The p-laplacian and geometric structure of the Riemannian manifold

Similar documents
Sharp gradient estimate and spectral rigidity for p-laplacian

NOTE ON ASYMPTOTICALLY CONICAL EXPANDING RICCI SOLITONS

Gradient Estimates and Sobolev Inequality

Calderón-Zygmund inequality on noncompact Riem. manifolds

The volume growth of complete gradient shrinking Ricci solitons

Liouville Properties for Nonsymmetric Diffusion Operators. Nelson Castañeda. Central Connecticut State University

arxiv:math/ v1 [math.dg] 19 Nov 2004

Harmonic Functions on Complete Riemannian Manifolds

Lecture No 1 Introduction to Diffusion equations The heat equat

arxiv:math/ v1 [math.dg] 7 Jun 2004

Geometry of Ricci Solitons

RICCI SOLITONS ON COMPACT KAHLER SURFACES. Thomas Ivey

Section 6. Laplacian, volume and Hessian comparison theorems

Essential Spectra of complete manifolds

FOUR-DIMENSIONAL GRADIENT SHRINKING SOLITONS WITH POSITIVE ISOTROPIC CURVATURE

Eigenvalues of Collapsing Domains and Drift Laplacian

Some Remarks on Ricci Solitons

COMPLETE GRADIENT SHRINKING RICCI SOLITONS WITH PINCHED CURVATURE

Introduction In this paper, we will prove the following Liouville-type results for harmonic

CMS winter meeting 2008, Ottawa. The heat kernel on connected sums

arxiv: v1 [math.dg] 25 Nov 2009

BOUNDARY EFFECT OF RICCI CURVATURE

HARNACK INEQUALITY FOR NONDIVERGENT ELLIPTIC OPERATORS ON RIEMANNIAN MANIFOLDS. Seick Kim

Deforming conformal metrics with negative Bakry-Émery Ricci Tensor on manifolds with boundary

Pseudo-Poincaré Inequalities and Applications to Sobolev Inequalities

On extensions of Myers theorem

The eigenvalue problem in Finsler geometry

Geometry of Shrinking Ricci Solitons

theorem for harmonic diffeomorphisms. Theorem. Let n be a complete manifold with Ricci 0, and let n be a simplyconnected manifold with nonpositive sec

Kähler-Ricci flow on complete manifolds

Rough metrics, the Kato square root problem, and the continuity of a flow tangent to the Ricci flow

Rigidity and Non-rigidity Results on the Sphere

Preprint Preprint Preprint Preprint

L -uniqueness of Schrödinger operators on a Riemannian manifold

The Entropy Formula for Linear Heat Equation

ELLIPTIC GRADIENT ESTIMATES FOR A NONLINEAR HEAT EQUATION AND APPLICATIONS arxiv: v1 [math.dg] 1 Mar 2016

Compactness of Symplectic critical surfaces

arxiv: v1 [math.dg] 1 Jul 2014

Lecture 1 Introduction

Ricci Curvature and Bochner Formula on Alexandrov Spaces

ICM 2014: The Structure and Meaning. of Ricci Curvature. Aaron Naber ICM 2014: Aaron Naber

EXISTENCE THEORY FOR HARMONIC METRICS

Complete spacelike hypersurfaces with positive r-th mean curvature in a semi-riemannian warped product

f -Minimal Surface and Manifold with Positive m-bakry Émery Ricci Curvature

arxiv:math/ v2 [math.dg] 14 Feb 2007

RESEARCH STATEMENT GANG LIU

An Alexandroff Bakelman Pucci estimate on Riemannian manifolds

Volume comparison theorems without Jacobi fields

Rigidity of Gradient Ricci Solitons

Riemannian Curvature Functionals: Lecture III

ON THE REGULARITY OF SAMPLE PATHS OF SUB-ELLIPTIC DIFFUSIONS ON MANIFOLDS

M. Ledoux Université de Toulouse, France

ERRATUM TO AFFINE MANIFOLDS, SYZ GEOMETRY AND THE Y VERTEX

Logarithmic Harnack inequalities

The Laplace-Beltrami-Operator on Riemannian Manifolds. 1 Why do we need the Laplace-Beltrami-Operator?

