  If high-energy neutrinos propagate in a background of ultralight scalar field
particles of dark matter ($m_\varphi \sim 10^{-23}$eV), neutrino-dark matter
interactions can play a role and affect the neutrino flux. In this work we
analyse this effect using transport equations that account for the neutrino
regeneration as well as absorption, and we consider the neutrino flux
propagation in the extragalactic medium and also through the galactic halo of
dark matter. We show the results for the final flux to arrive on Earth for
different cases of point and diffuse neutrino fluxes. {We conclude that this
type of neutrino interactions with ultralight scalar particles as dark matter
can yield very different results in the neutrino flux and in the flavor ratios
that can be measured in neutrino detectors such as IceCube.
