# Developments, Problems, and Extensions of Electrodynamic

#### French‐German WE-Heraeus-Seminar

19 Aug - 23 Aug 2024

Where:

Physikzentrum Bad Honnef / Germany

Scientific organizers:

Prof. Dr. Claus Lämmerzahl, U Bremen • PD Dr. Volker Perlick, U Bremen • Prof. Alessandro Spallicci, U Orléans/F

Electromagnetic fields are the most important systems in physics. Without electro-magnetic fields no observations could be made and no instrument would work. This holds for the classical as well as the quantum sector of physics. Though electromagnetism is the most intensely studied and used system in physics, and though we have it well under control in all technical applications, including quantum optics and the new quantum technologies, there are still aspects of the physics of the electromagnetic field to be investigated, and there are also open problems in the understanding and consistent description of all electromagnetic phenomena, like problems in the radiation reaction of charged partciies and divergence in the self energy. Some of these problems could be solved by, e.g., non-linear or non-local extensions of the Maxwell equations. Furthermore, a theory of quantum gravity also is expected to modifiy fundamental laws as the Maxwell equations. Accordingly, it is very reasonable to discuss general extension of the Maxwell equations in a systematic way.

This is the topic of this French-German WE-Heraeus-seminar, which results from an existing cooperation between German and French scientists. With this seminar, we want to deepen and broaden this cooperation between German and French groups and will involve other colleagues, theorists as well as experimentalists, and from areas like quantum optics, relativistic astrophysics, and cosmology.*[The Figure shows a self-knotted electromagnetic field (Lechtenfeld 2023).]*

The conference language will be English. The Wilhelm and Else Heraeus-Foundation bears the cost of full-board accommodation for all participants.