published Research

A review of Paolo Mancosu (ed.): The Philosophy of Mathematical Practice.

Correspondences Of Hypersurfaces In Hyperbolic Poincaré Manifolds And Conformally Invariant Pdes, Vincent Bonini, José M. Espinar, Jie Qing

Mathematics

On a hyperbolic Poincaré manifold, we derive an explicit relationship between the eigenvalues of Weyl-Schouten tensor of a conformal representative of the conformal infinity and the principal curvatures of the level sets of the associated geodesic defining function. This considerably simplifies the arguments and generalizes the results of Gálvez, Mira and the second author. In particular, we obtain the equivalence between Christoffel-type problems for hypersurfaces in a hyperbolic Poincar´e manifold and scalar curvature problems on the conformal infinity.