Theoretically motivated dark electromagnetism as the origin of relativistic MOND (2312.08811v3)

Abstract: The present paper is a modest attempt to initiate the research program outlined in this abstract. We propose that general relativity and relativistic MOND (RelMOND) are analogues of the broken electroweak symmetry. That is, $SU(2)R \times U(1){YDEM} \rightarrow U(1){DEM}$ (DEM stands for dark electromagnetism), and GR is assumed to arise from the broken $SU(2)_R$ symmetry, and is analogous to the weak force. RelMOND is identified with dark electromagnetism $U(1){DEM}$, which is the remaining unbroken symmetry after spontaneous symmetry breaking of the darkelectro-grav sector $SU(2)R \times U(1){YDEM}$. This sector, as well as the electroweak sector, arise from the breaking of an $E_8 \times E_8$ symmetry, in a recently proposed model of unification of the standard model with pre-gravitation, this latter being an $SU(2)R$ gauge theory. The source charge for the dark electromagnetic force is square-root of mass, motivated by the experimental fact that the square-roots of the masses of the electron, up quark, and down quark, are in the ratio 1:2:3, which is a flip of their electric charge ratios 3:2:1 The introduction of the dark electromagnetic force helps understand the weird mass ratios of the second and third generation of charged fermions. We also note that in the deep MOND regime, acceleration is proportional to square-root of mass, which motivates us to propose the relativistic $U(1){DEM}$ gauge symmetry as the origin of MOND. We explain why the dark electromagnetic force falls inversely with distance, as in MOND, and not as the inverse square of distance. We conclude that dark electromagnetism is a good mimicker of cold dark matter, and the two are essentially indistinguishable in those cosmological situations where CDM is successful in explaining observations, such as CMB anisotropies, and gravitational lensing.

• The paper introduces a dark electromagnetism framework via symmetry breaking to account for relativistic MOND without invoking dark matter.
• It employs an E8×E8 symmetry breakdown that distinguishes electroweak interactions from dark electromagnetism to modify low-acceleration gravitational dynamics.
• The model explains galaxy rotation curves and cosmic phenomena like CMB anisotropies, providing a compelling alternative to the cold dark matter hypothesis.

Insights on "Theoretically Motivated Dark Electromagnetism as the Origin of Relativistic MOND"

The paper by Finster, Isidro, Paganini, and Singh introduces a noteworthy framework that seeks to bridge certain cosmological challenges by proposing the concept of "dark electromagnetism" as a source for understanding Modified Newtonian Dynamics (MOND) in a relativistic framework. The authors present a compelling alternative to the dark matter paradigm by developing a connection through symmetry breaking processes reminiscent of those observed in the electroweak sector. Their framework posits that MOND may arise not from dark matter, as traditionally proposed, but rather from modifications in gravitational theory linked to unbroken symmetries in this newly proposed sector.

Theoretical Foundation and Symmetry Breaking

The authors propose a unification of interactions via an E8× E8 symmetry group, where the breaking process yields both the electroweak and dark electromagnetism sectors. In this view, standard general relativity (GR) is a low-acceleration limit of a more comprehensive framework where dark electromagnetism (U(1)DEM) acts similarly to a relativistic MOND theory. This is achieved by introducing a new interaction associated with the square root of mass as the source charge, challenging conventional understanding by drawing parallels to well-established particle mass ratios.

Dark Electromagnetism Mimicking Cold Dark Matter

A fundamental claim in the paper is that dark electromagnetism can effectively simulate the effects attributed to cold dark matter (CDM) under specific cosmological conditions. The authors argue that this model can account for phenomena traditionally explained by CDM, such as cosmic microwave background (CMB) anisotropies and gravitational lensing effects. This approach posits that such empirical observations do not necessarily require a dark matter particle but could instead stem from modified gravitational regimes and forces that take precedence at certain acceleration scales.

Empirical and Theoretical Implications

The hypothesis offers potential explanations for the observed success of MOND in predicting galaxy rotation curves while addressing MOND’s challenges at larger scales. Directly critiquing the conventional dark matter model, the paper emphasizes the absence of detected dark matter particles despite extensive searches, suggesting that modifications to gravity via a fifth force, identified with dark electromagnetism, could suffice.

Furthermore, the paper suggests that the observed mass and charge ratios of elementary particles are not inherent mysteries but can be understood within this theoretical framework, thereby offering insights into mass hierarchies across fermion generations.

Cosmological Implications and Future Directions

The research makes speculative yet intriguing connections between emerging concepts from high energy physics and unresolved puzzles in cosmology. Notable among these is the possible relevance of a de Sitter-like model in the early universe, from which the proposed U(1)DEM symmetry emerges as a cosmological remnant. This theoretical stance sets a fertile ground for exploring modifications to standard cosmological models, influenced by the elastic properties of spacetime that allow coherence with Verlinde's entropic gravity arguments.

The implications of this work extend into future empirical realms, where endeavors such as the forthcoming GAIA mission and analyses of wide binaries could serve as critical test beds for evaluating the viability of MOND and thereby the theoretical model presented. If observations continue to diverge from Newtonian predictions at low accelerations, they may offer corroborative evidence for the authors' theoretical proposals.

Conclusion

Overall, this research offers an innovative approach to redefining the gravitation paradigm by theoretically linking MOND to a higher-order symmetry derivation. While not yet definitive, this approach provides a significant contribution to ongoing debates in gravitational physics and cosmology, presenting a potential roadmap for future theoretical and observational work. Further exploration into the properties of dark electromagnetism and their observables remains a vital next step in validating this promising theoretical platform.