As of Aug. 1st 2012, I moved to Tsukuba University. This page will be no longer updated. My new web site is here.
Current favorate: Quasiperiodic self-inducing (self-similar) structures. Here are some nice pictures:
First: Minimal Pisot number tiling, Second: sofic Pisot TilingYou find different ones in Japanese side. This research has close connection with ergodic theory, symbolic dynamics and Diophantine approximation.
HomePage on Analytic Number Theory (in Japanese)