Stephen Gelbart

The Nicki and J. Ira Harris Professorial Chair

 

The purpose of number theory is to unravel the mysteries of the set of integers 1,2,3,..., and to explore the patterns which arise from using integers to solve polynomial equations. For example, it turns out that some integers can be written as the sum of two squares (e.g. 5), but others (like 7) cannot. Exactly which integers can be so expressed, and what is their pattern? Questions like these are difficult to answer precisely because there are infinitely many integers, and hence infinitely many equations M = x2+y2 to solve. In particular, checking things directly (say with a large computer) is useless (since a computer can deal with only finitely many calculations in any given time). Instead, answers to these questions come from esoteric mathematical theories such as group representations and automorphic forms. These are my particular areas of research. Though the motivation at present is theoretical, it is clear that our work will eventually have applications to other branches of mathematics and science, just as the number theory developed hundreds of years ago has already had applications to such fields as cryptography.

 

Recent Publications

 

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