Entropy and renormalized solutions for nonlinear elliptic problem involving variable exponent and measure data

We give an existence result of entropy and renormalized solutions for strongly nonlinear elliptic equations in the framework of Sobolev spaces with variable exponents of the type:-div(a(x, u, u) + φ(u)) + g(x, u, u) = μ, where the right-hand side belongs to L1(Ω) + W-1,p(x)(Ω),-div(a(x, u, u)) is a Leray–Lions oper- ator defined from W-1,p(x)(Ω) into its dual and φ∈ C0(R, RN). The function g(x, u, u) is a non linear lower order term with natural growth with respect to |u| satisfying the sign condition, that is,g(x, u, u)u ≥ 0.     

Renormalized solutions of elliptic equations with Robin boundary conditions

In the present paper, we consider elliptic equations with nonlinear and nonhomogeneous Robin boundary conditions of the type{-div(B(x, u)▽u) = f in ?,u = 0 on Γ_0,B(x, u)▽u·n→+γ(x)h(u) =g on Γ_1,where f and g are the element of L~1(?) and L~1(Γ_1), respectively. We define a notion of renormalized solution and we prove the existence of a solution. Under additional assumptions on the matrix field B we show that the renormalized solution is unique.     

Smoothness of the gradient of weak solutions of degenerate linear equations

Let Q(x) be a nonnegative definite, symmetric matrix such that (Q(x))(1/2) is Lipschitz continuous. Given a real-valued function b(x) and a weak solution u(x) of div(Q▽u) = b, we find sufficient conditions in order that Q(1/2)▽u has some first order smoothness. Specifically, if Ω is a bounded open set in R~n, we study when the components of Q(1/2)▽u belong to the first order Sobolev space W_Q~(1,2)(Ω)defined by Sawyer and Wheeden. Alternately, we study when each of n first order Lipschitz vector field derivatives X_iu has some first order smoothness if u is a weak solution in Ω of ∑_(i=1)~n X′_iX_(iu) + b = 0.We do not assume that {X_i} is a Hormander collection of vector fields in Ω. The results signal ones for more general equations.     

CHINESE ANNALS OF MATHEMATICS Vol.6 Ser.A No.4 CONTENTS AND ABSTRACTS

Approximation of Nonlinear Dirichlet Problem by Finite Element MethodsLi Likang(李立康)The author obtains approximate solution of the nonlinear Dirichlet problem-▽·(a(x,u)▽u)=f(x),x∈Ω,u(x)=g(x),x∈Γby finite element method.In this paper finite element spaces V_h is defined by the followingV_h={v_h|v_h∈C~0(Ω),v_h is a linear function on each K_i},     

Problem with Critical Sobolev Exponent and with Weight

The authors consider the problem: -div(p▽u) = uq-1 λu, u > 0 inΩ, u = 0 on (?)Ω, whereΩis a bounded domain in Rn, n≥3, p :Ω→R is a given positive weight such that p∈H1 (Ω)∩C(Ω),λis a real constant and q = 2n/n-2, and study the effect of the behavior of p near its minima and the impact of the geometry of domain on the existence of solutions for the above problem.     

EXISTENCE OF POSITIVE SOLUTIONS FOR A CLASS OF PARABOLIC EQUATIONS WITH NATURAL GROWTH TERMS AND L^1 DATA

We study a class of nonlinear parabolic equations of the type:b(u)t- div a(x, t, u)▽u + g(u)|▽u|2= f,where the right hand side belongs to L1(Q), b is a strictly increasing C1-function and-div(a(x, t, u)▽u) is a Leray-Lions operator. The function g is just assumed to be continuous on R and to satisfy a sign condition. Without any additional growth assumption on u, we prove the existence of a renormalized solution.     

Regularity for solutions to anisotropic obstacle problems

For Ω a bounded subset of R n,n 2,ψ any function in Ω with values in R∪{±∞}andθ∈W1,(q i)(Ω),let K(q i)ψ,θ(Ω)={v∈W1,(q i)(Ω):vψ,a.e.and v-θ∈W1,(q i)0(Ω}.This paper deals with solutions to K(q i)ψ,θ-obstacle problems for the A-harmonic equation-divA(x,u(x),u(x))=-divf(x)as well as the integral functional I(u;Ω)=Ωf(x,u(x),u(x))dx.Local regularity and local boundedness results are obtained under some coercive and controllable growth conditions on the operator A and some growth conditions on the integrand f.     

