PhysicsarXiv
Ranked by formulaVerdict: NotableThe formation of the first cosmic structures in hybrid Milgromian cosmology
Tackling cosmology with Milgromian Dynamics (MOND) has been a challenge ever since its theoretical inception.
VerdictWorth a reader's time today.
Abstract
Tackling cosmology with Milgromian Dynamics (MOND) has been a challenge ever since its theoretical inception. In a hybrid MOND scheme, a hypothesized light sterile neutrino of ≈ 11 eV/c² rest-mass is able to provide realistic initial conditions, fitting the third peak of the Planck CMB power spectrum as a Hot Dark Matter (HDM) component. At the same time, MOND governs the gravitational dynamics of density perturbations, while the background expansion follows the standard FLRW metric. We conduct and analyze hydrodynamical simulations of the fiducial $Λ$CDM model (H₀ = 67.8 km/s/Mpc, Ω_m ≈ 0.31, Ω_CDM ≈ 0.26), the progenitor $ν$HDM model (H₀ = 67.64 km/s/Mpc, Ω_m = 0.3, Ω_ν≈ 0.26), and its optimized version (opt-$ν$HDM model, H₀ ≈ 55.6 km/s/Mpc, Ω_m ≈ 0.49, Ω_ν ≈ 0.42), utilizing the publicly available codes RAMSES and Phantom of RAMSES. We compare for the first time the total matter power spectrum P(k) of the hydrodynamical simulations at various redshifts, examining the systematic differences of the three investigated cosmologies. The redshift evolution of the power spectrum of the $Λ$CDM model compared to the $ν$HDM variants' counterpart offers important insight about the onset of structure formation. The combination of a light sterile neutrino and MOND gravity exceeds the $Λ$CDM model's matter P(k) over all collapsing scales at late times (zlesssim 1). The density and velocity fields reveal a distinct difference between the underlying laws of gravity. Regardless of the modeled dependence in the jointly estimated data from Planck, DES Y1, SDSS, and eBOSS, the $ν$HDM hybrid models seem to produce an excess of power at associated resolution scales due to their cosmological design.
The editor's rubric
- Leverage2 / 5
- Reusable within one subfield (a technique, dataset, or protocol a few groups will adopt).
- Magnitude4 / 5
- A qualitative jump: a capability or regime that did not exist before.
- Evidence3 / 5
- Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data.
- Novelty2 / 5
- A new combination of known ideas.
- Trajectory2 / 5
- Some room to improve with obvious engineering.
- Stakes2 / 5
- Benefits a professional community (practitioners, clinicians, engineers).
Editor’s rationale
Heuristic triage from title and abstract text only, not a reading of the paper. Cues found: gains (outperforms); firsts (for the first time, first); verification (error bars); scale (scalable). Red flags: derivative (modified version, comparative study).
How the score was computed
Desks place stronger verdicts first, then use this score to order work within the same verdict.
- Merit
- 5.2 / 10
- Adjusted merit
- 4.5 / 10
- Attention
- 0%
- Freshness
- 85%