Radio signals from galactic and extragalactic dark matter

Among the indirect-detection signals of dark-matter particles present in our Galaxy and in the extragalactic environment, radio signals have recently gained interest since it has been shown that current and proposed radio detectors could have the capabilities to identify a signal over the astrophysical radio background, at the same level if not better than the other techniques based on higher-energy multiwavelength emission or low-energy cosmic rays. In this report we summarize the field of dark matter searches in the radio band, by discussing both the galactic signal and the cosmological emission. A recently reported extragalactic excess in the radio sky, commonly referred to as the "ARCADE excess", will be discussed and shown to be compatible with a dark matter emisison.