Related papers: Gravitational waves from supercooled phase transit…
Pulsar timing arrays (PTA) are a promising probe to the cosmologically novel nanohertz gravitational wave (GW) regime through the stochastic GW background. In this work, we consider subluminal GW modes as a possible source of correlations…
An explicit realistic model featuring a supercooled phase transition, which allows us to explain the background of gravitational waves recently detected by pulsar timing arrays, is constructed. In this model the phase transition corresponds…
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…
Gravitational waves (GWs) at ultra-low frequencies (${\lesssim 100\,\mathrm{nHz}}$) are key to understanding the assembly and evolution of astrophysical black hole (BH) binaries with masses $\sim 10^{6}-10^{9}\,M_\odot$ at low redshifts.…
Gravitational waves from a first-order cosmological phase transition, at temperatures at the MeV-scale, would arguably be the most exciting explanation of the common red spectrum reported by the NANOGrav collaboration, not the least because…
Recently, the Hellings Downs correlation has been observed by different pulsar timing array (PTA) collaborations, such as NANOGrav, European PTA, Parkes PTA, and Chinese PTA. These PTA measurements of the most precise pulsars within the…
We present a comprehensive analysis of high-temperature vacuum decay and the resulting stochastic gravitational wave (GW) background within the framework of general scale-invariant models. The effective potential is constructed to include…
We consider a holographic study of coupling dependent gravitational waves produced by the cosmic first order QCD phase transition at finite baryochemical potential. In the dual description, the first-order QCD phase transition corresponds…
Recent evidence for the stochastic gravitational wave backgorund reported by the pulsar timing arrays (PTA) can be interpreted as a signal from the cosmological phase transition. We use up-to-date models of the gravitational wave power…
The NANOGrav collaboration has recently observed first evidence of a gravitational wave background (GWB) in pulsar timing data. Here we explore the possibility that this GWB is due to new physics, and show that the signal can be well fit…
In anticipation of upcoming gravitational wave experiments, we provide a comprehensive overview of the spectra predicted by phase transitions triggered by states from a large variety of dark sector models. Such spectra are functions of the…
Pulsar Timing Array (PTA) experiments have entered a new era with evidence for a nanoHertz gravitational wave background (GWB). This review describes the physics of detection, detailing the noise models and cross-correlation techniques…
Gravitational waves signatures from dynamical scalar field configurations provide a compelling observational window on the early universe. Here we identify intriguing connections between dark matter and scalars fields that emit…
In order to explain the large amplitude of the nano-Hertz stochastic gravitational wave background observed in pulsar timing arrays (PTA), primordial sources must be particularly energetic. This is correlated to the generation of large…
We discuss spectra of gravitational waves which are originated by the strongly first order phase transition at the electroweak symmetry breaking, which is required for a successful scenario of electroweak baryogenesis. Such spectra are…
A cosmological first-order phase transition is expected to produce a stochastic gravitational wave background. If the phase transition temperature is on the MeV scale, the power spectrum of the induced stochastic gravitational waves peaks…
We perform a Bayesian search in the latest Pulsar Timing Array (PTA) datasets for a stochastic gravitational wave (GW) background sourced by curvature perturbations at scales $10^5~\text{Mpc}^{-1}\lesssim k\lesssim 10^8~\text{Mpc}^{-1}$.…
We explore the potential of gravitational waves (GWs) to probe the pre-BBN era of the early universe, focusing on the effects of energy injection. Specifically, we examine a hidden sector alongside the Standard Model that undergoes a strong…
The nature of dark matter remains one of the greatest unsolved mysteries in elementary particle physics. It might well be that the dark matter particle belongs to a dark sector completely secluded or extremely weakly coupled to the visible…
We update predictions for the gravitational wave (GW) signal from a strongly supercooled phase transition in an illustrative classically conformal U(1)$_{B-L}$ model. We implement $\propto \gamma^2$ scaling of the friction on the bubble…