On the numerical range of sectorial forms
- ter Elst, A.F. M.
- Linke, Alexander
- Rehberg, Joachim
2010 Mathematics Subject Classification
- 47A12 47B44 47A60
- Numerical range, sectorial form, H∞-angle
We provide a sharp and optimal generic bound for the angle of the sectorial form associated to a non-symmetric second-order elliptic differential operator with various boundary conditions. Consequently this gives an, in general, sharper H∞-angle for the H∞-calculus on Lp for all p ∈ (1, ∞) if the coefficients are real valued.