简介:Letf(x)∈C[-1,1],pn*(x)bethebestapproximationpolynomialofdegreentof(x).G.Iorentzconjecturedthatifforalln,p2n*(x)=p2n+1*(x),thenfiseven;andifp2n+1*(x)=p2n+2*(x),po*(z)=0,thenfisodd.Inthispaper,itisprovedthat,undertheL1-norm,theLorentzconjectureisvalidconditionally,i.e.if(i)(1-x2)f(x)canbeextendedtoanabsolutelyconvergentTehebyshevsories;(ii)foreveryn,f(x)-p2n+1*(x)hasexactly2n+2zeros(or,inthearcondsituation,f(x)-p2n+2*(x)hasexaetly2n+3zeros),thenLorentzconjectureisvalid.
简介:A.simplicialmesh(triangulation)isconstructedthatgeneralizesthetwo-dimensional4-directionmeshtoR~m.Thismesh,withsymmetric,shift-invariantvaluesatthevertices,isshowntoadmitaboundedC~1interpolantifandonlyifthealternatingsumofthevaluesattheverticesofany1-cubeiszero.Thisim-pliesthaiinterpolationattheverticesofanm-dimensional,simplicialmeshbyaC~1piecewisepolynomialofdegreem+1withonepiecepersimplexisunstable.
简介:SupposethatwewanttoapproximatefC[0,1]bypolynomialsinPn,usingonlyitsvaluesonXn={i/n,0≤i≤n}.ThiscanbedonebytheLagrangeinterpolantLnfortheclassicalBernsteinpolynomialBnf.But,whenntendstoinfinity,LnfdoesnotconvergetofingeneralandtheconvergenceofBnftofisveryslow.WedefineafamilyofoperatorsBkn,n≥k,whichareintermediateonesbetweenB(0)n=B1n=BnandBnn=Ln,andwestudysomeoftheirproperties.Inparticular,weproveaVoronovskaja-typetheoremwhichassertsthatBknf-f=0(n-[(k+2)/2)forfsufficientlyregular.Moreover,B(k)nfusesonlyvaluesofBnfanditsderivatiesandcanbecomputedbyDeCasteljauorsubdivisionalgorithms.
简介:性质awc1被许多作者使用由弱Chebyshevsubspaces的元素有关近似获得结果。在这份报纸,作者在细节学习这个性质,由收集有关它并且由发现新的散布结果。
简介:TwoestimatesusefulinapplicationsareprovedfortheFouriertransforminthespaceL2(X),whereXasymmetricspace,asappliedtosomeclassesoffunctionscharacterizedbyageneralizedmodulusofcontinuity.
简介:K1,k┐FACTORIZATIONOFBIPARTITEGRAPHSDUBEILIANGAbstract.Inthispaper,anecessaryconditionforabipartitegraphλKm,ntobeK1,k-factoriz...
简介:S.M.LozinskiiprovedtheexactconvergencerateatthezeroofLagrangeinterpolationpolynomialsto|x|basedonequidistantnodesin[-1,1].In2000,M.RevergeneralizedS.M.Lozinskii'sresultto|x|α(0≤α≤1).Inthispaperwewillpresenttheexactrateofconvergenceatthepointzerofortheinterpolantsof|x|α(1<α<2)..
简介:Anticipatedbackwardstochasticdifferentialequation(ABSDE)studiedthefirsttimein2007isanewtypeofstochasticdifferentialequations.Inthispaper,weestablishageneralcomparisontheoremforABSDEs.
简介:Radialfunctionshavebecomeausefultoolinnumericalmathematics.Onthespheretheyhavetobeidentifiedwiththezonalfunctions.Weinvestigatezonalpolynomialswithmassconcentrationatthepole,inthesenseoftheirL1-normisattainingtheminimumvalue.Suchpolynomialssatisfyacomplicatedsystemofnonlineare-quations(algebraicifthespacedimensionisodd,only)andalsoasingulardifferentialequationofthirdorder.Theexactorderofdecayoftheminimumvaluewithrespecttothepolynomialdegreeisdetermined.Byourresultswecanprovethatsomenodalsystemsonthesphere,whicharedefinedbyaminimum-property,areprovidingfundamentalmatriceswhicharediagonal-dominantorboundedwithrespecttothe∞-norm,atleast,asthepolynomialdegreetendstoinfinity.
简介:<正>Inthisnote.wewillshowthatnononuniformlatticeofSO(3,1)canbethefundamentalgroupofaquasi-compactKhlermanifold.Thus,combiningwiththeresultin[1].onegetsthatanonuniformlatticeinSO(n,1)(n≥3)cannotbeπ1ofanyquasi-compactKhlerianmanifold.
简介:Inthispaper,wegetW1,p(Rn)-boundednessfortangentialmaximalfunc-tionandnontangentialmaximalfunction,whichimprovesJ.Kinnunen,P.LindqvistandTananka’sresults.