Gradient Estimates and Sobolev Inequality
|
|
- Sarah Gibbs
- 5 years ago
- Views:
Transcription
1 Gradient Estimates and Sobolev Inequality Jiaping Wang University of Minnesota ( Joint work with Linfeng Zhou) Conference on Geometric Analysis in honor of Peter Li University of California, Irvine January 15, 2012 (University of Minnesota) Gradient Estimates and Sobolev Inequality 1 / 30
2 1 Introduction 2 Function case 3 Differential form case (University of Minnesota) Gradient Estimates and Sobolev Inequality 2 / 30
3 Setup Notations (M n, g), a compact oriented Riemannian manifold without boundary. Hodge Laplacian : A p (M) A p (M), acting on the space of smooth p-forms A p (M) on M, is defined by = dδ δd. As usual, d is the exterior differential operator and δ the adjoint of d with respect to the L 2 inner product on A p (M). Eigenvalues of are denoted by {0 λ 1... λ k... } with a corresponding orthonormal basis of eigenforms {φ i } i=1. (University of Minnesota) Gradient Estimates and Sobolev Inequality 3 / 30
4 Projection Obviously, {φ i } bp i=1 is a basis of the space Hp (M) of p-harmonic forms, where b p is the p-th Betti number of M. Projection of a p-form ω onto H p (M) is then given by with For function f, b p P(ω) = a i φ i a i = M i=1 ω, φ i. P(f ) = 1 f. V (M) M (University of Minnesota) Gradient Estimates and Sobolev Inequality 4 / 30
5 Sobolev Inequality There exists a constant c > 0 such that c ( M ) n 2 ω P(ω) 2n n n 2 M { dω 2 + δω 2 } for all smooth p form ω on M, where P(ω) denotes the projection of ω on to the space of harmonic p forms. Objective: obtain an explicit estimate of the constant c in terms of the geometry of M. (University of Minnesota) Gradient Estimates and Sobolev Inequality 5 / 30
6 Gradient Estimate, function case For acting on functions, denoted its eigenvalues by {0 = λ 0 < λ 1... λ k... }, and a corresponding orthonormal basis of eigenfunctions {φ i } i=0. Let (M n, g) be a closed Riemannian manifold with Ricci curvature lower bound (n 1)K, where K 0 is a constant. Let and E k = {v = k k a i φ i, ai 2 = 1} i=1 i=1 β k = max v E k max v (x). x M Lemma v 2 + (λ k + (n 1)K) v 2 (λ k + (n 1)K) β 2 k. (University of Minnesota) Gradient Estimates and Sobolev Inequality 6 / 30
7 Consequences Theorem There exists an explicit constant c(k, d, V, n), where d and V are the diameter and volume of M respectively, such that (1) v 2 cλ n+2 2 k, v 2 cλ n 2 k, for all v E k. (2) For all k 1, (3) The function H(x, y, t) given by λ k c 1 k 2 n. H(x, y, t) = 1 V + e λkt φ k (x) φ k (y) k=1 is the heat kernel of M. Moreover, for all t > 0, H(x, y, t) 1 V c t n 2. (University of Minnesota) Gradient Estimates and Sobolev Inequality 7 / 30
8 Proof Applying the gradient estimate, we have β k c(k, d, V, n) λ n 4 k For each x M, there exists an orthogonal matrix (a ij ) k k such that ψ j (x) = 0 for j = n + 1,, k, where ψ j = k i=1 a ij φ i. Now k φ i 2 (x) = i=1 n j=1 ψ j 2 (x) n β k c λ n+2 2 k. (University of Minnesota) Gradient Estimates and Sobolev Inequality 8 / 30
9 Proof, continued Integrating the inequality with respect to x, one concludes which implies λ 1 + λ λ k c 2 λ n+2 2 k, λ k c 3 k 2/n It is straightforward to see that H(x, y, t) 1 V e λkt φ k (x) φ k (y) k=1 c t n 2. (University of Minnesota) Gradient Estimates and Sobolev Inequality 9 / 30
10 Varopoulos Result The Sobolev inequality follows from a result of Varopoulos. Theorem If H(x, y, t) 1 V A t n 2, then the following Sobolev inequality holds with some c = c(a). c ( M ) n 2 f 2n n n 2 for all smooth function f on M with M f = 0. M f 2 (University of Minnesota) Gradient Estimates and Sobolev Inequality 10 / 30
11 Another Consequence c 1 k βk c 2 k. That is, for each k, there exist a 1, a 2,, a k with k i=1 a2 i = 1 such that k max a i φ i c k. x M i=1 (University of Minnesota) Gradient Estimates and Sobolev Inequality 11 / 30
12 Remarks The arguments work for M with non-empty boundary by some modifications. For the Dirichlet boundary conditions, the constants involve the mean curvature of the boundary, while for the Neumann boundary conditions, the constants involve both the second fundamental form and the size of the rolling ball along the boundary. The arguments rely crucially on a result of Li and Yau, which says that λ 1 c(n, d, K). One can in fact strengthen the gradient estimate so that it also incorporates Li and Yau s result. Indeed, one has for v E k and β > β k, Lemma v 2 (β v) 2 (n 1)( 2(n 1)K + (2k + 1)β λ k β β k ). (University of Minnesota) Gradient Estimates and Sobolev Inequality 12 / 30
13 Remarks, continued The Sobolev inequality can also be obtained from Li and Yau s famous heat kernel estimates. However, it relies on both Li and Yau s estimate of λ 1 and the existence of heat kernel. Historically, Yau and Croke have estimated the isoperimetric constant in terms of the geometry of M, which leads to the Sobolev inequality. The lower bound estimate of λ k was first established by Cheng and Li using the Sobolev inequality. Later, it was also derived by Li and Yau from their heat kernel estimates. (University of Minnesota) Gradient Estimates and Sobolev Inequality 13 / 30
