简介:LetB(H)bethealgebraofalltheboundedlinearoperatorsonaHilbertspaceH.ForA,PandQinB(H),ifthereexistsanoperatorX∈B(H)suchthatAPXQA=A,XQAPX=X,(QAPX)*=QAPXand(XQAP)*=XQAP,thenXissaidtobetheΓ-inverseofAassociatedwithPandQ,anddenotedbyAP,Q+.Inthisnote,wepresentsomenecessaryandsu?cientconditionsforwhichA+P,Qexists,andgiveanexplicitrepresentationofAP,Q+(ifAP,Q+exists).
简介:Letp(z)=akzkbesuchthat|p(eip)|≤1forRand|p(1)|=a[0,1].AninequalityofDewanandCavilforthesum|av|+|au|,0≤u
简介:Theboundedparameterestimationproblemanditssolutionleadtomoiemeaningfulresults.Itssuperiorperformanceisduetothefactthatthenewmethodguaranteesthattheeffectoftheuncertaintieswillneverbeunnecessarilyoverestimated.Wethenconsiderhowtoupdateanddowndatetheboundedparameterestimationproblem.WhenupdatinganddowndatingofSVDareusedtothenewproblem,specialtechnologiesaretakentoavoidformingUandVexplicitly,thenincreasethealgorithmperformance.BecauseofthelinkbetweentheboundedparameterestimationandTikhonovregularizationprocedure,wepointoutthatouralgorithmscanalsobeusedtomodifyregularizationproblem.
简介:ThispaperpresentsanewfamilyofsolutionstothesingularlyperturbedAllen-Cahnequationα~2Δu+u(1-u~2)=0inasmoothboundeddomainΩR~3,withNeumannboundaryconditionandα>0asmallparameter.Thesesolutionshavethepropertythatasα→0,theirlevelsetscollapseontoaboundedportionofacompleteembeddedminimalsurfacewithfinitetotalcurvatureintersecting?Ωorthogonallyandthatisnon-degeneraterespectto?Ω.Theauthorsprovideexplicitexamplesofsurfacestowhichtheresultapplies.
简介:Inthispaper,thenotionoftheboundedcompactapproximationproperty(BCAP)ofapair[Banachspaceanditssubspace]isusedtoprovethatifXisaclosedsubspaceofL∞withtheBCAP,thenL∞/XhastheBCAP.WealsoshowthatX*hastheλ-BCAPwithconjugateoperatorsifandonlyifthepair(X,Y)hastheλ-BCAPforeachfinitecodimensionalsubspaceY∈X.LetMbeaclosedsubspaceofXsuchthatM⊥iscomplementedinX*.IfXhasthe(bounded)approximationpropertyoforderp,thenMhasthe(bounded)approximationpropertyoforderp.
简介:LetDbeaboundedC3-domaininRdand(aij)beaboundedsymmetricmatrixdefinedonD.Considerthesymmetricform(u,v)=1/2∫Daij(x)(u(x))/(xi)(v(x))/(xj)dx,u,v∈H1(D).UndersomeassumptionsitisshownthatthediffusionprocessassociatedwiththeregularDirichletspace(,(H1(D))onL2(D)canbecharacterizedasauniquesolutionofacertainstochasticdifferentialequation.
简介:InthisarticlewestudyholomorphicisometriesofthePoincar'ediskintoboundedsymmetricdomains.EarlierwesolvedtheproblemofanalyticcontinuationofgermsofholomorphicmapsbetweenboundeddomainswhichareisometriesuptonormalizingconstantswithrespecttotheBergmanmetric,showinginparticularthatthegraphV0ofanygermofholomorphicisometryofthePoincar'ediskΔintoanirreducibleboundedsymmetricdomainΩ€CNinitsHarish-Chandrarealizationmustextendtoanaffine-algebraicsubvarietyVC×CN=CN+1,andthattheirreduciblecomponentofV∩(Δ×Ω)containingV0isthegraphofaproperholomorphicisometricembeddingF:Δ→Ω.Inthisarticlewestudyholomorphicisometricembeddingswhichareasymptoticallygeodesicatageneralboundarypointb∈Δ.Startingwiththestructuralequationforholomor-phicisometriesarisingfromtheGaussequation,weobtainbycovariantdifferentiationanidentityrelatingcertainholomorphicbisectionalcurvaturestotheboundarybehaviorofthesecondfundamentalformσoftheholomorphicisometricembedding.Usingthenonpositivityofholomorphicbisectionalcurvaturesonaboundedsymmetricdomain,weprovethatσmustvanishatageneralboundarypointeithertotheorder1ortotheorder21,calledaholomorphicisometryofthefirstresp.secondkind.Wedealwithspecialcasesofnon-standardholomorphicisometricembeddingsofsuchmaps,showingthattheymustbeasymptoticallytotallygeodesicatageneralboundarypointandinfactofthefirstkindwheneverthetargetdomainisaCartesianproductofcomplexunitballs.WealsostudytheboundarybehaviorofanexampleofholomorphicisometricembeddingfromthePoincar'ediskintoaSiegelupperhalf-planebyanexplicitdeterminationoftheboundarybehaviorofholomorphicsectionalcurvaturesinthedirectionstangenttotheembeddedPoincar'edisk,showingthatthemapisindeedasymptoticallytotallygeodesicatageneralboundarypointandofthefirstkind.Fo
简介:为>1,让d在bidisk和一项复杂措施上表示加权的Lebesgue措施令人满意一些Carleson类型条件。在这份报纸,我们为Toeplitz操作员$T_显示出一个足够、必要的条件{\bar\mu}在加权的Bergman空间L上要跳或压缩的^\alpha$一1(d)。
简介:RecentlyGuointroducedintegratedMeyer-KonigandZelleroperatorsandstudiedtherateofconvergenceforfunctionofboundedvariation.Inthisnotewegiveasharpestimatefortheseoperators.
简介: