Compressed Spacetime Halo Theory (CSHT): A Geometric, Physical, and Falsifiable Alternative to Dark Matter

Compressed Spacetime Halo Theory (CSHT) proposes that the phenomena traditionally attributed to particle dark matter halos arise instead from large-scale, persistent compression states of spacetime itself.In this framework, spacetime is treated as a physical medium capable of entering compressed and relaxed geometric states, rather than as a purely passive geometric background. Baryonic matter induces spacetime compression during galaxy and cluster formation, and these compression structures can persist dynamically even after baryonic matter is displaced, such as during cluster–cluster collisions.CSHT provides a unified physical mechanism to explain:Flat galaxy rotation curves without invoking collisionless dark matter particlesFinite halo boundaries and environment-dependent halo sizesSmooth gravitational lensing profilesLensing–baryon offsets observed in systems such as merging galaxy clustersThe theory makes testable and falsifiable predictions, including:Smooth (non-clumpy) gravitational lensing at galactic and cluster scalesEnvironment-correlated halo truncation in isolated versus cluster galaxiesPersistent lensing peaks during cluster collisions independent of baryonic gas distributionSharp kinematic transitions in outer galactic halos unrelated to stellar population changesThis upload serves as a theoretical preprint and conceptual framework, intended to be tested against upcoming high-precision observational data from missions such as Euclid, Rubin Observatory (LSST), Gaia, and JWST.The work is released as an open scientific contribution to encourage independent scrutiny, testing, and comparison with ΛCDM and modified-gravity frameworks. CSHT suggests that if spacetime compression influences the propagation of light and time-governing processes, then, although spacetime is locally compressed, the effective traversal path through the compressed structure may become greater than in uncompressed regions. Consequently, light signals and time-dependent physical processes may require longer effective propagation intervals. The converse possibility—spacetime expansion producing corresponding changes in effective propagation intervals—may also contribute to the apparent temporal stretching observed in signals from extremely distant astronomical sources. This possibility remains speculative and requires further theoretical and observational investigation.