English

Interpolation between domains of powers of operators in quaternionic Banach spaces

Functional Analysis 2024-02-19 v1

Abstract

In contrast to the classical complex spectral theory, where the spectrum is related to the invertibility of λA:D(A)XCXC\lambda-A:D(A)\subseteq X_\mathbb{C}\rightarrow X_\mathbb{C}, in the noncommutative quaternionic SS-spectral theory one uses the invertibility of the second order polynomial Qs(T):=T22Re(s)T+s2:D(T2)XXQ_s(T):=T^2-2\text{Re}(s)T+|s|^2:D(T^2)\subseteq X\rightarrow X to define the SS-spectrum, where XX is a quaternionic Banach space. In this paper we will consider quaternionic operators TT, for which at least one ray {teiω    t>0}\{te^{i\omega}\;|\;t>0\}, ω[0,π]\omega\in[0,\pi], iSi\in\mathbb{S} is contained in the SS-resolvent set, and the inverse operator Qs1(T)Q_s^{-1}(T) admits certain decay properties on this ray. Utilizing the KK-interpolation method, we then demonstrate that the domain D(Tk)D(T^k) of the kk-th power of TT is an intermediate space between D(Tn)D(T^n) and D(Tm)D(T^m), whenever n<k<mN0n<k<m\in\mathbb{N}_0. Moreover, also a characterization of the interpolation space (X,D(Tn))θ,p(X,D(T^n))_{\theta,p}, θ(0,1)\theta\in(0,1), p[1,]p\in[1,\infty], in is given in terms of integrability conditions on the pseudo SS-resolvent Qs1(T)Q_s^{-1}(T).

Keywords

Cite

@article{arxiv.2402.10383,
  title  = {Interpolation between domains of powers of operators in quaternionic Banach spaces},
  author = {Fabrizio Colombo and Peter Schlosser},
  journal= {arXiv preprint arXiv:2402.10383},
  year   = {2024}
}