I work in continuous optimization, usually motivated by problems arising in machine learning. My main interest lies in the analysis of first-order methods in stochastic, nonconvex, nonsmooth, and semialgebraic settings. I am also interested in optimization on manifolds, the theory of deep learning, and more generally in the geometry underlying optimization.

Publications & preprints

2026

On convergence rates of subgradient descent on semialgebraic functions

E. Chzhen, S. Schechtman

arXiv preprint, 2026

Animation of the subgradient method: iterates descend a semialgebraic landscape, crossing the strata S0 and S1, while the objective value decreases over iterations k.
Constant-step subgradient descent crossing the strata S₀, S₁ of a semialgebraic landscape — the iterates locally shadow a Riemannian gradient descent on strata.

The gradient's limit of a definable family of functions admits a variational stratification

S. Schechtman

SIAM Journal on Optimization 36(2):1075–1099

2025

The late-stage training dynamics of (stochastic) subgradient descent on homogeneous neural networks

S. Schechtman, N. Schreuder

COLT 2025 · PMLR 291:5143–5172

2024

Stochastic subgradient descent escapes active strict saddles on weakly convex functions

P. Bianchi, W. Hachem, S. Schechtman

Mathematics of Operations Research 49(3):1761–1790

2023

Stochastic proximal subgradient descent oscillates in the vicinity of its accumulation set

S. Schechtman

Optimization Letters 17(1):177–190

Orthogonal directions constrained gradient method: from non-linear equality constraints to the Stiefel manifold

S. Schechtman, D. Tiapkin, M. Muehlebach, É. Moulines

COLT 2023 · PMLR 195:1228–1258

ASkewSGD: an annealed interval-constrained optimisation method to train quantized neural networks

L. Leconte, S. Schechtman, É. Moulines

AISTATS 2023 · PMLR 206:3644–3663

2022

Convergence of constant step stochastic gradient descent for non-smooth non-convex functions

P. Bianchi, W. Hachem, S. Schechtman

Set-Valued and Variational Analysis 30(3):1117–1147

First-order constrained optimization: non-smooth dynamical system viewpoint

S. Schechtman, D. Tiapkin, É. Moulines, M. I. Jordan, M. Muehlebach

IFAC-PapersOnLine 55(16):236–241 · CAO 2022

2021

Stochastic optimization with momentum: convergence, fluctuations, and traps avoidance

A. Barakat, P. Bianchi, W. Hachem, S. Schechtman

Electronic Journal of Statistics 15(2):3892–3947

2019

Passty Langevin

S. Schechtman, A. Salim, P. Bianchi

CAP, Toulouse, France

Work experience

2022 –

Télécom SudParis (SAMOVAR) — Assistant Professor

2021 – 22

École Polytechnique (CMAP) — postdoc, with Éric Moulines

2018 – 21

Université Gustave Eiffel (LIGM) — PhD, with Pascal Bianchi and Walid Hachem