简介:AgraphGiscalledchromatic-choosableifitschoicenumberisequaltoitschromaticnumber,namelych(G)=χ(G).Ohba’sconjecturestatesthateverygraphGwith2χ(G)+1orfewerverticesischromaticchoosable.ItisclearthatOhba’sconjectureistrueifandonlyifitistrueforcompletemultipartitegraphs.Recently,Kostochka,StiebitzandWoodallshowedthatOhba’sconjectureholdsforcompletemultipartitegraphswithpartitesizeatmostfive.Butthecompletemultipartitegraphswithnorestrictionontheirpartitesize,forwhichOhba’sconjecturehasbeenverifiedarenothingmorethanthegraphsKt+3,2*(k-t-1),1*tbyEnotomoetal.,andKt+2,3,2*(k-t-2),1*tfort≤4byShenetal..Inthispaper,usingtheconceptoff-choosable(orL0-size-choosable)ofgraphs,weshowthatOhba’sconjectureisalsotrueforthegraphsKt+2,3,2*(k-t-2),1*twhent≥5.Thus,Ohba’sconjectureistrueforgraphsKt+2,3,2*(k-t-2),1*tforallintegerst≥1.
简介:LiuandYangavethedegreeconditionforabalancedbipartitegraphG=(V_1,V_2;E)tohavekvertex-disjointquadrilateralscontaininganygivenkindependentedgese_1,...,e_kofG,respectively.Theyalsoconjecturedthatforanykindependentedgese_1,...,e_kofG,Ghasa2-factorwithkcyclesC_1,C_2,…,C_kwithrespectto{e_1,e_2,...,e_k}suchthatk-1ofthemarequadrilaterals.Inthispaper,weprovethisconjecture.
简介:Inthispaper,weuseamethodinordertofindexactexplicittravelingsolutionsinthesubspaceofthephasespaceforCH2equations.Thekeyideaisremovingacoupledrelationforthegivensystemsothatthenewsystemscanbesolved.Theexistenceofsolitarywavesolutionsisobtained.Itisshownthatbifurcationtheoryofdynamicalsystemsprovidesapowerfulmathematicaltoolforsolvingagreatmanynonlinearpartialdifferentialequationsinmathematicalphysics.
简介:ConsiderL2-projectionuhofuton-degreefiniteelementspaceonone-dimensionaluniformgrids.TwodifferentclassesoftheorthogonalexpansioninanelementforconstructingasuperclosetofunctionuhareproposedandthensuperconvergenceforbothuhandDuhareproved.Whennisoddandnoboundaryconditionsareprescribed,thenuhisofsuperconvergenceatn+1orderGausspointsGn+1ineachelement.Whennisevenandfunctionvaluesontheboundaryareprescribed,thenuhisofsuperconvergenceatn+1orderpointsZn+1ineachelement.Iftheotherboundaryconditionsaregiven,thentheconclusionsarevalidinallelementsthatitsdistancefromtheboundary≥ch|lnh|.Theaboveconclusionsarealsovalid.forn-dergreerectangularelementQ1(n).
简介:本文中,我们讨论了矩阵方程AXB=D的最小二乘Hermite解,通过运用广义奇异值分解(GSVD),获得了解的通式。此外,对于给定矩阵F,也得到了它的加权最佳逼近表达式。
简介:Inthispaper,weareconcernedwiththeglobalexistenceandconvergenceratesofthesmoothsolutionsforthecompressiblemagnetohydrodynamicequationswithoutheatconductivity,whichisahyperbolic-parabolicsystem.TheglobalsolutionsareobtainedbycombiningthelocalexistenceandaprioriestimatesifH3-normoftheinitialperturbationaroundaconstantstatesissmallenoughanditsL1-normisbounded.Aprioridecay-intimeestimatesonthepressure,velocityandmagneticfieldareusedtogettheuniformboundofentropy.Moreover,theoptimalconvergenceratesarealsoobtained.
简介:AconstructiveproofisgivenfortheinversionformulaforzonalfunctionsonSL(2,R).AconcretelyconstructedsequenceofzonalfunctionsareprovedtosatisfytheinversionformulaobtaAnedbyHarish-Chandraforcompactsupportedinfinitelydifferentiablezonalfunctfons.Makinguseofthepropertyofthissequencesomehowsimilartothatofapproximationkernels,theauthorndeducethattheinversionformulaistrueforcontinuouszonalfunctiotmon8L(2,R)somecondition.Theclassicalresultcanbeviewedasacorollaryoftheresultshere.
简介:LetAbead×drealexpansivematrix.AnA-dilationParsevalframewaveletisafunctionψ∈L2(Rd),suchthattheset{|detA|n/2ψ(Ant-l):n∈Z,l∈Zd}formsaParsevalframeforL2(R~d).AmeasurablefunctionfiscalledanA-dilationParsevalframewaveletmultiplieriftheinverseFouriertransformoff■isanA-dilationParsevalframewaveletwheneverψisanA-dilationParsevalframewavelet,where■denotestheFouriertransformofψ.Inthispaper,theauthorscompletelycharacterizeallA-dilationParsevalframewaveletmultipliersforanyintegralexpansivematrixAwith|det(A)|=2.Asanapplication,thepath-connectivityofthesetofallA-dilationParsevalframewaveletswithaframeMRAinL2(Rd)isdiscussed.
简介:我们证明复杂c0上的每个2-homogeneous多项式有一个唯一的标准保存扩展到它的双性人双ℓ∞。
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)..