Nonlinear Liouville Theorem in the Quaternionic Heisenberg Group

This paper deals with the problem of the type triangle open_H f+ f^p =O inquaternionic Heisenberg group, where triangle open_H is the quaternionic Heisenberg Laplacian. Itis proved that, under suitable conditions on p and /, the only solution of triangle open_H f+ f^p=O.

Quantum mechanical version of the classical Liouville theorem

In terms of the coherent state evolution in phase space,we present a quantum mechanical version of the classical Liouville theorem.The evolution of the coherent state from ｜z〉to｜sz-rz＊〉 corresponds to the motion from a point z（q,p） to another point sz-rz＊ with ｜s｜2-｜r｜2=1.The evolution is governed by the so-called Fresnel operator U（s,r） that was recently proposed in quantum optics theory,which classically corresponds to the matrix optics law and the optical Fresnel transformation,and obeys group product rules.In other words,we can recapitulate the Liouville theorem in the context of quantum mechanics by virtue of coherent state evolution in phase space,which seems to be a combination of quantum statistics and quantum optics.

GRADIENT ESTIMATES AND LIOUVILLE THEOREMS FOR LINEAR AND NONLINEAR PARABOLIC EQUATIONS ON RIEMANNIAN MANIFOLDS

In this article, we will derive local elliptic type gradient estimates for positive solutions of linear parabolic equations （△-e/et）u（x,t）＋q（x,t）u^p（x,t）=0 and nonlinear parabolic equations （△-e/et）u（x,t）＋h（x,t）u^p（x,t）=0（p 〉 1） on Riemannian manifolds.As applications, we obtain some theorems of Liouville type for positive ancient solutions of such equations. Our results generalize that of Souplet-Zhang （[1], Bull. London Math. Soc. 38（2006）, 1045-1053） and the author （[2], Nonlinear Anal. 74 （2011）, 5141-5146）.

LIOUVILLE THEOREM FOR CHOQUARD EQUATION WITH FINITE MORSE INDICES

In this article, we study the nonexistence of solution with finite Morse index for the following Choquaxd type equation -△u=∫Rn｜u（y）｜p/｜x-y｜αdy｜u（x）｜p-2u（x） in RN,where N≥3,0〈α〈min {4,N}.Suppose that 2 〈 p 〈2N-α/N-2,we will show that this problem does not possess nontrivial solution with finite Morse index. While for p =2N-α/N-2,if i（u） 〈∞, then we have ∫RN∫RN｜u（x）｜p｜u（y）｜p dxdy 〈∞ and ∫RN｜△u｜2 dx=｜∫RN∫RN｜u（x）｜p/｜x-y｜a dxdy.

A Liouville Theorem for Möbius Invariant Equations

In this paper, we classify Mobius invariant differential operators of second orderin two-dimensional Euclidean space, and establish a Liouville type theorem forgeneral Mobius invariant elliptic equations. The equationsare naturally associ-ated with a continuous family of convex cones Γ_(p) in R^(2), with parameter p∈[1,2],joining the half plane Γ_(1) := {(λ_(1),λ_(2)) : λ_(1)+λ_(2)> 0} and the first quadrant Γ_(2) := {(λ_(1),λ_(2)) : λ_(1),λ_(2)> 0}. Chen and C. M. Li established in 1991 a Liouvilletype theorem corresponding to Γ_(1) under an integrability assumption on the solution. The uniqueness result does not hold without this assumption. The Liouville typetheorem we establish in this paper for Γ_(p),1 < p ≤ 2, does not require any additionalassumption on the solution as for Γ_(1). This is reminiscent of the I iouville type theo-rems in dimensions n≥3 established by Caffarelli, Gidas and Spruck in 1989 andby A.B. Li and Y. Y. Li in 2003-2005, where no additional assumption was neededeither. On the other hand, there is a striking new phenomena in dimension n=2 that Γ_(p) ,for p=1 is a sharp dividing line for such uniqueness result to hold without anyfurther assumption on the solution. In dimensions n≥3, there is no such dividing line.

Liouville theorems for an integral system with Poisson kernel on the upper half space

We investigate the Liouville theorem for an integral system with Poisson kernel on the upper half space R+n,{u（x） =2/（nωn）∫?R+n（xnf（v（y）））/（|x- y|n）dy, x ∈R+n,v（y） =2/（nωn）∫R+n（xng（u（x）））/（|x- y|n）dx, y ∈?R+n,where n 3, ωn is the volume of the unit ball in Rn. This integral system arises from the Euler-Lagrange equation corresponding to an integral inequality on the upper half space established by Hang et al.（2008）.With natural structure conditions on f and g, we classify the positive solutions of the above system based on the method of moving spheres in integral form and the inequality mentioned above.

Kato's inequality and Liouville theorems on locally finite graphs

In this paper,we study the Kato's inequality on locally finite graphs.We also study the application of Kato's inequality to Ginzburg-Landau equations on such graphs.Interesting properties of elliptic and parabolic equations on the graphs and a Liouville type theorem are also derived.

A radial symmetry and Liouville theorem for systems involving fractional Laplacian

We investigate the nonnegative solutions of the system involving the fractional Laplacian：{（-△）^αui（x）=fi（u）,x∈R^n,i=1,2,…,m, u（x）=（u1（x）,u2（x）,……,um（x））,where 0 〈 α 〈 1, n 〉 2, fi（u）, 1 4 ≤ 4 ≤m, are real-valued nonnegative functions of homogeneous degree Pi ≥0 and nondecreasing with respect to the independent variables ul, u2,..., urn. By the method of moving planes, we show that under the above conditions, all the positive solutions are radially symmetric and monotone decreasing about some point x0 if Pi = （n ＋ 2α）/（n- 2α） for each 1 ≤ i ≤ m; and the only nonnegative solution of this system is u ≡ 0 if 1〈pi〈（n＋2α）/（n-2α） for all 1≤i≤m.

THE GRADIENT ESTIMATE OF SUBELLIPTIC HARMONIC MAPS WITH A POTENTIAL

In this paper,we investigate subelliptic harmonic maps with a potential from noncompact complete sub-Riemannian manifolds corresponding to totally geodesic Riemannian foliations.Under some suitable conditions,we give the gradient estimates of these maps and establish a Liouville type result.

Liouville Type Theorems for Nonlinear p-Laplacian Equation on Complete Noncompact Riemannian Manifolds

In this paper,the authors study the gradient estimates for positive weak solutions to the following p-Laplacian equation△_(p)u+au^(σ)=0 on complete noncompact Riemannian manifold,where a,σare two nonzero real constants with p≠2.Using the gradient estimate,they can get the corresponding Lionville theorem.On the other hand,by virtue of the Poincare inequality,they also obtain a Liouville theorem under some integral conditions with respect to positive weak solutions.

Uniform Hölder Bounds for Competition Systems with Strong Interaction on a Subdomain

We prove the uniform Hölder bounds of solutions to a singularly perturbed elliptic system arising in competing models in population dynamics. In this system, two species compete to some extent throughout the whole domain but compete strongly on a subdomain. The proof relies upon the blow up technique and the monotonicity formula by Alt, Caffarelli and Friedman.

~ Transform Demonstration of Dark Soliton Solutions Found by Inverse Scattering

One of the basic problems about the inverse scattering transform for solving a completely integrable nonlinear evolutions equation is to demonstrate that the Jost solutions obtained from the inverse scattering equations of Cauchy integral satisfy the Lax equations. Such a basic problem still exists in the procedure of deriving the dark soliton solutions of the NLS equation in normal dispersion with non-vanishing boundary conditions through the inverse scattering transform. In this paper, a pair of Jost solutions with same analytic properties are composed to be a 2 × 2 matrix and then another pair are introduced to be its right inverse confirmed by the Liouville theorem. As they are both 2 × 2 matrices, the right inverse should be the left inverse too, based upon which it is not difficult to show that these Jost solutions satisfy both the first and second Lax equations. As a result of compatibility condition, the dark soliton solutions definitely satisfy the NLS equation in normal dispersion with non-vanishing boundary conditions.

