Dark sector at BESIII

Dark matter (DM) plays a crucial role in explaining the observed astrophysical anomalies, galaxy rotation curves, and other fundamental characteristics of the Universe. Many extensions of the Standard Model (SM), such as the dark hidden-sector model, provide an attractive framework in which DM can couple to SM particles via various portals. These portals give rise to several possible new particles beyond the SM, such as light Higgs bosons, dark photons, and axion-like particles. Furthermore, the origin of DM and the observed asymmetry between visible matter and antimatter may be connected through the introduction of a dark baryon. If the masses of these hypothetical particles lie in the few-GeV range, they can be explored at high-intensity $e^+e^-$ collider experiments, such as the BESIII experiment. This report presents a review of recent BESIII results related to searches for dark-sector particles.