wu :: forums
« wu :: forums - Re: eigenvalues property ? »

Welcome, Guest. Please Login or Register.
Nov 28th, 2024, 3:00am

RIDDLES SITE WRITE MATH! Home Home Help Help Search Search Members Members Login Login Register Register
   wu :: forums
   general
   wanted
(Moderators: towr, Eigenray, william wu, SMQ, Grimbal, Icarus, ThudnBlunder)
   Re: eigenvalues property ?
« Previous topic | Next topic »
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print
   Author  Topic: Re: eigenvalues property ?  (Read 2217 times)
MonicaMath
Newbie
*





   


Gender: female
Posts: 43
Re: eigenvalues property ?  
« on: Mar 28th, 2009, 8:29pm »
Quote Quote Modify Modify

maybe you can start with:
 
since r is not an eigenvalue for A then det(r*I - A) not zero, so (A-r*I) is nonsingular, and use the fact that Bx=r*x, then show that  
|| inv(r*I - A) (B-A) ||<1  to obtain a contradiction.
IP Logged
trusure
Newbie
*





   


Gender: female
Posts: 24
Re: eigenvalues property ?  
« Reply #1 on: Mar 28th, 2009, 9:33pm »
Quote Quote Modify Modify

I tried your method but there is no result ?!
 
can anyone give me a hint ! Roll Eyes
IP Logged
Eigenray
wu::riddles Moderator
Uberpuzzler
*****






   


Gender: male
Posts: 1948
Re: eigenvalues property ?  
« Reply #2 on: Mar 29th, 2009, 5:31pm »
Quote Quote Modify Modify

Well that's a funny problem.  Note that  
 
(r I - A)-1(B-A)
 = (r I - A)-1( (r I - A) + (B - r I) )
 = I + C,
where C = (r I - A)-1(B - r I) is a singular matrix.  Do you know the following result: if || I + C || < 1, then C is non-singular?
IP Logged
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print

« Previous topic | Next topic »

Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board