James Mercer FRS[1] (15 January 1883 – 21 February 1932) was a mathematician, born in Bootle, close to Liverpool, England.
He became a Fellow, saw active service at the Battle of Jutland in World War I and, after decades of ill health, died in London.
He proved Mercer's theorem, which states that positive-definite kernels can be expressed as a dot product in a high-dimensional space.
This theorem is the basis of the kernel trick (applied by Aizerman), which allows linear algorithms to be easily converted into non-linear algorithms.
This article about a United Kingdom mathematician is a stub.