Reevaluating the Necessity of Dark Matter and Dark Energy within Cosmological Models

This work re‑examines the need for Dark Matter and Dark Energy by questioning whether their introduction stems from observational evidence or from the assumptions of the standard cosmological framework. It reviews the role of Λ, gravitational lensing, and galaxy dynamics, highlighting how several inferences depend on model‑dependent distances or approximations. Spiral and elliptical galaxies are reconsidered within a unified baryonic framework, and current direct‑detection efforts are noted as inconclusive. To properly and comprehensively address a cosmological discussion, we must not focus solely on the standard model but instead consider multiple models. This analysis draws a clear line between its findings and a topic that, by its very nature, inevitably enters a speculative framework. The remaining topic is presented in the final appendices, including a brief exploratory note on a possible observational interpretation of certain CMB anisotropy features—developed without assuming a global FLRW geometry. The alternative model chosen as a reference does not invoke dark matter or dark energy, maintains a reversible evolution of the CMB that contrasts with the standard kinematic picture, and neither predicts nor observes BAO within its framework. A brief dynamical application is also included in the final Appendix, presenting a bound MW–M31 solution obtained without invoking dark matter.