数学物理学报 ›› 1999, Vol. 19 ›› Issue (3): 318-321.

• 论文 • 上一篇    下一篇

一个Jordan 块的平方根矩阵

  

  1. 华中师范大学数学系  |武汉 430079
  • 出版日期:1999-08-03 发布日期:1999-08-03

On Square-Rooting Matrices of A Jordan Block

  1. department of mathemativs,central china normal university,wuhan 430079
  • Online:1999-08-03 Published:1999-08-03

摘要:

 

 J=J\-m(λ)是一个特征值为λ的m阶Jordan块矩阵,则J能开平方的充要条件是m=1,或者m2时,λ≠0.且当m2,λ≠0 ,J的平方根矩阵恰有两个:±A,这里a1 = c , a2 = 1/2c , a3 = -1/8c3 , ,

 ak = -(a2ak-1+a3ak-2++ak-2a3+ak-1a2)/2a1 , (k=3,4,,m), c2 = λ.

 

关键词:  平方根矩阵, Jordan块, 特征值, 阶.

Abstract:

in this paper ,we give that a  jordan block Jm(λ)   has square -rooting matrices if and only if m=11 or λ≠0,Jm(λ)  has exactly two square-rooting matrices::±A,where a1 = c , a2 = 1/2c , a3 = -1/8c3 , ,

 ak = -(a2ak-1+a3ak-2++ak-2a3+ak-1a2)/2a1 , (k=3,4,,m), c2 = λ.

Key words:  Squarerootingmatrix, Jordanblock, Eigenvalue, Order.

中图分类号: 

  • 15A