线性常微分方程组解的特征数的估计

Estimate of Characteristic Numbers of Linear Ordinary Differential Equations System

复数域上线性系统ｘ＝Ａ（ｔ）ｘ，当Ａ（ｔ）＝（ａｉｊ（ｔ））ｎ×ｎ具有（ｎ，Ｎ，ｒ）差异性质且ｒｎ时，解的特征数ｊ有估计λｊ－ｌｉｍｔ→∞１ｔ∫ｔｔ０Ｒｅａｊ（τ）ｄτｎ－１ｒ＋１－ｎｌｉｍｔ→∞１ｔ∫ｔｔ０Ａ（τ）ｄτ，ｊ＝１，２，…，ｎ，其中Ａ（ｔ）＝ｍａｘ｛｜ａｉｊ（ｔ）｜：ｉ，ｊ＝１，２，…，ｎ，ｉ≠ｊ．｝

Let λ1,λ2,…,λn be characteristic numbers of linear differential equation system in complex field =A(t)x, t∈(0,∞), and A(t) =(aij(t))n×n has (n,N,r)diversity, rn, then  λj -limt→∞ 1t∫tt0Reajj (τ)dτn-1r+1-nlimt→∞ 1t∫tt0A*(τ)dτ, where j=1,2,…,n, A* (t)=max{|aij (t)|: i,j=1,2,…,n, i≠j}, t00.