Polytropic models of filamentary molecular clouds & Sub-structure formation in starless cores

Recent observations made by the Herschel Space Observatory and the
Planck Satellite have shown that molecular clouds are made by networks
of filaments, shaped by interstellar turbulence and magnetic fields. We
analyse the stability of filamentary molecular clouds with the help of
cylindrical polytropic models with and without helical magnetic fields.
We then focus on the growth of hydrodynamical density perturbations and
the formation of sub-structures and fragments in pre-stellar cores.