ON THE GROUND STATE OF QUANTUM LAYERS

Using heat invariants to hear the geometry of orbifolds. Emily Dryden CAMGSD

THE POISSON EQUATION ON MANIFOLDS WITH POSITIVE ESSENTIAL SPECTRUM

Heat kernels of some Schrödinger operators

Functions with bounded variation on Riemannian manifolds with Ricci curvature unbounded from below

Lecture No 2 Degenerate Diffusion Free boundary problems

arxiv: v1 [math.dg] 11 Jan 2009

arxiv: v3 [math.dg] 13 Mar 2011

p-laplace operator, quasiregular mappings, and Picard-type theorems

Logarithmic Sobolev Inequalities

RIEMANNIAN SUBMERSIONS NEED NOT PRESERVE POSITIVE RICCI CURVATURE

Universal inequalities for eigenvalues. of elliptic operators in divergence. form on domains in complete. noncompact Riemannian manifolds

Ancient solutions to Ricci flow

Symplectic critical surfaces in Kähler surfaces

RESEARCH STATEMENT MICHAEL MUNN

Recent developments in elliptic partial differential equations of Monge Ampère type

arxiv: v1 [math.dg] 31 Oct 2012

Hyperbolic Geometric Flow

Mass under the Ricci flow

Inverse Spectral Problems in Riemannian Geometry

Kähler-Ricci Flow and the Poincaré-Lelong Equation

Fifth Abel Conference : Celebrating the Mathematical Impact of John F. Nash Jr. and Louis Nirenberg

Hermitian vs. Riemannian Geometry

PLURISUBHARMONIC FUNCTIONS AND THE STRUCTURE OF COMPLETE KÄHLER MANIFOLDS WITH NONNEGATIVE CURVATURE

One can hear the corners of a drum

A Characterization of Einstein Manifolds

RIGIDITY OF GRADIENT RICCI SOLITONS

WARPED PRODUCTS PETER PETERSEN

MEAN VALUE INEQUALITIES AND CONDITIONS TO EXTEND RICCI FLOW

Spacelike surfaces with positive definite second fundamental form in 3-dimensional Lorentzian manifolds

Bounding scalar curvature and diameter along the Kähler Ricci flow (after Perelman) and some applications

THE SELBERG TRACE FORMULA OF COMPACT RIEMANN SURFACES

Spectral theory, geometry and dynamical systems

Negative sectional curvature and the product complex structure. Harish Sheshadri. Department of Mathematics Indian Institute of Science Bangalore

arxiv: v1 [math.dg] 21 Jun 2013

Section 2. Basic formulas and identities in Riemannian geometry

Geometry and the Kato square root problem

Intrinsic Geometry. Andrejs Treibergs. Friday, March 7, 2008

Plurisubharmonic functions and the Kahler-Ricci flow

VOLUME INTEGRAL MEANS OF HOLOMORPHIC FUNCTIONS

1 First and second variational formulas for area

HYPERSURFACES OF EUCLIDEAN SPACE AS GRADIENT RICCI SOLITONS *

Let F be a foliation of dimension p and codimension q on a smooth manifold of dimension n.

HARMONIC FUNCTIONS, ENTROPY, AND A CHARACTERIZATION OF THE HYPERBOLIC SPACE

RICCI FLOW ON KÄHLER-EINSTEIN MANIFOLDS

Transcription:

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 Nguyen Thac Dung (VIASM) Vietnam Institute for Advanced Study in Mathematics December 9, 2014

Outline 1 Analysis on manifolds via the p-laplacian 2

Let (M, g) be a Riemannian manifold with metric tensor g = g ij dx i dx j. The Laplacian on M is defined by ( ) 1 := (det g ij )g ij det gij x i x j where (g ij ) t = (g ij ) 1. It is well-known that 1 is a self-adjoint operator. 2 0 < λ 1 λ 2 <... < λ k <..., lim k λ k =, where λ k is the k-th eigenvalue of φ k = λ k φ k for some 0 φ C (M).

Let (M, g) be a Riemannian manifold with metric tensor g = g ij dx i dx j. The Laplacian on M is defined by ( ) 1 := (det g ij )g ij det gij x i x j where (g ij ) t = (g ij ) 1. It is well-known that 1 is a self-adjoint operator. 2 0 < λ 1 λ 2 <... < λ k <..., lim k λ k =, where λ k is the k-th eigenvalue of φ k = λ k φ k for some 0 φ C (M).

A panoramic view of Riemannian Geometry - Berger Already in the middle ages bell makers knew how to detect invisible cracks by sounding a bell on the ground before lifting it up to the belfry. How can one test the resistance to vibrations of large modern structures by nondestructive essays?... A small crack will not only change the boundary shape of our domain, one side of the crack will strike the other during vibrations invalidating our use of the simple linear wave equation Schuster 1882 Can we hear the shape of a drum? Answer: No by Gordon, Web and Wolpert (1982).

