181 citations · 398 across the 14 of their papers we have counts for
14 papers
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…
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…
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…
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…
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…
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…
High-energy neutrino signals from supernova explosions: a new window into dark photon parameter space
Vsevolod Syvolap, Oleg Ruchayskiy
Dark photons, hypothetical feebly interacting massive vector bosons, appear in many extensions of the Standard Model. This study investigates their production and subsequent decay…
Testing heavy neutral leptons produced in the supernovae explosions with future neutrino detectors
Vsevolod Syvolap
Hypothetical particles called heavy neutral leptons (HNLs) can be produced in large quantities in the cores of supernovae during the first seconds of the explosion. These particles…
lepton number survival in the cosmic neutrino background
Oleg Ruchayskiy, Vsevolod Syvolap, Robin Wursch
The Hot Big Bang model predicts the existence of a \emph{cosmic neutrino background}. The number of particles and anti-particles in this primordial bath of neutrinos can be differe…
The Present and Future Status of Heavy Neutral Leptons
Asli M. Abdullahi, Pablo Barham Alzas, Brian Batell +42
The existence of non-zero neutrino masses points to the likely existence of multiple SM neutral fermions. When such states are heavy enough that they cannot be produced in oscillat…
When FIMPs Decay into Neutrinos: The Story
Alexey Boyarsky, Maksym Ovchynnikov, Nashwan Sabti +1
The existence of feebly interacting massive particles (FIMPs) could have significant implications on the effective number of relativistic species in the early Univ…
An allowed window for heavy neutral leptons below the kaon mass
Kyrylo Bondarenko, Alexey Boyarsky, Juraj Klaric +4
The extension of the Standard Model with two gauge-singlet Majorana fermions can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses and oscillations, a…
Improved BBN constraints on Heavy Neutral Leptons
Alexey Boyarsky, Maksym Ovchynnikov, Oleg Ruchayskiy +1
We constrain the lifetime of thermally produced Heavy Neutral Leptons (HNLs) from primordial nucleosynthesis. We show that even a small fraction of mesons present in the primordial…
Resonance production of keV sterile neutrinos in core-collapse supernovae and lepton number diffusion
Vsevolod Syvolap, Oleg Ruchayskiy, Alexey Boyarsky
We investigate how hypothetical particles - sterile neutrinos - can be produced in the interior of exploding supernovae via the resonant conversion of and . The…