Helsinki (AFP) - Four mathematicians won Tuesday in Helsinki the Fields Medal , which is described as the "Nobel in Mathematics", including Ukrainian Marina Vyazovska, the second woman to win this prestigious award since its launch in 1936.

The other winners of this medal, which is awarded every four years, are France's Hugo Dominil Copan, US-based researcher John Huh, and Britain's James Maynard.

Awarded by the International Mathematical Union, the medal honors the "extraordinary discoveries" of mathematicians under the age of 40.

The winners were announced during a ceremony held in the Finnish capital in the framework of the International Conference of Mathematics.

The event was scheduled to be held in the Russian city of St. Petersburg, but those in charge of the ceremony moved it to Helsinki because of the war in Ukraine.

Frenchman Ugo Dominil Copan, 36, devotes his work to statistical physics.

This specialist in probability mathematicians and university professor since the age of twenty-nine distributes his time between the Institute of Higher Scientific Studies near Paris and the Swiss University of Geneva.

He won the award after solving “chronic issues related to the probabilistic theory of phase transitions,” which allowed the opening of “new research directions,” according to the award-winning committee.

As for Marina Viazovska, who is the second woman to win the award since its inception eight decades ago, she was born 37 years ago in Ukraine during the Soviet era.

Since 2017, she has been a professor at the Federal Polytechnic College in Lausanne, Switzerland.

The mathematician was awarded the prize for solving a version of a centuries-old geometry problem, by proving the densest stacking of identical spheres outside three-dimensional space, in this case the eighth dimension where symmetry is optimal.

The "compact stacking problem", more commonly known as the "merchant's orange problem", has troubled mathematicians since the 16th century, when the question arose of stacking as many cannonballs as possible.

In 2014, Iranian Maryam Mirzakhani, who died of cancer three years later, was the first woman to win the Fields Medal.

Also, the 35-year-old British James Maynard, a professor at the British University of Oxford, won this medal "for his contributions to analytical number theory, which led to significant progress in understanding the structure of prime numbers and in the Diophantine approximation."

For his part, Professor at Princeton University John Huh, 39, was chosen to win the award in recognition of his "transformation" of the field of harmonic geometry "using methods from Hodge theory, tropical geometry, and the theory of singularities."