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 Theory-Cosmology 2: Dark Cosmology (Room 302, Chair Sheng-Feng Yan)

20 Apr 2026, 13:30

29. How large are curvature perturbations from slow first-order phase transitions?

驰 田 (安徽大学)

20/04/2026, 13:30

When strongly supercooled cosmological first-order phase transitions (FOPTs) are sufficiently slow, super-horizon inhomogeneities can be generated. We compute these super-horizon curvature perturbations by employing a gauge-invariant, multi-fluid formalism. By resolving the gauge ambiguities inherent in conventional separate-universe simulations, we demonstrate that Primordial Black Holes are...

26. Exploring Inelastic Self-Interacting Dark Matter with Linear Cosmology

欣辰 段 (中国科学院紫金山天文台)

20/04/2026, 13:55

Inelastic self-interacting dark matter (iSIDM) provides a well-motivated extension of the cold dark matter paradigm, featuring multiple internal states connected by inelastic conversion processes. In this presentation, I will present a linear-cosmology framework for iSIDM, starting from a model-independent microphysical parameterization of the inelastic cross section and deriving the...

6. Strongly Coupled Dark Sectors from the Dark Matter–Baryon Coincidence

Yi Chung (IBS, CTPU-PTC)

20/04/2026, 14:10

There are many reasons to believe in the existence of a strongly coupled dark sector. One of them is the observed similarity between the energy densities of dark matter and baryons, known as the dark matter–baryon coincidence problem. In this talk, I will explain why this comparability points toward an asymmetric strongly coupled dark sector at the QCD scale. I will further discuss...

39. Equivalence Principle Violation from Dark Matter Coherent Scattering

Dr Chuan-Yang Xing (China University of Petroleum (East China))

20/04/2026, 14:25

We discuss how coherent scattering of dark matter with macroscopic targets can generate observable forces and lead to signals of equivalence principle violation. For dark matter masses around the eV scale, coherent enhancement in homogeneous or random materials opens new possibilities for torsion-balance experiments and related searches.