In this paper we present the physics of the city, a new approach in order to investigate the urban dynamics. In particular we focus on the citizens’ mobility observation and modeling. Being in principle the social dynamics not directly observable, our main idea is that observing the human...

In this paper we propose a statistical physics approach to experimental results on bacterial mutations (Escherichia coli). We get scaling laws that describe some generic traits and suggest some features of the underlying dynamical structure for the considered evolution process. Our main...

In this paper we study noise-induced bimodality in a specific circuit with many biological implications, namely a single-step enzymatic cycle described by Michaelis–Menten equations. We study the biological feasibility of this phenomenon, which allows for switch-like behavior in response to...

We consider the problem of modeling urban mobility using the complex systems key of lecture. We discuss the properties of the Auto-mobilis model, a virtual simulator for private car mobility based on the individual citizen propensities and the existence of "chronotopoi", which are the primary...

In this preface we propose a synthetic survey of the main ideas which are in our aim at the origin of the "Physics and the City" Symposium (Bologna–Italy, 15–17 December 2005). These ideas are developed from different point of view in the following collected papers, also with different...

We consider the processes defined by a Langevin equation and the associated continuity equation. The average of the density function, solution of the continuity equation, satisfies the Fokker–Planck equation. For a volume preserving vector field the same equation is satisfied by the average of...

In this paper, we propose an urban mobility model based on individual stochastic dynamics driven by the chronotopic action with a deterministic public transportation network. Such a model is inspired by a new approach to the problem of urban mobility that focuses the attention to the individuals...

We consider the diffusion processes defined by stochastic differential equations when the noise is correlated. A functional method based on the Dyson expansion for the evolution operator, associated to the stochastic continuity equation, is proposed to obtain the Fokker–Planck equation, after...