arXiv subjects

Yuefeng Di

Publications and source records attributed to Yuefeng Di.

7 recordsLinked to original sources

arXiv2025

Collapse of Axion Domain Wall Induced by Helical Primordial Magnetic Fields

Stable domain wall (DW) must decay to avoid overclose the Universe. A commonly used solution is to slightly break the PQ symmetry by introducing a bias term in the potential. In this work, we propose an alternative, symmetry-preserving mechanism: coupling the axion field to a helical primordial magnetic field (PMF) via the Chern-Simons term. Using three-dimensional lattice simulations, we evolve the DW network and demonstrate that it can successfully drive DW decay. Our quantitative results further show that the correlation length of the PMF plays a crucial role in determining the decay rate of the DW network and the resulting axion and gravitational wave radiation.

astro-ph.CO↗

arXiv2025

Impact of Primordial Magnetic Fields on the First-Order Electroweak Phase Transition

We numerically study how the primordial magnetic field affects the first-order electroweak phase transition in the early Universe. We observe that: 1) the phase transition process would be slowed down by the magnetic field; 2) the phenomenon of vortex structure of the Higgs condensation appears when the homogenesis hypermagentic field $g'B_Y^{ex}/m_W^2\gtrsim3.63$; and, 3) the helical hypermagnetic field can dramatically enhance the sphaleron rate and validate the generation of the baryon asymmetry through the chiral anomaly.

hep-ph↗

arXiv2025

Numerical simulations on First-order phase transition through thermal fluctuation

In this Letter, we numerically present the possibility of the first-order phase transition occurring through the thermal fluctuation in the early universe. We find that when the temperature is slightly higher than the mass scale of the background field, the bubble-like field configurations appear proceeded by oscillons, which expand and collide to finish the phase transition. We provide the false vacuum decay rate and the accompanied gravitational waves. We also present the vacuum phase transition comparison of the quantum tunneling case and thermal fluctuation case.

hep-ph↗

arXiv2024

Baryogenesis Induced by Magnetic Field Effects During the Electroweak Phase Transition

We numerically investigate the first-order electroweak phase transition in the background of a hypermagnetic field with three-dimensional lattice simulation. The generation of baryon asymmetry is observed, and we present the relationship between baryon number asymmetry and magnetic field strength and its helicity. We find the magnetic field strength required to achieve the correct matter-antimatter asymmetry is about $10^{-17}\sim10^{-14}$ Gauss at present, depending on the correlation length of the helical magnetic field. This study provides a mechanism for explaining the baryon number asymmetry with cosmic magnetic fields.

hep-ph↗

arXiv2022

Probing the electroweak symmetry breaking history with Gravitational waves

We perform a three dimensional lattice simulation of the electroweak symmetry breaking process through a two-step phase transition, where one of the two steps is a first order phase transition. Our results show that: 1) when the electroweak symmetry breaking is driven by the beyond Standard Model sector around $\sim \mathcal{O}(10^{2-3})$ GeV, the gravitational wave spectra produced from the phase transitions are of broken power-law double-peak shapes; 2) when the electroweak symmetry breaking is induced by a first-order phase transition of a high-scale global U(1) theory, cosmic strings can form and then disappear through particle radiation, and the yielded gravitational wave spectra are of plateau shapes. The two scenarios can be distinguished through probing gravitational wave spectra. Our study suggests that the stochastic gravitational waves provide an alternative way to probe the beyond Standard Model sector relevant to the electroweak symmetry breaking pattern in the early Universe.

hep-ph↗

arXiv2021

Probing the $B+L$ violation process with the observation of cosmic magnetic field

We investigate the $B+L$ violation process by performing three-dimensional lattice simulations in an electroweak theory with first-order phase transition and the electroweak sphaleron decay. The simulation results indicate that the Chern-Simons number changes along with the helical magnetic field production when the sphaleron decay occurs. Our study suggests that, for the electroweak phase transition with nucleation rate being smaller than $\sim \mathcal{O}(10)$, the helical magnetic field with the fractional magnetic helicity $ε_M\leq 0.2$ can be probed by Cherenkov Telescope Array through the intergalactic magnetic field measurements. Based on our numerical results, we suggest a method to probe the baryon asymmetry generation of the Universe, which is a general consequence of the electroweak sphaleron process, through the astronomical observation of the corresponding helical magnetic field.

hep-ph↗

arXiv2021

Magnetic field and gravitational waves from the first-order Phase Transition

We perform the three dimensional lattice simulation of the magnetic field and gravitational wave productions from bubble collisions during the first-order electroweak phase transition. Except that of the gravitational wave, the power-law spectrum of the magnetic field strength is numerically calculated for the first time, which is of a broken power-law spectrum: $B_ξ\propto f^{0.91}$ for low frequency region of $f f_\star$ in the thin-wall limit, with the peak frequency being $f_\star\sim 5$ Hz at the phase transition temperature 100 GeV. When the hydrodynamics is taken into account, the generated magnetic field strength can reach $B_ξ\sim 10^{-7}$G at a correlation length $ξ\sim 10^{-7}$pc, which may seed the large scale magnetic fields. Our study shows that the measurements of cosmic magnetic field strength and gravitational waves are complementary to probe new physics admitting electroweak phase transition.

astro-ph.CO↗