1. Branching exponential flights: travelled lengths and collision statistics.
- Author
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Zoia, Andrea, Dumonteil, Eric, Mazzolo, Alain, and Mohamed, Sameh
- Subjects
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BRANCHING processes , *COLLISIONS (Nuclear physics) , *BIOLOGICAL systems , *EPIDEMICS , *POPULATION dynamics , *NUCLEAR reactors , *FEYNMAN integrals , *PHASE space - Abstract
The evolution of several physical and biological systems, ranging from neutron transport in multiplying media to epidemics or population dynamics, can be described in terms of branching exponential flights, a stochastic process which couples a Galton-Watson birth-death mechanism with random spatial displacements. Within this context, one is often called to assess the length …V that the process travels in a given region V of the phase space, or the number of visits nV to this same region. In this paper, we address this issue by resorting to the Feynman-Kac formalism, which allows characterizing the full distribution of …V and nV and in particular deriving explicit moment formulas. Some other significant physical observables associated to … V and nV, such as the survival probability, are discussed as well, and results are illustrated by revisiting the classical example of the rod model in nuclear reactor physics. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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