A Unifying Theory of Dark Energy and Dark Matter: Negative Masses and Matter Creation within a Modified $Λ$CDM Framework

Abstract: Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive cosmic expansion and cannot coalesce into light-emitting structures. However, contemporary cosmological results are derived upon the reasonable assumption that the Universe only contains positive masses. By reconsidering this assumption, I have constructed a toy model which suggests that both dark phenomena can be unified into a single negative mass fluid. The model is a modified $\Lambda$CDM cosmology, and indicates that continuously-created negative masses can resemble the cosmological constant and can flatten the rotation curves of galaxies. The model leads to a cyclic universe with a time-variable Hubble parameter, potentially providing compatibility with the current tension that is emerging in cosmological measurements. In the first three-dimensional N-body simulations of negative mass matter in the scientific literature, this exotic material naturally forms haloes around galaxies that extend to several galactic radii. These haloes are not cuspy. The proposed cosmological model is therefore able to predict the observed distribution of dark matter in galaxies from first principles. The model makes several testable predictions and seems to have the potential to be consistent with observational evidence from distant supernovae, the cosmic microwave background, and galaxy clusters. These findings may imply that negative masses are a real and physical aspect of our Universe, or alternatively may imply the existence of a superseding theory that in some limit can be modelled by effective negative masses. Both cases lead to the surprising conclusion that the compelling puzzle of the dark Universe may have been due to a simple sign error.

• The paper introduces a unified model that integrates negative masses to explain both dark energy and dark matter effects, challenging conventional cosmology.
• It employs innovative 3D N-body simulations that reveal non-cuspy halo formation and flat galaxy rotation curves consistent with astrophysical observations.
• The study implies that continuous matter creation of negative masses may resolve key discrepancies in cosmic acceleration and dark matter distribution.

A Unifying Theory of Dark Energy and Dark Matter: Insights into Negative Masses and Matter Creation

The paper "A unifying theory of dark energy and dark matter: Negative masses and matter creation within a modified $\Lambda$CDM framework" by J. S. Farnes proposes a novel theoretical framework that integrates concepts of negative masses and matter creation to explain the elusive phenomena of dark energy and dark matter. This work revisits a largely neglected idea rooted in Einstein's early considerations of gravitationally repulsive negative masses, suggesting that such masses might offer a unified explanation for cosmic acceleration traditionally attributed to dark energy and for the additional gravitational effects attributed to dark matter.

Theoretical Outlook

The central proposition of Farnes' paper is a re-evaluation of the assumption that the universe comprises exclusively of positive masses. By incorporating negative masses in a modified $\Lambda$CDM cosmology, the paper proposes that a fluid of continuously-created negative masses might effectively mimic the properties attributed to the cosmological constant $\Lambda$. This model posits that negative masses exert repulsive gravity, manifesting as cosmic expansion and flattening galaxy rotation curves—a phenomenon typically associated with dark matter's gravitational pull.

Strong Numerical Insights

Key numerical results are presented through the first 3D N-body simulations of negative mass matter, which display intriguing behaviors consistent with various astrophysical observations. Notably, these simulations suggest that a distribution of negative masses can naturally form non-cuspy halos around galaxies, resolving the longstanding cuspy-halo problem observed in typical cold dark matter scenarios. Furthermore, the simulations reveal that these halos, extending to several galactic radii, can adequately account for the observed flat rotation curves of galaxies without requiring additional hypothesized matter.

Implications and Observational Consistency

The implications of this work are profound. The paper suggests that if negative masses are genuine, they could inherently embody the role of dark energy by driving the universe's accelerated expansion. Additionally, the modeled "dark fluid" of negative masses could serve the dual role of dark matter by exerting gravitational influence that flattens galaxy rotation curves and contributes to large-scale structure formation.

In addressing observational phenomena, the paper speculates on the compatibility of this negative mass framework with current supernova, cosmic microwave background (CMB), and galaxy cluster observations. It highlights the potential observational signatures of such a framework that align with supernova data, suggesting that a relaxation of positive-only mass assumptions might reveal indirect evidence of negative masses. Similarly, it posits that the CMB observations indicating a flat universe could potentially coexist with the proposed model's open geometry if the universe is sufficiently large.

Future Prospects

Farnes outlines several critical future directions, including the need to reanalyze supernova and CMB data within this new framework and explore the consequences for particle physics, potentially involving extensions to the standard model or invoking supersymmetry. There is also a call for further simulations incorporating matter creation and higher particle counts to enrich our understanding and validate the theory against extensive astrophysical data.

Conclusion

Farnes' paper challenges conventional cosmological paradigms by proposing a framework that unites dark matter and dark energy as manifestations of a single, cohesive physical entity: negative mass. While current cosmological models effectively describe a wide range of phenomena, this paper posits an alternative pathway that might resolve some of the most perplexing issues in modern physics. This approach, if validated, could significantly alter our theoretical understanding of the universe's composition and the fundamental principles governing it, marking a critical juncture in cosmological research.