Our Universe is expanding faster and faster. What is the force behind it? Is it the fifth fundamental force predicted by some alternative theories of gravity? Scientists have chosen the Sun as their laboratory to find out.
Our Universe is expanding in a way that defies the law of gravity as we know it from Newton and Einstein. We don’t know yet the force behind it, and this mysterious observation has been dubbed as the dark energy problem, a very puzzling problem in modern physics.
Ippocratis Saltas at FZU – the Institute of Physics of the Czech Academy of Sciences in Prague and Jørgen Christensen-Dalsgaard at Aarhus University in Denmark decided to tackle the problem by searching for imprints of the fifth force in the interior of our nearest star, the Sun.
They used state-of-the-art simulations to model the solar evolution in the presence of the new force, which they then compared with observations. They found no signs of the fifth force, which allowed them to place strong constraints on the magnitude of the fifth power.
Physicists have been searching intensively for the fifth force in our Universe, from the laboratory to astrophysics and cosmology. The results of Ippocratis Saltas and Jørgen Christensen-Dalsgaard have been chosen by the journal Nature as Research Highlight 2022.