14 Remarks, continued Polya conjecture: For all k 1, λ k c n ( k V ) n/2, where 0 < λ 1 < λ 2 are the Dirichlet eigenvalues of a compact Euclidean domain Ω R n, and c n = (2π) 2 /(ω n ) 2/n, ω n the volume of the unit ball in R n. Theorem (Li-Yau) k λ i i=1 n n + 2 c n k ( ) k n/2. V (University of Minnesota) Gradient Estimates and Sobolev Inequality 14 / 30
15 Form case, Difficulty Using the well-known Bochner-Weitzenbock formula, one can directly apply the preceding proof of the function case to the Hodge Laplacian acting on the smooth p forms on M. However, the resulting estimates will depend on the bounds of the covariant derivative of the curvature tensor of M. On the other hand, by working with the eigenforms, but not their covariant derivatives, Li had obtained the following interesting results 30 years ago. (University of Minnesota) Gradient Estimates and Sobolev Inequality 15 / 30
16 Work of Li Let E k = {v = k k a i φ i, ai 2 = 1}. i=1 i=1 Theorem For a compact manifold with its curvature operator Rm K, the following estimates hold for k c(k, b p, n). (1) For all v E k, v (x) c λ n 1 2 k. (2) Consequently, λ k c k 1 n 1. Note that in both estimates, the order is not sharp. (University of Minnesota) Gradient Estimates and Sobolev Inequality 16 / 30
17 Gradient estimate for forms Theorem Let (M n, g) be a closed manifold with curvature bound Rm K. Then for any form v E k, it satisfies the estimate v 2 + (λ k + 1) v 2 c (λ k + 1) n 2 +1, where c = c(n, V, d, K) is an explicit constant depending on the dimension n, volume V, diameter d and the curvature bound K. (University of Minnesota) Gradient Estimates and Sobolev Inequality 17 / 30
18 Proof Consider the function f = ω 2 + A ω 2, where A 1 is a fixed constant and ω a smooth p-form. Lemma For m 1, M f m 1 f 2 where c = 2nK(K + 2) + 18 K 2. M ( ω, ω + A ω, ω ) f m 1 c m 2 M f m, (University of Minnesota) Gradient Estimates and Sobolev Inequality 18 / 30
19 Proof, continued Proof of the gradient estimate: For each m 1, let I m = max f 2m, where f = v 2 + A v 2, A = λ k + K + 1, and the maximum is taken over all v E k. Note that where k i=1 b2 i 1. The lemma implies v = M M k λ i a i φ i = λ k i=1 k b i φ i, i=1 f 2m 1 f (2 λ k + c m 2 ) I m, (1) where c 1 = 8nK(K + 2) + 72 K 2. (University of Minnesota) Gradient Estimates and Sobolev Inequality 19 / 30
20 Proof, continued On the other hand M f 2m 1 f = 2m 1 m 2 Applying the Sobolev inequality, we get ( M f 2mβ ) 1 β M c m (λk + c m 2 ) I m f m 2. (2) Since this is true for all v E k, we maximize the left hand side over v and conclude (I βm ) 1 βm ( c m (λ k + c m 2 ) ) 1 m (I m ) 1 m for all m 1, where β = n n 1. The result then follows from iteration. (University of Minnesota) Gradient Estimates and Sobolev Inequality 20 / 30
21 Consequences Using a result of Mantuano that λ bp+1 c(n, V, d, K), we have There exists a constant c(k, d, V, n) such that (1) φ k c (λ k + 1) n+2 4 and φ k c (λ k + 1) n 4. (2) For all k > b p, λ k c 1 k 2 n. (3) The tensor H p (x, y, t) is the heat kernel of, where Moreover, for all t > 0, H p (x, y, t) = e λkt φ k (x) φ k (y) k=1 b(p) H p (x, y, t) φ k (x) φ k (y) c t n 2 k=1 (University of Minnesota) Gradient Estimates and Sobolev Inequality 21 / 30
22 Consequences, continued Let (M n, g) be a closed manifold with curvature bound Rm K. Then there exists a constant c(k, d, V, n) such that for v E k. d v c λ n+4 4 k In particular, this gives a Hessian estimate for eigenfunctions on M. (University of Minnesota) Gradient Estimates and Sobolev Inequality 22 / 30
23 Sobolev Inequality Theorem The following Sobolev inequality holds. c ( M ) n 2 ω P(ω) 2n n n 2 M { dω 2 + δω 2 } for all smooth p form ω on M, where P(ω) denotes the projection of ω on to the space H p (M) of harmonic p forms. (University of Minnesota) Gradient Estimates and Sobolev Inequality 23 / 30
24 Rumin s result Let A : L 2 (X, µ) L 2 (X, µ) be a non-negative self-adjoint operator. Let V = L 2 (X, µ) (kera). Suppose M(t) = t L(s) ds <, where L(t) = e ta Π V 1, and Π V : L 2 (X, µ) V the orthogonal projection. Then for f V, X N ( f 2 (x)) ln 2, 4D(f ) where D(f ) = Af, f L 2 and N(y) = y M 1 (y). (University of Minnesota) Gradient Estimates and Sobolev Inequality 24 / 30
25 Special case of Rumin s result If then and The inequality becomes c ( X L(t) c t n/2, M(t) = c t 2 n 2 M 1 (t) = c t 2 2 n. f 2n ) n 2 n 2 (x) dµ n X f Af dµ. (University of Minnesota) Gradient Estimates and Sobolev Inequality 25 / 30
26 Proof of Rumin s result For f V, Claim: On {x X : f 2 (x) 4 M 2 (t) D(f )}, Indeed, But, So f (x) 4 (I e ta/2 )f 2 (x). e ta/2 f D(f ) 1/2 A 1 e ta Π V 1,. A 1 e ta Π V = t e sa Π V ds. e ta/2 f D(f ) 1/2 e sa Π V 1, ds D(f ) 1/2 M(t). t (University of Minnesota) Gradient Estimates and Sobolev Inequality 26 / 30
