Faster Than Light?

TL;DR

The paper questions the view that the speed of light imposes a universal signal-speed limit and that special relativity must forbid superluminal signaling. It develops a unified framework based on first-order, quasilinear PDEs with hyperbolizations to define causal cones and well-posed initial-value problems, showing that interactions do not alter the hyperbolization. A key result is that superluminal signals can be reconciled with a consistent causal structure, since the causal cones of combined systems are given by the convex hull of the constituent cones, leading to a democracy of causal cones where SR is just one system among many. This perspective reframes the role of the light-cone, suggesting broader possibilities for causality in classical field theories while preserving a form of Lorentz-invariant structure.

Abstract

It is argued that special relativity remains a viable physical theory even when there is permitted signals traveling faster than light.