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nLab > Latest Changes: MOND

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  1.  
    • CommentRowNumber1.
    • CommentAuthorUrs
    • CommentTimeNov 26th 2012

    recorded some recent surveys of the status of MOND at MOND

    • CommentRowNumber2.
    • CommentAuthorUrs
    • CommentTimeMar 15th 2017

    I have been expanding slightly (mostly references) at MOND and related entries, such as fuzzy dark matter and axion.

    • CommentRowNumber3.
    • CommentAuthorUrs
    • CommentTimeOct 23rd 2017
    • (edited Oct 23rd 2017)

    Added pointers to articles discussing the constraints on MOND phenomenology due to the recent multi-channel observation of merging neutron stars: here

    • CommentRowNumber4.
    • CommentAuthorDavid_Corfield
    • CommentTimeOct 23rd 2017

    That was quick, or have the authors of those articles had access to the results for longer?

    Are rival theories, such as axionic dark matter, left unscathed by such observations? Perhaps further work by LIGO is needed there, at least according to Black Hole Mergers and the QCD Axion at Advanced LIGO.

    • CommentRowNumber5.
    • CommentAuthorUrs
    • CommentTimeOct 23rd 2017
    • (edited Oct 23rd 2017)

    At least for arXiv:1710.06168 the computations were done earlier, and now that the expected results came in, it’s easy to draw the conclusion. They write:

    More details on DM emulator theories and some of their predictions made for externally triggered GW searches [45] during the era of initial and enhanced LIGO can be found in our previous works [46–48]. Now that the first simultaneous observation of GWs and photons has occurred, we can carry out our proposed tests.

    I think it’s fair to say that, while interesting, it is not particularly hard to obtain these kinds of conclusions – after all this is not about excluding subtle effects, but excluding brutal modification of the basic laws of physics. But since these modifications keep being promoted, these constraints are nevertheless worth recording.

    further work by LIGO is needed there, at least according to Black Hole Mergers and the QCD Axion at Advanced LIGO

    Thanks for the pointer, I had not seen this. So that’s about using future versions of LIGO not just to constrain axion dark matter models, but to directly verify some versions of them. We’ll have to wait and see…

    • CommentRowNumber6.
    • CommentAuthorUrs
    • CommentTimeApr 13th 2018

    added snippet from Bekenstein 04, p. 9 which makes manifest that the proposed “TeVeS” theory making MOND a relativistic theory is itself just Einstein gravity coupled to a very peculiar matter sector (and necessarily “dark” if this is to be realistic).

    diff, v13, current

    • CommentRowNumber7.
    • CommentAuthorUrs
    • CommentTimeApr 13th 2018

    also added the pointer to van Dokkum 18 on an observation of a galaxy that does not in fact show the effect which MOND claims is universal

    diff, v13, current

    • CommentRowNumber8.
    • CommentAuthorUrs
    • CommentTimeJul 2nd 2020

    added pointer to yesterday’s

    • Kris Pardo, David Spergel, What is the price of abandoning dark matter? Cosmological constraints on alternative gravity theories (arXiv:2007.00555)

    diff, v14, current

    • CommentRowNumber9.
    • CommentAuthorUrs
    • CommentTimeAug 16th 2022

    added pointer to:

    diff, v15, current

  10. adding new section “Hybrid MOND dark matter models” in references section, and adding references

    Anonymous

    diff, v16, current

  11. Added “relativisitic MOND models” section under references, and added reference

    Anonymous

    diff, v16, current

    • CommentRowNumber12.
    • CommentAuthorUrs
    • CommentTimeDec 7th 2022

    Thanks, that’s an interesting reference.