27 Proof, continued By the claim, f 2 (x) X 4D(f ) /M 1( f 2 (x)) 4D(f ) 1 (I e ta/2 )f 2 dt 2 D(f ) 0 t 2 1 = (1 e tλ/2 ) 2 d Π λ f, f dt D(f ) 0 t 2 = ln 2. (University of Minnesota) Gradient Estimates and Sobolev Inequality 27 / 30
28 Remarks Compare with Li s result. While our estimates are sharp in terms of the order of k, the constant however depends on both upper and lower bounds of the curvature operator. A natural issue is to see if this dependency can be improved. The results can be extended to the case that M has nonempty boundary. It is desirable to get a lower bound estimate of λ bp+1 of Mantuano by a more analytical proof. (University of Minnesota) Gradient Estimates and Sobolev Inequality 28 / 30
29 Remarks, continued It is unclear to me how to establish Sobolev type inequalities on complete, noncompact manifolds for differential forms. For the function case, this issue has been largely settled through the heat kernel estimates of Li and Yau. (University of Minnesota) Gradient Estimates and Sobolev Inequality 29 / 30
30 Thank you for your attention. (University of Minnesota) Gradient Estimates and Sobolev Inequality 30 / 30
On the spectrum of the Hodge Laplacian and the John ellipsoid
Banff, July 203 On the spectrum of the Hodge Laplacian and the John ellipsoid Alessandro Savo, Sapienza Università di Roma We give upper and lower bounds for the first eigenvalue of the Hodge Laplacian
More informationEigenvalues of Collapsing Domains and Drift Laplacian
Eigenvalues of Collapsing Domains and Drift Laplacian Zhiqin Lu Dedicate to Professor Peter Li on his 60th Birthday Department of Mathematics, UC Irvine, Irvine CA 92697 January 17, 2012 Zhiqin Lu, Dept.
More informationPseudo-Poincaré Inequalities and Applications to Sobolev Inequalities
Pseudo-Poincaré Inequalities and Applications to Sobolev Inequalities Laurent Saloff-Coste Abstract Most smoothing procedures are via averaging. Pseudo-Poincaré inequalities give a basic L p -norm control
More informationThe p-laplacian and geometric structure of the Riemannian manifold
Workshop on Partial Differential Equation and its Applications Institute for Mathematical Sciences - National University of Singapore The p-laplacian and geometric structure of the Riemannian manifold
More informationarxiv:math/ v1 [math.dg] 19 Nov 2004
arxiv:math/04426v [math.dg] 9 Nov 2004 REMARKS ON GRADIENT RICCI SOLITONS LI MA Abstract. In this paper, we study the gradient Ricci soliton equation on a complete Riemannian manifold. We show that under
More informationSection 2. Basic formulas and identities in Riemannian geometry
Section 2. Basic formulas and identities in Riemannian geometry Weimin Sheng and 1. Bianchi identities The first and second Bianchi identities are R ijkl + R iklj + R iljk = 0 R ijkl,m + R ijlm,k + R ijmk,l
More informationEssential Spectra of complete manifolds
Essential Spectra of complete manifolds Zhiqin Lu Analysis, Complex Geometry, and Mathematical Physics: A Conference in Honor of Duong H. Phong May 7, 2013 Zhiqin Lu, Dept. Math, UCI Essential Spectra
More informationCalderón-Zygmund inequality on noncompact Riem. manifolds
The Calderón-Zygmund inequality on noncompact Riemannian manifolds Institut für Mathematik Humboldt-Universität zu Berlin Geometric Structures and Spectral Invariants Berlin, May 16, 2014 This talk is
More informationLiouville Properties for Nonsymmetric Diffusion Operators. Nelson Castañeda. Central Connecticut State University
Liouville Properties for Nonsymmetric Diffusion Operators Nelson Castañeda Central Connecticut State University VII Americas School in Differential Equations and Nonlinear Analysis We consider nonsymmetric
More informationCMS winter meeting 2008, Ottawa. The heat kernel on connected sums
CMS winter meeting 2008, Ottawa The heat kernel on connected sums Laurent Saloff-Coste (Cornell University) December 8 2008 p(t, x, y) = The heat kernel ) 1 x y 2 exp ( (4πt) n/2 4t The heat kernel is:
More informationDefinition and basic properties of heat kernels I, An introduction
Definition and basic properties of heat kernels I, An introduction Zhiqin Lu, Department of Mathematics, UC Irvine, Irvine CA 92697 April 23, 2010 In this lecture, we will answer the following questions:
More informationtheorem for harmonic diffeomorphisms. Theorem. Let n be a complete manifold with Ricci 0, and let n be a simplyconnected manifold with nonpositive sec
on-existence of Some Quasi-conformal Harmonic Diffeomorphisms Lei i Λ Department of athematics University of California, Irvine Irvine, CA 92697 lni@math.uci.edu October 5 997 Introduction The property
More informationSharp gradient estimate and spectral rigidity for p-laplacian
