Emanuels Grīnbergs

Grinbergs and his collaborators wrote many papers on the design of electrical circuits and electronic filters, stemming from his radio work. He earned the State Prize of the Latvian SSR in 1980 for his research on nonlinear electronic circuit theory.

In 1954, Grinbergs was allowed to return to the University of Latvia faculty. In 1956, he joined the Institute of Physics of the Latvian Academy of Sciences, and in 1960, he began working at the Computer Center of the University of Latvia, where he remained for the rest of his career, eventually becoming Chief Scientist there.

In the meantime, the Soviet Union had annexed Latvia in 1940, and the army of Nazi Germany had occupied it and incorporated it into the Reichskommissariat Ostland. Grinbergs was drafted into the Latvian Legion, part of the German military, in 1944. After the war, because of his service as a German soldier, he was held prisoner in a camp in Kutaisi, Georgia, until 1946; he lost his university position, and his doctorate (awarded during the German occupation) was annulled.

In 1927, he won a high school mathematics competition, the prize for which was to study in Lille, France. He then studied mathematics at the University of Latvia beginning in 1930. On graduating in 1934, he won a prize that again funded study in France; he did graduate studies in 1935 and 1936 at the École Normale Supérieure in Paris, during which he published his first paper, in geometry. He returned to the University of Latvia as a privatdozent in 1937, and joined the faculty as a dozent in 1940. His lectures at that time covered subjects including geometry, probability theory, and group theory. While there, he defended a thesis in geometry at the University of Latvia in 1943, entitled On Oscillations, Superoscillations and Characteristic Points.

Emanuels Donats Frīdrihs Jānis Grinbergs (1911–1982, westernized as Emanuel Grinberg) was a Latvian mathematician, known for Grinberg's theorem on the Hamiltonicity of planar graphs.

Grinbergs was born on January 25, 1911 in St. Petersburg, the son of a Lutheran bishop from Latvia. Latvia became independent from Russia in 1917, and on the death of his father in 1923, Grinbergs' family returned to Riga, taking Grinbergs with them.