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500 个结果
  • 简介:LetAbearealsquarematrixandVTAV=GbeanupperHessenbergmatrixwithpositivesubdiagonalentries,whereVisanorthogonalmatrix.ThentheimplicitQ-theoremstatesthatoncethefirstcolumnofVisgiventhenVandGareuniquelydetermined.Inthispaper,threeresultsareestablished.First,itholdsareverseorderimplicitQ-theorem:oncethelastcolumnofVisgiven,thenVandGareuniquelydeterminedtoo.Second,itisprovedthatforaKrylovsubspacetwoformulationsoftheArnoldiprocessareequivalentandinonetoonecorrespondence.Finally,bytheequivalencerelationandthereverseorderimplicitQ-theorem,itisprovedthatfortheKrylovsubspace,ifthelastvectorofvectorsequencegeneratedbytheArnoldiprocessisgiven,thenthevectorsequenceandresultingHessenbergmatrixareuniquelydetermined.

  • 标签: IMPLICIT Q-theorem REVERSE order IMPLICIT Q-theorem
  • 简介:Inthispaper,thecorrespondencetheoremfortheusualalgebraicsystemsisgeneralizedtocoalgebra.Moreover,oneexample,whichillustratethepreimageofasubcoalgebraneednottobeasubcoalgebraforgeneralcoalgebrahomomorphism,isgiven.

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  • 简介:LetpdenoteaprimeandP2denoteanalmostprimewithatmosttwoprimefactors.Theauthorprovesthatforsuffcientlylargex,sumfromp≤xp+2=P21>(1.13Cx)/(log~2x),wheretheconstant1.13constitutesanimprovementofthepreviousresult1.104duetoJ.Wu.

  • 标签: Chen理论 均值定理 数论 数学研究
  • 简介:<正>WeareconcernedwiththefollowingDirichletproblem:-△u(x)=f(x,u),x∈Ω.u∈H01(Ω).(P)wheref(x,t)∈C(Ω×R),f(x,t)/tisnondecreasingint∈RandtendstoanL∝-functionq(x)uniformlyinx∈Ωast→+∝(i.e.,f(x,t)isasymptoticallylinearintatinfinity).Inthiscase.anAmbrosetti-Rabinowitz-typecondition,thatis.forsomeθ>2.M>0,0<θF(x.s)≤f(x,s)s,forall|s|≥Mandx∈Ω,(AR)isnolongertrue,whereF(x,s)=integralfromn=0tosf(x,t)dt.Asiswellknown,(AR)isanimportanttechnicalconditioninapplyingMountainPassTheorem.Inthispaper,withoutassuming(AR)weprove,byusingavariantversionofMountainPassTheorem,thatproblem(P)hasapositivesolutionundersuitable,conditionsonf(x,t)andq(x).Ourmethodsalsoworkforthecasewheref(x,f)issuperlinearintatinfinity.i.e.,q(x)≡∞.

  • 标签: DIRICHLET PROBLEM MOUNTAIN Pass THEOREM ASYMPTOTICALLY
  • 简介:AssumethatBisacompactsubsetontherealaxiscontainingatleastn+1points,C(B)thenormedlinearspaceofallcontinuousfunctionsdefinedonB,withChebyshevnorm‖·‖,andG=span(g1,…,gn)ann-dimensionalsubspaceofC(B).LetGR={g=sumfromj=1tonajgj:v(x)≤g(x)≤u(x),qi≤sumfromj=1tondijaj≤pifori=1,…,l}whereu,vareextendedreal-valuedfunctionsonBsubjectto-∞≤v(x)

  • 标签: NORMED VALUED SUBSET SUBSPACE interior instead
  • 简介:In1972,Fullerprovedthatacompleteadditivesubeategory_RCofR-Modisequivalenttoamodulecategory⊿-Modifandonlyif_RC=Gen(_RU)forsomequasiprogenerator_RUand⊿≌End_RUcanonically.Inthisnotetheauthorgivesacharacterizationof_RCwhichmakes_RUaprojectiveR-moduleinthecasewhenRisarightperfectringwithidentity,andshowsthatR-ModistheuniquecompleteadditivesubcategoryofR-ModwhichisequivalenttoR-ModforaleftArtinianringR.

  • 标签: ADDITIVE FULLER PROJECTIVE category PERFECT holds
  • 简介:Aboundoduesscriterionissetup/orsomeconvolutionoperatorsonacompaotLiegroup,BythiscriterionaHoermandermultipliertheoremisprovedintheHardyspacesonSU(2).

  • 标签: 原子成分 多项式
  • 简介:我们证明为四元数海森堡组上的sublaplacian的限制操作员从Lp被围住到Lp如果1p$\tfrac{4}{3}$\tfrac{4}{3}。这与海森堡组,限制操作员没从Lp在上被围住到Lp不同除非p=1。

  • 标签: HEISENBERG群 限制定理 四元 运营商 有界
  • 简介:InthispaperwepresentacorrectionoftheproofofustronguniquenesstheoremgivenbyH.Struuss[1]in1992onapproximationbyreciprocalsoffunctionsufann-dimensionalspace(u,…un)satisfyingcoefficientconstraints.

  • 标签:
  • 简介:<正>Inthispaper,weinvestigatethegeneralizedSublaplacian.Wegivetheexpressionoftherestrictionoperatorsexplicitly.Byintroducingthegeneralizedλ-twistedconvolutions,weobtaintheestimatesoftherestrictionoperatorsinthemixedL~Pspaces.Finally,wegetarestrictiontheoremassociatedwiththegeneralizedSublaplacian.

  • 标签: GENERALIZED Sublaplacian RESTRICTION THEOREM GENERALIZED CONVOLUTION
  • 简介:在这篇论文,由介绍等轴的联盟者Pc0性质,集中定理的一种分离形式被介绍;结果概括;在最近的年里统一几个有趣的结论。

  • 标签: 基质 无穷值 收敛 数学定理
  • 简介:InthispaperwepresentacorrectionoftheproofofastronguniquenesstheoremgivenbyH.Straussin1992onapproximationbyreciprocalsoffunctionsofann-dimensionalspacespan(u1,…,un)satisfyingcoefficientconstraints.

  • 标签: UNIQUENESS Strauss correction constraints SUBSET proof
  • 简介:Aseveryoneknows,theclassicalJacksontheoreminapproximationtheorywasgeneralizedinLpspacesbyR.A.Devore.Inthispaper,weprovedtheJacksontheoreminB,spaceswhichintroducedbyDingXiaXi,

  • 标签: 产气 异音 裂丝