Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Branching exponential flights: travelled lengths and collision
  statistics   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
$\ell_V$ that the process travels in a given region $V$ of the phase space, or
the number of visits $n_V$ 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 $\ell_V$ and $n_V$ and in particular deriving explicit
moment formulas. Some other significant physical observables associated to
$\ell_V $ and $n_V$, 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.

21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph