Warp Drive: a Gedankenexperiment taken too far
Abstract: In this talk, I provide a systematic classification and critical evaluation of warp-drive spacetimes within General Relativity (GR). Moving beyond the popular "creative" approach, I adopt a rigorous "agonistic" methodology to address the recent renaissance of claims regarding physically feasible, positive-energy warp drives. By applying a basic principle, which mandates mathematical consistency within GR prior to physical speculation, we identified fundamental errors and misconceptions in existing literature. I will present a model hierarchy distinguishing between Restricted Warp (R-Warp) ‒ encompassing most proposals ‒ and more generalized configurations. The presentation focuses on demystifying these models through several no-go theorems, e.g.: 1) It is impossible to construct a superluminal R-Warp model that is globally hyperbolic. 2) The ADM energy for R-Warp models is generically zero, exposing the mathematical ambiguity of "total mass" calculations used in many studies. 3) I will contrast the "creative" approach (Synge G-method) with the "realistic" one, highlighting how the former often leads to "fantastic" but unphysical results. Finally, by recalling a proof that R-Warp models fundamentally violate the null energy condition (due to Santiago et al. 2022), we conclude that warp drives are best viewed as Gedankenexperiments for probing the boundaries of GR rather than viable technological blueprints. Time permitting, I will link these spacetimes to cosmological models.