Seminarium Gamma

Pseudo-gauge freedom, the inherent non-uniqueness in defining conserved currents such as the energy-momentum tensor, has recently emerged as a key challenge in relativistic hydrodynamics, with potential implications for physical observables. This talk introduces a novel geometric framework founded on k-contact geometry to systematically address this ambiguity. We demonstrate that the origin of pseudo-gauge freedom is rooted in the non-uniqueness of solutions to the k-contact Hamilton-de Donder-Weyl (HdDW) equations. The formal equivalence between this mathematical non-uniqueness and the physical pseudo-gauge freedom is then established for general hydrodynamic-like theories and illustrated through the specific example of Bjorken-like flow.