首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
Thetheoryofharmonicmapsintoacompactnonpositivelycurvedtargetiswell-developed.TheexistenceofsuchaharmonicmappinginanygivenhomotopyclassisestablishedbyEellsandSampson[1]in1964,andlater,in1967,Hartman[2]gaveaproofoftheuniqueness.Thispaperisdevotedtoanapplicationo…  相似文献   

2.
§ 1.Introduction LetBnbetheunitballinCn,anddvthenormalizedLebesguemeasureonBn.SobolevspaceL2 ,1isthespaceoffunctionsu :Bn→C ,forwhichthenorm‖u‖1/ 2 =∑ni=1 ∫Bn u zi(z) 2 + u zi(z) 2 dν1/ 2 <∞ .L2 ,1/ 2 isaHilbertspacewiththeinnerproduct〈u ,v〉1/ 2 =∑ni=1〈 u zi, u zi〉L2 (dν) +∑ni=1〈 u zi, u …  相似文献   

3.
LetB ={0 ,1 }betheusualbinaryBooleanalgebra .ThematricesoverBarecalledBooleanmatrices.Ann×nBooleanmatrixAiscalledaprimitivematrixifthereexistsapositiveintegerksuchthatAk=J (whereJistheuniversalmatrix) .TheleastsuchkiscalledtheexponentofA ,denotedbyγ(A) . In proj…  相似文献   

4.
§ 1 IntroductionInthispaper ,wewillconsiderthesemilinearSchr dingerequationinonespacedimensionofthetypeut-iuxx =F(u) .  (x ,t)∈R×R+,( 1 )u(x ,0 ) =u0 , x ∈R ,( 2 )whereu =u(x ,t)iscomplex valuedfunction ,andFisasmoothfunctionofusuchthat|F(u) | =O( |u|α+1)for |u|sufficientlysmalland…  相似文献   

5.
1 IntroductionInthepaper,weconsiderthefollowingK -Sequation (forexample,see [1 ] -[3]andreferencestherein)inspacedimension≥ 3:Δ2 u+Δu+ 12 | u|2 -12 Ni=1li∫IN| u|2 dx=0 ,x∈IN,(1 )withL periodicboundaryconditions,L =(l1,l2 ,… ,lN)beingthesizeofatypicalpatterncell (alsobifurcationpar…  相似文献   

6.
§ 1.ProblemandAssumptions Thispaperdealswiththesolutionsofthefollowingdifferentialinclusionproblem :Au∈f(x,u) ,x∈Ω ;u=0 ,x∈ Ω ,(1 )whereAu(x) =-∑Ni=1Di[ai(x ,Du(x) ) ] ,Ω RNisaboundeddomainwithpiecewiseLipschitzboundary Ω ,Du =(D1u ,D2 u ,… ,DNu) ,Diu = u xi,i=1 ,2 ,… ,N ,andf:Ω×R→ 2 Risa…  相似文献   

7.
§ 1.Introduction Inthispaperwestudythestrongandweakpropertyoftravellingwavefrontsolutions (TWFS)forthefollowingdegenerateparabolicequation : ψ(u) t = 2 u x2 +f(u) . ( 1 .1 ) Welookforsolutionsof( 1 .1 )oftheformu(x,t) =q(x -ct) (cisthewavespeed) ,whereq( ξ) ,ξ=x -ct,asafunctionofas…  相似文献   

8.
§ 1.Introduction LetRbearingwithidentityandMaleftR module .AleftR moduleUiscalledM injectiveif,foreverysubmoduleNofMandeveryhomomorphism :N→U ,canbeextendedtoahomomorphism ψ :M→U .AleftR moduleMiscalledaV modulebyRamamurthi[1]andTominaga[2 ](andiscalledaco semis…  相似文献   

9.
SOME EXTENSIONS OF PALEY-WIENNER THEOREM   总被引:1,自引:0,他引:1  
§1.IntroductionandMotivationTheclasicalShannon’ssamplingtheoremholdsduetothefolowingtworeasons:(i)q(t,u)=sinπ(t-u)π(t-u)isthe...  相似文献   