A panoramic view of Riemannian Geometry - Berger Already in the middle ages bell makers knew how to detect invisible cracks by sounding a bell on the ground before lifting it up to the belfry. How can one test the resistance to vibrations of large modern structures by nondestructive essays?... A small crack will not only change the boundary shape of our domain, one side of the crack will strike the other during vibrations invalidating our use of the simple linear wave equation Schuster 1882 Can we hear the shape of a drum? Answer: No by Gordon, Web and Wolpert (1982).

Let Ω be a polygon in R n Mark Kac - 1966 e λkt 1 ( area(ω) 4πtlength(Ω) + 2πt ) (1 γ(ω)), 4πt 3 k=1 where γ(ω) is the genus of Ω. 1967, McKean and Singer: Riemannian manifolds with boundary. 1953, Minakshisundaram: compact Riemmanian manifold M without boundary, ( e λkt 1 V ol(m) t ) R (4πt) n/2 g dv g + O(t 2 ), 6 M k=1 where R g denotes scalar curvature.

Let Ω be a polygon in R n Mark Kac - 1966 e λkt 1 ( area(ω) 4πtlength(Ω) + 2πt ) (1 γ(ω)), 4πt 3 k=1 where γ(ω) is the genus of Ω. 1967, McKean and Singer: Riemannian manifolds with boundary. 1953, Minakshisundaram: compact Riemmanian manifold M without boundary, ( e λkt 1 V ol(m) t ) R (4πt) n/2 g dv g + O(t 2 ), 6 M k=1 where R g denotes scalar curvature.

Question: How about the shape of a complete non-compact Riemannian manifold?

Let M be a complete Riemannian manifold. λ 1 (M): the lower bound of the spectrum of the Laplacian on M } { M λ 1 (M) = inf M φ 2 : φ C φ2 0 (M). Informations on λ 1 (M) = geometry of the manifold. 1 Analytic properties implies geometric properties. 2 Geometric structures of complete Riemannian manifolds.

Let M be a complete Riemannian manifold. λ 1 (M): the lower bound of the spectrum of the Laplacian on M } { M λ 1 (M) = inf M φ 2 : φ C φ2 0 (M). Informations on λ 1 (M) = geometry of the manifold. 1 Analytic properties implies geometric properties. 2 Geometric structures of complete Riemannian manifolds.

Li-Wang: Jour. Diff. Geom., 2002 Let M be an m-dimensional complete Riemannian manifold with n 4. Suppose that Ric M (n 1) and Then either: 1 M has only one end; or λ 1 (M) (n 1)2. 4 2 M = R N with warped product metric ds 2 M = dt 2 + e 2t ds 2 N where N is a compact manifold with nonnegative Ricci curvature.

Li-Wang: Jour. Diff. Geom., 2002 Let M be an m-dimensional complete Riemannian manifold with n 4. Suppose that Ric M (n 1) and Then either: 1 M has only one end; or λ 1 (M) (n 1)2. 4 2 M = R N with warped product metric ds 2 M = dt 2 + e 2t ds 2 N where N is a compact manifold with nonnegative Ricci curvature.

For p > 1, the p-laplacian is defined by p f := div( f p 2 f). Let λ 1 ( p ) be the smallest eigenvalue of p in M. { M λ 1 ( p ) = inf M u p, u u p } C0 (M). 1 Moser (J.Eur. M.S. 2007): Inverse mean curvature flow 2 Kotschwar and Ni (2009), X.D. Wang and L. Zhang (2011): Gradient estimate 3 Y. Wang and J.Y. Chen (2014, preprint): Steady gradient Ricci soliton.

For p > 1, the p-laplacian is defined by p f := div( f p 2 f). Let λ 1 ( p ) be the smallest eigenvalue of p in M. { M λ 1 ( p ) = inf M u p, u u p } C0 (M). 1 Moser (J.Eur. M.S. 2007): Inverse mean curvature flow 2 Kotschwar and Ni (2009), X.D. Wang and L. Zhang (2011): Gradient estimate 3 Y. Wang and J.Y. Chen (2014, preprint): Steady gradient Ricci soliton.

