We study the phenomenon of internal avalanching within the context of recently proposed “Tetris” lattice models for granular media. We consider a packing of particles subjected to two different dynamics. In the first case, we arrest the system at different instances during an “aging”...

We introduce a microscopic model of double-auction markets based on random order placement. Traders post market or limit orders which are stored in the book of the exchange and executed via a central order matching mechanism. We use dimensional analysis, simulations and analytical approximations...