简介:1.IntroductionInthispaperweconsidertheCauchyproblemforthefastdiffusionequationwheremaxandpositivefunction.Thistypeofequationhasbeenextensivelystudiedasamathematicalmodelofalotofphysicalproblems(see[1-3]).Amajortopicofstudyistheexistenceandnonexistenc...
简介:Inthispaper,byusingthecriticalpointtheory,theexistenceofperiodicandsubharmonicsolutionstoaclassofsecondorderfunctionaldifferenceequationsisobtained.ThemainapproachusedinourpaperisvariationaltechniqueandtheSaddlePointTheorem.Theproblemistosolvetheexistenceofperiodicandsubharmonicsolutionsofsecondorderforwardandbackwarddifferenceequations.
简介:Inthispaper,westudyanddiscusstheexistenceofmultiplesolutionsofaclassofnon-linearellipticequationswithNeumannboundarycondition,andobtainatleastsevennon-trivialsolutionsinwhichtwoarepositive,twoarenegativeandthreearesign-changing.Thestudyofproblem(1.1):{-△u+αu=f(u),x∈Ω,x∈Ω,δu/δr=0,x∈δΩ,isbasedonthevariationalmethodsandcriticalpointtheory.Weformourconclusionbyusingthesub-supsolutionmethod,MountainPassTheoreminorderintervals,Leray-Schauderdegreetheoryandtheinvarianceofdecreasingflow.
简介:WestudytheexistenceanduniquenessproblemforthenonhomogeneouspressurelessEulersystemwiththeinitialdensitybeingaRadonmeasure.Ouruniquenessresultisobtainedinthesamespaceastheexistencetheorem.Besides,bycounterexampleweprovethatHuang-Wang'senergyconditionisalsonecessaryforournonhomogeneoussystem.
简介:AnexampleofcompletsRiemannianmetricofpositive(ornonnagative)curvatureonR^nsuchasds^2=a(x)dx^2isobtainedbydirectcaculations.Furthermore,byusingageodesicconvexconditionandatheoremforcompletenoncompactRiemannianmanifold,anexistenceresultofperiodicsulutionofprescribedenergyforasingularHamiltoniansystemisalsoobtained.
简介:§1.IntroductionWeconsiderthesingularnonlinearboundaryvalueproblemwherel=v+3/v-1,l+1isthecriticalexponentoftheembeddingofweightedSobolevspaceWt21,2(O,+∞)intoLt2q(O,∞),v>2.Whenv=N-1wecangettheradialsolutionsofproblemwhere2*=2N/N-2isthecriticalexponentoftheSobolevembeddingH1(Rn)→LQ(RN).Kurtzhasdiscussedtheexistenceofκ-nodesolutionof(1.1),(1.2)foreachκ∈NU{0}whenthegrowthrateof|u|l-1u+f(u)islowerthen|u|v+3/v-1i.e.
简介:Thispaperisasequeltoapreviouspaper(Yang,Y.andZhang,J.H.Existenceofsolutionsforsomefourth-orderboundaryvalueproblemswithparameters.NonlinearAnal.69(2),1364–1375(2008))inwhichthenontrivialsolutionstothefourthorderboundaryvalueproblemswerestudied.Inthecurrentworkwiththesameconditionsnearinfinitybutdifferentnearzero,thepositive,negative,andsign-changingsolutionsareobtainedbythecriticalpointtheory,retractingproperty,andinvariantsets.
简介:Inthispaper,weconsiderexistenceanduniquenessofpositivesolutionstothreecouplednonlinearSchrdingerequationswhichappearinnonlinearoptics.Weusethebehaviorsofminimizingsequencesforaboundtoobtaintheexistenceofpositivesolutionsforthreecoupledsystem.Toprovetheuniquenessofpositivesolutions,weusetheradialsymmetryofpositivesolutionstotransformthesystemintoanordinarydifferentialsystem,andthenintegratethesystem.Inparticular,forN=1,weprovetheuniquenessofpositivesolutionswhen0≤β=μ1=μ2=μ3orβ>max{μ1,μ2,μ3}.