Multiplicity of solutions of weighted (p,q)-Laplacian with small source

In this article, we study the existence of infinitely many solutions to the degenerate quasilinear elliptic system-div(h_1(x)|▽u|~(p-2)▽u)=d(x)|u|~(r-2)u+G_u(x,u,v) in Ω,-div(h_2(x)|▽u|~(p-2)▽v)=f(x)|v|~(s-2)v + G_u(x,u,v) in Ω,u=v=0 on ■Ω where Ω is a bonded domain in R~N with smooth boundary ■Ω,N≥2,1 r p ∞,1 s q ∞; h_1(x) and h_2(x) are allowed to have "essential" zeroes at some points inΩ; d(x)|u|~(r-2)u and f(x)|v|~(s-2)v are small sources with Gu(x,u,v), Gv(x,u,v) being their high-order perturbations with respect to(u,v) near the origin, respectively.     

Holder Continuity for Solutions of Degenerate Parabolic Equation with Two Degenerate Points

In this paper we discuss the quasilinear parabolic equationU_■=▽(u~u(1-u)~β.Vu)+■(x,t.u)▽u+C(x,t,u)which is degenerate at u =0 and u=1.Let u(x,t)be a weak solution of the equation satisfying0相似文献   

THE EXISTENCE OF NONTRIVIAL SOLUTIONS TO A SEMILINEAR ELLIPTIC SYSTEM ON RN WITHOUT THE AMBROSETTI-RABINOWITZ CONDITION

In this paper, we prove the existence of at least one positive solution pair (u, v) ∈ H 1 (R N ) × H 1 (R N ) to the following semilinear elliptic system{-u + u = f(x, v), x ∈RN ,-v + v = g(x,u), x ∈ R N ,(0.1) by using a linking theorem and the concentration-compactness principle. The main con-ditions we imposed on the nonnegative functions f, g ∈ C 0 (R N × R 1 ) are that, f (x, t) and g(x, t) are superlinear at t = 0 as well as at t = +∞, that f and g are subcritical in t and satisfy a kind of monotonic conditions. We mention that we do not assume that f or g satisfies the Ambrosetti-Rabinowitz condition as usual. Our main result can be viewed as an extension to a recent result of Miyagaki and Souto [J. Diff. Equ. 245(2008), 3628-3638] concerning the existence of a positive solution to the semilinear elliptic boundary value problem{-u + u = f(x, u), x ∈Ω,u ∈H10(Ω)where ΩRN is bounded and a result of Li and Yang [G. Li and J. Yang: Communications in P.D.E. Vol. 29(2004) Nos.5 6.pp.925–954, 2004] concerning (0.1) when f and g are asymptotically linear.     

Degenerate Nonlinear Elliptic Equations Lacking in Compactness

In this paper, the authors prove the existence of solutions for degenerate elliptic equations of the form-div(a(x)▽_p u(x)) = g(λ, x, |u|~(p-2)u) in R~N, where ▽_pu =|▽u|~(p-2)▽u and a(x) is a degenerate nonnegative weight. The authors also investigate a related nonlinear eigenvalue problem obtaining an existence result which contains information about the location and multiplicity of eigensolutions. The proofs of the main results are obtained by using the critical point theory in Sobolev weighted spaces combined with a Caffarelli-Kohn-Nirenberg-type inequality and by using a specific minimax method, but without making use of the Palais-Smale condition.     

EXISTENCE OF SOLUTIONS TO THE PARABOLIC EQUATION WITH A SINGULAR POTENTIAL OF THE SOBOLEV-HARDY TYPE

We study the existence of solutions to the following parabolic equation{ut-△pu=λ/|x|s|u|q-2u,(x,t)∈Ω×(0,∞),u(x,0)=f(x),x∈Ω,u(x,t)=0,(x,t)∈Ω×(0,∞),(P)}where-△pu ≡-div(|▽u|p-2▽u),1相似文献   

一类拟线性方程的非平凡解

为了研究泛函数I(u)=integral from Ω ({1/aH(|▽u|~a)+G(x,u)}dx)在空间W~(192a)(Ω)中的临界点,我们寻求它的Euler方程的广义解。在适当条件下,利用山路引理,我们证明了方程sum from i=1 to n (α/αx_i{h(|▽u)|~a|▽u|~(a-2)αu/αx_i})-g(x,u)=0在空间W~(192a)(Ω)中非平凡广义解的存在。     

