What question did this study set out to answer?

This work aims to improve the understanding of the MOND acceleration scale through an evolving symmetron coupling mechanism.

May 10, 2026Open Access

Improved Information-Coupled Scalar-Tensor Theory (i-ICST v11): Evolving Symmetron Coupling as the Origin of the Redshift-Dependent MOND Acceleration Scale — Calibration Against MUSE-DARK III

Key Points

This work aims to improve the understanding of the MOND acceleration scale through an evolving symmetron coupling mechanism.
Developed i-ICST v11 to replace old MOND formulas with a new symmetron coupling method.
Calibrated the model against data from the MUSE-DARK III survey.
Compared the fit of the new model with that of prior versions using chi-square analysis.
The new model significantly improves the fit with a chi2/N of 3.01 compared to 4.37 from v10, an improvement factor of 1.4x.
Predicted MOND acceleration scale at redshift 1 aligns closely with MUSE measurements at 2.54 × 10^-10 m/s².
Three major issues from the previous model were addressed, while two issues remain unresolved.

Abstract

We present i-ICST v11, whose principal revision is the replacement of the v10 holographic formula for the MOND acceleration scale a0 with a physically motivated evolving Symmetron coupling mechanism calibrated against the MUSE-DARK III survey (Ciocan et al. 2026). The effective coupling is parameterised as: betaₑff (rho, z) = beta0ᵣef (1+z) ᵍamma sqrtmax (0, 1 - rho/rhoSSB (z) ) with beta0ᵣef = 0. 2963 and gamma = 1. 06, yielding an effective MOND acceleration scale: a0ₑff (z) = sqrt (1 + 2 betaₑff² (z) ) cH (z) / (2pi) The Symmetron screening threshold co-evolves as: rhoSSB (z) = rhoSSB0 (1+z) ³ ensuring that the cosmological background remains fully screened (Geff, cosmo = 1. 0000) at all redshifts while the MOND enhancement grows inside galaxy halos. Fits against MUSE-DARK III redshift bins yield chi2/N = 3. 01, compared to 4. 37 for v10, corresponding to an improvement factor of 1. 4x. The predicted a0 (z=1) = 2. 54 × 10^-10 m/s² agrees within 1-sigma with the MUSE measurement 2. 38 (+0. 12/-0. 10) × 10^-10 m/s². The SPARC RAR fit and S8 = 0. 804 from v10 are preserved. Three critical issues from v10 are resolved, while two remain open.

Read Full Paperexternally

اسأل الذكاء الاصطناعي

Bookmark

View Full Paper