Jean-Louis Nicolas

Jean-Louis Nicolas is a French number theorist.

He is the namesake (with Paul Erdős) of the Erdős–Nicolas numbers,^[1] and was a frequent co-author of Erdős,^[2] who would take over the desk of Nicolas' wife Anne-Marie (also a mathematician) whenever he would visit.^[3] Nicolas is also known for his research on partitions,^[3] and for his unusual proof that there exist infinitely many n for which

$\varphi(n) < e^{-\gamma}\frac {n} {\log \log n}$

where $\varphi(n)$ is Euler's totient function and γ is Euler's constant: he proved this bound unconditionally by providing two different proofs, one in the case that the Riemann hypothesis holds and another in the case that it fails.^[4]

Nicolas earned his Ph.D. in 1968 as a student of Charles Pisot.^[5] He works at Claude Bernard University Lyon 1.^[6]

A conference in honor of Nicolas' 60th birthday was held on January 14–19, 2002 at the Centre International de Rencontres Mathématiques in Marseille. The proceedings of the conference were published as a festschrift in The Ramanujan Journal.^[7]

References

1. De Koninck, Jean-Marie (2009), Those Fascinating Numbers, p. 141, ISBN 978-0-8218-4807-4
2. List of collaborators of Erdős by number of joint papers, from the Erdős number project web site.
3. Sárközy, A. (2005), "Jean-Louis Nicolas and the partitions", The Ramanujan Journal 9 (1-2): 7–17, doi:10.1007/s11139-005-0820-x, MR 2166373.
4. Ribenboim, Paulo (1996), The New Book of Prime Number Records, New York: Springer, p. 320, ISBN 0-387-94457-5.
5. Jean-Louis Nicolas at the Mathematics Genealogy Project
6. Jean-Marie Nicolas, Claude Bernard University Lyon 1, retrieved 2015-01-13.
7. Editors (2005), "Preface", The Ramanujan Journal 9 (1-2): 5, doi:10.1007/s11139-005-0819-3.