Is Space a Superfluid? A Helium-Like Vacuum Hypothesis and Its Cosmological Implications

This thesis explores the hypothesis that space behaves as a quantum superfluid, analogous in part to helium-4, and examines whether the vacuum’s compressibility and pressure gradients can explain gravitational effects. Building on the Pressure Driven Gravity (PDG) framework, it proposes that the vacuum is a condensate-like medium that supports fluid-like phenomena such as rarefaction waves, vortex dynamics, and emergent gravitational forces.The model draws parallels with helium-4 near the cosmic microwave background temperature (2.7 K), but ultimately interprets the vacuum as an effective or emergent medium rather than literal atomic helium. The thesis addresses challenges of Lorentz invariance, discusses recent evidence for high-pressure hydrogen superfluidity, and proposes observational tests through gravitational wave dispersion using LIGO, Virgo, and LISA.By bridging condensed matter physics with cosmology, this work offers a falsifiable alternative to general relativity at large scales, grounded in quantum hydrodynamics. It invites further exploration of the vacuum as a physical medium and outlines experimental pathways toward detecting its properties.