Download or read book A Sufficient Criterion for a Cone to be Area Minimizing written by Gary Reid Lawlor and published by American Mathematical Soc.. This book was released on 1991 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the fundamental objects of study in geometric measure theory is an "area-minimizing surface." A compact, k-dimensional surface (with boundary) is called area-minimizing if no other surface with the same boundary has less surface area. An area-minimizing surface can have singularities. The main purpose of this paper is to investigate some of the shapes that such singularities can have. A key concept in this study is that of an area-minimizing cone. We present a general method for proving that a cone with an isolated singularity is area-minimizing. The calculation involves the curvature (second fundamental form) and a sort of "embedding radius" of the normal bundle to the cone. We can also prove that certain cones are not area-minimizing. Using this method, we complete the classification of minimizing cones over products of spheres. We also give other examples, including the first known unorientable minimizing cones. The method also lends itself to perturbation arguments. We show that certain surfaces are area-minimizing in a small neighborhood of an isolated singularity.
Download or read book Minimal Surfaces written by Ulrich Dierkes and published by Springer Science & Business Media. This book was released on 2010-08-16 with total page 699 pages. Available in PDF, EPUB and Kindle. Book excerpt: Minimal Surfaces is the first volume of a three volume treatise on minimal surfaces (Grundlehren Nr. 339-341). Each volume can be read and studied independently of the others. The central theme is boundary value problems for minimal surfaces. The treatise is a substantially revised and extended version of the monograph Minimal Surfaces I, II (Grundlehren Nr. 295 & 296). The first volume begins with an exposition of basic ideas of the theory of surfaces in three-dimensional Euclidean space, followed by an introduction of minimal surfaces as stationary points of area, or equivalently, as surfaces of zero mean curvature. The final definition of a minimal surface is that of a nonconstant harmonic mapping X: \Omega\to\R^3 which is conformally parametrized on \Omega\subset\R^2 and may have branch points. Thereafter the classical theory of minimal surfaces is surveyed, comprising many examples, a treatment of Björling ́s initial value problem, reflection principles, a formula of the second variation of area, the theorems of Bernstein, Heinz, Osserman, and Fujimoto. The second part of this volume begins with a survey of Plateau ́s problem and of some of its modifications. One of the main features is a new, completely elementary proof of the fact that area A and Dirichlet integral D have the same infimum in the class C(G) of admissible surfaces spanning a prescribed contour G. This leads to a new, simplified solution of the simultaneous problem of minimizing A and D in C(G), as well as to new proofs of the mapping theorems of Riemann and Korn-Lichtenstein, and to a new solution of the simultaneous Douglas problem for A and D where G consists of several closed components. Then basic facts of stable minimal surfaces are derived; this is done in the context of stable H-surfaces (i.e. of stable surfaces of prescribed mean curvature H), especially of cmc-surfaces (H = const), and leads to curvature estimates for stable, immersed cmc-surfaces and to Nitsche ́s uniqueness theorem and Tomi ́s finiteness result. In addition, a theory of unstable solutions of Plateau ́s problems is developed which is based on Courant ́s mountain pass lemma. Furthermore, Dirichlet ́s problem for nonparametric H-surfaces is solved, using the solution of Plateau ́s problem for H-surfaces and the pertinent estimates.
Download or read book Differential Geometry Partial Differential Equations on Manifolds written by Robert Everist Greene and published by American Mathematical Soc.. This book was released on 1993 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first of three parts comprising Volume 54, the proceedings of the Summer Research Institute on Differential Geometry, held at the University of California, Los Angeles, July 1990 (ISBN for the set is 0-8218-1493-1). Part 1 begins with a problem list by S.T. Yau, successor to his 1980 list ( Sem
Download or read book Minimal Surfaces written by A. T. Fomenko and published by American Mathematical Soc.. This book was released on 1993 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains recent results from a group focusing on minimal surfaces in the Moscow State University seminar on modern geometrical methods, headed by A. V. Bolsinov, A. T. Fomenko, and V. V. Trofimov. The papers collected here fall into three areas: one-dimensional minimal graphs on Riemannian surfaces and the Steiner problem, two-dimensional minimal surfaces and surfaces of constant mean curvature in three-dimensional Euclidean space, and multidimensional globally minimal and harmonic surfaces in Riemannian manifolds. The volume opens with an exposition of several important problems in the modern theory of minimal surfaces that will be of interest to newcomers to the field. Prepared with attention to clarity and accessibility, these papers will appeal to mathematicians, physicists, and other researchers interested in the application of geometrical methods to specific problems.
Download or read book Sets of Finite Perimeter and Geometric Variational Problems written by Francesco Maggi and published by Cambridge University Press. This book was released on 2012-08-09 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: An engaging graduate-level introduction that bridges analysis and geometry. Suitable for self-study and a useful reference for researchers.
Download or read book Brownian Motion on Nested Fractals written by Tom Lindstrøm and published by American Mathematical Soc.. This book was released on 1990 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lindstrom (U. of Oslo) constructs Brownian motion on a reasonably general class of self-similar fractals. He deals with diffusions, self-similar fractals, fractal Laplacians, asymptotic distribution of eigenvalues, nonstandard analysis. Annotation copyright Book News, Inc. Portland, Or.
