activity
20132026
most citedStability of Stochastic Gradient Descent on Nonsmooth Convex Losses

18 citations · 42 across the 16 of their papers we have counts for

collaborators

18 papers

stat.OT2026

Differentially Private Learning of Markov Chains: Near-Optimal Sample Complexity for Item and User Level Privacy

Devansh Gupta, Cristóbal Guzman, Enayat Ullah

Sequential data such as documents, conversations, and trajectories are naturally partitioned across users, motivating privacy guarantees that protect each user's entire trajectory.…

cs.LG2026

Calibeating for general proper losses: A Bregman divergence approach

Maximilian Fichtl, Cristóbal Guzmán, Nishant A. Mehta

This work introduces a general framework for calibeating based on regret minimization. As compared to Foster and Hart's seminal calibeating work which had specialized treatments of…

cs.LG2023

Differentially Private Non-Convex Optimization under the KL Condition with Optimal Rates

Michael Menart, Enayat Ullah, Raman Arora +2

We study private empirical risk minimization (ERM) problem for losses satisfying the -Kurdyka-Łojasiewicz (KL) condition. The Polyak-Łojasiewicz (PL) condition is a special…

cs.LG2023

Differentially Private Algorithms for the Stochastic Saddle Point Problem with Optimal Rates for the Strong Gap

Raef Bassily, Cristóbal Guzmán, Michael Menart

We show that convex-concave Lipschitz stochastic saddle point problems (also known as stochastic minimax optimization) can be solved under the constraint of -differential pr…

cs.LG2022

Optimal Algorithms for Stochastic Complementary Composite Minimization

Alexandre d'Aspremont, Cristóbal Guzmán, Clément Lezane

Inspired by regularization techniques in statistics and machine learning, we study complementary composite minimization in the stochastic setting. This problem corresponds to the m…

cs.LG2022★ 2 cited

Faster Rates of Convergence to Stationary Points in Differentially Private Optimization

Raman Arora, Raef Bassily, Tomás González +3

We study the problem of approximating stationary points of Lipschitz and smooth functions under -differential privacy (DP) in both the finite-sum and stochastic se…

cs.LG2022★ 2 cited

Differentially Private Generalized Linear Models Revisited

Raman Arora, Raef Bassily, Cristóbal Guzmán +2

We study the problem of -differentially private learning of linear predictors with convex losses. We provide results for two subclasses of loss functions. The first case is…

math.OC2022

Stochastic Halpern Iteration with Variance Reduction for Stochastic Monotone Inclusions

Xufeng Cai, Chaobing Song, Cristóbal Guzmán +1

We study stochastic monotone inclusion problems, which widely appear in machine learning applications, including robust regression and adversarial learning. We propose novel varian…

cs.LG2022★ 3 cited

Between Stochastic and Adversarial Online Convex Optimization: Improved Regret Bounds via Smoothness

Sarah Sachs, Hédi Hadiji, Tim van Erven +1

Stochastic and adversarial data are two widely studied settings in online learning. But many optimization tasks are neither i.i.d. nor fully adversarial, which makes it of fundamen…

cs.LG2021★ 6 cited

Differentially Private Stochastic Optimization: New Results in Convex and Non-Convex Settings

Raef Bassily, Cristóbal Guzmán, Michael Menart

We study differentially private stochastic optimization in convex and non-convex settings. For the convex case, we focus on the family of non-smooth generalized linear losses (GLLs…

cs.LG2021

Best-Case Lower Bounds in Online Learning

Cristóbal Guzmán, Nishant A. Mehta, Ali Mortazavi

Much of the work in online learning focuses on the study of sublinear upper bounds on the regret. In this work, we initiate the study of best-case lower bounds in online convex opt…

cs.DS2021

An Optimal Algorithm for Strict Circular Seriation

Santiago Armstrong, Cristóbal Guzmán, Carlos A. Sing-Long

We study the problem of circular seriation, where we are given a matrix of pairwise dissimilarities between objects, and the goal is to find a {\em circular order} of the objec…

math.OC2021

Optimal Algorithms for Differentially Private Stochastic Monotone Variational Inequalities and Saddle-Point Problems

Digvijay Boob, Cristóbal Guzmán

In this work, we conduct the first systematic study of stochastic variational inequality (SVI) and stochastic saddle point (SSP) problems under the constraint of differential priva…

math.OC2021★ 10 cited

The Complexity of Nonconvex-Strongly-Concave Minimax Optimization

Siqi Zhang, Junchi Yang, Cristóbal Guzmán +2

This paper studies the complexity for finding approximate stationary points of nonconvex-strongly-concave (NC-SC) smooth minimax problems, in both general and averaged smooth finit…

cs.LG2021

Non-Euclidean Differentially Private Stochastic Convex Optimization: Optimal Rates in Linear Time

Raef Bassily, Cristóbal Guzmán, Anupama Nandi

Differentially private (DP) stochastic convex optimization (SCO) is a fundamental problem, where the goal is to approximately minimize the population risk with respect to a convex…

math.OC2021

Complementary Composite Minimization, Small Gradients in General Norms, and Applications

Jelena Diakonikolas, Cristóbal Guzmán

Composite minimization is a powerful framework in large-scale convex optimization, based on decoupling of the objective function into terms with structurally different properties a…

cs.LG2020★ 18 cited

Stability of Stochastic Gradient Descent on Nonsmooth Convex Losses

Raef Bassily, Vitaly Feldman, Cristóbal Guzmán +1

Uniform stability is a notion of algorithmic stability that bounds the worst case change in the model output by the algorithm when a single data point in the dataset is replaced. A…

math.OC2013★ 1 cited

An Optimal Affine Invariant Smooth Minimization Algorithm

Alexandre d'Aspremont, Cristóbal Guzmán, Martin Jaggi

We formulate an affine invariant implementation of the accelerated first-order algorithm in Nesterov (1983). Its complexity bound is proportional to an affine invariant regularity…