The 4th Topics of Particle, Astro and Cosmo Frontiers (TOPAC 2026) 第4届粒子物理、天体物理和宇宙学前沿国际学术研讨会

Session

Parallel Cosmology: Early Universe (Room 302, Chair Yong Tang)

17 Apr 2026, 17:40

16. Chiral gravitational wave background from axion-like fields

Yun-Long Zhang (NAOC)

17/04/2026, 17:40

Axions and axion-like particles can be probed through gravitational waves indirectly, often referred to as “audible axions”. The usual concept of audible axion relies on the coupling between the axions and the gauge fields. Here we consider an axion-like mechanism with coupling to the Nieh–Yan term. This interaction leads to the direct and efficient production of gravitational waves during the...

83. Impact of Cosmological Phase Transitions on FIMP Dark Matter

阳 张 (河南师范大学)

17/04/2026, 18:05

For feebly interacting massive dark matter particle (FIMP) dark matter, variations in particle mass during cosmological phase transitions can affect the dark matter production mechanism. Meanwhile, reheating, entropy injection, and phase coexistence during phase transitions, especially supercooled phase transitions, also influence the evolution of dark matter abundance to varying degrees. This...

11. Gravitational Wave Signature of Aspherical Bubbles Driven by Thermal Fluctuation

Mr Yang Xiao (Henan Normal University)

17/04/2026, 18:30

Cosmological first-order phase transitions are a well-motivated source of stochastic gravitational waves (GWs), but most predictions are made based on the highly idealized model of perfectly spherical vacuum bubbles, neglecting thermal fluctuations. In this work we use $(3+1)$-dimensional lattice simulations of a scalar model with thermal initial conditions to quantify how thermal fluctuations...