In this paper we will obtain a Stone type theorem under the frame of Hilbert C*-module, such that the classical Stone theorem is our special case. Then we use it as a main tool to obtain a spectrum decomposition theorem of certain stationary quantum stochastic process. In the end, we will give it an interpretation in statistical mechanics of multi-linear response.
A∈B(H) is called Drazin invertible if A has finite ascent and descent. Let σD (A)={λ∈ C : A -λI is not Drazin invertible } be the Drazin .spectrum. This paper shows that if Mc =(A C 0 B)is a 2 × 2 upper triangular operator matrix acting on the Hilbert space H + K, then the passage from OσD(A) U σD(B) to σD(Mc) is accomplished by removing certain open subsets of σD(A)∩σD(B) from the former, that is, there is equality σD(A)∪σD(B)=σD(MC)∪Gwhere G is the union of certain holes in σD (Me) which happen to be subsets of σD (A)∩σD (B). Weyl's theorem and Browder's theorem are liable to fail for 2×2 operator matrices. By using Drazin spectrum, it also explores how Weyl's theorem, Browder's theorem, a-Weyl's theorem and a-Browder's theorem survive for 2×2 upper triangular operator matrices on the Hilbert space.
We give a simpler proof of a result on operator-valued Fourier multipliers on Lp([0, 2π]d; X) using an induction argument based on a known result when d= 1.
Using known Ca-multiplier result, we give necessary and sufficient conditions for the second order delay equations:u″(t)=Au(t)+Fut+Gu′+f(t),t∈Rto have maximal regularity in HSlder continuous function spaces C^α (R, X), where X is a Banach space, A is a closed operator in X, F, G ∈L(C([-r, 0], X), X) are delay operators for some fixed r 〉 0.
In this paper we obtain a Douglas type factor decomposition theorem about certain important bounded module maps. Thus, we come to the discussion of the topological continuity of bounded generalized inverse module maps. Let X be a topological space, x →Tx : X→L(E) be a continuous map, and each R(Tx) be a closed submodule in E, for every fixed x C X. Then the map x→ Tx^+: X→L(E) is continuous if and only if ||Tx^+|| is locally bounded, where Tx^+ is the bounded generalized inverse module map of Tx. Furthermore, this is equivalent to the following statement: For each x0 in X, there exists a neighborhood ∪0 at x0 and a positive number λ such that (0, λ^2)lohtatn in ∩x∈∪0C/σ(Tx^+Tx), where a(T) denotes the spectrum of operator T.