    But then we need to also move Bekenstein’s original to the new subsection. Have done so now (here)

    diff, v17, current

  13. adding reference

    Anonymous

    diff, v18, current

  14. Adding reference

    Anonymous

    diff, v19, current

    • CommentRowNumber15.
    • CommentAuthorGuest
    • CommentTimeMar 7th 2023

    adding reference

    diff, v20, current

    • CommentRowNumber16.
    • CommentAuthorGuest
    • CommentTimeMar 7th 2023

    Adding reference

    diff, v20, current

    • CommentRowNumber17.
    • CommentAuthorGuest
    • CommentTimeMar 7th 2023

    adding reference

    diff, v20, current

    • CommentRowNumber18.
    • CommentAuthorGuest
    • CommentTimeMar 7th 2023

    Adding reference

    • Shuxun Tian, Shaoqi Hou, Shuo Cao, Zong-Hong Zhu Time evolution of the local gravitational parameters and gravitational wave polarizations in a relativistic MOND theory (arXiv:2302.13304)

    diff, v20, current

    • CommentRowNumber19.
    • CommentAuthorGuest
    • CommentTimeMar 7th 2023

    added full publication data for previous reference, as such:

    • Shuxun Tian, Shaoqi Hou, Shuo Cao, Zong-Hong Zhu, Time evolution of the local gravitational parameters and gravitational wave polarizations in a relativistic MOND theory, Physical Review D, Volume 107, Issue 4. Published 24 February 2023. (doi:10.1103/PhysRevD.107.044062, arXiv:2302.13304)

    diff, v20, current

    • CommentRowNumber20.
    • CommentAuthorGuest
    • CommentTimeMar 25th 2023

    The section “Consistent theory embedding?” seems to be out of date. Especially the sentence

    The only proposal for such a theory apart from gravity+dark matter itself (Kaplinghat-Turner 02, BLSF 09, Chan 13) is to add to Einstein gravity a unit vector field and a scalar field (Bekenstein 04, “TeVeS”), themselves thus otherwise unobserved “dark fields”, as it were, but, as opposed to say the axion dark matter candidate, not motivated beyond the desire to fit galaxy rotation curves.

    seems to be contradicted by all the references under “Relativistic MOND models”.

    • CommentRowNumber21.
    • CommentAuthorUrs
    • CommentTimeMar 25th 2023

    seems to be out of date

    It might almost seem as if anonymous users added more recent references after that paragraph was written.

  22. updated section formerly called “Consistent theory embedding?”, now renamed to “Relativistic MOND”, with a list of theories which have unified MOND with relativity. The information specifically about TeVeS have been moved into a separate section titled “Tensor-Vector-Scalar gravity”

    Frank Kramer

    diff, v21, current

  23. renamed title to “Relativistic extensions of MOND”

    Frank Kramer

    diff, v21, current

  24. also added a sentence about David Merritt’s review of MOND vs Dark matter and the corresponding citation for his book

    David Merritt, A Philosophical Approach to MOND: Assessing the Milgromian Research Program in Cosmology, Cambridge University Press. April 30, 2020.

    Frank Kramer

    diff, v21, current

    • CommentRowNumber25.
    • CommentAuthorUrs
    • CommentTimeMar 26th 2023

    Added the following paragraph after the list of relativistic MOND theories (here):

    These theories tend to postulate new relativistic fields adjoined to plain Einstein gravity. While their relativistic interactions are designed to mimic the originally postulated MOdfied Newtonian Dynamics in appropriate regimes, to be phenomenologically viable they must otherwise be effectively unobservable and as such are rather like the dark matter fields whose introduction the original idea of MOND it was to avoid. The difference between the oxymoronic “relativistic MOND” and mainstream dark matter is now more one of style and focus than of principle.

    diff, v22, current

    • CommentRowNumber26.
    • CommentAuthorGuest
    • CommentTimeJun 5th 2023

    adding reference

    diff, v24, current

  27. adding preprint from last month:

    • Katherine Jones-Smith, Harsh Mathur, Modified Newtonian Dynamics as an Alternative to the Planet Nine Hypothesis (arXiv:)

    astronomer

    diff, v25, current

  28. another preprint from earlier this year:

    • Cezary Migaszewski, On the origin of extreme trans-Neptunian objects within Modified Newtonian Dynamics (arXiv:2303.13339)

    astronomer

    diff, v25, current

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