arXiv subjects

Dominik Hellmann

Publications and source records attributed to Dominik Hellmann.

5 recordsLinked to original sources

arXiv2024

Potential of Neutrino Telescopes to Detect Quantum Gravity-Induced Decoherence in the Presence of Dark Fermions

We assess the potential of neutrino telescopes to discover quantum-gravity-induced decoherence effects modeled in the open-quantum system framework and with arbitrary numbers of active and dark fermion generations, such as particle dark matter or sterile neutrinos. The expected damping of neutrino flavor oscillation probabilities as a function of energy and propagation length thus encodes information about quantum gravity effects and the fermion generation multiplicity in the dark sector. We employ a public Monte-Carlo dataset provided by the IceCube Collaboration to model the detector response and estimate the sensitivity of IceCube to oscillation effects in atmospheric neutrinos induced by the presented model. Our findings confirm the potential of very-large-volume neutrino telescopes to test this class of models and indicate higher sensitivities for increasing numbers of dark fermions.

hep-ph↗

arXiv2024

Neutrino Oscillations as a Gravitational Wave Detector?

Gravitational waves (GWs) can alter the neutrino propagation distance and thus affect neutrino oscillations. This can result in a complete disappearance of the oscillatory behavior that competes with other sources of neutrino decoherence. We develop a set of criteria that determines under which conditions neutrino oscillations are sensitive to this effect. We find that current or near future neutrino oscillation experiments are not sufficiently sensitive to coherent GW signals but may probe the stochastic gravitational wave background if the energy resolution improves drastically by several orders of magnitude.

hep-ph↗

arXiv2023

Light Sterile Neutrinos in the Early Universe: Effects of Altered Dispersion Relations and a coupling to Axion-Like Dark Matter

We investigate the cosmological consequences of light sterile neutrinos with altered dispersion relations (ADRs) and couplings to an ultra-light, axion-like scalar field. In particular we study the impact on the number of additional, light, fermionic degrees of freedom and primordial nucleosynthesis. While the ADR leads to a new potential term in the Hamiltonian, the coupling to the scalar field results in a time dependent, effective mass contribution. We solve the quantum kinetic equations (QKEs) for the neutrino density matrix and find that in certain parameter regions both new physics effects can individually yield a suppressed population of sterile neutrino species and the correct observed amount of helium in nucleosynthesis. Combining both effects opens up new patches of parameter space excluded by experimental bounds applying to models featuring only one of the effects.

hep-ph↗

arXiv2022

Quantum Gravitational Decoherence in the 3 Neutrino Flavor Scheme

In many theories of quantum gravity quantum fluctuations of spacetime may serve as an environment for decoherence. Here we study quantum-gravitational decoherence of high energy astrophysical neutrinos in the presence of fermionic dark sectors and for a realistic three neutrino scenario. We show how violation of global symmetries expected to arise in quantum gravitational interactions provides a possibility to pin down the number of dark matter fermions in the universe. Furthermore, we predict the expected total neutrino flux and flavor ratios at experiments depending on the flavor composition at the source.

hep-ph↗

arXiv2021

Searching New Particles at Neutrino Telescopes with Quantum-Gravitational Decoherence

We discuss the interplay of wave packet decoherence and decoherence induced by quantum gravity via interactions with spacetime foam for high energy astrophysical neutrinos. In this context we point out a compelling consequence of the expectation that quantum gravity should break global symmetries, namely that quantum-gravity induced decoherence may not only be the most sensitive probe for quantum properties of spacetime, but also can provide both a powerful tool for the search for new particles, including totally decoupled backgrounds interacting only gravitationally, and at the same time a window into the intricacies of black hole information processing.

hep-ph↗