what did he work on, with the last person mentioned here?
He with Albert Einstein on a unified field theory encompassing all physical interactions.
Peter Bergmann
Peter Gabriel Bergmann (Berlin, 24 March 1915 – Seattle, 19 October 2002) was a German-American physicist of Jewish origins best known for his work with Albert Einstein on a unified field theory encompassing all physical interactions. 
who came up with the theory of continuous matter Albert Einstein are there any other scientists or physicists associated with the theory mentioned? Yes, Robert Brown. any theories named after him? Yes, the "Brownian Motion". what does this theory state? It states that pattern of motion typically consists of random fluctuations in a particle's position inside a fluid sub-domain, followed by a relocation to another sub-domain. did this scientist write any books? Yes, the "Prodromus Florae Novae Hollandiae et Insulae Van Diemen". when was it published? 1810 when did the first scientist mentioned above publish his first scientific paper? 1900 what was it on? Capillary Attraction what other interests did he have, apart from science? UNANSWERABLE has he collaborated with other scientists on any work? Yes, Leopold Infeld, Nathan Rosen, Peter Bergmann and others.
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Peter Bergmann [SEP] Introduction
Peter Gabriel Bergmann (Berlin, 24 March 1915 – Seattle, 19 October 2002) was a German-American physicist of Jewish origins best known for his work with Albert Einstein on a unified field theory encompassing all physical interactions. He also introduced primary and secondary constraints into mechanics. After obtaining his Ph.D at the German University in Prague in 1936 under the direction of Philipp Frank he went to work with Einstein, as his research assistant, at the Institute for Advanced Study between 1936 and 1941. In 1942, Bergmann published the first textbook on general relativity, "Introduction to the Theory of Relativity", with a foreword by Einstein.