Higgs Potential 2025: Exploring Symmetry Breaking in Particle Physics and the Early Universe

Session

Special Session of Higgs Cosmology III

21 Dec 2025, 16:20

Conveners

Special Session of Higgs Cosmology III

• Ye-Ling Zhou (HIAS-UCAS)

20. Charge-breaking opportunities for the early Universe

Prof. Igor Ivanov (Sun Yat-sen University)

21/12/2025, 16:20

The hot early Universe must have evolved through phase transitions around the electroweak epoch. In multi-Higgs models, this evolution could be much more intricate than a single-step EWPT. In this talk, I will discuss a peculiar regime in the two-Higgs-doublet model, in which thermal evolution of the early Universe passes through an intermediate phase with a charge-breaking vacuum. Remarkably,...

31. Darkogenesis via Supercooled Phase Transition

Yuichiro Nakai

21/12/2025, 16:50

We discuss the intriguing possibility that the recently reported nano-Hz gravitational wave signal by Pulsar Timing Array (PTA) experiments is sourced by a strong first-order phase transition in a dark sector. The phase transition has to be strongly supercooled to explain the signal amplitude. However, such strong supercooling exponentially dilutes away any pre-existing baryon asymmetry and...

11. Cosmological phase transitions with low nucleation rates

Yun Jiang

21/12/2025, 17:20

Cosmological phase transitions played a crucial role in shaping the early universe. This talk explores non-standard first-order transitions with extremely low nucleation rates, highlighting two novel possibilities: transitions completing with super-Hubble bubble separation, and bubble-free transitions driven by collapsing domain-wall structures. These scenarios lead to distinctive cosmological...