10.
§ 1 IntroductionWeconsiderthefourthordersemilinearsubellipticboundaryvalueproblemΔ2 Hu +cΔHu =f( (z ,t) ,u) inD ,u|D =ΔHu|D =0 ,( 1 .1 )whereDisaboundedopensubsetoftheHeisenberggroupHnandΔHisthesubellipticLapla cianonHn.WerecallthatHnistheLiegroupwhoseunderlyingmani…  相似文献   

11.
Abstract. The existence and uniqueness of classical global solutions and the nonexistence of global solutions to the first boundary value problem and the second boundary value problem for the equation ua-a1uxx-a2uxxl-a3uxxu=ψ(ux)x are proved  相似文献   

12.
By variational methods, for a kind of Yamabe problem whose scalar curvature vanishes in the unit ball BN and on the boundary S^N-1 the mean curvature is prescribed, we construct multi-peak solutions whose maxima are located on the boundary as the parameter tends to 0^+ under certain assumptions. We also obtain the asymptotic behaviors of the solutions.  相似文献   

13.
In this paper we shall consider the nonresonance Dirichlet boundary value problemwhere λ>0 is a parameter, p>0 is a constant. Intervals of A are determined to ensure the existence of a nonnegative solution of the boundary value problem. For λ=1, we shall also offer criteria for the existence of eigenfunctions. The main results include and improve on those of [2,4,6,8].  相似文献   

14.
This paper discusses the Cauchy problem of elliptic-elliptic-type Davey-Stewartson systems with zero-order dissipation on R^2. Making use of the Fourier spectral projector, together with a long time comparison between the solutions to the Davey-Stewartson systems and to an auxiliary problem, we prove that the global attractor in H^1 (R^2) for the addressed Davey-Stewartson systems is a compact subset of H^2(R^2), and thus reveal the asymptotic smoothing effect of the solutions for the systems.  相似文献   

15.
§ 1 IntroductionIn this paperwe shall study successively the equationsgiven in [1 ,2 ] .Underthe sameconditions(i.e.the initial boundary value and other conditions) as in[1 ,2 ] ,the upperbound of the dimension of their global attractor will be obtained respectively.Theexistence of the global attractors have been proved in[1 ,2 ] .This paper is organized as follows:In§ 2 ,we derive the Frechet differential of the solution operator s(t) for theperturbed system.In§ 3 ,we show the finite di…  相似文献   

16.
This paper deals with the properties of positive solutions to a quasilinear parabolic equation with the nonlinear absorption and the boundary flux. The necessary and sufficient conditions on the global existence of solutions are described in terms of different parameters appearing in this problem. Moreover, by a result of Chasseign and Vazquez and the comparison principle, we deduce that the blow-up occurs only on the boundary (?)Ω. In addition, for a bounded Lipschitz domainΩ, we establish the blow-up rate estimates for the positive solution to this problem with a= 0.  相似文献   

17.
In this paper,the Dirichlet problem of Stokes approximate of non-homogeneous incompressibleNavier-Stokes equations is studied.It is shown that there exist global weak solutions as well as global andunique strong solution for this problem,under the assumption that initial density ρ_0(x)is bounded away from0 and other appropriate assumptions(see Theorem 1 and Theorem 2).The semi-Galerkin method is applied toconstruct the approximate solutions and a prior estimates are made to elaborate upon the compactness of theapproximate solutions.  相似文献   

18.
In this paper we consider a p-Laplacian equation with the homogeneous Dirichlet boundary condition. We establish a blow-up result for certain solution with positive initial energy. This work was supported by the National Natural Science Foundation of China 10771032, and the Natural Science Foundation of Jiangsu province BK2006088.  相似文献   

19.
In this paper, we investigate the large-time behavior of solutions to the initial-boundary value problem for n × n hyperbolic system of conservation laws with artificial viscosity in the half line (0, ∞). We first show that a boundary layer exists if the corresponding hyperbolic part contains at least one characteristic field with negative propagation speed. We further show that such boundary layer is nonlinearly stable under small initial perturbation. The proofs are given by an elementary energy method.  相似文献   

20.
This paper is devoted to the study ofthe existence of single and multiple positive solutions forthe first order boundary value problem x′= f(t,x),x(0)=x(T),where f ∈ C([0,T]×R).In addition,weapply our existence theorems to a class of nonlinear periodic boundary value problems with a singularity at theorigin.Our proofs are based on a fixed point theorem in cones.Our results improve some recent results in theliteratures.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号