Swampland bounds on dark sectors

A bstract We use Swampland principles to theoretically disfavor regions of the parameter space dark matter and other darkly charged particles that may exist. The Festina Lente bound, analogue Weak-Gravity conjecture in de Sitter, places constraints on mass charge particles, which here we show cover are currently allowed by observations. As a consequence, broad set new ultra-light Swampland, independently their cosmic abundance, showing complementarity Quantum Gravity limits with laboratory astrophysical studies. In parallel, bound UV cutoff associated axion giving Stückelberg photon its longitudinal mode translates constraint kinetic mixings masses photons. This covers part targeted upcoming dark-photon direct-detection experiments. Moreover, it puts astrophysically interesting models including freeze-in through an photon, as well radio invoked explain 21-cm EDGES anomaly.