Theorem (Sung-Wang, MRL 2014) Let (M n, g) be a complete manifold of dimension n 2. Suppose that Ric M (n 1) and ( ) p n 1 λ 1 ( p ) =. p Then either 1 M has no finite volume ends; or 2 M = R N with warped product metric ds 2 M = dt 2 + e 2t ds 2 N and N being a compact manifold with nonnegative Ricci curvature.

M. Batista, M. P. Cavalcante, N. L. Santos (Geo. Dedi. 2014) 1 M 2m : complete non-compact Kähler manifold with holomorphic bisectional curvature BK M 1 then λ 1 ( p ) 4p m p p p. 2 M 4m : complete non-compact quaternionic Kähler manifold with scaltar curvature S M 16m(m + 2) then λ 1 ( p ) 2p (2m + 1) p p p.

Theorem 1 Let M 2m be a complete Kähler manifold of complex dimension m 1 with holomorphic bisectional curvature bounded by ( ) p, 2m If λ 1,p p then either 1 M has no p-parabolic end; or BK M 1. 2 M splits as a warped product M = R N where N is a compact manifold. Moreover, the metric is given by 2m ds 2 M = dt 2 + e 4t ω2 2 + e 2t ωα, 2 α=3 where {ω 2,..., ω 2m } are orthonormal coframes for N.

Theorem 2 Let M 4m be a complete noncompact quaternionic Kähler manifold of real dimension 4m with the scalar curvature of M bounded by If λ 1,p ( ) 2(2m+1) p, p then either 1 M has no p-parabolic end; or S M 16m(m + 2). 2 M splits as a warped product M = R N where N is a compact manifold. Moreover, the metric is given by ds 2 M = dt 2 + e 4t 4 4m ωp 2 + e 2t ωα, 2 p=2 α=5 where {ω 2,..., ω 4m } are orthonormal coframes for N.

Let E M be an end. E is p-parabolic if it does not admit a p-harmonic function f : E R such that { f E = 1; lim inf f(y) < 1. y E,y Remark Li-Wang (Amer. Jour. Math, 2009) proved the Theorem 1, when p = 2 Kong-Li-Zhou (JDG, 2008) proved the Theorem 2, when p = 2.

Suppose that M has a p-parabolic end E. Let β be the Busemann function associated with a geodesic ray γ contained in E, namely, β(q) = lim t (t dist(q, γ(t))). The Laplacian comparison theorems (by LW, KLZ) imply β a, where a = 2m in theorem 1 (Li-Wang) and a = 2(2m + 1) in theorem 2 (Kong-Li-Zhou). Claim β = a Idea: for b = a p, let g = ebβ, we can show p (g) λ 1,p g p 1. Using the volume estimate of S. Buckley and P. Koskela (Matth. Zeits., 2005), it turns out that p (g) = λ 1,p g p 1.

Suppose that M has a p-parabolic end E. Let β be the Busemann function associated with a geodesic ray γ contained in E, namely, β(q) = lim t (t dist(q, γ(t))). The Laplacian comparison theorems (by LW, KLZ) imply β a, where a = 2m in theorem 1 (Li-Wang) and a = 2(2m + 1) in theorem 2 (Kong-Li-Zhou). Claim β = a Idea: for b = a p, let g = ebβ, we can show p (g) λ 1,p g p 1. Using the volume estimate of S. Buckley and P. Koskela (Matth. Zeits., 2005), it turns out that p (g) = λ 1,p g p 1.

A smooth metric measure space (M, g, e f dv) contains a Riemannian manifold: (M, g) a weighted volume form: e f dv, where f C (M). dv is the volume element induced by the Riemannian metric g.

For p > 1, a function u is said to be weighted p-harmonic if f,p u := e f div(e f u p 2 u) = 0. Note that weighted p-harmonic functions are characterized as the critical points of the weighted Dirichlet energy u p e f dv. M If u is a weighted p-harmonic function and u p e f dv < + M then u is said to have finite p-energy. The bottom spectrum of the weighted Laplacian f,p, { } M λ 1,p := inf φ p e f dv M φp e f dv, φ C 0 (M).

For p > 1, a function u is said to be weighted p-harmonic if f,p u := e f div(e f u p 2 u) = 0. Note that weighted p-harmonic functions are characterized as the critical points of the weighted Dirichlet energy u p e f dv. M If u is a weighted p-harmonic function and u p e f dv < + M then u is said to have finite p-energy. The bottom spectrum of the weighted Laplacian f,p, { } M λ 1,p := inf φ p e f dv M φp e f dv, φ C 0 (M).

