Hédi Hadiji

I am a post-doc in the team of Tim van Erven at the Korteweg-de Vries Institute for Mathematics, of the University of Amsterdam, where I work on adaptive online learning.

I completed my PhD at the LMO of the Université Paris-Saclay, studying multi-armed bandits with a focus on adaptation problems, under the supervision of Gilles Stoltz and Pascal Massart. Before that, I graduated from the École Polytechnique in 2016. I completed the Part III of the Mathematical Tripos at the University of Cambridge (2015-2016) and also obtained a Master's degree (M2) in Probability and Statistics at Orsay in 2016-2017.

Contact me at: h dot hadiji at uva dot nl (or at) hedi dot hadiji at gmail dot com



Diversity-preserving K-armed bandits, revisited, with Sébastien Gerchinovitz, Jean-Michel Loubes, and Gilles Stoltz, 2020, submitted [HAL]

Adaptation to the Range in K-Armed Bandits, with Gilles Stoltz, 2020, submitted [HAL]

Polynomial cost of adaptation for X-armed bandits, Advances in Neural Information Processing Systems (NeurIPS), 2019 [arxiv, poster]

KL-UCB-switch: optimal regret bounds for stochastic bandits from both a distribution-dependent and a distribution-free viewpoints, with Aurélien Garivier, Pierre Ménard and Gilles Stoltz, 2018, submitted [arxiv]


Polynomial cost of adaptation for X-armed bandits, February 12th 2020, Thematic Statistics Seminar in Machine Learning, Leiden University

Polynomial cost of adaptation for X-armed bandits, October 17th 2019, Seminar of the Institut für Mathematische Stochastik (IMST), Otto-von-Guericke-Universität, Magdeburg.

Polynomial cost of adaptation for X-armed bandits, September 24th 2019, Workshop of the Celeste INRIA team

X-armed bandits, June 2019, Séminaire des doctorants, Orsay

KL-UCB-switch, May 29. 2018 50èmes Journées de Statistique, EDF Lab Paris Saclay


I have reviewed for NeurIPS 2019 (top 400 reviewer) and for Mathematics of Operations Research.

Here is a GitHub link to my personal python bandit laboratory for numerical experiments.


For the year 2019-2020, I was a teaching assistant for the following classes at Orsay:

  • Mathematical Statistics (M1, 1st year Master's students) [webpage]
  • Statistics for Biologists, including R lab sessions (L2, 2nd year students)

During the years 2017-2019, at the IUT de Sceaux. I TA'ed the courses:

  • Mathematics for Business, Mathematics and Personal Finance 1st year students
  • Elementary Statistics, 2nd year students


I enjoy bouldering and free climbing, and I'd like to be better at chess. I read a lot of comics/graphic novels, and sometimes real books. When I feel free, I like to go to the movies.

My first name is Hédi and my last name is Hadiji. In Arabic my first name is written هادي. In English (or in French, actually) pronounce my name like "Eddy".