相关论文: A first order dark $SU(2)_D$ phase transition with…

We study a possibility of a strong first-order phase transition (FOPT) taking place below the electroweak scale in the context of $U(1)_D$ gauge extension of the standard model. As pointed out recently by the NANOGrav collaboration,…

The recent NANOGrav evidence of a common-source stochastic background provides a hint to Gravitational Waves (GW) radiation from the Early Universe. We show that this result can be interpreted as a GW spectrum produced from First Order…

According to recent lore, it is difficult to explain the evidence for a stochastic gravitational wave background obtained by pulsar timing arrays with supercooled first-order phase transitions (FOPTs). We demonstrate that supercooled FOPTs…

Recent pulsar timing data reported by the NANOGrav collaboration indicates the existence of a stochastic gravitational wave (GW) background at a frequency $f\sim 10^{-8}~\rm Hz$. We show that a dark sector consisting of a Standard Model…

Light dark matter (DM) with mass around the GeV scale faces weaker bounds from direct detection experiments. If DM couples strongly to a light mediator, it is possible to have observable direct detection rate. However, this also leads to a…

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…

We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5 year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures…

First-order phase transitions (FOPTs) are ubiquitous in physics beyond the Standard Model (SM). Recently, models with no dimensionful parameters in the tree-level action have been attracting much attention because they can predict a very…

We show that the recent detection of a gravitational wave (GW) background reported by various pulsar timing array (PTA) collaborations including NANOGrav-15yr, PPTA, EPTA, and CPTA can be explained in terms of first order phase transitions…

The evidence of a Stochastic Gravitational Wave Background (SGWB) in the nHz frequency range is posed to open a new window on the Universe. A preferred explanation relies on a supercooled first order phase transition at the 100 MeV - GeV…

The QCD axion is a well-motivated hypothetical particle beyond the Standard Model (SM) and a compelling dark matter candidate. Its relic abundance is highly sensitive to the thermal history of the universe when the temperature is around the…

We explore the possibility that a confining first-order phase transition of a nearly-conformal dark sector generates the reported NANOGrav signal of a stochastic gravitational wave background. The visible Standard Model (SM) sector and the…

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…

We consider a first order phase transition (FOPT) for a Vector Dark Matter (VDM) in the early universe in which its mass may partially arise from such mechanism in the hidden sector. We calculate the ratio of VDM that may enter the bubble…

First-order phase transitions (FOPT) are ubiquitous in beyond the Standard Model physics and leave distinctive echoes in the history of early universe. We consider a FOPT serving the well-motivated role of dark matter mass generation and…

We consider a non-Abelian dark SU(2)$_{\rm D}$ model where the dark sector couples to the Standard Model (SM) through a Higgs portal. We investigate two different scenarios of the dark sector scalars with $Z_2$ symmetry, with Higgs portal…

We discuss gravitational waves in an electroweakly interacting vector dark matter model. In the model, the electroweak gauge symmetry is extended to SU(2)$_0 \times$ SU(2)$_1 \times$SU(2)$_2 \times$ U(1)$_Y$ and spontaneously broken into…

We study a conformal version of the Standard Model (SM), which apart from SM sector, containing a $ U_{D}(1) $ dark sector with a vector dark matter candidate and a scalar field (scalon). In this model the dark sector couples to the SM…

We investigate the possibility of a strong first-order electroweak phase transition during the early universe within the framework of the gauged two-Higgs doublet model (G2HDM) and explore its detectability through stochastic gravitational…

A strong first-order phase transition in a dark sector may produce all or part of the low-frequency gravitational wave signal recently reported by the NANOGrav Collaboration and other pulsar timing arrays. Here we point out, with a simple…