British theoretical physicists have developed a theory that can solve one of the biggest mysteries in the Universe: why the rate of expansion of our universe is accelerating, and not slowing down, as predicted by the laws of physics we know. According to an article published on the portal futurism.com, the hypothesis of "massive gravity" can modify Einstein's general theory of relativity, simultaneously explaining the inequality in the expansion rates of the universe.
Why is the universe expanding?
Currently, the main explanation of how exactly our universe appeared is the hypothesis of the Big Bang, as a result of which all the particles known to us, which make up not only the space around us, but also ourselves, flew out from one single point, thereby giving rise to the familiar The universe. According to Einstein's general theory of relativity, the gravitational forces of all objects in our universe should gradually attract the Universe, slowing down the rate of its expansion.
However, back in 1998, scientists realized that the expansion rate of the Universe is not only not slowing down, but even accelerating. Due to the fact that the researchers had no idea about the processes that provoke such a behavior of the universe, it was decided to introduce the concept of dark energy, which could somehow explain the problem of the expansion of the universe. Despite the fact that modern physics needs this type of energy to exist, it is not possible to prove its reality. So, even if it exists, energy should be fundamentally different from all the rest of the substance in the Universe, due to its anti-gravitational properties, as well as negative pressure. For a long time it was believed that the well-known vacuum can lay claim to the title of dark energy, but so far there have not been enough experiments to confirm such an unusual hypothesis.
The slow expansion of the universe can be explained without the participation of dark energy
The new idea, called de Rham's theory of massive gravity, removes the need for dark energy in the universe by changing Einstein's theory of general relativity. So, instead of massless gravitons from the theory of relativity, which are responsible for gravity, the new theory assumes the presence in the Universe of another type of hypothetical particles, but with a certain mass. In other words, gravity in the new physical model can fulfill the role currently attributed to that same dark energy.
The researchers hope that advances in gravitational wave astronomy will test predictions about the theory of massive gravity within the next decade. This historical moment can not only give humanity the opportunity to better understand the fundamental issues of the Universe, but also reveal the secret of the reality of the existence of dark matter and energy, which for a long time haunted researchers of the XX and XXI centuries.