For p > 1, a function u is said to be weighted p-harmonic if f,p u := e f div(e f u p 2 u) = 0. Note that weighted p-harmonic functions are characterized as the critical points of the weighted Dirichlet energy u p e f dv. M If u is a weighted p-harmonic function and u p e f dv < + M then u is said to have finite p-energy. The bottom spectrum of the weighted Laplacian f,p, { } M λ 1,p := inf φ p e f dv M φp e f dv, φ C 0 (M).

For any m N, the m dimensional Bakry-Émery curvature Ricm f associated to smooth metric measure space (M, g, e f dv) is defined by where Ric m f = Ric + Hess(f) f f m n, Ric denotes the Ricci curvature of (M, g), and Hess(f) the Hessian of f. m n. m = n if and only if f is constant. We also define Ric f := Ric + Hess(f)

Proposition (Y. Wang and J. Y. Chen, 2014) Let g = e 2f n p be a conformal change of g. Then u is a weighted p-harmonic function on (M, g) if and only if u is a p-harmonic function on (M, g).

Theorem 3 (Local gradient estimate) Let (M n, g, e f ) be a smooth metric measure space of dimension n with Ric m f (m 1)κ. Suppose that v is a positive smooth weighted p-harmonic function on the ball B R = B(o, R) M. Then there exists a constant C = C(p, m, n) such that v v C(1 + κr) R on B(o, R/2).

Ideas of proof. 1 Laplacian comparison f ρ := f, ρ (m 1) κ coth( κρ) provided that Ric m f (m 1)κ. Here ρ(x) := dist(o, x) stands for the distance between x M and a fixed point o M. 2 Volume comparison 3 Sobolev inequality. V f (B x (r 2 )) V f (B x (r 1 )) V Hm(r 2 ) V H m(r 1 )

Sobolev inequality Let (M, g, e f dµ) be an n-dimensional complete noncompact smooth metric measure space. If Ric m f (m 1)κ for some nonnegative constants κ, then for any p > 1, there exists a constant c = c(n, p, m) > 0 depending only on p, n, m such that ( B R ϕ 2p p 2 e f ) p 2 p R2.e c(1+ κr) ( ϕ 2 + R 2 ϕ 2) e f V f (B R ) 2 p B R for any ϕ C 0 (B p (R)).

By theorem 3, v v C(1 + κr) R on B(o, R/2). Harnack inequality Let (M, g, e f dv) be a complete smms of dimension n 2 with Ric m f (m 1)κ. Suppose that v is a positive weighted p-harmonic function on the geodesic ball B(o, R) M. There exists a constant C p,n,m depending only on p, n, m such that v(x) e Cp,n,m(1+ κr) v(y), x, y B(o, R/2). If κ = 0, we have a uniform constant c p,n,m (independent of R) such that sup B(o,R/2) v c p,n inf v. B(o,R/2)

Liouville property Assume that (M, g) is a smms with Ric m f 0. If u is a weighted p-harmonic function bounded from below on M then u is constant. Estimate of the first weighted eigenvalue Let (M n, g, e f dv) be an n-dimensional complete noncompact manifold with Ric m f (m 1). Then ( ) p m 1 λ 1,p. p 1 Volume estimate of Buckley and Koskela, 2 Volume comparison theorem V f (B(r)) Ce pλ1/p 1,p r, r large enough V f (B(r)) C 1 e (m 1)r.

Liouville property Assume that (M, g) is a smms with Ric m f 0. If u is a weighted p-harmonic function bounded from below on M then u is constant. Estimate of the first weighted eigenvalue Let (M n, g, e f dv) be an n-dimensional complete noncompact manifold with Ric m f (m 1). Then ( ) p m 1 λ 1,p. p 1 Volume estimate of Buckley and Koskela, 2 Volume comparison theorem V f (B(r)) Ce pλ1/p 1,p r, r large enough V f (B(r)) C 1 e (m 1)r.

Liouville property Assume that (M, g) is a smms with Ric m f 0. If u is a weighted p-harmonic function bounded from below on M then u is constant. Estimate of the first weighted eigenvalue Let (M n, g, e f dv) be an n-dimensional complete noncompact manifold with Ric m f (m 1). Then ( ) p m 1 λ 1,p. p 1 Volume estimate of Buckley and Koskela, 2 Volume comparison theorem V f (B(r)) Ce pλ1/p 1,p r, r large enough V f (B(r)) C 1 e (m 1)r.

