2025/07/08 by Jonathan Gratus, Gratus, Jonathan, S. A. R. Horsley +3
Materials Science · Physics and Astronomy · #Classical Physics (physics.class-ph) #FOS: Physical sciences #Metamaterials and Metasurfaces Applications #Optics (physics.optics) #Quantum and Classical Electrodynamics #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2507.05889
openalex publication_date 2025/07/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We give a general family of electromagnetic boundary conditions applicable to arbitrary space--time interfaces between electromagnetic media, which include the known space--only and time--only boundary conditions as special cases. These boundary conditions describe a broad class of electromagnetic interfaces, including surfaces in arbitrary motion, ultra-thin (metasurface) media, and cases where the media on one or both sides of the boundary can be both spatially and temporally dispersive. Our approach utilizes 4-dimensional spacetime and addresses the question of how, and in what ways, an electromagnetic field may be connected across a 3-dimensional hypersurface. We show that our proposed boundary conditions are the most general conditions consistent with causality and linearity.