collaborators

6 papers

hep-ph2026

Heavy neutral leptons beyond the BBN bound: probing the lepton asymmetry of the Universe

Kensuke Akita, Maksym Ovchynnikov, Vsevolod Syvolap

Hadronically decaying particles with lifetimes are excluded by Big Bang Nucleosynthesis almost independently of their abundance: the mesons from their decay…

hep-ph2025

Leptogenesis and Dark Matter in an Inverse Seesaw from gauged B-L breaking

Enrique Fernández-Martínez, Ana Luisa Foguel, Xabier Marcano +3

We study a dynamical realization of the low-scale Inverse Seesaw mechanism in which the approximate symmetry is gauged and spontaneously broken. Anomaly cancellation requires…

hep-ph2025

Dynamics of metastable Standard Model particles from long-lived particle decays in the MeV primordial plasma

Kensuke Akita, Gideon Baur, Maksym Ovchynnikov +2

We investigate the cosmological impact of hypothetical unstable new physics particles that decay in the MeV-scale plasma of the Early Universe. Focusing on scenarios where the deca…

hep-ph2025

New physics decaying into metastable particles: impact on cosmic neutrinos

Kensuke Akita, Gideon Baur, Maksym Ovchynnikov +2

We investigate decays of hypothetical unstable new physics particles into metastable species such as muons, pions, or kaons in the Early Universe, when temperatures are in the MeV…

hep-ph2025

Primordial neutrinos and new physics: novel approach to solving neutrino Boltzmann equation

Maksym Ovchynnikov, Vsevolod Syvolap

Understanding how new physics influences the dynamics of cosmic neutrinos during their decoupling is crucial in light of upcoming precise cosmological observations and the need to…

astro-ph.CO2025

How new physics affects primordial neutrinos decoupling: Direct Simulation Monte Carlo approach

Maksym Ovchynnikov, Vsevolod Syvolap

Cosmological observations from Big Bang Nucleosynthesis and the Cosmic Microwave Background (CMB) offer crucial insights into the Early Universe, enabling us to trace its evolution…