Astrophysicists tell the story of mathematical cosmology

Astrophysicists from RUDN University have collected the most important discoveries of modern cosmology from 1917 to the present day. The collected data became an introduction to Philosophical Transactions of the Royal Society A in two parts: from 1917 to 1980 and from 1980 to the present day.

Cosmology, the science of the properties and evolution of the universe, originated in antiquity in the form of religious myths about the creation of the world. Over the past hundred years, cosmology has become one of the most dynamic, albeit one of the most complex, fields of science. One of the last issues of Philosophical Transactions of the Royal Society A is devoted to the present and the future of mathematical cosmology.

RUDN professors Spiros Cotsakis and Alexander Yefremov are the editors of the issue. In the introduction, astrophysicists analyzed the entire history of the development of modern theoretical cosmology. The newspaper Philosophical transactions is one of the oldest journals in the world, and it has been published continuously since 1665, including articles by Newton, Leibniz, Huygens and Boyle.

“The beauty and great diversity of the ideas of modern mathematical cosmology are rooted in various types of geometry which must be developed and studied in parallel and in combination with these cosmological ideas. This is necessary to better understand various aspects of this most majestic of areas of theoretical physics,” said Alexander Yefremov, doctor of physical and mathematical sciences, professor at the Pedagogical-Scientific Institute of Gravity and Cosmology at RUDN University.

The authors divided the history of the development of cosmology into four stages. The first and longest covers the period from 1917 to 1960. The following three periods last 20 years. The year 1917, especially the date of February 8, 1917, is known for the birth of modern cosmology at RUDN astrophysics, when Einstein demonstrated the first application of the general theory of relativity to the universe. He created the first modern cosmological model in which matter is motionless and has finite volume, but has no boundaries. The static nature of the universe according to Einstein is obtained thanks to the cosmological constant. Other cosmological models soon appeared.

A real breakthrough in modern cosmology was achieved by the Russian mathematician Alexander Fridman. In 1922, he found a solution to Einstein’s equations describing a dynamically expanding universe; this theory was experimentally (and sensationally) confirmed by British astronomer Edwin Hubble, who in 1929 discovered the so-called redshift of galaxies, meaning that they are moving away from each other.

Later, based on this information, Georgy Gamov (USA) formulated the theory of the hot universe (at an early stage of its existence), and a little later (1949) the process of the birth of such a model of the universe became known as the Big Bang. The term is believed to have been coined by British astronomer Fred Hoyle.

In the late 1970s, discoveries in particle physics led to grand unifying models that had an immediate impact on cosmology. Later, the inflationary model of the universe, the multiverse theory and other important theoretical discoveries appeared. Since 1998, cosmologists have been mainly interested in dark energy, the main component of the universe.

“Theoretical mathematical cosmology is not a subject that can be easily understood. To overcome the difficulty of acquiring the necessary knowledge, you need a clear compass that shows what problems and directions of research are available, important or feasible We have described some key important developments in the field of modern theoretical cosmology since its inception in 1917. We have identified and discussed some of the important ideas that characterize the nature of this field within the framework of theoretical physics,” Spiros said. Cotsakis, professor at the Pedagogical and Scientific Institute of Gravity and Cosmology at RUDN University