简介:LetGbeasimplegraphwithnverticesandλn(G)betheleasteigenvalueofG.Inthispaper,weshowthat,ifGisconnectedbutnotcomplete,thenλn(G)≤λn(Kn-11)andtheequalityholdsifandonlyifGKn-11,whereKn-11,isthegraphobtainedbythecoalescenceofacompletegraphKn-1ofn-1verticeswithapathP2oflengthoneofitsvertices.
简介:isgainedbydeletingthekthrowandthekthcolumn(k=1,2,...,n)fromTn.Weputfor-wardaninverseeigenvalueproblemtobethat:Ifwedon’tknowthematrixT1,n,butweknowalleigenvaluesofmatrixT1,k-1,alleigenvaluesofmatrixTk+1,k,andalleigenvaluesofmatrixT1,ncouldweconstructthematrixT1,n.Letμ1,μ2,…,μk-1,μk,μk+1,…,μn-1,
简介:Derivativesofeigenvaluesandeigenvectorswithrespecttoparametersinsymmetricquadraticeigenvalueproblemarestudied.Thefirstandsecondorderderivativesofeigenpairsaregiven.Thederivativesarecalculatedintermsoftheeigenvaluesandeigenvectorsofthequadraticeigenvalueproblem,andtheuseofstatespacerepresentationisavoided,hencethecostofcomputationisgreatlyreduced.Theefficiencyofthepresentedmethodisdemonstratedbyconsideringaspring-mass-dampersystem.
简介:一张签署的图是一张图,一个符号属于每个边。这篇论文从图扩大拉普拉斯算符矩阵的一些基本概念到签署的图。Inparticular,在最少的拉普拉斯算符特征值之间的关系和一张签署的图的失衡的海角被调查。
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简介:Acouplingmethodoffiniteelementandinfinitelargeelementisproposedforthenumericalsolutionofaneigenvalueprobleminunboundeddomainsinthispaper.Withsomeconditionssatisfied,theconsideredproblemisprovedtohavediscretespectra.Severalnumericalexperimentsarepresented.Theresultsdemonstratethefeasibilityoftheproposedmethod.
简介:LetH∈Cn×nbeann×nunitaryupperHessenbergmatrixwhosesubdiagonalelementsareallpositive.PartitionHasH=[H11H12H21H22],(0.1)whereH11isitsk×kleadingprincipalsubmatrix;H22isthecomplementarymatrixofH11.Inthispaper,Hisconstructeduniquelywhenitseigenvaluesandtheeigenvaluesof(H|^)11and(H|^)22areknown.Here(H|^)11and(H|^)22arerank-onemodificationsofH11andH22respectively.
简介:Applyingconstructedhomotopyanditsproperties,wegelsomesufficientconditionsforthesolvabilityofalgebraicinverseeigenvalueproblems,whicharebetterthanthatofthepaper[4]insomecases.Inverseeigenvalueproblems,solvability,sufficientconditions.
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简介:Atwo-leveldiscretizationmethodforeigenvalueproblemsisstudied.ComparedtothestandardGalerkinfiniteelementdiscretizationtechniqueperformedonafinegridthismethoddiscretizestheeigenvalueproblemonacoarsegridandobtainsanimprovedeigenvector(eigenvalue)approximationbysolvingonlyalinearproblemonthefinegrid(ortwolinearproblemsforthecaseofeigenvalueapproximationofnonsymmetricproblems).TheimprovedsolutionhastheasymptoticaccuracyoftheGalerkindiscretizationsolution.ThelinkbetweenthemethodandtheiteratedGalerkinmethodisestablished.Errorestimatesforthegeneralnonsymmetriccasearederived.
简介:LetG=(V(G),E(G))beasimpleconnectedgraphofordern.Foranyverticesu,v,w∈V(G)withuv∈E(G)anduw∈E(G),anedge-rotatingofGmeansrotatingtheedgeuv(aroundu)tothenon-edgepositionuw.Inthiswork,weconsiderhowtheleasteigenvalueofagraphperturbswhenthegraphisperformedbyrotatinganedgefromtheshorterhangingpathtothelongerone.
简介:AbstractSomenewlocalandparallelfiniteelementalgorithmsareproposedandanalyzedinthispaperforeigenvalueproblems.Withthesealgorithms,thesolutionofaneigenvalueproblemonafinegridisreducedtothesolutionofaneigenvalueproblemonarelativelycoarsegridtogetherwithsolutionsofsomelinearalgebraicsystemsonfinegridbyusingsomelocalandparallelprocedure.Atheoreticaltoolforanalyzingthesealgorithmsissomelocalerrorestimatethatisalsoobtainedinthispaperforfiniteelementapproximationsofeigenvectorsongeneralshape-regulargrids.
简介:1IntroductionLetRn×nbethesetofalln×nrealmatrices.Rn=Rn×1.Cn×ndenotesthesetofalln×ncomplexmatrices.Weareinterestedinsolvingthefollowinginverseeigenvalueprob-lems:ProblemA(Additiveinverseeigenvalueproblem)Givenann×nrealmatrixA=(aij),andndistinctrealnumbersλ1,λ2,…,λn,findarealn×ndiagonalmatrixD=diag
简介:Inthispapertheunsolvabilityofgeneralizedinverseeigenvalueproblemsalmosteverywhereisdiscussed.Wefirstgivethedefinitionsfortheunsolvabilityofgeneralizedinverseeigenvalueproblemsalmosteverywhere.Thenadoptingthemethodusedin[14],wepresentsomesufficientconditionssuchthatthegeneralizedinverseeigenvalueproblemsareunsohablealmosteverywhere.
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简介:Nonlinearrank-onemodificationofthesymmetriceigenvalueproblemarisesfromeigen-vibrationsofmechanicalstructureswithelasticallyattachedloadsandcalculationofthepropagationmodesinopticalfiber.Inthispaper,wefirststudytheexistenceanduniquenessofeigenvalues,andtheninvestigatethreenumericalalgorithms,namelyPicarditeration,nonlinearRayleighquotientiterationandsuccessivelinearapproximationmethod(SLAM).TheglobalconvergenceoftheSLAMisprovenundersomemildassumptions.NumericalexamplesillustratethattheSLAMisthemostrobustmethod.