This preprint introduces the Thermodynamic Inertia of Vacuum (TIV) theory, a phenomenological framework that explores the nature of the "Dark Sector" through the lens of vacuum phase transitions. The paper proposes that Dark Matter and Dark Energy are not independent substances, but emergent macroscopic responses of a superfluid vacuum to matter density gradients. Key features of the model include in TIV v1. 0: A density-dependent vacuum term introduced into Einstein's field equations. Interpretation of Dark Matter as vacuum surface tension (inertia) at density interfaces. Interpretation of Dark Energy as latent heat released during vacuum crystallization in cosmic voids. A prediction of finite cosmic acceleration followed by a stable, asymptotic equilibrium state. This work is presented as a phenomenological ansatz intended to bridge the gap between abstract vacuum thermodynamics and observable cosmological dynamics. Key improvements and verification in TIV v2. 0: Unified Effective Lagrangian: A modified action has been constructed, unifying all macroscopic manifestations of the emergent vacuum response into a single fundamental equation. Rotation Curve Dynamics: A precise gradient term | ₘ|ₘ is introduced, enabling a mathematically rigorous derivation of flat galactic velocity profiles (v = const) and mapping the constant to the critical acceleration a₀ in MOND. Temperature Phase Transition: A phase function f (T) is incorporated to reconcile the model with cosmological evolution. During the CMB epoch (T Tc), the vacuum acts as an additional source of gravitational inertia, while the cooling of the Universe (T Tc) triggers the accelerated expansion mechanism. Astrophysical Verification: The model successfully replicates cluster gravitational lensing profiles without invoking hypothetical dark matter particles and tightly aligns with large-scale structure growth rates derived from modern SDSS catalogues.
Andriy Melnyk (Wed,) studied this question.