Infinite Dimensionless Vacuum — Elastic Vacuum Cosmology : A Unified Cosmological Framework of Elastic Spacetime Dynamics

This work presents an alternative cosmological framework in which cosmic acceleration emerges as a natural consequence of the elastic response of the vacuum, without invoking dark energy as an independent physical component. The vacuum is modeled as a dimensionless, self-sustained medium whose local gravitational deformations—induced by matter, structure formation, and compact objects—accumulate across scales and generate a coherent macroscopic elastic reaction. Within this framework, gravity is interpreted as a manifestation of vacuum deformation, while cosmic expansion results from the balance between deformation-driven contraction and elastic restoration. The model introduces two effective, dimensionless functions that quantify vacuum deformation and elastic rigidity, whose dynamical interplay governs the evolution of the cosmic scale factor. Cosmic acceleration arises when elastic response dominates over local deformation, leading to a self-regulating expansion mechanism. Large-scale structures, cosmic voids, and black holes play an indirect but essential role by enhancing local vacuum deformation and accelerating the buildup of elastic tension, without acting as independent sources of cosmic acceleration. In this picture, black holes function as local amplifiers of deformation rather than as direct drivers of expansion. The proposed framework is consistent with general relativistic principles at local scales, while offering an emergent explanation for large-scale acceleration that does not rely on a cosmological constant or exotic dark energy fields. The model is formulated in a falsifiable manner and provides clear conceptual links to structure formation, backreaction effects, and observational cosmology. It is intended as a foundational step toward a physically motivated, elastic-vacuum description of cosmic dynamics.