Olga Ladyzhenskaya: Why is Google Doodle celebrating the Russian mathematician’s 97th birthday?

Influential Russian mathematician Olga Ladyzhenskaya is being celebrated in today's Google Doodle.

Ladyzhenskaya, who would have turned 97-years-old today, overcame personal tragedy at a young age to become one of her country's top thinkers.

Known for her work on partial differential equations, Ladyzhenskaya authored hundreds of papers and was recognised with the Lomonosov Gold Medal in 2002.

Olga Ladyzhenskaya was born in the small town of Kologriv in 1922, the daughter of a maths teacher who was descended from Russian nobility.

It was her father who inspired in her a love of maths, in particular algebra, and she grew up in a loving family which struggled under the rule of the Soviets who made life hard for intellectuals and families from nobility.

She was devastated when, at 15-years-old, her father was thrown into jail and later executed by the Soviet authorities who accused him of being an "enemy of the people".

Unlike her two sisters who were forbidden to finish their studies, Ladyzhenskaya graduated high school with excellent grades.

But because of her father's status as an "enemy of the people" she was forbidden from entering Leningrad University and to get by the family sold dresses, shoes and soap.

At the beginning of World War II she was forced to leave Leningrad and eventually returned to Kologriv where she taught secondary school maths at the same place her father did.

Thanks to the intervention of the mother of one her pupils, Ladyzhenskaya was finally offered the opportunity to go to Moscow State University where she studied under famous mathematician Ivan Petrovsky.

She later became a postgraduate student at Leningrad State University but could not publish her thesis until the death of Joseph Stalin in 1953, meaning she could finally be granted the degree she had wanted.

After the publication of her thesis, Ladyzhenskaya started teaching at the university and later became a researcher at the Steklov Mathematical Institute, where she stayed until 1991 having climbed up the ranks to become head of the Laboratory of Mathematical Physics.

Even after the collapse of the Soviet Union, Ladyzhenskaya elected to stay in Russia despite the economic turmoil this brought.

She was a member of the St Petersburg Mathematical Society from 1959, and became its president in 1990.

She died on January 12, 2004 aged 81-years-old, having written more than 250 papers during her lifetime. Her work on solving partial differential equations has continued to remain hugely influential and recognised by institutions all over the world.