RADIATION THEORY
The investigation of radiative transfer in random media is of great
interest in astrophysics. The interstellar molecular clouds, in fact, present
a non-homogeneous structure with randomly-distributed clumps, i. e.,
small and dense ``cloudlets''. A correct estimation of the UV radiation
field within the cloud is crucial in the modeling of chemical reactions
that take place in the cloud itself.
We develop a ``finite parameter'' probabilistic description of a clumpy
cloud and investigated the related model by means of semigroup techniques.
Efficient estimation formulas for the expected value of the radiation field
are found.
The work is performed in cooperation with researcher of GIFCO (Italian
Group for Cosmic Physics) of CNR.
- C. Cecchi-Pestellini, L. Barletti, A. Belleni-Morante
and S. Aiello, ``Radiative transfer in the stochastic interstellar
medium'', technical report, Dip. di Matematica ``U. Dini'' - Università
di Firenze, 28/1997. Submitted to Transport Theory and Statistical
Physics.
- L. Barletti, ``A Fourier-like method for the expectation problem
in stochastic transport theory'', Transport Theory and Statistical
Physics, 27, 289-302 (1998).
- L. Barletti, ``Un modello matematico per il trasporto di radiazione
in mezzi aleatori'', PhD thesis, Università di Firenze, 1998.
- C. Cecchi-Pestellini, L. Barletti, A. Belleni-Morante and
S. Aiello, ``Mathematical methods for photon transport in random
media'', preprint (1998). Submitted to Atti dell'Accademia Nazionale
dei Lincei.