A sharp gradient estimate for the weighted p-Laplacian

Let M be an n-dimensional complete noncompact Riemannian manifold with sectional curvature bounded from below, dμ = e^h（x） dV（x） the weighted measure and △μ,p the weighted p-Laplacian. In this paper we consider the non-linear elliptic equation △μ,pu=-λμ,p｜u｜^p-2ufor p ∈ （1, 2）. We derive a sharp gradient estimate for positive smooth solutions of this equation. As applications, we get a Harnack inequality and a Liouville type theorem..

Demonstration of Inverse Scattering Transform for DNLS Equation

Since the Jost solutions of the DNLS equation does not tend to the free Jost solutioins as ｜λ｜→∞, the usual inverse scattering transform （IST） must be revised. Beside the Kaup and Newell＇s approach, we propose a simple revision in constructing the equations of IST, where the usual Zakharov-Shabat kern is revised by multiplying λ^-2 or λ^-1. To justify the revision we show that the Jost solutions obtained do satisfy the pair of compatibility equations.

A Liouville-Type Theorem for Higher-Order Parabolic Inequalities and Its Applications

In this paper, we establish a Liouville-type theorem for a system of higher-order parabolic inequalities by using the method of test functions and an integral estimate. As an application, we observe the Fujita blow-up phenomena for the corresponding parabolic system, which in particular fills up the gap in the recent result of Pang et. al. （Existence and nonexistence of global solutions for a higher-order semilinear parabolic system, Indiana Univ. Math. J., 55（2006）, 1113-1134）. Moreover, the importance of this observation is that we do not impose any regularity assumption on the initial data.

Liouville Type Theorems for a System of Integral Equations on Upper Half Space

In this paper,we consider the following system of integral equations on upper half space {u（x） = ∫Rn ＋ （1/｜x-y｜n-α-1/｜-y｜n-α） λ1up1（y） ＋ μ1vp2（y） ＋ β1up3（y）vp4（y） dy;v（x） = ∫Rn ＋ （1/｜x-y｜n-α-1/｜-y｜n-α）（λ2uq1（y） ＋ μ2vq2（y） ＋ β2uq3（y）vq4（y） dy,where Rn ＋ = {x =（x1,x2,...,xn） ∈ Rn｜xn〉 0}, =（x1,x2,...,xn-1,-xn） is the reflection of the point x about the hyperplane xn= 0,0 〈 α 〈 n,λi,μi,βi≥ 0（i = 1,2） are constants,pi≥ 0 and qi≥ 0（i = 1,2,3,4）.We prove the nonexistence of positive solutions to the above system with critical and subcritical exponents via moving sphere method.

The Blow-up Rate for Positive Solutions of Indefinite Parabolic Problems and Related Liouville Type Theorems

In this paper, we derive an upper bound estimate of the blow-up rate for positive solutions of indefinite parabolic equations from Liouville type theorems. We also use moving plane method to prove the related Liouville type theorems for semilinear parabolic problems.

Fujita-Liouville Type Theorem for Coupled Fourth-Order Parabolic Inequalities

This paper deals with a coupled system of fourth-order parabolic inequalities ｜u｜t ≥ -△2^u＋｜v｜^q, ｜v｜t ≥-△2v＋｜u｜p^ in S=R^n ×R^＋ withp, q 〉 1, n ≥1. AFujita- Liouville type theorem is established that the inequality system does not admit nontrivial nonnegative global solutions on S whenever n/4≤ max（ p＋1/pq-1, q＋1/pq-1 ）. Since the general maximum-comparison principle does not hold for the fourth-order problem, the authors use the test function method to get the global non-existence of nontrivial solutions.

SOME LIOUVILLE TYPE THEOREMS FOR THE P-SUB-LAPLACIAN ON THE GROUP OF HEISENBERG TYPE

In this paper we prove some Liouville type results for the p-sub-Laplacian on the group of Heisenberg type. A strong maximum principle and a Hopf type principle concerning p-sub-Laplacian are established.

Remarks on Liouville Type Result for the 3D Hall-MHD System

In this paper, we consider the 3D Hall-MHD system, and provide an improved Liouville type result for its stationary version.