The Kreiss Matrix Theorem on a General Complex Domain

نویسندگان

  • Kim-Chuan Toh
  • Lloyd N. Trefethen
چکیده

Let A be a bounded linear operator in a Hilbert space H with spectrum Λ(A). The Kreiss matrix theorem gives bounds based on the resolvent norm ‖(zI−A)−1‖ for ‖An‖ if Λ(A) is in the unit disk or for ‖etA‖ if Λ(A) is in the left half-plane. We generalize these results to a complex domain Ω, giving bounds for ‖Fn(A)‖ if Λ(A) ⊂ Ω, where Fn denotes the nth Faber polynomial associated with Ω. One of our bounds takes the form K̃(Ω) ≤ 2 sup n ‖Fn(A)‖, ‖Fn(A)‖ ≤ 2 e (n+ 1) K̃(Ω), where K̃(Ω) is the “Kreiss constant” defined by K̃(Ω) = inf { C : ‖(zI −A)−1‖ ≤ C/dist(z,Ω) ∀ z 6∈ Ω } . By means of an inequality due originally to Bernstein, the second inequality can be extended to general polynomials pn. In the case where H is finite-dimensional, say, dim(H) = N , analogous results are also established in which ‖Fn(A)‖ is bounded in terms of N instead of n when the boundary of Ω is twice continuously differentiable.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

On the Resolvent Condition I in the Kreiss

Abstrac t . The Kreiss Matrix Theorem asserts the uniform equivalence over all N x N matrices of power boundedness and a certain resolvent estimate. We show that the ratio of the constants in these two conditions grows linearly with N, and we obtain the optimal proportionality factor up to a factor of 2. Analogous results are also given for the related problem involving matrix exponentials e At...

متن کامل

MATRIX VALUATION PSEUDO RING (MVPR) AND AN EXTENSION THEOREM OF MATRIX VALUATION

Let R be a ring and V be a matrix valuation on R. It is shown that, there exists a correspondence between matrix valuations on R and some special subsets ?(MVPR) of the set of all square matrices over R, analogous to the correspondence between invariant valuation rings and abelian valuation functions on a division ring. Furthermore, based on Malcolmson’s localization, an alternative proof for t...

متن کامل

The Equivalence of L,StabiIity, the Resolvent Condition, and Strict H-Stability

The Kreiss matrix theorem asserts that a family of N X N matrices is L,-stable if and only if either a resolvent condition (R) or a Hennitian norm condition (H) is satisfied. We give a direct, considerahly shorter proof of the power-houndedness of an N X N matrix satisfying (R), sharpening former results by showing that powerhoundedness depends, at most, linearly on the dimension M. We also sho...

متن کامل

On the solving of matrix equation of Sylvester type

A solution of two problems related to the matrix equation of Sylvester type is given. In the first problem, the procedures for linear matrix inequalities are used to construct the solution of this equation. In the second problem, when a matrix is given which is not a solution of this equation, it is required to find such solution of the original equation, which most accurately approximates the ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • SIAM J. Matrix Analysis Applications

دوره 21  شماره 

صفحات  -

تاریخ انتشار 1999