相关论文: Have pulsar timing array methods detected a cosmol…

Recently, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) claimed the detection of a stochastic common-spectrum process of the pulsar timing array (PTA) time residuals from their 12.5 year data, which might be…

In the light of the evidence of a gravitational wave background from the NANOGrav 15yr data set, we reconsider the split majoron model as a new physics extension of the standard model able to generate a needed contribution to solve the…

Understanding whether primordial black holes form during strong first-order phase transition (FOPT) is a crucial open question in cosmology. We address this using a fully covariant formalism to study cosmological perturbations, highlighting…

First order phase transitions (FOPTs) constitute an active area of contemporary research as a promising cosmological source of observable gravitational waves. The spacetime dynamics of the background scalar field undergoing the phase…

We study the gravitational wave (GW) signature in the doublet left-right symmetric model (DLRSM) resulting from the strong first-order phase transition (SFOPT) associated with $SU(2)_R\times U(1)_{B-L}$-breaking. For different values of the…

Within a recently proposed classically conformal model, in which the generation of neutrino masses is linked to spontaneous scale symmetry breaking, we investigate the associated phase transition and find it to be of strong first order with…

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…

Dark matter (DM), in spite of being stable or long-lived on cosmological scales, can decay in the early Universe due to finite-temperature effects. In particular, a first order phase transition (FOPT) in the early Universe can provide a…

Abbreviated: We investigate the potential of detecting the gravitational wave from individual binary black hole systems using pulsar timing arrays (PTAs) and calculate the accuracy for determining the GW properties. This is done in a…

The recent claim by the NANOGrav collaboration of a possible detection of an isotropic gravitational wave background stimulated a series of investigations searching for the origin of such a signal. The QCD phase transition appears as a…

The possible occurrence of a first-order hadron-quark phase transition (FOPT) in neutron-star interiors remains an open question. Whether such a transition can be directly tested with improved observations is a key challenge. Here, we…

The detection of a stochastic signal by recent pulsar timing array (PTA) collaborations, including NANOGrav, PPTA, EPTA+InPTA, CPTA and MPTA, has opened a new window to explore gravitational waves (GWs) at nanohertz frequencies. Motivated…

Pulsar Timing Arrays (PTAs) have reported evidence for a stochastic gravitational wave (GW) background at nHz frequencies, possibly originating in the early Universe. We show that the spectral shape of the low-frequency (causality) tail of…

Radiative symmetry breaking provides an appealing explanation for electroweak symmetry breaking and addresses the hierarchy problem. We present a comprehensive phenomenological study of this scenario, focusing on its key feature: the…

Several pulsar timing array (PTA) collaborations recently announced the first detection of a stochastic gravitational wave (GW) background, leaving open the question of its source. We explore the possibility that it originates from cosmic…

We revisit phase transitions in Twin Higgs (TH) models. We show that strong first-order phase transitions (FOPTs) can occur provided that appropriate source of $\mathbb{Z}_2$ symmetry breaking between the twin and Standard Model (SM)…

At the extreme densities in neutron stars, a phase transition to deconfined quark matter is anticipated. Yet masses, radii and tidal deformabilities offer only indirect measures of a first-order phase transition, requiring many detections…

We discuss possibilities to observe stochastic gravitational wave backgrounds produced by the electroweak phase transition in the early universe. Once the first-order phase transition occurs, which is still predicted in a lot of theories…

Pulsar Timing Array (PTA) observations hinted towards the existence of a stochastic gravitational wave background (SGWB) in the nHz frequency band. Still, the nature of the SGWB signal cannot be confidently inferred from current data, and…

Pulsar timing arrays (PTAs) have recently provided compelling evidence for a stochastic gravitational wave background (SGWB) in the nanohertz frequency band, offering a unique window into fundamental physics. Here, we explore implications…