arXiv subjects

Jonas Matuszak

Publications and source records attributed to Jonas Matuszak.

5 recordsLinked to original sources

arXiv2026

TransitionListener v2.0 -- Robust gravitational wave predictions for cosmological phase transitions

Gravitational wave backgrounds from strong first-order cosmological phase transitions are key observational targets predicted by many SM extensions and might be observed by current and future observatories like LISA, the Einstein Telescope or pulsar timing arrays (PTAs). Still, their precise forecast given a specific model remains a challenge. In this article, we present TransitionListener v2.0, a Python framework for precision studies of cosmological phase transitions and their associated gravitational wave (GW) signals. The code provides an end-to-end pipeline from a user-defined scalar potential to GW spectra and signal-to-noise ratios, enabling both benchmark studies and large-scale parameter scans. Version 2 introduces a self-consistent treatment of the transition dynamics, including the evolution of the true-vacuum fraction and its backreaction on the Hubble expansion, as well as a consistent description of reheating during percolation. A direct computation of the mean bubble separation allows to faithfully map to the GW spectral templates from bubble collisions, sound waves, and turbulence stemming from state-of-the-art simulations. TransitionListener includes built-in sensitivity curves for space- and ground-based detectors and PTAs, interfaces to PTA likelihoods, and wrappers for Bayesian model inference and high-dimensional parameter scans. Compared to existing public tools, TransitionListener v2.0 improves the physical consistency and numerical stability of GW predictions across a wide range of models, with particular emphasis on the strongly supercooled and ultraslow transition regime where conventional approximations break down and the most promising GW signals are expected.

hep-ph↗

arXiv2026

Tuning the violins: dark sector phase transition models for the PTA signal

First-order phase transitions in a dark sector have been invoked as an intriguing possibility to explain the observed stochastic gravitational wave background at nanohertz frequencies. Here we perform a comprehensive study of the generic requirements for such a phase transition to explain the observed signal while being consistent with all relevant constraints. We consider three broad model classes for strong first-order transitions, realised by an Abelian dark Higgs boson, a two-step phase transition involving two scalar singlets, and a conformal scalar field with loop-induced symmetry breaking, respectively. We discuss the tuning that is required to successfully explain the Pulsar Timing Array (PTA) signal in each of these cases, and highlight the underlying physical mechanisms. We conclude that all three scenarios can in principle describe the data, but that conformal models stand out as the most generic, and least tuned, explanation. Future observations by the PTA collaborations and collider experiments will be crucial to test the viability of this hypothesis, and to further narrow in on the model parameters, if the PTA signal is indeed due to a strong first-order phase transition.

hep-ph↗

arXiv2025

Sub-GeV dark matter and nano-Hertz gravitational waves from a classically conformal dark sector

Strong first-order phase transitions in a dark sector offer a compelling explanation for the stochastic gravitational wave background in the nano-Hertz range recently detected by pulsar timing arrays (PTAs). We explore the possibility that such a phase transition at the same time gives mass to a stable fermion that accounts for the observed dark matter abundance and leads to testable effects in laboratory experiments. Concretely, we consider a classically conformal dark sector with a hidden $U(1)^\prime$ gauge symmetry that couples to the Standard Model via kinetic mixing. Since the PTA signal requires a phase transition in the MeV temperature range, spontaneous symmetry breaking gives rise to a sub-GeV dark matter candidate that couples to the Standard Model via a dark photon mediator and obtains its relic abundance via annihilations into electrons and dark Higgs bosons. Such a scenario is tightly constrained by laboratory searches for dark photons and cosmological constraints on the decays of dark Higgs bosons after the phase transition. We show that viable parameter regions can be found both for the case that the dark Higgs bosons remain in equilibrium with the Standard Model and that they decouple and only decay much later. In the latter case, the parameter regions preferred by the PTA signal and the dark matter relic abundance can be fully explored by future beam-dump experiments searching for missing energy.

hep-ph↗

arXiv2024

Hunting WIMPs with LISA: Correlating dark matter and gravitational wave signals

The thermal freeze-out mechanism in its classical form is tightly connected to physics beyond the Standard Model around the electroweak scale, which has been the target of enormous experimental efforts. In this work we study a dark matter model in which freeze-out is triggered by a strong first-order phase transition in a dark sector, and show that this phase transition must also happen close to the electroweak scale, i.e. in the temperature range relevant for gravitational wave searches with the LISA mission. Specifically, we consider the spontaneous breaking of a $U(1)^\prime$ gauge symmetry through the vacuum expectation value of a scalar field, which generates the mass of a fermionic dark matter candidate that subsequently annihilates into dark Higgs and gauge bosons. In this set-up the peak frequency of the gravitational wave background is tightly correlated with the dark matter relic abundance, and imposing the observed value for the latter implies that the former must lie in the milli-Hertz range. A peculiar feature of our set-up is that the dark sector is not necessarily in thermal equilibrium with the Standard Model during the phase transition, and hence the temperatures of the two sectors evolve independently. Nevertheless, the requirement that the universe does not enter an extended period of matter domination after the phase transition, which would strongly dilute any gravitational wave signal, places a lower bound on the portal coupling that governs the entropy transfer between the two sectors. As a result, the predictions for the peak frequency of gravitational waves in the LISA band are robust, while the amplitude can change depending on the initial dark sector temperature.

astro-ph.CO↗

arXiv2022

Shape optimizations for body-assisted light-matter interactions

We implement a shape optimization algorithm for body-assisted light-matter interactions described by the formalism of macroscopic quantum electrodynamics. The approach uses the level-set method to represent and incrementally evolve dielectric environments. Utilizing finite-difference time-domain techniques we demonstrate the ability of the algorithm by optimizing the rate of resonance energy transfer in two dimensions. The resulting geometries enhance the transfer rate by several orders of magnitude.

quant-ph↗