Related papers: A first order dark $SU(2)_D$ phase transition with…
We study the dilution of dark matter (DM) relic density caused by the electroweak first-order phase transition (FOPT) in the singlet extension models, including the singlet extension of the standard model (xSM), of the two-Higgs-doublet…
Several pulsar timing array collaborations recently reported evidence of a stochastic gravitational wave background (SGWB) at nHz frequencies. Whilst the SGWB could originate from the merger of supermassive black holes, it could be a…
In the minimal supersymmetric standard model (MSSM) extended by a singlet superfield, when the coupling between the singlet sector and the MSSM sector is tiny, the singlet sector can be a quasi dark sector with supersymmetry (SUSY). We…
We consider extensions of the Standard Model by a hidden sector consisting of a gauge field coupled with a scalar field. Assuming the absence of dimensionful parameters in the tree level potential, radiative symmetry breaking will make the…
We consider an extension of the Standard Model that explains the neutrino masses and has a rich dark matter phenomenology. The model has two dark matter candidates, a vector WIMP and a fermion FIMP, and the sum of their relic densities…
The detection of a stochastic background of gravitational waves can reveal details about first-order phase transitions (FOPTs) at a time of $10^{-13}s$ of the early universe. We specifically discuss quiver-type GUTs which avoid both proton…
We present an updated analysis of the first-order phase transition associated with symmetry breaking in the early Universe in a classically scale-invariant model extended with a new SU(2) gauge group. Including recent developments in…
In the framework of type-II two-Higgs-doublet model with a singlet scalar dark matter $S$, we study the dark matter observables, the electroweak phase transition, and the gravitational wave signals by such strongly first order phase…
In this work, we show that a large class of models with a composite dark sector undergo a strong first order phase transition in the early universe, which could lead to a detectable gravitational wave signal. We summarise the basic…
We investigate the non-zero temperature dynamics of a sub-GeV dark matter scenario freezing-out via self-interactions. As a prototype, we take up the case of a scalar dark matter species undergoing $3 \to 2$ number changing annihilations…
We study in this work a scenario that the universe undergoes a two step phase transition with the first step happened to the dark matter sector and the second step being the transition between the dark matter and the electroweak vacuums,…
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…
We consider an extension of the Standard Model with a complex singlet scalar, where a global $U(1)$ symmetry is explicitly broken to $\mathbb{Z}_3$ symmetry. We study the two-step electroweak phase transition in the model and find that it…
The 15-year pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) shows positive evidence for the presence of a low-frequency gravitational-wave (GW) background. In this paper, we…
We study the prospect of simultaneous explanation of tiny neutrino masses, dark matter (DM), and the observed baryon asymmetry of the Universe in a $Z_3$-symmetric complex singlet scalar extended type-II seesaw model. The complex singlet…
Theories with more than one scalar field often exhibit phase transitions producing potentially detectable gravitational wave (GW) signal. In this work we study the semi-annihilating $\mathbb{Z}_3$ dark matter model, whose dark sector…
Recent pulsar timing data reported by the NANOGrav collaboration may indicate the existence of a stochastic gravitational wave background around $f \sim 10^{-8}$ Hz. We explore a possibility to generate such low-frequency gravitational…
Our analysis shows that SM-like electroweak phase transition (EWPT) in the $SU(2)_1 \otimes SU(2)_2 \otimes U(1)_Y$ (2-2-1) model is a first-order phase transition at the $200$ GeV scale (the SM scale). Its strength ($S$) is about $1 - 2.7$…
We consider models with the $U(1)_X$ gauge symmetry, which is spontaneously broken by dark Higgs mechanism. We discuss patterns of the electroweak phase transition and detectability of gravitational waves (GWs) when strongly first order…
We have conducted a revised analysis of the first-order phase transition that is associated with symmetry breaking in a classically scale-invariant model that has been extended with a new $SU(2)$ gauge group. By incorporating recent…