The introduction to this forum lays out the background for theoretical issues concerning limits of narrative, and sets individual articles in context that larger debate.

We construct various limits of JT gravity, including Newton-Cartan and Carrollian versions dilaton gravity in two dimensions as well a theory on the three-dimensional light cone. In BF formulation our boundary conditions relate connection with scalar, yielding action particle group manifold or some Hamiltonian reduction thereof. After recovering Schwarzian for JT, we show that AdS-Carroll yield...

The Second Law of thermodynamics implies that no thermodynamic system with a single heat source at constant temperature can convert into mechanical work in recurrent manner. First, we note this is equivalent to cyclo-passivity the port system, while thermal kept constant. This leads question, which general systems two power ports have similar behavior: when cyclo-passive one its ports, output v...