Shar gradient estimate and sectral rigidity for -Lalacian Chiung-Jue Anna Sung and Jiaing Wang To aear in ath. Research Letters. Abstract We derive a shar gradient estimate for ositive eigenfunctions of
More informationSTABILITY OF THE ALMOST HERMITIAN CURVATURE FLOW
STABILITY OF THE ALOST HERITIAN CURVATURE FLOW DANIEL J. SITH Abstract. The almost Hermitian curvature flow was introduced in [9] by Streets and Tian in order to study almost Hermitian structures, with
More informationON THE REGULARITY OF SAMPLE PATHS OF SUB-ELLIPTIC DIFFUSIONS ON MANIFOLDS
Bendikov, A. and Saloff-Coste, L. Osaka J. Math. 4 (5), 677 7 ON THE REGULARITY OF SAMPLE PATHS OF SUB-ELLIPTIC DIFFUSIONS ON MANIFOLDS ALEXANDER BENDIKOV and LAURENT SALOFF-COSTE (Received March 4, 4)
More informationAn extremal eigenvalue problem for surfaces with boundary
An extremal eigenvalue problem for surfaces with boundary Richard Schoen Stanford University - Conference in Geometric Analysis, UC Irvine - January 15, 2012 - Joint project with Ailana Fraser Plan of
More informationarxiv: v1 [math.dg] 9 Nov 2018
INDEX AND FIRST BETTI NUMBER OF f-minimal HYPERSURFACES: GENERAL AMBIENTS DEBORA IMPERA AND MICHELE RIMOLDI arxiv:1811.04009v1 [math.dg] 9 Nov 018 Abstract. We generalize a method by L. Ambrozio, A. Carlotto,
More informationUniversal inequalities for eigenvalues. of elliptic operators in divergence. form on domains in complete. noncompact Riemannian manifolds
Theoretical athematics & Applications, vol.3, no., 03, 39-48 ISSN: 79-9687 print, 79-9709 online Scienpress Ltd, 03 Universal inequalities for eigenvalues of elliptic operators in divergence form on domains
More informationAnalysis in weighted spaces : preliminary version
Analysis in weighted spaces : preliminary version Frank Pacard To cite this version: Frank Pacard. Analysis in weighted spaces : preliminary version. 3rd cycle. Téhéran (Iran, 2006, pp.75.
More informationFrom the Brunn-Minkowski inequality to a class of Poincaré type inequalities
arxiv:math/0703584v1 [math.fa] 20 Mar 2007 From the Brunn-Minkowski inequality to a class of Poincaré type inequalities Andrea Colesanti Abstract We present an argument which leads from the Brunn-Minkowski
More informationGEOMETRICAL TOOLS FOR PDES ON A SURFACE WITH ROTATING SHALLOW WATER EQUATIONS ON A SPHERE
GEOETRICAL TOOLS FOR PDES ON A SURFACE WITH ROTATING SHALLOW WATER EQUATIONS ON A SPHERE BIN CHENG Abstract. This is an excerpt from my paper with A. ahalov [1]. PDE theories with Riemannian geometry are
More informationRicci Curvature and Bochner Formula on Alexandrov Spaces
Ricci Curvature and Bochner Formula on Alexandrov Spaces Sun Yat-sen University March 18, 2013 (work with Prof. Xi-Ping Zhu) Contents Alexandrov Spaces Generalized Ricci Curvature Geometric and Analytic
More informationCS 468 (Spring 2013) Discrete Differential Geometry
CS 468 (Spring 2013) Discrete Differential Geometry Lecture 13 13 May 2013 Tensors and Exterior Calculus Lecturer: Adrian Butscher Scribe: Cassidy Saenz 1 Vectors, Dual Vectors and Tensors 1.1 Inner Product
More informationDivergence Theorems in Path Space. Denis Bell University of North Florida
Divergence Theorems in Path Space Denis Bell University of North Florida Motivation Divergence theorem in Riemannian geometry Theorem. Let M be a closed d-dimensional Riemannian manifold. Then for any
More informationGeometric inequalities for black holes
Geometric inequalities for black holes Sergio Dain FaMAF-Universidad Nacional de Córdoba, CONICET, Argentina. 3 August, 2012 Einstein equations (vacuum) The spacetime is a four dimensional manifold M with
More informationPoincaré Duality Angles on Riemannian Manifolds with Boundary
Poincaré Duality Angles on Riemannian Manifolds with Boundary Clayton Shonkwiler Department of Mathematics University of Pennsylvania June 5, 2009 Realizing cohomology groups as spaces of differential
More informationRiemannian Curvature Functionals: Lecture III
Riemannian Curvature Functionals: Lecture III Jeff Viaclovsky Park City Mathematics Institute July 18, 2013 Lecture Outline Today we will discuss the following: Complete the local description of the moduli
More informationGeometric bounds for Steklov eigenvalues
Geometric bounds for Steklov eigenvalues Luigi Provenzano École Polytechnique Fédérale de Lausanne, Switzerland Joint work with Joachim Stubbe June 20, 2017 luigi.provenzano@epfl.ch (EPFL) Steklov eigenvalues
More informationIntroduction In this paper, we will prove the following Liouville-type results for harmonic
Mathematical Research Letters 2, 79 735 995 LIOUVILLE PROPERTIES OF HARMONIC MAPS Luen-fai Tam Introduction In this paper, we will prove the following Liouville-type results for harmonic maps: Let M be
More informationHarmonic Functions on Complete Riemannian Manifolds
* Vol. I?? Harmonic Functions on Complete Riemannian Manifolds Peter Li Abstract We present a brief description of certain aspects of the theory of harmonic functions on a complete Riemannian manifold.
