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

The existence of Dark Matter and Dark Energy is widely accepted within the Standard Cosmological Model. However, their introduction is not based on direct detection but rather on the need to reconcile observations with theoretical expectations. This paper explores whether the necessity of Dark Matter and Dark Energy arises inherently from our chosen cosmological framework rather than from an independent physical requirement. Regarding Einstein’s cosmological constant Λ, it was reintroduced into modern physics following supernova observations but, also after carefully analyzing the Baryon Acoustic Oscillations, it is difficult to overlook its connection to the standard cosmological model. The same applies to gravitational lensing, where classical optics is used, with distances estimated based on Redshift. The rotation curves of spiral galaxies have been explained without resorting to alternative gravity models. As for the complex case of elliptical galaxies, in essence they are the result of mergers between spiral galaxies. Based on the model discussed, if one assumes the Milky Way's Initial Mass Function (IMF)—that of a typical spiral—then the dark matter problem for ellipticals reduces to the identical dilemma already posed for spirals. This implies that if dark matter is not necessary to explain the dynamics of spiral galaxies, then it is not necessary for ellipticals either, which are simply their merger product without the creation of new non-baryonic mass. Moreover, in virial mass estimates the radius R is not a direct observable but is inferred from the angular diameter multiplied by a cosmological distance that depends on the adopted metric. Our analysis therefore casts doubt on the necessity of dark matter in elliptical galaxies, while not providing conclusive evidence for a definite alternative. Finally, the current status of direct dark matter detection has been reviewed, which so far has yielded no conclusive results. 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 final appendices.