3 papers
astro-ph.CO2026
Gravitational lensing time delay beyond the Shapiro/geometry split
Luca Teodori, Kfir Blum, Zhaoyu Bai
Time delays are a key observable in strong gravitational lensing systems. Their theoretical expression is usually written as a sum of a geometrical delay and a Shapiro delay, with…
hep-ph2026
Stellar Superradiance and Low-Energy Absorption in Dense Nuclear Media
Zhaoyu Bai, Vitor Cardoso, Yifan Chen +3
Ultralight bosons such as axions and dark photons are well-motivated hypothetical particles, whose couplings to ordinary matter can be effectively constrained by stellar cooling. L…
hep-ph2025
Probing Fundamental Constant Oscillation in the Galactic Center with S-Star Spectroscopy
Zhaoyu Bai, Vitor Cardoso, Yifan Chen +5
Astrophysical spectroscopy provides a powerful probe of spacetime variations of fundamental constants, as atomic and ionic emission and absorption lines depend sensitively on the f…