More informationM. Ledoux Université de Toulouse, France
ON MANIFOLDS WITH NON-NEGATIVE RICCI CURVATURE AND SOBOLEV INEQUALITIES M. Ledoux Université de Toulouse, France Abstract. Let M be a complete n-dimensional Riemanian manifold with non-negative Ricci curvature
More informationMATH 263: PROBLEM SET 1: BUNDLES, SHEAVES AND HODGE THEORY
MATH 263: PROBLEM SET 1: BUNDLES, SHEAVES AND HODGE THEORY 0.1. Vector Bundles and Connection 1-forms. Let E X be a complex vector bundle of rank r over a smooth manifold. Recall the following abstract
More informationSPECTRAL PROPERTIES OF THE LAPLACIAN ON BOUNDED DOMAINS
SPECTRAL PROPERTIES OF THE LAPLACIAN ON BOUNDED DOMAINS TSOGTGEREL GANTUMUR Abstract. After establishing discrete spectra for a large class of elliptic operators, we present some fundamental spectral properties
More informationCS 468. Differential Geometry for Computer Science. Lecture 13 Tensors and Exterior Calculus
CS 468 Differential Geometry for Computer Science Lecture 13 Tensors and Exterior Calculus Outline Linear and multilinear algebra with an inner product Tensor bundles over a surface Symmetric and alternating
More informationThe Hodge Star Operator
The Hodge Star Operator Rich Schwartz April 22, 2015 1 Basic Definitions We ll start out by defining the Hodge star operator as a map from k (R n ) to n k (R n ). Here k (R n ) denotes the vector space
More informationUPPER BOUNDS FOR EIGENVALUES OF THE DISCRETE AND CONTINUOUS LAPLACE OPERATORS
UPPER BOUNDS FOR EIGENVALUES OF THE DISCRETE AND CONTINUOUS LAPLACE OPERATORS F. R. K. Chung University of Pennsylvania, Philadelphia, Pennsylvania 904 A. Grigor yan Imperial College, London, SW7 B UK
More informationMinimal hypersurfaces with bounded index and area
Minimal hypersurfaces with bounded index and area Ben Sharp March 2017 Why should one care? Set-up and definitions Compactness and non-compactness Main results Why should one care? The work of Almgren
More informationCohomology of the Mumford Quotient
Cohomology of the Mumford Quotient Maxim Braverman Abstract. Let X be a smooth projective variety acted on by a reductive group G. Let L be a positive G-equivariant line bundle over X. We use a Witten
More informationGeometry and the Kato square root problem
Geometry and the Kato square root problem Lashi Bandara Centre for Mathematics and its Applications Australian National University 29 July 2014 Geometric Analysis Seminar Beijing International Center for
More informationNotes on Cartan s Method of Moving Frames
Math 553 σιι June 4, 996 Notes on Cartan s Method of Moving Frames Andrejs Treibergs The method of moving frames is a very efficient way to carry out computations on surfaces Chern s Notes give an elementary
More informationarxiv:math/ v1 [math.dg] 7 Jun 2004
arxiv:math/46v [math.dg] 7 Jun 4 The First Dirichlet Eigenvalue and Li s Conjecture Jun LING Abstract We give a new estimate on the lower bound for the first Dirichlet eigenvalue for the compact manifolds
More informationICM 2014: The Structure and Meaning. of Ricci Curvature. Aaron Naber ICM 2014: Aaron Naber
Outline of Talk Background and Limit Spaces Structure of Spaces with Lower Ricci Regularity of Spaces with Bounded Ricci Characterizing Ricci Background: s (M n, g, x) n-dimensional pointed Riemannian
More informationSubmanifolds of. Total Mean Curvature and. Finite Type. Bang-Yen Chen. Series in Pure Mathematics Volume. Second Edition.
le 27 AIPEI CHENNAI TAIPEI - Series in Pure Mathematics Volume 27 Total Mean Curvature and Submanifolds of Finite Type Second Edition Bang-Yen Chen Michigan State University, USA World Scientific NEW JERSEY
More informationSection 6. Laplacian, volume and Hessian comparison theorems
Section 6. Laplacian, volume and Hessian comparison theorems Weimin Sheng December 27, 2009 Two fundamental results in Riemannian geometry are the Laplacian and Hessian comparison theorems for the distance
More informationLECTURE 10: THE PARALLEL TRANSPORT
LECTURE 10: THE PARALLEL TRANSPORT 1. The parallel transport We shall start with the geometric meaning of linear connections. Suppose M is a smooth manifold with a linear connection. Let γ : [a, b] M be
More informationThe volume growth of complete gradient shrinking Ricci solitons
arxiv:0904.0798v [math.dg] Apr 009 The volume growth of complete gradient shrinking Ricci solitons Ovidiu Munteanu Abstract We prove that any gradient shrinking Ricci soliton has at most Euclidean volume
More informationLECTURE 21: THE HESSIAN, LAPLACE AND TOPOROGOV COMPARISON THEOREMS. 1. The Hessian Comparison Theorem. We recall from last lecture that
LECTURE 21: THE HESSIAN, LAPLACE AND TOPOROGOV COMPARISON THEOREMS We recall from last lecture that 1. The Hessian Comparison Theorem K t) = min{kπ γt) ) γt) Π γt) }, K + t) = max{k Π γt) ) γt) Π γt) }.
