Paper

{
  "raw_xml": "<entry>\n    <id>http://arxiv.org/abs/2602.21975v1</id>\n    <title>How does a MOND cosmology fare on Gpc scales? - Collisionless $N$-body simulations of $ν$HDM</title>\n    <updated>2026-02-25T14:55:22Z</updated>\n    <link href='https://arxiv.org/abs/2602.21975v1' rel='alternate' type='text/html'/>\n    <link href='https://arxiv.org/pdf/2602.21975v1' rel='related' title='pdf' type='application/pdf'/>\n    <summary>We present the largest collisionless $N$-body cosmological simulations in a MOdified Newtonian Dynamics (MOND) cosmology to date. Our 4 simulations cover $Λ$CDM as a baseline, a MOND with hot dark matter model known as $ν$HDM, and 2 unphysical models we call $Λ$HDM and $ν$CDM to test the individual contributions of hot dark matter and MOND gravity, respectively. $ν$HDM reproduces the CMB power spectrum whilst also theoretically matching cluster dynamics and preserving MOND predictions for galactic rotation curves. We test its viability on cosmological scales using simulations with $256^{3}$ particles in a box of size $800/h$ comoving Mpc. We find generically that the MOND models massively overproduce large-scale structures by $z=0$, with a most massive cluster in $ν$HDM of $\\approx 5 \\times 10^{17} M_{\\odot}/h$ and typical peculiar velocities of several thousand km/s. We also explore a local void solution to the Hubble tension in these models. Analogues to the observed \"Local Hole'' do form in the MOND models, but values for the deceleration parameter $&lt;-1.5$ in these regions prevent a satisfactory resolution to the Hubble tension. Whilst $Λ$CDM significantly underpredicts the observed bulk flow in Cosmicflows-4, the high peculiar velocities that arise in the MOND models create the opposite problem, ruling out $ν$HDM at $&gt;5σ$ confidence. Observations clearly require a much milder enhancement to the rate of structure growth in $Λ$CDM than is provided by the $ν$HDM paradigm. Our results also suggest that replacing cold dark matter with hot dark matter is unlikely to provide a viable cosmological model, regardless of the gravity law.</summary>\n    <category scheme='http://arxiv.org/schemas/atom' term='astro-ph.CO'/>\n    <published>2026-02-25T14:55:22Z</published>\n    <arxiv:comment>Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS). 24 pages, 9 figures, 2 tables</arxiv:comment>\n    <arxiv:primary_category term='astro-ph.CO'/>\n    <author>\n      <name>Alfie Russell</name>\n    </author>\n    <author>\n      <name>Indranil Banik</name>\n    </author>\n    <author>\n      <name>Oscar Cray</name>\n    </author>\n    <author>\n      <name>Hongsheng Zhao</name>\n    </author>\n    <arxiv:doi>10.1093/mnras/stag399</arxiv:doi>\n    <link href='https://doi.org/10.1093/mnras/stag399' rel='related' title='doi'/>\n  </entry>"
}