English

Functional calculus for $C_{0}$-groups using (co)type

Functional Analysis 2019-03-22 v2 Numerical Analysis

Abstract

We study the functional calculus properties of generators of C0C_{0}-groups under type and cotype assumptions on the underlying Banach space. In particular, we show the following. Let iA-iA generate a C0C_{0}-group on a Banach space XX with type p[1,2]p\in[1,2] and cotype q[2,)q\in[2,\infty). Then AA has a bounded H\mathcal{H}^{\infty}-calculus from DA(1p1q,1)\mathrm{D}_{A}(\tfrac{1}{p}-\tfrac{1}{q},1) to XX, i.e. f(A):DA(1p1q,1)Xf(A):\mathrm{D}_{A}(\tfrac{1}{p}-\tfrac{1}{q},1)\to X is bounded for each bounded holomorphic function ff on a sufficiently large strip. As a corollary of our main theorem, for sectorial operators we quantify the gap between bounded imaginary powers and a bounded H\mathcal{H}^{\infty}-calculus in terms of the type and cotype of the underlying Banach space. For cosine functions we obtain similar results as for C0C_{0}-groups. We extend our results to RR-bounded operator-valued calculi, and we give an application to the theory of rational approximation of C0C_{0}-groups.

Keywords

Cite

@article{arxiv.1508.02036,
  title  = {Functional calculus for $C_{0}$-groups using (co)type},
  author = {Jan Rozendaal},
  journal= {arXiv preprint arXiv:1508.02036},
  year   = {2019}
}

Comments

Minor modifications, 27 pages. Published online in Quarterly Journal of Mathematics

R2 v1 2026-06-22T10:29:27.142Z