From December 9-13, 2024, the gravitational-wave explorers of the Strong group at the Niels Bohr Institute attended a conference on Lensing and Wave optics in Strong gravity at the Erwin Schrödinger Institute in Vienna.

Gravitational lensing represents a characteristic feature of astrophysical systems in strong gravitational fields, such as the supermassive black holes recently observed by the Event Horizon Telescope, and with the rapidly increasing number of observed gravitational waves, it is expected that a small portion of these events will be gravitationally lensed.

The workshop hosted by the University of Vienna's Erwin Schrödinger International Institute covered a wide range of topics on lensing: the state of the art for the known techniques to approach the problem, how to apply our knowledge of the lensing of light waves to gravitational waves, and other future endeavors of the field. Being the very first conference on the specific topic of lensing, the workshop featured talks from mathematicians, cosmologists as well as theoretical and observational astrophysicists, who all joined in a collective effort to approach the problem of strong-field lensing of gravitational waves using different tools and techniques.

The researchers from the Strong group at NBI actively participated and contributed to the conference, highlighted by a talk on the first day by Assistant Professor José M. Ezquiaga (NBI) entitled ‘Gravitational Lensing: Current Searches and Future Prospects’ (please find the link to the talk here).

In addition to actively participating in relevant scientific discussions, the Strong researchers also watched the fantastic opera piece ‘Tosca’ at the Wiener Staatsoper, and visited the lovely Kunsthistorisches Museum (see picture).