简介:本文研究了Hilbert空间L^2(R^2)上由势函数V(x)(V≥0,连续)给出的一类Schrǒdinger算子H=-△+V的谱。本文的主要结果:(1)H的谱σ(H)不会出现本性谱与离散谱交替出现的情况,其谱要么是离散的,要么从infσcos(H)开始全是本性谱;(2)lim‖x‖→∞V(x)=∞是σcos(H)=φ的充要条件。(3)借助于讨论H的Zhis-lin谱,在一定的条件下。lim‖x‖→∞V(x)=0是σcos(H)=[∞,0)的充要条件。我们还提出了几个没有解决的问题。
简介:WediscussseparabilityofsolutionstoaSchr?dingerequationthatdescribesacompositequantumsystemandgivesomekindsofHamiltoniansH(t)suchthatthesolutiontoSchr?dingerequationinducedbyH(t)isseparableatanytimeprovidedthatitisseparableatt=0.Forexample,weprovethatiftheHamiltonianHistime-independentandequalstotheproductPA■PBoftwoprojectionsonthesubsystemsKAandKB,respectively,thenthestate|ψ(t)ofthecompositesystemstartingfromaseparableinitial|ψ(0)=|ψA■|ψBisseparableforallt∈[0,T]ifandonlyifeither|ψAisaneigenstateofPA,or|ψBisaneigenstateofPB.
简介:VariationalmethodsareusedtostudythenonlinearSchrdinger-Poissontypeequationswhichmodeltheelectromagneticwavepropagatingintheplasmainphysics.ByanalyzingtheHamiltonianpropertytoconstructaconstrainedvariationalproblem,theexistenceofthegroundstateofthesystemisobtained.Furthermore,itisshownthatthegroundstateisorbitallystable.
简介:Inthispaper,weinvestigatethesemiclassicallimitofthegeneralizednonlinearSchr?dingerequationforinitialdatawithSobolevregularity.Also,wewillanalyzethestructureofthefluiddynamicalsystemwithquantumeffectcorrespondingtothesemiclassicallimitofthegeneralizednonlinearSchr?dingerequation.
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简介:Weprovetheexistenceandtheorbitalstabilityofstandingwavesforthenonau-tonomousSchrdingersystemiut+ua(x)u+(|u|2p+b(x)|u|p-1|v|p+1)u=0,x∈RN,ivt+va(x)v+|v|2p+b(x)|v|p-1|u|p+1v=0,x∈RNundersuitableconditionsonthecoefficientfunctionsaandb.Wefollowtheideaofanalyzingthecompactnessofminimizingsequenceoftheconstrainedminimizationproblems.
简介:Westudythedynamicsofthecubic–quinticnonlinearSchr?dingerequationbythesymplecticmethod.Thebehaviorsoftheequationarediscussedwithharmonicallymodulatedinitialconditions,andthecontributionsfromthequintictermarediscussed.Weobservetheellipticorbit,homoclinicorbitcrossing,quasirecurrence,andstochasticmotionwithdifferentnonlinearparametersinthissystem.Numericalsimulationsshowthatthechangingprocessesofthemotionofthesystemandthetrajectoriesinthephasespacearevariousfordifferentcubicnonlinearparameterswiththeincreaseofthequinticnonlinearparameter.
简介:Thispaperconsiderstheone-dimensionaldissipativecubicnonlinearSchrdingerequationwithzeroDirichletboundaryconditionsonaboundeddomain.Theequationisdiscretizedintimebyalinearimplicitthree-levelcentraldifferencescheme,whichhasanalogousdiscreteconservationlawsofchargeandenergy.Theconvergencewithtwoordersandthestabilityoftheschemeareanalysedusingaprioriestimates.Numericaltestsshowthatthethree-levelschemeismoreefficient.
简介:LetL=-?+VbeaSchrdingeroperatoractingonL2(Rn),n≥1,whereV≡0isanonnegativelocallyintegrablefunctiononRn.Inthisarticle,wewillintropduceweightedHardyspacesHL(w)associatedwithLbymeansofthesquarefunctionandthenstudytheiratomicdecompositiontheory.WewillalsoshowthattheRiesztransform?L-1/2associatedwithLisboundedfromournewspaceHpL(w)totheclassicalweightedHardyspaceHp(w)whenn/(n+1)
简介:利用二阶微商的四阶精度紧致差分逼近公式,给出解Schroedinger方程的精度为O((1-2θ)τ+τ^2h^4)的一个新的加权差分格式,当1/2≤θ≤1时格式绝对稳定.特别地,当θ=1/2时,文章所给出的差分格式可高达四阶精度,数值结果与理论分析相一致.
