The statement from the Vatican Astronomical Observatory points out that Albert Einstein’s theory of general relativity, which postulates that gravity is the curvature of space-time rather than a force as proposed by Isaac Newton’s theory of gravity, remains the best physical theory “for understanding the large-scale structure of the universe today.” However, he adds that there are still unresolved questions about the laws of physics during the first moments of the universe and about how gravity works on extremely small scales, which can be studied using quantum mechanics.
Currently, there are alternative or modified theories of gravity that suggest that gravity might behave differently than general relativity predicts, even with respect to the large-scale structure of the universe.
In his new article, “On the canonical equivalence between the Jordan and Einstein frameworks”, Father Gionti and Father Galaverni demonstrate how they can “map” the solution to a physical problem from an alternative theory of gravity to general relativity, using a mathematical trick. This trick consists of analyzing the problem through two different mathematical frameworks, known as the “Jordan” and “Einstein” frameworks, which are different approaches to describing the geometry of space-time in general relativity, each with its own advantages and specific applications.