Accelerated expansion of the Universe, discovered 25 years ago, remains one of the largest mysteries of modern science. Studies of scientists are aimed at checking the foundations of physics, including the general theory of relativity of Albert Einstein. In particular, the team from the University of Geneva and the University of Toulouse III – Paul Sabatier conducted the analysis of the Dark Energy Survey (DES) project, comparing them with Einstein’s predictions. Results, published in the journal of Nature Communications revealed a slight discrepancy, which changes depending on the era in space history, casting doubt on the universality of Einstein’s theory outside the solar system.
According to Einstein, the space of the Universe is deformed under the influence of mass, like a flexible sheet, subject to curvature. Such curvatures caused by gravity of celestial bodies are called “ gravitational wells “. Passing through this distorted frame, the light deviates, similarly to how the lens refracts light. This phenomenon was called “gravitational lenslation” and was first measured during the solar eclipse of 1919, when Einstein’s predictions were confirmed by double deviation of light. Unlike Newton’s theories, Einstein’s theory takes into account not only the deformation of space, but also the time, which leads to the exact curvature of light rays.
Using Dark Energy Survey, a team from Geneva and Toulouse was able to analyze the distribution of matter and the influence of gravitational deformations, comparing the results with Einstein’s theory. As a result of the study of 100 million galaxies in four temporary segments covering periods of 3.5, 5, 6, and 7 billion years ago, scientists have found that gravitational wells 6-7 billion years ago correspond to Einstein’s predictions. However, more “young” wells (3.5 and 5 billion years ago) turned out to be a little less deep than the theory predicted.
It is interesting that it was on these time intervals that the Universe began to expand acceleratedly. This may indicate the overall