In the tradition of the meetings in Blaubeuren (2003 and 2005), Regensburg (2010 and 2014) and Leipzig (2007 and 2018), the conference brings together mathematicians and physicists working in foundations of mathematical physics. This time, the topic will be more focused on mathematical and physical aspects of the Theory of Causal Fermion Systems.

In the past few years, the research has made progress in various directions, both from the mathematical side and concerning the physical applications. The goal of the conference is to present open problems in different physical domains and discuss proposals for addressing them from the perspective of causal fermion systems and other novel approaches. Introductory talks (in the style of a summer school) provide a common basis and set the stage for the later discussions. The core emphasis of the workshop is to foster discussions between different schools of thoughts and to make a connection between fundamental theories and phenomenology.

The topics covered by the conference include the following directions of research:

• Analysis of the causal action principle: Structure of minimizers, flow by minimizing movements, surface layer integrals describing quasi-local and total mass
• Non-smooth Lorentzian and quantum geometry: Singular limits of Lorentzian spacetimes, connection to Lorentzian length spaces and synthetic curvature
• Algebraic structures in causal fermion systems and the standard model: Division algebras, Clifford algebras, octonions
• Baryogenesis and related topics from cosmology
• Quantum field theory and beyond: The quantum state and its dynamics, corrections to standard quantum field theory
• Foundations of quantum theory: The measurement problem, reduction of the wave function, collapse phenomena
• Quantum information: Entanglement entropy, relative entropy, black hole entropy

Other topics can be suggested by the participants and will be taken up in the parallel discussions.