More informationSupersymmetric Quantum Mechanics and Geometry by Nicholas Mee of Trinity College, Cambridge. October 1989
Supersymmetric Quantum Mechanics and Geometry by Nicholas Mee of Trinity College Cambridge October 1989 Preface This dissertation is the result of my own individual effort except where reference is explicitly
More informationEigenvalues and eigenfunctions of the Laplacian. Andrew Hassell
Eigenvalues and eigenfunctions of the Laplacian Andrew Hassell 1 2 The setting In this talk I will consider the Laplace operator,, on various geometric spaces M. Here, M will be either a bounded Euclidean
More information1 Directional Derivatives and Differentiability
Wednesday, January 18, 2012 1 Directional Derivatives and Differentiability Let E R N, let f : E R and let x 0 E. Given a direction v R N, let L be the line through x 0 in the direction v, that is, L :=
More informationInvariance Theory, the Heat Equation, and the Atiyah-Singer Index Theorem
PETER B. GILKEY Department of Mathematics, University of Oregon Invariance Theory, the Heat Equation, and the Atiyah-Singer Index Theorem Second Edition CRC PRESS Boca Raton Ann Arbor London Tokyo Contents
More informationInequalities for the ADM-mass and capacity of asymptotically flat manifolds with minimal boundary
Inequalities for the ADM-mass and capacity of asymptotically flat manifolds with minimal boundary Fernando Schwartz Abstract. We present some recent developments involving inequalities for the ADM-mass
More informationA Remark on -harmonic Functions on Riemannian Manifolds
Electronic Journal of ifferential Equations Vol. 1995(1995), No. 07, pp. 1-10. Published June 15, 1995. ISSN 1072-6691. URL: http://ejde.math.swt.edu or http://ejde.math.unt.edu ftp (login: ftp) 147.26.103.110
More informationA Brief History of Morse Homology
A Brief History of Morse Homology Yanfeng Chen Abstract Morse theory was originally due to Marston Morse [5]. It gives us a method to study the topology of a manifold using the information of the critical
More information1 Normal (geodesic) coordinates
Riemannian Geometry The Bochner- Weitzenbock formula If we need to verify some tensor identity (or inequality) on Riemannina manifolds, we only need to choose, at every point, a suitable local coordinate,
More informationA Concise Course on Stochastic Partial Differential Equations
A Concise Course on Stochastic Partial Differential Equations Michael Röckner Reference: C. Prevot, M. Röckner: Springer LN in Math. 1905, Berlin (2007) And see the references therein for the original
More informationTWISTOR AND KILLING FORMS IN RIEMANNIAN GEOMETRY
TWISTOR AND KILLING FORMS IN RIEMANNIAN GEOMETRY Andrei Moroianu CNRS - Ecole Polytechnique Palaiseau Prague, September 1 st, 2004 joint work with Uwe Semmelmann Plan of the talk Algebraic preliminaries
More informationPoisson Equation on Closed Manifolds
Poisson Equation on Closed anifolds Andrew acdougall December 15, 2011 1 Introduction The purpose of this project is to investigate the poisson equation φ = ρ on closed manifolds (compact manifolds without
More informationOn the BCOV Conjecture
Department of Mathematics University of California, Irvine December 14, 2007 Mirror Symmetry The objects to study By Mirror Symmetry, for any CY threefold, there should be another CY threefold X, called
More informationarxiv: v2 [math.dg] 26 May 2017
A NOTE ON THE INDEX OF CLOSED MINIMAL HYPERSURFACES OF FLAT TORI arxiv:1701.06901v2 [math.dg] 26 May 2017 LUCAS AMBROZIO, ALESSANDRO CARLOTTO AND BEN SHARP Abstract. Generalizing earlier work by Ros in
More informationThis theorem gives us a corollary about the geometric height inequality which is originally due to Vojta [V].
694 KEFENG LIU This theorem gives us a corollary about the geometric height inequality which is originally due to Vojta [V]. Corollary 0.3. Given any ε>0, there exists a constant O ε (1) depending on ε,
More informationarxiv: v2 [math.dg] 27 Jan 2017
AREA BOUNDS FOR MINIMAL SURFACES THAT PASS THROUGH A PRESCRIBED POINT IN A BALL arxiv:1607.04631v [math.dg] 7 Jan 017 SIMON BRENDLE AND PEI-KEN HUNG Abstract. Let Σ be a k-dimensional minimal submanifold
More informationELLIPTIC GRADIENT ESTIMATES FOR A NONLINEAR HEAT EQUATION AND APPLICATIONS arxiv: v1 [math.dg] 1 Mar 2016
ELLIPTIC GRADIENT ESTIMATES FOR A NONLINEAR HEAT EQUATION AND APPLICATIONS arxiv:603.0066v [math.dg] Mar 206 JIA-YONG WU Abstract. In this paper, we study elliptic gradient estimates for a nonlinear f-heat
More informationA GLOBAL PINCHING THEOREM OF MINIMAL HYPERSURFACES IN THE SPHERE
proceedings of the american mathematical society Volume 105, Number I. January 1989 A GLOBAL PINCHING THEOREM OF MINIMAL HYPERSURFACES IN THE SPHERE SHEN CHUN-LI (Communicated by David G. Ebin) Abstract.
