The Elastic Cosmos: Eliminating Dark Energy Through Planck-Scale Rebound and Holographic Entropy Renewal

This study presents a cyclic cosmological model where the universe’s accelerated expansion arises from spacetime’s intrinsic rebound mechanics, eliminating the need for dark energy. Central to this framework is a conserved Cosmic Scale (C_s), a finite spatial extent derived from the Planck length (l_p) via a dimensionless constant N≈10^61. The model unifies holographic entropy principles, modified Friedmann dynamics, and Planck-scale quantum gravity to resolve the cosmological constant problem, Hubble tension, and Tolman’s entropy paradox. By postulating spacetime’s elastic response to contraction-phase potential energy, the rebound mechanism triggers expansion without singularities, mimicking dark energy’s effects. Key predictions include suppressed large-scale CMB polarization (l<30), phase shifts in baryon acoustic oscillations (BAO), and gravitational wave signatures detectable by LISA. Observational validation shows H_0=73.2±1.3 "km/s/Mpc" , resolving the Hubble tension between SH0ES and Planck data. The entropy reset at V_"min" ∼l_p^3 avoids infinite entropy growth, addressing Tolman’s paradox. This work bridges quantum geometry and cosmic evolution, offering a falsifiable alternative to ΛCDM cosmology with implications for unifying general relativity and quantum mechanics. Future efforts will focus on quantizing the rebound mechanism and leveraging next-generation telescopes for validation.