LetP(z)andP(z)bepolynomialsofthesamedegree.Weconsidertheequationsu''=P(z)uandu''=P(z)u(z∈C)whosesolutionsareu(z)andu(z),respectively.Letzk(u)andzk(u),k=1,2,···,bethezerosofu(z)andu(z),respectively.Wederiveboundsforthequantitysupinfjk[1/zk(u)-1/zj(u).
数学物理学报：B辑英文版
2012年3期