Download or read book Imbeddings of Three Manifold Groups written by Francisco González-Acuña and published by American Mathematical Soc.. This book was released on 1992 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper deals with the two broad questions of how 3-manifold groups imbed in one another and how such imbeddings relate to any corresponding [lowercase Greek]Pi1-injective maps. In particular, we are interested in 1) determining which 3-manifold groups are no cohopfian, that is, which 3-manifold groups imbed properly in themselves, 2) determining the knot subgroups of a knot group, and 3) determining when surgery on a knot [italic]K yields a lens (or "lens-like") space and the relationship of such a surgery to the knot-subgroup structure of [lowercase Greek]Pi1([italic]S3 - [italic]K). Our work requires the formulation of a deformation theorem for [lowercase Greek]Pi1-injective maps between certain kinds of Haken manifolds and the development of some algebraic tools.
Download or read book Deformation Quantization for Actions of R d written by Marc Aristide Rieffel and published by American Mathematical Soc.. This book was released on 1993 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work describes a general construction of a deformation quantization for any Poisson bracket on a manifold which comes from an action of R ]d on that manifold. These deformation quantizations are strict, in the sense that the deformed product of any two functions is again a function and that there are corresponding involutions and operator norms. Many of the techniques involved are adapted from the theory of pseudo-differential operators. The construction is shown to have many favorable properties. A number of specific examples are described, ranging from basic ones such as quantum disks, quantum tori, and quantum spheres, to aspects of quantum groups.
Download or read book Coarse Cohomology and Index Theory on Complete Riemannian Manifolds written by John Roe and published by American Mathematical Soc.. This book was released on 1993 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: "July 1993, volume 104, number 497 (fourth of 6 numbers)."
Download or read book Selberg Trace Formulae and Equidistribution Theorems for Closed Geodesics and Laplace written by Steven Zelditch and published by American Mathematical Soc.. This book was released on 1992 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is concerned with a pair of dual asymptotics problems on a finite-area hyperbolic surface. The first problem is to determine the distribution of closed geodesics in the unit tangent bundle. The second problem is to determine the distribution of eigenfunctions (in microlocal sense) in the unit tangent bundle.
Download or read book Weakly Nonlinear Dirichlet Problems on Long Or Thin Domains written by and published by Taylor & Francis. This book was released on with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rankin Selberg Convolutions for mathrm SO 2 ell 1 times mathrm GL n Local Theory written by David Soudry and published by American Mathematical Soc.. This book was released on 1993 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: On t.p. "o2olo+o1" and "on" are subscript.
Download or read book Invariant Subsemigroups of Lie Groups written by Karl-Hermann Neeb and published by American Mathematical Soc.. This book was released on 1993 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: First we investigate the structure of Lie algebras with invariant cones and give a characterization of those Lie algebras containing pointed and generating invariant cones. Then we study the global structure of invariant Lie semigroups, and how far Lie's third theorem remains true for invariant cones and Lie semigroups.
Download or read book Duality and Definability in First Order Logic written by Michael Makkai and published by American Mathematical Soc.. This book was released on 1993 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: We develop a duality theory for small Boolean pretoposes in which the dual of the [italic capital]T is the groupoid of models of a Boolean pretopos [italic capital]T equipped with additional structure derived from ultraproducts. The duality theorem states that any small Boolean pretopos is canonically equivalent to its double dual. We use a strong version of the duality theorem to prove the so-called descent theorem for Boolean pretoposes which says that category of descent data derived from a conservative pretopos morphism between Boolean pretoposes is canonically equivalent to the domain-pretopos. The descent theorem contains the Beth definability theorem for classical first order logic. Moreover, it gives, via the standard translation from the language of categories to symbolic logic, a new definability theorem for classical first order logic concerning set-valued functors on models, expressible in purely syntactical (arithmetical) terms.
Download or read book The Continued Fractions Found in the Unorganized Portions of Ramanujan s Notebooks written by George E. Andrews and published by American Mathematical Soc.. This book was released on 1992 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among his thirty-three published papers, Ramanujan had only one continued fraction, the Rogers-Ramanujan continued fraction. However, his notebooks contain over 100 results on continued fractions. At the end of his second notebook are 100 pages of unorganized material, and the third notebook comprises thirty-three pages of disorganized results. In these 133 pages of material are approximately sixty theorems on continued fractions, most of them new results. In this monograph, the authors discuss and prove each of these theorems. Aimed at those interested in Ramanujan and his work, this monograph will be of special interest to those who work in continued fractions q -series, special function, theta-functions, and combinatorics. The work is likely to be of interest to those in number theory as well. The only required background is some knowledge of continued fractions and a course in complex analysis.
Download or read book Semistability of Amalgamated Products and HNN Extensions written by Michael L. Mihalik and published by American Mathematical Soc.. This book was released on 1992 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the authors show that amalgamated products and HNN-extensions of finitely presented semistable at infinity groups are also semistable at infinity. A major step toward determining whether all finitely presented groups are semistable at infinity, this result easily generalizes to finite graphs of groups. The theory of group actions on trees and techniques derived from the proof of Dunwoody's accessibility theorem are key ingredients in this work.
Download or read book The Inverse Problem of the Calculus of Variations for Ordinary Differential Equations written by Ian Anderson and published by American Mathematical Soc.. This book was released on 1992 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph explores various aspects of the inverse problem of the calculus of variations for systems of ordinary differential equations. The main problem centres on determining the existence and degree of generality of Lagrangians whose system of Euler-Lagrange equations coicides with a given system of ordinary differential equations. The authors rederive the basic necessary and sufficient conditions of Douglas for second order equations and extend them to equations of higher order using methods of the variational bicomplex of Tulcyjew, Vinogradov, and Tsujishita. The authors present an algorithm, based upon exterior differential systems techniques, for solving the inverse problem for second order equations. a number of new examples illustrate the effectiveness of this approach.