简介:Inthispaper,severalnewconstant-amplitudeandvariable-amplitudewavesolutions(namely,travelingwavesolutions)ofageneralizednonlinearSchrdingerequationareinvestigatedbyusingtheextendedhomogeneousbalancemethod,wherethebalancemethodisappliedtosolvetheRiccatiequationandthereducednonlinearordinarydifferentialequation,respectively.Inaddition,stabilityanalysisofthosesolutionsarealsoconductedbyregularphaseplanetechnique.
简介:WestudythegeneralizedDarbouxtransformationtothethree-componentcouplednonlinearSchr¨odingerequation.First-andsecond-orderlocalizedwavesareobtainedbythistechnique.Infirst-orderlocalizedwave,wegettheinteractionalsolutionsbetweenfirst-orderroguewaveandone-dark,one-brightsolitonrespectively.Meanwhile,theinteractionalsolutionsbetweenone-breatherandfirst-orderroguewavearealsogiven.Insecond-orderlocalizedwave,one-dark-one-brightsolitontogetherwithsecond-orderroguewaveispresentedinthefirstcomponent,andtwo-brightsolitontogetherwithsecond-orderroguewavearegainedrespectivelyintheothertwocomponents.Besides,weobservesecond-orderroguewavetogetherwithone-breatherinthreecomponents.Moreover,byincreasingtheabsolutevaluesoftwofreeparameters,thenonlinearwavesmergewitheachotherdistinctly.Theseresultsfurtherrevealtheinterestingdynamicstructuresoflocalizedwavesinthethree-componentcoupledsystem.
简介:ThefollowingcoupledSchrdingersystemwithasmallperturbationuxx+u-u3+βuv2+f(,u,ux,v,vx)=0inR,vxx-v+v3+βu2v+g(,u,ux,v,vx)=0inRisconsidered,whereβandaresmallparameters.ThewholesystemhasaperiodicsolutionwiththeaidofaFourierseriesexpansiontechnique,anditsdominantsystemhasaheteroclinicsolution.Thenadjustingsomeappropriateconstantsandapplyingthefixedpointtheoremandtheperturbationmethodyieldthatthisheteroclinicsolutiondeformstoaheteroclinicsolutionexponentiallyapproachingtheobtainedperiodicsolution(calledthegeneralizedheteroclinicsolutionthereafter).
简介:TheprimarygoalofthispaperistopresentacomprehensivestudyofthenonlinearSchrdingerequationswithcombinednonlinearitiesofthepower-typeandHartreetype.Undercertainstructuralconditions,theauthorsareabletoprovideacompletepictureofhowthenonlinearSchrdingerequationswithcombinednonlinearitiesinteractinthegivenenergyspace.ThemethodusedinthepaperisbasedupontheMorawetzestimatesandperturbationprinciples.
简介:Byusingthemethodofdynamicalsystem,theexacttravellingwavesolutionsofthecouplednonlinearSchrdinger-KdVequationsarestudied.Basedonthismethod,allphaseportraitsofthesystemintheparametricspacearegiven.Allpossibleboundedtravellingwavesolutionssuchassolitarywavesolutionsandperiodictravellingwavesolutionsareobtained.WiththeaidofMaplesoftware,thenumericalsimulationsareconductedforsolitarywavesolutionsandperiodictravellingwavesolutionstothecouplednonlinearSchrdinger-KdVequations.Theresultsshowthatthepresentedfindingsimprovetherelatedpreviousconclusions.
简介:WeinvestigatethePainlevéintegrabilityofnonautonomousnonlinearSchrdinger(NLS)equationswithbothspace-andtime-dependentdispersion,nonlinearity,andexternalpotentials.ThePainlevéanalysisiscarriedoutwithoutusingtheKruskal'ssimplification,whichresultsinmoregeneralizedformofinhomogeneousequations.TheobtainedequationsareshowntobereducibletothestandardNLSequationbyusingapointtransformation.WealsoconstructthecorrespondingLaxpairandcarryoutitsKundu-typereductiontothestandardLaxpair.SpecialcasesofequationsfromchoosinglimitedformofcoefficientscoincidewiththeequationsfromthepreviousPainlevéanalysesand/orbecomeunknownnewequations.
简介:LetL=L0+VbethehigherorderSchrdigertypeoperatorwhereL0isahomogeneousellipticoperatoroforder2mindivergenceformwithboundedcoefficientsandVisarealmeasurablefunctionasmultiplicationoperator(e.g.,including(-?)m+V(m∈N)asspecialexamples).Inthispaper,assumethatVsatisfiesastronglysubcriticalformconditionassociatedwithL0,theauthorsattempttoestablishatheoryofHardyspaceHpL(Rn)(0