3 papers
gr-qc2026
A fresh look at boundary terms in Einstein-Hilbert gravity via an initial value variational principle
Songmin Ha, Alexander Rothkopf
A key tenet of general relativity is the dynamical nature of space-time, ideally represented as an initial value problem. Here we explore the variational formulation of classical E…
physics.optics2026
Topology-Enabled Switchable Unidirectional Radiative Band in a Bilayer Photonic Crystal
Zhiyi Yuan, Vytautas Valuckas, Yuhao Wang +6
Controlling how an open photonic system exchanges energy with its environment-and in particular how it radiates into the far field-is a cornerstone of non-Hermitian wave physics an…
physics.optics2025
Generalized Non-Hermitian Hamiltonian for Guided Resonances in Photonic Crystal Slabs
Viet Anh Nguyen, Hung Son Nguyen, Zhiyi Yuan +6
We develop a generalized non-Hermitian Hamiltonian formalism for guided resonances in photonic crystal slabs, derived directly from Maxwell's equations through a systematic guided-…