INVARIANT SETS AND THE HUKUHARA-KNESER PROPERTY FOR PARABOLIC SYSTEMS

In this paper we are concerned with the nonlinear boundary value problem forparabolic system(Lu=f(x,t,u,▽u),x∈Ω,0相似文献   

EXISTENCE OF MINIMISERS FOR A CLASS OF FREE DISCONTINUITY PROBLEMS IN THE HEISENBERG GROUP Hn

The purpose of this paper is to prove existence of minimisers of the functional J(K,u):=∫Ω\K f(Lu)dx α∫Ω\K |u - g|qdx βSQ-1d(K∩Ω),where Ω is an open set of the Heisenberg group Hn, K runs over all closed sets of Hn, u varies in C1H(Ω\K), α,β＞0,q ≥ 1,g ∈ Lq(Ω) ∩L∞(Ω) and f: R2n → R is a convex function satisfying some structure conditions (H1)(H2)(H3) (see below).     

THE EXISTENCE OF GLOBAL SOLUTION AND THE BLOWUP PROBLEM FOR SOME p-LAPLACE HEAT EQUATIONS

This article consider, for the following heat equation ut/|x|s-△pu=uq,(x,t)∈Ω×(0,T), u(x,t)=0,(x,t)∈(?)Ω×(0,T), u(x,0)=u0(x),u0(x)≥0,u0(x)(?)0 the existence of global solution under some conditions and give two sufficient conditions for the blow up of local solution in finite time, whereΩis a smooth bounded domain in RN(N>p),0∈Ω,△pu=div(|▽u|p-2▽u),0≤s≤2,p≥2,p-1相似文献   

Sobolev方程的基于H~1-Galerkin混合方法的新分裂格式

正1引言考虑如下Sobolev方程u_t-▽·(a(x)▽u_t+a(x)▽u)+u=f(x,t),(x,t)∈Ω×J,u(x,t)=0,(x,t)∈аΩ×J,(1)u(x,0)=u_0(x),x∈Ω.其中Ω是R~d(d=1,2,3)中具有边界     

本刊英文版Vol.36(2020),No.4论文摘要（英文）

正A Weighted Trudinger-Moser Inequality on R~N and Its Application to Grushin Operator Jia Jun WANG Qiao Hua YANGAbstract Let x=(x′,x″) with x′∈R~k and x″∈R~(N-k)andΩbe a x′-symmetric and bounded domain in R~N (N≥2).We show that if 0≤a≤k-2,then there exists a positive constant C 0 such that for all x′-symmetric function u∈C_0~∞(Ω) with∫_Ω|▽u(x)|~(N-a)|x′|~(-a)dx≤1,the following uniform inequality holds     

一类带有Neumann边值条件的拟线性椭圆外部问题的多解性

该文考虑下面的带有Neumann边值条件的拟线性椭圆外部问题-div(a(x)|▽u|p-2▽u)+b(x)|u|p-2u=λh1(x)|u|q-2u+h2(x)|u|r-2u+g(x),x∈Ω,u/n=0,x∈Ω其中1pN,1qprp*,p*=Np/(N-p),Ω是欧几里德空间(R~N,|·|)(N≥3)中的光滑外部区域,也就是说,Ω是某个带有C~(1,δ)(0δ1)边界的有界区域Ω'的补集,n是其边界Ω的单位外法向量,λ是一个正参数.由山路引理和Ekeland变分原理,我们得出:当函数a(x),b(x),h_1(x),h_2(x)和g(x)满足一定的条件时,该方程至少有两个非平凡弱解.     

Jacobian-determinant equation in the critical Besov spaces

Let Ω be a bounded domain in R~n with smooth boundary. Here we consider the following Jacobian-determinant equation det u(x)=f(x),x∈Ω;u(x)=x,x∈?Ω where f is a function on Ω with min_Ω f = δ 0 and Ωf(x)dx = |Ω|. We prove that if f ∈B_(p1)~(np)(Ω) for some p∈(n,∞), then there exists a solution u ∈ B_(p1)~(np+1)(Ω)C~1(Ω) to this equation. On the other hand, we give a simple example such that u ∈ C_0~1(R~2, R~2) while detu does not lie in B_(p1)~(2p)(R~2) for any p∞.