Higher-form (Quasi)Hydrodynamics from Holography: Deformations and Dualities

We study the low-energy dynamics of systems with exact and approximate higher-form symmetries using gauge/gravity duality. These symmetries are realised holographically via Maxwell-type theories for massless and massive $p$-forms in AlAdS spacetimes. Double-trace deformations of the boundary theory are considered. While massless theories describe systems with conserved higher-form current, the massive case provides a controlled linearised framework for explicit symmetry breaking induced by defects and charged operators. We perform holographic renormalisation and establish a unified holographic dictionary across a broad theory space, parametrised by spacetime dimension, form rank, quantisation scheme and deformation scale. We compute thermal correlation functions in isotropic black brane backgrounds to characterise the hydrodynamic and quasihydrodynamic regimes of the dual boundary theories. Our analysis reveals a rich structure of relaxation dynamics, emergent photons and duality relations -- including the conventional electric-magnetic Hodge duality and its massive counterpart. These results extend bottom-up holography to include weakly broken higher-form symmetries and open avenues for exploring generalised self-duality constraints and new classes of deformed holographic duals.