Dark Matters on the Scale of Galaxies

Martino, Iván de; Chakrabarty, Sankha Subhra; Cesare, Valentina; Gallo, Arianna; Ostorero, L.; Diaferio, Antonaldo

doi:10.3390/universe6080107

Cited by 84 publications

(57 citation statements)

References 655 publications

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“…More astronomical observations confirming or denying, indirectly, DM are on the horizon, involving hundreds of people [49]. We wonder if the results of these will make any difference to the opinions of astronomers since observations to data of distant galaxies yielding results that both confirm and deny DM are continually reported to this day; the opinions of astronomers seem to be data-independent [50,51].…”

Section: Discussionmentioning

confidence: 99%

Dark Matter in Spiral Galaxies as the Gravitational Redshift of Gravitons

Oliveira¹,

Smith²

2022

Dark Matter - Recent Observations and Theoretical Advances

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Several recent attempts to observe dark matter with characteristics similar to atomic or subatomic particles as Weakly Interacting Massive Particles (WIMPs) have failed to detect anything real over a wide energy range. Likewise, considerations of large, non-emitting objects as the source of most dark matter fall short of expectations. Here we consider the possibility that massless gravitons suffering slow redshift may be responsible for the properties of spiral galaxies attributed to dark matter. Particles such as gravitons will be extremely difficult to directly detect; the best we can envision is measuring this influence on stellar and galactic motions. Since the motions of stars and galaxies are non-relativistic, we can apply our idea to describe the expected large-scale motions using only Newtonian mechanics. Using our assumption about the importance of the graviton, we here describe the well-known Tully-Fisher relationship of spiral galaxies without resorting to hypothesizing exotic WIMPs or invoking modifications of Newtonian dynamics (MoND).

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Section: Discussionmentioning

confidence: 99%

Dark Matter in Spiral Galaxies as the Gravitational Redshift of Gravitons

Oliveira¹,

Smith²

2022

Dark Matter - Recent Observations and Theoretical Advances

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“…However, such divergences are absent in self-gravitating systems of fermions [24,25], which predict the formation of a core-halo structure with a degenerate core for low energies. In other words, WDM may be capable to solve the called cusp-core problem [43].…”

Section: Incidence Of Evaporation Effectsmentioning

confidence: 99%

New Bounds for the Mass of Warm Dark Matter Particles Using Results from Fermionic King Model

Velázquez

2021

Universe

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After reviewing several aspects about the thermodynamics of self-gravitating systems that undergo the evaporation (escape) of their constituents, some recent results obtained in the framework of fermionic King model are applied here to the analysis of galactic halos considering warm dark matter (WDM) particles. According to the present approach, the reported structural parameters of dwarf galaxies are consistent with the existence of a WDM particle with mass in the keV scale. Assuming that the dwarf galaxy Willman 1 belongs to the region III of fermionic King model (whose gravothermal collapse is a continuous phase transition), one obtains the interval 1.2 keV ≤ m ≤ 2.6 keV for the mass of WDM particle. This analysis improves previous estimates by de Vega and co-workers [Astropart. Phys. 46 (2013) 14–22] considering both the quantum degeneration and the incidence of the constituents evaporation. This same analysis evidences that most of galaxies are massive enough to undergo a violent gravothermal collapse (a discontinuous microcanonical phase transition) that leads to the formation of a degenerate core of WDM particles. It is also suggested that quantum-relativistic processes governing the cores of large galaxies (e.g., the formation of supermassive black holes) are somehow related to the gravothermal collapse of the WDM degenerate cores when the total mass of these systems are comparable to the quantum-relativistic characteristic mass Mc=ℏc/G3/2m−2≃1012M⊙ obtained for WDM particles with mass m in the keV scale. The fact that a WDM particle with mass in the keV scale seems to be consistent with the observed properties of dwarf and large galaxies provides a strong support to this dark matter candidate.

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“…Currently, the two greatest mysteries in physics seem to be dark matter and dark energy. Almost all models of dark matter resort to largely-unspecified never-discovered subatomic particles or introduce new physical laws [1]- [8], and references therein. One exception is papers showing the possibility that dark [10].…”

Section: Introductionmentioning

confidence: 99%

Possible Explanation of the Dynamics of the Universe Expansion without Dark Energy and without New Gravitational Degrees of Freedom

Oks¹

2021

OJM

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The commonly accepted view is that the Universe is currently in the dark energy dominance era (estimated to start about 5 billion years ago)-the era where yet unknown dark energy dominates over the gravitation and is responsible for the observed acceleration of the Universe expansion. In the present paper, we consider a "gas" of a large number of gravitating neutral nonrelativistic particles having a practically infinite lifetime and zero or very little interaction with the rest of the matter (neutrinos could be an example). One of the central points is the application of Dirac's Generalized Hamiltonian Dynamics to pairs of these particles. Another central point is the application of the virial theorem to pairs of zero total energy. We demonstrate that as a result, the gravitational interaction within the entire system effectively decreases. Together with the observational fact of the Universe rotation (according to Shamir's study of 2020), this model provides a possible explanation of the entire history of the Universe expansion: both the era of the decelerating expansion and the current era of the accelerated expansion.

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Dark Matters on the Scale of Galaxies

Cited by 84 publications

References 655 publications

Dark Matter in Spiral Galaxies as the Gravitational Redshift of Gravitons

Dark Matter in Spiral Galaxies as the Gravitational Redshift of Gravitons

New Bounds for the Mass of Warm Dark Matter Particles Using Results from Fermionic King Model

Possible Explanation of the Dynamics of the Universe Expansion without Dark Energy and without New Gravitational Degrees of Freedom

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