Nayel Bettache, PhD
Visiting Assistant Professor
Cornell University – Department of Statistics and Data Science
- Office
- Surge B 158, 220 Tower Road, Ithaca, NY 14853
- nbb45@cornell.edu
About Me
I am a Jacob Wolfzwitz Visiting Assistant Professor at Cornell University.
I hold a PhD in Mathematical Statistics from CREST and Institut Polytechnique de Paris. My supervisor was Cristina Butucea. My manuscript is available here and you can find the slides from the defense here.
My research delves into the foundational aspects of mathematical statistics and machine learning, placing a special emphasis on crafting practical and efficient learning methods with provable theoretical guarantees. I am particularly interested in time series, random matrix theory and high dimensional estimation problems.
Current CoursesSpring 2025
Publications
Preprints
- Bivariate Matrix-valued Linear Regression (BMLR): Finite-sample performance under Identifiability and Sparsity Assumptions Preprint ArXiv, 2024.
Journal
- Low-rank regularization in two-sided matrix regression Accepted by Electronic Journal of Statistics (EJS), 2025.
- Fast nonasymptotic testing and support recovery for large sparse Toeplitz covariance matrices Accepted by Journal of Multivariate Analysis (JMVA), 2022.
Academic Appointments
- Visiting Assistant Professor Since Aug. 2024 Cornell University, Department of Statistics and Data Science
- Visiting Researcher April 2023 Harvard University, Invited by Tracy Ke
- Visiting Researcher May 2023 Cornell University, Invited by Florentina Bunea
- Graduate Researcher Jan. 2023 – Aug. 2023 CREST-ENSAE, Supervised by Cristina Butucea
- Research Intern Jun. 2018 – Sep. 2018 CREST-ENSAE, Supervised by Cristina Butucea
Industrial Experience
- Quantitative Research Intern Jul. 2020 – Dec. 2020 BNP Paribas (London), Under the supervision of Philippe Amzelek
- Quantitative Research Intern Jun. 2019 – Oct. 2019 Advestis (Paris), Under the supervision of Christophe Geissler
Education
- PhD in Mathematical Statistics Sep. 2021 – Jul. 2024 Institut Polytechnique de Paris
- M.Sc Statistics and Learning Sep. 2017 – Jul. 2020 ENSAE IP Paris
- M.Sc Data Science Sep. 2019 – Jul. 2020 École Polytechnique
- Classes Préparatoires MPSI-MP Sep. 2014 – Jul. 2017 Institution Aux Lazaristes
Teaching
Cornell University – Visiting Assistant Professor
- Statistical Methods II, STSCI 6020 Spring 2025 PhD Level – Class Roster
- Introduction to R Programming, STSCI 2120/5120 Fall 2024 Undergraduate and Graduate – Class Roster
- Data Mining and Machine Learning, STSCI 3740/5740 Fall 2024 Undergraduate and Graduate – Class Roster
ENSAE – Teaching Assistant
Honored in the top 1% of teachers for exceptional pedagogical quality.
- Probability Theory Spring 2024 & 2023 Undergraduate (L3) – Professor: Victor-Emmanuel Brunel
- Measure Theory Fall 2023 & 2022 Undergraduate (L3) – Professor: Cristina Butucea
- Optimization Spring 2023 & 2022 Undergraduate (L3) – Professor: Guillaume Lecué
- Statistical Learning Fall 2022 & 2021 Graduate (M2) – Professor: Cristina Butucea
- Machine Learning Spring 2022 Graduate (M1) – Professor: Vianney Perchet
- Linear Algebra Fall 2021 Undergraduate (L3) – Professor: Mathieu Lerasle
- Numerical Methods Spring 2021 Undergraduate (L3) – Professor: Sidi Mahmoud Kaber
- Introduction to Statistics Spring 2021 Undergraduate (L3) – Professor: Mathieu Lerasle
Nayel Prepa – Founder
Received a stellar 100% 5-star rating on Trustpilot.
- Founding a company democratising access to high-quality mathematics education for undergraduate students.
- Publishing 80 videos, garnered 7.5k subscribers and amassed over 315k views on YouTube.
- Training successfully 100+ students.
Grants, Talks & Conferences
Grants
- Junior Scientific Visibility 2023 Fondation Mathématique Jacques Hadamard (2300€)
- PhD Grant 2021–2024 Genes (100k€)
Talks
- PhD Defense July 2024 Palaiseau (France)
- European Meeting of Statisticians July 2023 Warsaw (Poland)
- Harvard Stat 300 Seminar May 2023 Harvard University, Cambridge (MA, USA)
International Conferences
- Meeting in Mathematical Statistics December 2024 Luminy (France)
- Statistics and Learning Theory in the Era of Artificial Intelligence June 2024 Oberwolfach (Germany)
- Jianqing Fan's 60th Birthday Celebration May 2023 Princeton (NJ, USA)