P. Kivokurtseva | Searcharxiv

arXiv2026

Axion-neutrino interactions in seesaw models and astrophysical probes

We study axion-neutrino interactions in neutrino-mass extensions of the Standard Model, focusing on the Type-I and inverse seesaw. In these frameworks the effective coupling $g_{aν}$ is tied to the axion scale and can be constrained using existing astrophysical limits on axion couplings to electrons. We then estimate the impact of axion-mediated scattering on neutrino propagation in two benchmarks: resonant interactions with the C$ν$B and scattering on axion dark matter. In the parameter space allowed by current bounds, the resulting optical depths are extremely small, implying no observable signatures with present sensitivities.

hep-ph↗

arXiv2023

Neutrino production in blazar radio cores

Models of the origin of astrophysical neutrinos with energies from TeVs to PeVs are strongly constrained by multimessenger observations and population studies. Recent results point to statistically significant associations between these neutrinos and active galactic nuclei (AGN) selected by their radio flux observed with very-long-baseline interferometry (VLBI). This suggests that the neutrinos are produced in central parsecs of blazars, AGN with relativistic jets pointing to the observer. However, conventional AGN models tend to explain only the highest-energy part of the neutrino flux observationally associated with blazars. Here we discuss in detail how the neutrinos can be produced in the part of an AGN giving the dominant contribution to the VLBI radio flux, the radio core located close to the jet base. Physical conditions there differ both from the immediate environment of the central black hole and from the plasma blobs moving along the jet. Required neutrino fluxes, considerably smaller than those of photons, can be produced in interactions of relativistic protons, accelerated closer to the black hole, with radiation in the core.

astro-ph.HE↗