Hi, to offer a slightly different perspective on the cosmological constant: The concept of dark energy remains one of the most profound mysteries in modern cosmology. In the standard ΛCDM model, the observed accelerated expansion of the universe is explained by introducing the cosmological constant, Λ, into Einstein's field equations. Within this framework, Λ is intimately linked to dark energy, serving as its physical representation.
However, whatever its value, Λ is an element specific to the ΛCDM. My question is whether it should feature in the Einstein field equation, given that our fundamental physics doesn't depend on the validity of that particular cosmological model: Einstein dismissed Λ as his "greatest blunder," deeming it unnecessary. Despite the remarkable successes of ΛCDM, it is not yet as firmly established a theory as General Relativity.
So, I'm writing regarding my paper:
Reevaluating the Necessity of Dark Matter and Dark Energy within Cosmological Models
Except for the BAO discussion which involved some speculation, I consider the claims presented to be self-evident. The content is released under the Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license. (A standardized way to grant the public permission to use creative work under copyright law).
The latest version of the document is always freely available to everyone, after you click the link: 10.5281/zenodo.15220590, to the Zenodo page (View and download are free and require no registration; at the time of writing, all other cited documents, most of them from arXiv, are also freely accessible.)
That's the thing:
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.
In the first version of my paper, the paragraph on the cosmological constant in the field equation was initially based on the argument that supernova observations are difficult to interpret independently of the adopted cosmological model. Therefore, I considered Einstein's original intuition to remain crucial. However, he did not live long enough to witness the discovery of the CMB, evidence that would have led him to develop further formulations. Consequently, the paragraph needed to be supplemented with observations of cosmological origin, particularly through the study of Baryon Acoustic Oscillations (BAO). This analysis, inevitably entering a speculative domain, is completed and presented as an appendix using an alternative model introduced in viXra:2504.0144. This model is built upon the Big Bang and Hubble's law, offering a framework that diverges, by excluding FLRW.
Here, due to the high density, temperature, and dynamic viscosity at recombination, the propagation of pressure waves is heavily damped. As a result, the equivalent of the acoustic horizon, the maximum distance over which a sound wave could travel before being frozen, corresponds to less than one parsec today. This is drastically smaller than about 150 Mpc scale observed in the standard model.
Viscosity plays a dissipative role on acoustic waves and baryon oscillations, but it does not significantly hinder the presence of primordial density fluctuations, which can therefore leave imprints on the CMB anisotropies from the earliest stages. Consequently, the large-scale structures we observe in the Universe today, such as galaxy groups, clusters, and filaments, are not the result of baryon acoustic oscillations, but rather the direct imprint of primordial density ripples. These ripples were generated during the violent initial phase and froze out quickly, leaving behind the seeds of matter distribution without forming coherent sound waves on large scales. And the same goes for the CMB anisotropies.
This raises questions about using BAO-correlated observations to demonstrate the existence of Dark Energy.
In conclusion, Dark Energy must be considered within a cosmological model. Einstein's field equation should be maintained in its original formulation, without the introduction of the cosmological constant Λ, except for future evidence that requires its revision.
