Frédéric Chyzak

(senior researcher)     orcid.org/0000-0003-3114-1191     frederic-chyzak

Research Interests

I am a researcher at Inria, in the team MATHEXP (an evolution of SPECFUN). My general domain of interest is Computer Algebra, that is, the design of fast algebraic algorithms on representations of mathematical objects in the computer.

Book

I have coauthored a book on “Efficient Algorithms in Computer Algebra” (in French). You can order an inexpensive copy of it, or download a (legal) electronic version with identical contents, but enhanced by colors and hyperlinks. See the book webpage.

Publications, Talks

See my list of publications in full or by categories. There is also a list of talks I've given.

Additional material, related to publications:

• Maple implementation and bench of the Gröbner-basis algorithms for divide-and-conquer recurrences (2020)
• Julia and Maple implementations and examples of the bijections between Łukasiewicz walks and generalized tandem walks (2020)
• Maple implementation of the reduction-based creative-telescoping algorithm for D-finite functions (2018)
• Mathematical tables that present the data computed in relation to the work on small-step walks (2016)
• Coq and Maple scripts used for the formal proof of Apéry's theorem (2014)
• Maple scripts used for the work on diagonal 3D rook paths (2011)

And here is my list of coauthors.

Software

My main activity in (research) software concerns Maple packages to perform symbolic summation and integration of special functions, namely Mgfun and related packages, as well as the generation of the online dictionary of special functions, DDMF. I have written part or all of what follows. (Dates of last release between parentheses.)

• DDMF (May 2013). Interactive website on elementary and special functions, with properties, truncated expansions, numerical evaluations, plots, and more. This project was started as a project in the MSR-Inria joint centre (2007–2013). A complete port to the new DynaMoW is currently in progress.
• ECS (June 2016). Interactive online encyclopedia of combinatorial structures. Initial work by Stéphanie Petit and Bruno Salvy (1998). Port to DynaMoW with Alexis Darrasse (2008–2011). Port to new DynaMoW with Maxence Guesdon (2015–2016).
• DynaMoW (September 2011). OCaml language extension to design interactive mathematical web sites. Initial release with Alexis Darrasse (2007–2013). Complete, modern rewrite for more responsiveness and other enhancements with Maxence Guesdon (2015–).
• Mgfun (June 2013). Creative telescoping for symbolic summation and integration. (Download Mgfun 4.1.)
• algolib (June 2013). A gathering of Maple packages written by the former Algorithms project at Inria. (No longer maintained.)
• Holonomy (June 2013). Calculates with holonomic and differentiably finite functions at the level of systems of operators. (Subsumed by Mgfun; no longer maintained.)
• Groebner (June 2013). Implements Gröbner-basis methods in commutative polynomial algebras and skew polynomial algebras. (Part of the commercial release of Maple and no longer maintained independently.)
• Ore_algebra (June 2013). Deals with algebras of linear operators and skew polynomials. (Part of the commercial release of Maple and no longer maintained independently.)

Current Students

• Alexandre Goyer (PhD, 2020–present, co-advised with Marc Mezzarobba)
• Hadrien Brochet (PhD, 2022-present, co-advised with Pierre Lairez)

Students I've Advised

• Hadrien Notarantonio (PhD, 2021–2024, co-advised with Alin Bostan and Mohab Safey El Din)
• Alexandre Roullet (Intern, 2024)
• Pingchuan Ma (PhD, 2022–2024, co-advised with Shaoshi Chen)
• Geoffrey Datchanamourtty (Master, 2023)
• Hadrien Notarantonio (Master, 2021, co-advised with Alin Bostan and Mohab Safey El Din)
• Lucas Morisset (Intern, 2020, co-advised with Jérémy Berthomieu)
• Alexandre Goyer (Master, 2020, co-advised with Marc Mezzarobba)
• Nicholas Rumiz (Master, 2020)
• Rémy Garnier (Intern, 2017, co-advised with Alin Bostan)
• Augustin Barillec (PhD, 2014, co-advised with Assia Mahboubi)
• Stéphane Henriot (Intern, 2012)
• Thomas Sibut-Pinote (Intern, 2012, co-advised with Assia Mahboubi)
• Shaoshi Chen (PhD, co-advised with Ziming Li, defended in 2011)
• Élie de Panafieu (Master, 2010, co-advised with Alin Bostan; then intern in 2011)
• Lucien Pech (Master, 2009; then intern in 2010)
• Pierre Guilleminot (Intern, 2004)
• Cyril Germa (Intern, 1999)

Post-docs and More Visitors I've Worked With

• Antonio Jiménez-Pastor (Pre-doc, fall 2019, winter-fall 2020)
• Svyatoslav Covanov (Post-doc, 2018-2019)
• Suzy Maddah (Post-doc, 2016)
• Christoph Koutschan (Post-doc, 2011-2012)
• Alexis Darrasse (Post-doc, 2010)
• Stefan Gerhold (Post-doc, 2009)
• Manuel Kauers (Post-doc, 2007-2008)
• Nicolas Le Roux (Post-doc, 2007-2008)

Teaching Activities

From 2005 to 2022, I have taught a yearly course in computer algebra in the MPRI (a former version of the current course). I co-authored a related book!

I have also taught 8 years at École Polytechnique, including a course on computer algebra (M1 level).

See also

• GDR IM (Informatique Mathématique) and its GT CF (Calcul Formel) and GT ALÉA
• RT EFI (Équations Fonctionnelles et Interactions), formerly a GDR
• ongoing ANR Project De rerum natura (a.k.a. ANR-19-CE40-0018)
• ongoing Joint MATHEXP–PolSys Seminar (since 2021)
• the former Computations and Proofs Seminar (2012–2020)
• recent Special Session at ACA 2023 in Warsaw, July 17–21, 2023: D-Finite Functions and Beyond: Algorithms, Combinatorics, and Arithmetic

Contact

Since 2012, my office is in the Inria Research Centre of Saclay, located in Palaiseau (building Alan Turing on École Polytechnique campus, full address at the bottom). See it on a map. Before that, I have worked for more than 15 years in the Inria Research Centre at Rocquencourt, ancestor of the current Paris centre.

Frédéric Chyzak, Centre Inria de Saclay, Bât. Alan Turing, 1 rue Honoré d'Estienne d'Orves, 91120 Palaiseau, France
Tel: +33 1 69 35 69 74
E-mail: frederic.chyzak@inria.fr