Emergent Gravitation from Vacuum Contraction: A Ghost-Free Scalar-Tensor Framework for the Unification of Cosmology

The Relativistic Contraction–Shrinkage Theory (RKST) is a novel theoretical framework for gravity and cosmology. It challenges the common assumption that cosmic observations necessarily imply an expansion of space, and demonstrates that the same data can be consistently interpreted as a gradual contraction of the physical vacuum. Within this perspective, gravity, dark matter, and dark energy emerge as interconnected effects of vacuum dynamics rather than as separate or unknown substances. RKST provides coherent explanations for several major open problems in modern physics, including galaxy rotation curves, the Hubble tension, and the cosmological constant problem—without introducing new hypothetical particles. This work presents the conceptual and mathematical foundations of the theory in a compact and self-consistent form, serving as a reference point for future focused studies on its individual implications.