Titol: Studies of cosmic black holes and dark matter in the radio regime

Lloc: Seminari del DAA. Edifici Investigació Jeroni Muñoz, planta quarta, a Burjassot.

Dia: dijous, 19 de febrer de 2026. Hora: 12:00.

Resum:

Radio astronomy and radio astronomical methods of detection are widely applied to studies of extreme states of matter including cosmic black holes and dark matter. Astrophysical observations and laboratory experiments carried out in the 10—1000 GHz frequency range (30—0.3 mm wavelengths) bring unique perspectives on physical conditions near the event horizon scale of cosmic black holes and provide a robust basis for direct searches for ultralight particles that may constitute the dark matter. Very long baseline interferometry (VLBI) observations of M87 and Sgr A* with the Event Horizon Telescope (EHT) at 230 GHz and Global Millimeter VLBI Array (GMVA) at 86 GHz constitute the best evidence for the existence of cosmic black holes, while our project M2FINDERS uses VLBI measurements of magnetic fields on scales up to ten thousand gravitational radii for discriminating between the canonical black holes and a range of alternative models involving compact horizonless objects such as wormholes and gravastars. A number of technological developments enabling the above state-of-the art VLBI studies are also being used for carrying out most sensitive laboratory searches for ultralight dark matter consisting of dark photons, axions, or axion-like particles (ALP). Together with the University of Hamburg, we have carried out such searches using a tunable microwave cavity (WISPDMX) at 0.01—500 MHz and engaged in the development of a novel broad band setup (BRASS) suitable for measurements in the entire 10 1000 GHz frequency range. Recent results from M2FINDERS, WISPDMX, and BRASS prototyping work will be presented and discussed in the context of our respective plans for future developments in these areas of study.