Although the concept of dark matter is the key point of the LCDM cosmological model (Lambda-CDM model), there are several problems with this concept. And the real problem is that, despite all their efforts, scientists have yet to find direct evidence for the existence of dark matter particles in the so-called species. In this regard, some scientists are inclined to alternative options such as modified Newtonian dynamics (MoND) or modified gravity theory. At most, some of the more recent research speaks directly to support these alternative theories.

The MoND theory arose as a result of inconsistencies in observations of the rotation of galaxies. Most of the matter in galaxies is clustered in the central portion, so stars near the center would be expected to have higher orbital velocities. But practically everything is different, in almost all galaxies the stars revolve around the center at more or less the same speed. And in 1983, Israeli astrophysicist Mordehai Milgrom put forward the first hypothesis regarding the “falseness” of the current model of gravity.

At interstellar distances, gravitational forces between stars clearly obey Newtonian dynamics and the law of gravity. Instead of starting a change in Albert Einstein’s General Theory of Relativity, Milgrom proposed a change in Newton’s law of universal gravitation. Gravity, they claim, is not a pure inverse square relationship, there is another component to this law that does not depend on distance. This component adds up to only 10 parts per trillion g, but this is enough to explain some of the inconsistencies in the rotation of galaxies.

Of course, adding a tiny constant component to Newton’s equation means the need to change Einstein’s equations as well. This has led to some different ways of representing thorium MoND, such as AQUAL (A QUADrAdic Lagrangian). Both the AQUAL and the standard LCDM model can explain observed galaxy rotations with small, subtle differences.

One of the differences between AQUAL and LCDM is the difference in the rotation rates of the stars in the inner and outer parts of the galaxies. According to the LCDM model, the curves of the distribution of stellar velocities should be smooth, but the AQUAL model predicts the presence of a small loop in the curve, which is associated with a modified theory of gravity. This difference is too small to be seen and measured in a single galaxy sample. But statistics compiled from observations of many galaxies can reveal this.

And recently, a group of scientists conducted a study of 152 galaxies whose data were taken from the SPARC database (Spitzer Photometry and Accurate Rotation Curves). According to these data, corresponding high-resolution graphs were made and their comparative analyzes were performed, the results of which exactly correspond to the predictions of the AQUAL model.

This is certainly an exciting result, and some proponents of the alternative theory are already saying, “Long live MoND!” she shouts. However, all this does not mean that the possibility of the existence of dark matter is completely ruled out, because the AQUAL model has its own problems, for example, with gravitational lenses and the galaxies that make them up.