Seminarium "High Energy, Cosmology and Astro-particle Physics (HECA)"

Cosmology and particle physics are two distinct branches of physics, but they are interconnected in several ways, and cosmological observations can provide valuable insights into particle physics. With the ever-advancing precision of astronomical cosmological observations, the classical LCDM model faces challenges posed by precise data points, including the Hubble tension, S_8 tension, and nHz gravitational waves. Mirror twin Higgs model has been put forward to explain the Higgs hierarchy problem from only particle physics side. Our research indicates that this model not only offers a particle physics solution but also has the potential to alleviate tensions observed in cosmological observations. The introduction of additional dark radiation during the early universe may alleviate the Hubble tension. Twin recombination mechanisms can help explain the S_8 tension. Furthermore, the potential occurrence of a first-order dQCD phase transition could provide an explanation for the nHz gravitational waves detected by Pulsar Timing Arrays. These findings show that cosmology serves as an ideal laboratory for exploring the particle physics.

https://us02web.zoom.us/j/85478248551