# 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

${\displaystyle \varphi (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.[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 Archived 2008-08-04 at the Wayback Machine., from the Erdős number project web site.
3. ^ a b 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. ^
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.