We use tetrahedral microwave networks consisting of coaxial cables and attenuators connected by T-joints to make an experimental study of Wigner's reaction K matrix for irregular graphs in the presence of absorption. From measurements of the scattering matrix S for each realization of the microwave network we obtain distributions of the imaginary and real parts of K. Our experimental results are in good agreement with theoretical predictions.
@article{arxiv.0903.2133,
title = {Experimental investigation of Wigner's reaction matrix for irregular graphs with absorption},
author = {Oleh Hul and Oleg Tymoshchuk and Szymon Bauch and Peter M. Koch and Leszek Sirko},
journal= {arXiv preprint arXiv:0903.2133},
year = {2009}
}