Rotation curve for the Milky Way galaxy in conformal gravity

O’Brien, James; Moss, Robert J.

doi:10.1088/1742-6596/615/1/012002

Cited by 14 publications

(25 citation statements)

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“…Observed orbital velocities for 138 galaxies are fitted assuming γ = γ0 + γG, where γG = N * γ * (Mannheim 1997(Mannheim , 2006 for N * = M/M⊙. Constants inferred from this rotation data are γ0 = 3.06 × 10 −28 /m, γ * = 5.42 × 10 −39 /m, and κ = 9.54 × 10 −50 /m 2 (Mannheim 1997;O'Brien 2011, 2012;O'Brien and Mannheim 2012;O'Brien and Moss 2015;O'Brien et al 2017).…”

Section: Conformal Gravity Backgroundmentioning

confidence: 99%

Theoretical implications of the galactic radial acceleration relation of McGaugh, Lelli, and Schombert

Nesbet

2018

Monthly Notices of the Royal Astronomical Society: Letters

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Velocities in stable circular orbits about galaxies, a measure of centripetal gravitation, exceed the expected Kepler/Newton velocity as orbital radius increases. Standard LCDM attributes this anomaly to galactic dark matter. McGaugh et al have recently shown for 153 disc galaxies that observed radial acceleration is an apparently universal function of classical acceleration computed for observed galactic baryonic mass density. This is consistent with the empirical MOND model, not requiring dark matter. It is shown here that suitably constrained LCDM and conformal gravity (CG) also produce such a universal correlation function. LCDM requires a very specific dark matter distribution, while the implied CG nonclassical acceleration must be independent of galactic mass. All three constrained radial acceleration functions agree with the empirical baryonic v 4 Tully-Fisher relation. Accurate rotation data in the nominally flat velocity range could distinguish between MOND, LCDM, and conformal gravity.

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Section: Conformal Gravity Backgroundmentioning

confidence: 99%

Theoretical implications of the galactic radial acceleration relation of McGaugh, Lelli, and Schombert

Nesbet

2018

Monthly Notices of the Royal Astronomical Society: Letters

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“…) last seems to be of order one, for now over 200 galaxies [3][4][5][6] fit by the theory. This universality found in the last data point of each galaxies centripetal acceleration (scaled here to 1 c 2 ) provides argument for the recent work of McGaugh 7 et al, and this phenomena will be explored in more detail below.…”

Section: Rotation Curves Of the Whisp Surveymentioning

confidence: 81%

“…In recent years, Mannheim and O'Brien have shown that conformal gravity can be used to accurately describe the rotation curves of a diverse set of galaxies without the need to invoke dark matter. [3][4][5][6] Since all attempts to find any direct evidence of dark matter have been unsuccessful so far, alternative theories of gravity have become increasingly worth considering as an explanation for phenomena ascribed to dark matter. Its success in fitting galactic rotations makes conformal gravity an ideal candidate to explore in an effort to theoretically describe these additional effects.…”

Section: Introductionmentioning

confidence: 99%

“…While the rotation curve fitting provides direct data that can be tested against the predictions of an alternative model of gravity, there are other observational motivations for the existence of dark matter, such as the motion of galaxies in clusters and gravitational lensing. The goal of this paper is to summarize some recent conformal gravity fits to rotation [3][4][5][6] curves, to show how conformal gravity can address the cluster motion problem without invoking dark matter, and develop the initial framework for gravitational lensing formalism in conformal gravity. Since the actual IWARA meeting, recent work was published in Physical Review Letters 7 (PRL), which generalizes rotation curve data to instead encapsulate what appears to be universality in the centripetal accelerations of the rotation curve data.…”

Section: Introductionmentioning

confidence: 99%

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Conformal Gravity Solutions to Standard Gravity Problems

O’Brien

Chaykov

Chiarelli

et al. 2017

Int. J. Mod. Phys. Conf. Ser.

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Gravitational theories outside standard general relativity have been drawing increased attention over the past several years, mostly due to the lack of direct observational evidence of dark matter. With some recent very high level dark matter searches continuing, and the parameter space to search decreasing has lead to a new interest in rethinking gravity at the largest of scales. As an alternative gravitational theory, conformal gravity has enjoyed much of the success of Modified Newtonian Dynamics (MOND) in predicting phenomenology, but differs dramatically in its initial construction. In this work, we explore some recent advances in conformal gravity, which help to build the case for support of such an alternative theory. Here, we highlight conformal gravity's success in This is an Open Access article published by World Scientific Publishing Company. It is distributed under the terms of the Creative Commons Attribution 4.0 (CC-BY) License. Further distribution of this work is permitted, provided the original work is properly cited. fitting new rotation curves, its ability to explain velocity dispersions in clusters, the initial steps towards gravitational lensing and finally, some preliminary work on explaining universal centripetal acceleration trends in galaxies.

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“…This action, when varied with respect to the metric (as in standard gravity) [1], yields the conformal gravity field equations, These equations were later solved by Mannheim and Kazanas [2] for a spherical mass, exterior solution, which behaves as a conformal gravity Schwarzchild like solution, and allows for application of the theory to various data sets. In recent years, Mannheim and O'Brien have shown that conformal gravity can be used to accurately describe the rotation curves of a diverse set of galaxies without the need to invoke dark matter [3], [4], [5], [6]. Since all attempts to find any direct evidence of dark matter have been unsuccessful so far, alternative theories of gravity have become increasingly worth considering as an explanation for phenomena ascribed to dark matter.…”

Section: Introductionmentioning

confidence: 99%

Recent advancements in conformal gravity

O’Brien

Chaykov

Dentico³

et al. 2017

J. Phys.: Conf. Ser.

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Abstract. In recent years, due to the lack of direct observed evidence of cold dark matter, coupled with the shrinking parameter space to search for new dark matter particles, there has been increased interest in Alternative Gravitational theories. This paper, addresses three recent advances in conformal gravity, a fourth order renormalizable metric theory of gravitation originally formulated by Weyl, and later advanced by Mannheim and Kazanas. The first section of the paper applies conformal gravity to the rotation curves of the LITTLE THINGS survey, extending the total number of rotation curves successfully fit by conformal gravity to well over 200 individual data sets without the need for additional dark matter. Further, in this rotation curve study, we show how MOND and conformal gravity compare for each galaxy in the sample. Second, we look at the original Zwicky problem of applying the virial theorem to the Coma cluster in order to get an estimate for the cluster mass. However, instead of using the standard Newtonian potential, here we use the weak field approximation of conformal gravity. We show that in the conformal case we can get a much smaller mass estimate and thus there is no apparent need to include dark matter. We then show that this calculation is in agreement with the observational data from other well studied clusters. Last, we explore the calculation of the deflection of starlight through conformal gravity, as a first step towards applying conformal gravity to gravitaitonal lensing.

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Rotation curve for the Milky Way galaxy in conformal gravity

Cited by 14 publications

References 14 publications

Theoretical implications of the galactic radial acceleration relation of McGaugh, Lelli, and Schombert

Theoretical implications of the galactic radial acceleration relation of McGaugh, Lelli, and Schombert

Conformal Gravity Solutions to Standard Gravity Problems

Recent advancements in conformal gravity

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