简介:LetAbearealsquarematrixandVTAV=GbeanupperHessenbergmatrixwithpositivesubdiagonalentries,whereVisanorthogonalmatrix.ThentheimplicitQ-theoremstatesthatoncethefirstcolumnofVisgiventhenVandGareuniquelydetermined.Inthispaper,threeresultsareestablished.First,itholdsareverseorderimplicitQ-theorem:oncethelastcolumnofVisgiven,thenVandGareuniquelydeterminedtoo.Second,itisprovedthatforaKrylovsubspacetwoformulationsoftheArnoldiprocessareequivalentandinonetoonecorrespondence.Finally,bytheequivalencerelationandthereverseorderimplicitQ-theorem,itisprovedthatfortheKrylovsubspace,ifthelastvectorofvectorsequencegeneratedbytheArnoldiprocessisgiven,thenthevectorsequenceandresultingHessenbergmatrixareuniquelydetermined.
简介:Inthispaper,thecorrespondencetheoremfortheusualalgebraicsystemsisgeneralizedtocoalgebra.Moreover,oneexample,whichillustratethepreimageofasubcoalgebraneednottobeasubcoalgebraforgeneralcoalgebrahomomorphism,isgiven.
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)≡∞.
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)
简介:In1972,Fullerprovedthatacompleteadditivesubeategory_RCofR-Modisequivalenttoamodulecategory⊿-Modifandonlyif_RC=Gen(_RU)forsomequasiprogenerator_RUand⊿≌End_RUcanonically.Inthisnotetheauthorgivesacharacterizationof_RCwhichmakes_RUaprojectiveR-moduleinthecasewhenRisarightperfectringwithidentity,andshowsthatR-ModistheuniquecompleteadditivesubcategoryofR-ModwhichisequivalenttoR-ModforaleftArtinianringR.
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。
简介:InthispaperwepresentacorrectionoftheproofofustronguniquenesstheoremgivenbyH.Struuss[1]in1992onapproximationbyreciprocalsoffunctionsufann-dimensionalspace(u,…un)satisfyingcoefficientconstraints.
简介:<正>Inthispaper,weinvestigatethegeneralizedSublaplacian.Wegivetheexpressionoftherestrictionoperatorsexplicitly.Byintroducingthegeneralizedλ-twistedconvolutions,weobtaintheestimatesoftherestrictionoperatorsinthemixedL~Pspaces.Finally,wegetarestrictiontheoremassociatedwiththegeneralizedSublaplacian.
简介:InthispaperwepresentacorrectionoftheproofofastronguniquenesstheoremgivenbyH.Straussin1992onapproximationbyreciprocalsoffunctionsofann-dimensionalspacespan(u1,…,un)satisfyingcoefficientconstraints.