Computer Model Supports MOND Hypothesis

February 12, 2020 | 12:34
Simulated matter distribution after 1.5 billion years. Lighter regions correspond to higher gas density. Image: AG Kroupa/Uni Bonn.
Simulated matter distribution after 1.5 billion years. Lighter regions correspond to higher gas density. Image: AG Kroupa/Uni Bonn.
The search for Dark Matter in the cosmos has so far proved fruitless. It must be there otherwise— according to Newtonian physics — stars travelling round in some rotating galaxies are moving so quickly they should be flung outwards. There must be some other source of gravity at work here to explain the observations. Hence dark matter; something invisible, exerting a pull to keep stars orbiting around the galactic centre.   

An alternative explanation for this cosmic anomaly is known as the MOND hypothesis. This Modified Newtonian Dynamics (MOND) model was first published in 1983 by Mordehai Milgrom and is just one of the ‘modified gravity’ hypotheses which propose an adjustment to Newton's laws to account for the observed anomalies.

MOND Simulation
It has now been demonstrated by researchers working with Prof. Dr. Pavel Kroupa from the Helmholtz Institute for Radiation and Nuclear Physics at the University of Bonn and the Astronomical Institute of Charles University in Prague at the University of Strasbourg, how galaxies can form in a MOND universe without the need for any additional dark matter forces. The software simulation developed by the researchers was used to show the formation of stars and galaxies from a gas cloud several hundred thousand years after the Big Bang. The distribution and speed of the resulting stars showed a surprisingly high correlation to observed galaxy topologies. In contrast, simulations using the ‘dark matter force’ predominantly show galaxy formation without real, pronounced matter disks.

According to Pro. Dr. Kroupa this  simulation is just first step; the model is based on assumptions about the original distribution of matter in the early universe and will now be modified to include more complex influencing factors to test if the model and MOND hypothesis is robust. The results are published in the Astrophysical Journal.

 
Loading comments...
related items