This proposes a natural [[renormalization]] for the extended and usual sandpile groups, meaning a mapping of recurrent configurations on a given grid to recurrent configurations on a sub-grid.<font color="#ff8000"> Informaly, this renormalization simply maps configurations appearing at a given time <math>t</math> in the sandpile dynamics induced by some harmonic function <math>H</math> on the larger grid to the corresponding configurations which appear at the same time in the sandpile dynamics induced by the restriction of <math>H</math> to the respective sub-grid.<ref name="Lang2019" /></font> | This proposes a natural [[renormalization]] for the extended and usual sandpile groups, meaning a mapping of recurrent configurations on a given grid to recurrent configurations on a sub-grid.<font color="#ff8000"> Informaly, this renormalization simply maps configurations appearing at a given time <math>t</math> in the sandpile dynamics induced by some harmonic function <math>H</math> on the larger grid to the corresponding configurations which appear at the same time in the sandpile dynamics induced by the restriction of <math>H</math> to the respective sub-grid.<ref name="Lang2019" /></font> |