Comparison of MOND and Verlinde's emergent gravity in dwarf spheroidals

We apply Modified Newtonian Dynamics (MOND) and Verlinde’s emergent gravity separately to calculate the radial accelerations in 23 dwarf spheroidals. Then, we compare them with the observed radial accelerations. In our earlier work, we determined that, when the data set is considered in its entirety without isolating individual dwarf spheroidal, Verlinde’s emergent gravity is in close agreement with the observed values. In the present work, we additionally confirm that, for 21 of the 23 samples examined, Verlinde’s emergent gravity follows the trend of the observed values within each dwarf spheroidal more closely than MOND. Combining the statistical significance of all the 23 samples, ranging from $-0.25σ$ to 3.41$σ$, we conclude that Verlinde’s emergent gravity is favored over MOND at 5.2$σ$.

💡 Research Summary

The paper presents a systematic comparison between Modified Newtonian Dynamics (MOND) and Erik Verlinde’s emergent gravity (EG) using radial acceleration data from 23 dwarf spheroidal galaxies (dSphs). The authors build on their earlier work, which showed that when all dSph data are treated as a single ensemble, EG reproduces the observed accelerations better than MOND. Here they drill down to the level of individual galaxies, asking whether the trend of observed acceleration (g_obs) as a function of radius matches the theoretical predictions of each model more closely.

Methodologically, each dSph is approximated as a spherically symmetric system. The baryonic mass profile M(r) is taken from the authors’ previous study, allowing the Newtonian baryonic acceleration ḡ(r)=GM(r)/r² to be calculated. For MOND they adopt the empirical interpolating function g_MOND = ḡ / (1 – exp