  Scattering of electromagnetic waves in billiard-like systems has become a
standard experimental tool of studying properties associated with Quantum
Chaos. Random Matrix Theory (RMT) describing statistics of eigenfrequencies and
associated eigenfunctions remains one of the pillars of theoretical
understanding of quantum chaotic systems. In a scattering system coupling to
continuum via antennae converts real eigenfrequencies into poles of the
scattering matrix in the complex frequency plane and the associated
eigenfunctions into decaying resonance states. Understanding statistics of
these poles, as well as associated non-orthogonal resonance eigenfunctions
within RMT approach is still possible, though much more challenging task.