More informationGeometry and the Kato square root problem
Geometry and the Kato square root problem Lashi Bandara Centre for Mathematics and its Applications Australian National University 7 June 2013 Geometric Analysis Seminar University of Wollongong Lashi
More informationThe eigenvalue problem in Finsler geometry
The eigenvalue problem in Finsler geometry Qiaoling Xia Abstract. One of the fundamental problems is to study the eigenvalue problem for the differential operator in geometric analysis. In this article,
More informationUNIQUENESS RESULTS ON SURFACES WITH BOUNDARY
UNIQUENESS RESULTS ON SURFACES WITH BOUNDARY XIAODONG WANG. Introduction The following theorem is proved by Bidaut-Veron and Veron [BVV]. Theorem. Let (M n, g) be a compact Riemannian manifold and u C
More informationStationary Kirchhoff equations with powers by Emmanuel Hebey (Université de Cergy-Pontoise)
Stationary Kirchhoff equations with powers by Emmanuel Hebey (Université de Cergy-Pontoise) Lectures at the Riemann center at Varese, at the SNS Pise, at Paris 13 and at the university of Nice. June 2017
More informationRigidity and Non-rigidity Results on the Sphere
Rigidity and Non-rigidity Results on the Sphere Fengbo Hang Xiaodong Wang Department of Mathematics Michigan State University Oct., 00 1 Introduction It is a simple consequence of the maximum principle
More informationDiameters and eigenvalues
CHAPTER 3 Diameters and eigenvalues 31 The diameter of a graph In a graph G, the distance between two vertices u and v, denoted by d(u, v), is defined to be the length of a shortest path joining u and
More information1 First and second variational formulas for area
1 First and second variational formulas for area In this chapter, we will derive the first and second variational formulas for the area of a submanifold. This will be useful in our later discussion on
More informationNumerical Minimization of Potential Energies on Specific Manifolds
Numerical Minimization of Potential Energies on Specific Manifolds SIAM Conference on Applied Linear Algebra 2012 22 June 2012, Valencia Manuel Gra f 1 1 Chemnitz University of Technology, Germany, supported
More informationCohomology of Harmonic Forms on Riemannian Manifolds With Boundary
Cohomology of Harmonic Forms on Riemannian Manifolds With Boundary Sylvain Cappell, Dennis DeTurck, Herman Gluck, and Edward Y. Miller 1. Introduction To Julius Shaneson on the occasion of his 60th birthday
More informationGENERALIZED ISOPERIMETRIC INEQUALITIES FOR EXTRINSIC BALLS IN MINIMAL SUBMANIFOLDS. Steen Markvorsen and Vicente Palmer*
GENEALIZED ISOPEIMETIC INEQUALITIES FO EXTINSIC BALLS IN MINIMAL SUBMANIFOLDS Steen Markvorsen and Vicente Palmer* Abstract. The volume of an extrinsic ball in a minimal submanifold has a well defined
More informationHeat Kernel and Analysis on Manifolds Excerpt with Exercises. Alexander Grigor yan
Heat Kernel and Analysis on Manifolds Excerpt with Exercises Alexander Grigor yan Department of Mathematics, University of Bielefeld, 33501 Bielefeld, Germany 2000 Mathematics Subject Classification. Primary
More informationEstimates on Neumann eigenfunctions at the boundary, and the Method of Particular Solutions" for computing them
Estimates on Neumann eigenfunctions at the boundary, and the Method of Particular Solutions" for computing them Department of Mathematics Australian National University Dartmouth, July 2010 Outline Introduction
More informationPoincaré Inequalities and Moment Maps
Tel-Aviv University Analysis Seminar at the Technion, Haifa, March 2012 Poincaré-type inequalities Poincaré-type inequalities (in this lecture): Bounds for the variance of a function in terms of the gradient.
More informationMaxwell s equations in Carnot groups
Maxwell s equations in Carnot groups B. Franchi (U. Bologna) INDAM Meeting on Geometric Control and sub-riemannian Geometry Cortona, May 21-25, 2012 in honor of Andrey Agrachev s 60th birthday Researches
More informationTHE LOCAL THEORY OF ELLIPTIC OPERATORS AND THE HODGE THEOREM
THE LOCAL THEORY OF ELLIPTIC OPERATORS AND THE HODGE THEOREM BEN LOWE Abstract. In this paper, we develop the local theory of elliptic operators with a mind to proving the Hodge Decomposition Theorem.
