Jørgen Pedersen Gram

Jørgen Pedersen Gram ( * June 27, 1850 in Nustrup in Haderslev, † April 29, 1916 in Copenhagen) was a Danish mathematician.

Gram was the son of a farmer and went to the Kathedralsschule in Ribe. From 1868, he studied mathematics in Copenhagen, with a diploma in 1873. A year later, his first release on invariant theory appeared in the Tidskrift for mathematics and the Mathematische Annalen. Since 1875 he worked for the Hafnia Insurance Company. In 1879 he received his doctorate for a publication on infinite series in the least squares method ( published in Crelle Journal for Pure and Applied Mathematics ).

In addition to purely mathematical work, he also published works on forestry, where he pursued both the mathematical side, as well as your own experiments with trees carried out to adapt its models. In 1884 he founded his own insurance company Skjold, was a Director until 1910. He remained but continue in a senior position in the Hafnia insurance works and was from 1895 to 1910 in its Executive Board. 1910 to 1916 he was chairman of the Danish Insurance Council.

Although Gram gave no lectures at the University, but gave lectures in front of the Danish Mathematical Society from 1883 to 1889, and was editor of the Tidskrift for mathematics. He also peer reviewed Danish mathematical work for the yearbook on the progress of mathematics.

Gram was married since 1879 and after the death of his first wife in second marriage from 1896. He was a member of the Danish Academy of Sciences since 1888, was for many years the treasurer and received the 1884 Gold Medal for a paper on distribution of primes. Gram died on the way to a meeting of the Danish Academy of Sciences after he was hit by a bicycle.

His achievements include the Gram -Schmidt orthogonalization ( but that was already known, for example, Laplace and Cauchy ) and its series representation of the Riemann zeta function. In particular, he was one of the first who calculated the non-trivial zeros of the Riemann zeta function with a higher numerical accuracy. He published his results in 1903 for the first fifteen nontrivial zeros. As a result of his investigations to Gram- named points, Gram- Gram blocks and the rule for these zeros.

In the field of number theory he corresponded with Ernst chisel. In theory, the grid it is the matrix of dot products of all pairs of vectors of a base in honor referred to as Gram- matrix and its determinant as Gram determinant.