Confusing the extragalactic neutrino flux limit with a neutrino propagation limit

Understand

We study the possible suppression of the extragalactic neutrino flux due to a nonstandard interaction during its propagation.

• In particular, we study neutrino interaction with an ultra-light scalar field dark matter.
• It is shown that the extragalactic neutrino flux may be suppressed by such an interaction, leading to a new mechanism to reduce the ultra-high energy neutrino flux.
• We study both the cases of non-self-conjugate as well as self-conjugate dark matter.