  The development of scalable and wavenumber-robust iterative solvers for
Helmholtz problems is challenging but also relevant for various application
fields. In this work, two-level Schwarz domain decomposition preconditioners
are enhanced by coarse space constructed using higher-order B\'ezier
interpolation. The numerical results indicate numerical scalability and
robustness with respect the wavenumber, as long as the wavenumber times the
element size of the coarse mesh is sufficiently low.