Theorem 4 (Global sharp gradient estimate) Let (M n, g, e f dv) be an n-dimensional complete noncompact manifold with Ric m f (m 1). If v is a positive weighted p-eigenfunction with respect to the first eigenvalue λ 1,p, that is, then e f div(e f v p 2 v) = λ 1,p v p 1 ln v y. Here y is the unique positive root of the equation Corollary (p 1)y p (m 1)y p 1 + λ 1,p = 0. Let (M n, g, e f dv) be an n-dimensional complete noncompact manifold with Ric m f (m 1). If v is a positive weighted p-harmonic function then ln v m 1 p 1.

Theorem 4 (Global sharp gradient estimate) Let (M n, g, e f dv) be an n-dimensional complete noncompact manifold with Ric m f (m 1). If v is a positive weighted p-eigenfunction with respect to the first eigenvalue λ 1,p, that is, then e f div(e f v p 2 v) = λ 1,p v p 1 ln v y. Here y is the unique positive root of the equation Corollary (p 1)y p (m 1)y p 1 + λ 1,p = 0. Let (M n, g, e f dv) be an n-dimensional complete noncompact manifold with Ric m f (m 1). If v is a positive weighted p-harmonic function then ln v m 1 p 1.

Let M n = R N n 1 with a warped product metric ds 2 = dt 2 + e 2t ds 2 N, where N is a complete manifold with non-negative Ricci curvature. Then we can compute Ric M (n 1) = 2 t 2 + (n 1) t + e 2t N. Choose weighted function f = (m n)t, then Ric m f (m 1). Let v(t, x) = e at, where m 1 p a m 1 p 1, we have v v = a. e f div(e f v p 2 v) = ((p 1)a (m 1))a p 1 v p 1. This implies that λ 1,p = (m 1 (p 1)a)a p 1, or (p 1)a p (m 1)a p 1 + λ 1,p = 0.

Let M n = R N n 1 with a warped product metric ds 2 = dt 2 + e 2t ds 2 N, where N is a complete manifold with non-negative Ricci curvature. Then we can compute Ric M (n 1) = 2 t 2 + (n 1) t + e 2t N. Choose weighted function f = (m n)t, then Ric m f (m 1). Let v(t, x) = e at, where m 1 p a m 1 p 1, we have v v = a. e f div(e f v p 2 v) = ((p 1)a (m 1))a p 1 v p 1. This implies that λ 1,p = (m 1 (p 1)a)a p 1, or (p 1)a p (m 1)a p 1 + λ 1,p = 0.

Theorem 5 Let (M n, g, e f dv) be a smooth metric measure space ( of dimension ) p. n 2. Suppose that Ric m f (m 1) and λ 1,p = Then m 1 p either M has no p-parabolic ends or M = R N n 1 for some compact manifold N. Suppose that M has a p-parabolic end E. Let β be the Busemann function associated with a geodesic ray γ containd in E, namely, β(x) = lim t (t dist(x, γ(t))). 1 Laplacian comparison theorem, 2 let ω := e m 1 p β, we obtain f β (m 1). p,f (ω) λ 1,p ω p 1.

Theorem 5 Let (M n, g, e f dv) be a smooth metric measure space ( of dimension ) p. n 2. Suppose that Ric m f (m 1) and λ 1,p = Then m 1 p either M has no p-parabolic ends or M = R N n 1 for some compact manifold N. Suppose that M has a p-parabolic end E. Let β be the Busemann function associated with a geodesic ray γ containd in E, namely, β(x) = lim t (t dist(x, γ(t))). 1 Laplacian comparison theorem, 2 let ω := e m 1 p β, we obtain f β (m 1). p,f (ω) λ 1,p ω p 1.

Theorem 6 (Rigidity - D) Let (M n, g, e f dv) be a smooth metric measure space ( of dimension ) p n 3. Suppose that Ric m f (m 1) and λ 1,p = for some m 1 p 2 p (m 1)2 2(m 2). Then either M has only one p-nonparabolic end or M = R N n 1 for some compact manifold N. An open and interesting problem Can we get the same results if Ric f (m 1).

Theorem 6 (Rigidity - D) Let (M n, g, e f dv) be a smooth metric measure space ( of dimension ) p n 3. Suppose that Ric m f (m 1) and λ 1,p = for some m 1 p 2 p (m 1)2 2(m 2). Then either M has only one p-nonparabolic end or M = R N n 1 for some compact manifold N. An open and interesting problem Can we get the same results if Ric f (m 1).