Wealth distribution on complex networks

We study the wealth distribution of the Bouchaud--M\'ezard (BM) model on complex networks. It has been known that this distribution depends on the topology of network by numerical simulations, however, no one have succeeded to explain it. Using "adiabatic" and "independent" assumptions along with the central-limit theorem, we derive equations that determine the probability distribution function. The results are compared to those of simulations for various networks. We find good agreement between our theory and the simulations, except the case of Watts--Strogatz networks with a low rewiring rate, due to the breakdown of independent assumption.