New Method for Charges on Leaky Boundaries in Theoretical Physics

Researchers Robert McNees and Céline Zwikel have introduced a new method for defining charges associated with gauge symmetries on the boundaries of spacetimes in their paper titled "The symplectic potential for leaky boundaries". This work addresses the challenges posed by divergent quantities that arise when considering asymptotic boundaries in theoretical physics. The authors propose a framework that is particularly effective for leaky boundaries, which are spacetimes capable of exchanging matter or radiation with their surroundings.

The primary advantage of this new approach is its reliance solely on the bulk Lagrangian, making it independent of specific boundary conditions. This flexibility allows for a more generalized application across various scenarios in theoretical physics. The method has been applied to four-dimensional Einstein-Hilbert gravity in the partial Bondi gauge, resulting in a finite symplectic potential for unconstrained boundary data. Additionally, the authors have identified two new corner symplectic pairs that emerge from the relaxation of the gauge.

This research has significant implications for the understanding of gauge theories and their applications in gravitational physics. By providing a clearer framework for dealing with boundary conditions, it may facilitate advancements in the study of gravitational waves and other phenomena where boundary interactions play a crucial role.

The paper can be accessed through the arXiv repository at arXiv:2408.13203.