One of the founders of the theory of cosmic inflation, a cosmologist and a Russian academician, Alexei Starobinsky visited Belgrade this September. Together with a number of colleagues around the world, he participated in the International Conference of Mathematical Physics (MPHYS) organized by the Institute of Physics Belgrade (IPB). Starobinsky, who, from the 1970s, has steadily worked at the Landau Institute for Theoretical Physics in Moscow, came to Belgrade only a month after he had won the prestigious Dirac Medal.
Together with his colleagues Viatcheslav Fyodorovich Mukhanov and Rashid Alievich Sunyaev, he received the medal for their outstanding contributions to the physics of the Cosmic Microwave Background (CMB). Experimentally tested implications that have helped to transform cosmology into a precision scientific discipline have particularly been highlighted. ‘One of the main accomplishments of cosmology is that our models have stopped being models from our heads, and they transformed into real things, with predictions that can be tested,’ states Starobinsky.
In the late 1970s, Professor Starobinsky developed the early cosmic inflation model and calculated the propagation of gravitational waves during inflation. Independently from Alen Guth and Andrei Linde, he proposed the theory of cosmic inflation in 1979, and it has been attributed to all three scientists. ‘When I built the model, I did not know what would happen, but it has turned out that the observations were correct,’ says Starobinsky, who perceives physics both as experimental and theoretical science. ‘We come up with ever more models, but it is necessary to choose the ones which have results in nature since there is only one nature,’ he asserts, adding that only through experiments we can determine which model will be the one.
Alexei Starobinsky believes that forty years after the cosmic inflation theory formation, the basic ideas have remained the same, but that the number of experiments has risen dramatically, and correspondingly, the amount of proof. ‘Cosmology is replete with dramatic discoveries,’ claims Starobinsky, exemplifying the confirmation of gravitational waves formed by two black holes colliding. If periodical gravitational waves, proposed by the Starobinsky inflation model, were discovered, it would, according to him, be even more dramatic because it would impact quantum gravity.
Although he considers cosmology as a very exciting field with a plethora of puzzles and conundrums, one of them is the most important of our times – what dark matter consists of.