Homogenization of periodically perforate media Carlos ConcaD. GomezM. LoboM. Perez homogenizationBloch wavesspectral perturbation Indiana University Mathematics Journal 1999 text pdf 10.1512/iumj.1999.48.1780 10.1512/iumj.1999.48.1780 en Indiana Univ. Math. J. 48 (1999) 1447 - 1470 state-of-the-art mathematics http://iumj.org/access/