Jean-Louis Nicolas

Jean-Louis Nicolas is a French number theorist.

He is the namesake (with Paul Erdős) of the Erdős–Nicolas numbers,^[1][2] and was a frequent co-author of Erdős,^[3] who would take over the desk of Nicolas' wife Anne-Marie (also a mathematician) whenever he would visit.^[4] Nicolas is also known for his research on integer partitions,^[4] and for his unusual proof that there exist infinitely many n for which

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

where ${\displaystyle \varphi (n)}$ 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.^[5]

Nicolas earned his Ph.D. in 1968 as a student of Charles Pisot.^[6] He works at Claude Bernard University Lyon 1.^[7]

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.^[8]

References

1. De Koninck, Jean-Marie (2009), Those Fascinating Numbers, American Mathematical Soc., p. 141, ISBN 978-0-8218-4807-4
2. Erdős, P.; Nicolas, J.L. (1975), "Répartition des nombres superabondants" (PDF), Bull. Soc. Math. France, 79 (103): 65–90, doi:10.24033/bsmf.1793, Zbl 0306.10025
3. List of collaborators of Erdős by number of joint papers Archived 2008-08-04 at the Wayback Machine, from the Erdős number project web site.
4. 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, S2CID 119401679.
5. Ribenboim, Paulo (1996), The New Book of Prime Number Records, New York: Springer, p. 320, ISBN 0-387-94457-5.
6. Jean-Louis Nicolas at the Mathematics Genealogy Project
7. Jean-Louis Nicolas, Claude Bernard University Lyon 1, retrieved 2015-01-13.
8. "Preface", The Ramanujan Journal, 9 (1–2): 5, 2005, doi:10.1007/s11139-005-0819-3.