Dark Matter and MOND successes and degeneracies in reproducing SPARC rotation curves and weak lensing data

@misc{smith2026dark,
  title = {{Dark Matter and MOND successes and degeneracies in reproducing SPARC rotation curves and weak lensing data}},
  author = {Amy Smith and Francesco Shankar and Daeun Jeong and Nicola Menci and Andrea Lapi and Hao Fu and Xinyu Dai and Mariangela Bernardi and Arianna Di Cintio and Annagrazia Puglisi and Alexander Belyaev and Hendrik Ulbricht and Ivette Fuentes-Guridi},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.33157},
  eprint = {2610.33157},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.33157},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Dark Matter and MOND successes and degeneracies in reproducing SPARC rotation curves and weak lensing data
AU  - Amy Smith
AU  - Francesco Shankar
AU  - Daeun Jeong
AU  - Nicola Menci
AU  - Andrea Lapi
AU  - Hao Fu
AU  - Xinyu Dai
AU  - Mariangela Bernardi
AU  - Arianna Di Cintio
AU  - Annagrazia Puglisi
AU  - Alexander Belyaev
AU  - Hendrik Ulbricht
AU  - Ivette Fuentes-Guridi
PY  - 2026
DA  - 2026/10/23
PB  - arXiv
DO  - 10.48550/arxiv.2610.33157
UR  - https://arxiv.org/abs/2610.33157
AB  - The observed rotation velocities of spiral galaxies at large scales exceed those predicted by their baryonic components, motivating the need for dark matter (DM) or Modified Newtonian Dynamics (MOND). We fit the rotation curves of 147 late-type galaxies from the SPARC database, using a suite of models including Cold Dark Matter (CDM) models with and without baryonic feedback, Warm DM, Fuzzy DM, and MOND. We also combine SPARC kinematics with weak-lensing data to extend the mean rotation curves to ~1 Mpc. On a galaxy-by-galaxy basis, the inner SPARC rotation curves marginally favour CDM models with baryonic feedback, although accounting for the uncertainties in distances and inclinations increases the degeneracy among DM-based models and MOND. All DM models predict host halo masses larger than abundance-matching expectations, with only the CDM model with baryonic feedback reducing the scatter around the mean luminosity-halo mass relation. MOND is able to reproduce the flatness of the mean galactic rotation curves on scales up to 1 Mpc, providing stellar mass-to-light ratios within observational uncertainties. In contrast, all DM models, without the contribution of mass external to the bound halo, struggle to explain the flat rotation curves. The inclusion of the current weak-lensing data tends to favour MOND over DM models, at least at the largest scales. Future observations from BIG-SPARC, the Square Kilometre Array, and most importantly, upcoming weak-lensing surveys such as EUCLID and Rubin will provide more stringent and independent tests of these competing frameworks
ER  -