More informationNontangential limits and Fatou-type theorems on post-critically finite self-similar sets
Nontangential limits and on post-critically finite self-similar sets 4th Cornell Conference on Analysis, Probability, and Mathematical Physics on Fractals Universidad de Colima Setting Boundary limits
More informationarxiv: v1 [math.dg] 25 Nov 2009
arxiv:09.4830v [math.dg] 25 Nov 2009 EXTENSION OF REILLY FORULA WITH APPLICATIONS TO EIGENVALUE ESTIATES FOR DRIFTING LAPLACINS LI A, SHENG-HUA DU Abstract. In this paper, we extend the Reilly formula
More informationHyperkähler geometry lecture 3
Hyperkähler geometry lecture 3 Misha Verbitsky Cohomology in Mathematics and Physics Euler Institute, September 25, 2013, St. Petersburg 1 Broom Bridge Here as he walked by on the 16th of October 1843
More informationVolume comparison theorems without Jacobi fields
Volume comparison theorems without Jacobi fields Dominique Bakry Laboratoire de Statistique et Probabilités Université Paul Sabatier 118 route de Narbonne 31062 Toulouse, FRANCE Zhongmin Qian Mathematical
More informationLevel sets of the lapse function in static GR
Level sets of the lapse function in static GR Carla Cederbaum Mathematisches Institut Universität Tübingen Auf der Morgenstelle 10 72076 Tübingen, Germany September 4, 2014 Abstract We present a novel
More informationThe harmonic map flow
Chapter 2 The harmonic map flow 2.1 Definition of the flow The harmonic map flow was introduced by Eells-Sampson in 1964; their work could be considered the start of the field of geometric flows. The flow
More informationDISTRIBUTION THEORY ON P.C.F. FRACTALS
DISTRIBUTION THEORY ON P.C.F. FRACTALS LUKE G. ROGERS AND ROBERT S. STRICHARTZ Abstract. We construct a theory of distributions in the setting of analysis on post-critically finite self-similar fractals,
More informationLocalizing solutions of the Einstein equations
Localizing solutions of the Einstein equations Richard Schoen UC, Irvine and Stanford University - General Relativity: A Celebration of the 100th Anniversary, IHP - November 20, 2015 Plan of Lecture The
More informationn 2 xi = x i. x i 2. r r ; i r 2 + V ( r) V ( r) = 0 r > 0. ( 1 1 ) a r n 1 ( 1 2) V( r) = b ln r + c n = 2 b r n 2 + c n 3 ( 1 3)
Sep. 7 The L aplace/ P oisson Equations: Explicit Formulas In this lecture we study the properties of the Laplace equation and the Poisson equation with Dirichlet boundary conditions through explicit representations
More informationHeat Flows, Geometric and Functional Inequalities
Heat Flows, Geometric and Functional Inequalities M. Ledoux Institut de Mathématiques de Toulouse, France heat flow and semigroup interpolations Duhamel formula (19th century) pde, probability, dynamics
More informationExercise 1 (Formula for connection 1-forms) Using the first structure equation, show that
1 Stokes s Theorem Let D R 2 be a connected compact smooth domain, so that D is a smooth embedded circle. Given a smooth function f : D R, define fdx dy fdxdy, D where the left-hand side is the integral
More information1.13 The Levi-Civita Tensor and Hodge Dualisation
ν + + ν ν + + ν H + H S ( S ) dφ + ( dφ) 2π + 2π 4π. (.225) S ( S ) Here, we have split the volume integral over S 2 into the sum over the two hemispheres, and in each case we have replaced the volume-form
More informationThe spectral zeta function
The spectral zeta function Bernd Ammann June 4, 215 Abstract In this talk we introduce spectral zeta functions. The spectral zeta function of the Laplace-Beltrami operator was already introduced by Minakshisundaram
More informationarxiv:math/ v2 [math.dg] 14 Feb 2007
WIGHTD POINCARÉ INQUALITY AND RIGIDITY OF COPLT ANIFOLDS arxiv:math/0701693v2 [math.dg] 14 Feb 2007 Peter Li Jiaping Wang University of California, Irvine University of innesota Abstract. We prove structure
More informationStrichartz estimates for the Schrödinger equation on polygonal domains
estimates for the Schrödinger equation on Joint work with Matt Blair (UNM), G. Austin Ford (Northwestern U) and Sebastian Herr (U Bonn and U Düsseldorf)... With a discussion of previous work with Andrew
More informationPREPRINT 2005:50. L 2 -estimates for the d-equation and Witten s Proof of the Morse Inequalities BO BERNDTSSON
PREPRINT 2005:50 L 2 -estimates for the d-equation and Witten s Proof of the Morse Inequalities BO BERNDTSSON Department of Mathematical Sciences Division of Mathematics CHALMERS UNIVERSITY OF TECHNOLOGY
More informationRESEARCH STATEMENT MICHAEL MUNN
RESEARCH STATEMENT MICHAEL MUNN Ricci curvature plays an important role in understanding the relationship between the geometry and topology of Riemannian manifolds. Perhaps the most notable results in
More informationNew Proof of Hörmander multiplier Theorem on compact manifolds without boundary
New Proof of Hörmander multiplier Theorem on compact manifolds without boundary Xiangjin Xu Department of athematics Johns Hopkins University Baltimore, D, 21218, USA xxu@math.jhu.edu Abstract On compact
More informationComplex manifolds, Kahler metrics, differential and harmonic forms
Complex manifolds, Kahler metrics, differential and harmonic forms Cattani June 16, 2010 1 Lecture 1 Definition 1.1 (Complex Manifold). A complex manifold is a manifold with coordinates holomorphic on
More informationWave equation on manifolds and finite speed of propagation
Wave equation on manifolds and finite speed of propagation Ethan Y. Jaffe Let M be a Riemannian manifold (without boundary), and let be the (negative of) the Laplace-Beltrami operator. In this note, we
More informationCONNECTIONS BETWEEN A CONJECTURE OF SCHIFFER S AND INCOMPRESSIBLE FLUID MECHANICS
CONNECTIONS BETWEEN A CONJECTURE OF SCHIFFER S AND INCOMPRESSIBLE FLUID MECHANICS JAMES P. KELLIHER Abstract. We demonstrate connections that exists between a conjecture of Schiffer s (which is equivalent
More information