activity
20172026
most citedCalibrating Deep Neural Networks using Focal Loss

86 citations · 286 across the 31 of their papers we have counts for

collaborators

33 papers

cs.LG2026

Private online learning and prediction for Littlestone classes

Amartya Sanyal

We study mistake bounds for differentially private online learning and online prediction under oblivious realisable adversaries. Online learning requires the learner to release a h…

cs.LG2026

Adaptive Sampling and Clipping for Private Worst-Case Group Optimization

Max Cairney-Leeming, Amartya Sanyal, Christoph H. Lampert

A central requirement for the acceptance of machine learning methods for human-centric tasks is that they should be fair, in the sense that they should work comparably well for ind…

cs.LG2026

LoRA and Privacy: When Random Projections Help (and When They Don't)

Yaxi Hu, Johanna Düngler, Bernhard Schölkopf +1

We introduce the (Wishart) projection mechanism, a randomized map of the form with and study its differential privacy properties. For ve…

cs.LG2025

Learning in an Echo Chamber: Online Learning with Replay Adversary

Daniil Dmitriev, Harald Eskelund Franck, Carolin Heinzler +1

As machine learning systems increasingly train on self-annotated data, they risk reinforcing errors and becoming echo chambers of their own beliefs. We model this phenomenon by int…

cs.LG2025

Online Learning and Unlearning

Yaxi Hu, Bernhard Schölkopf, Amartya Sanyal

We formalize the problem of online learning-unlearning, where a model is updated sequentially in an online setting while accommodating unlearning requests between updates. After a…

cs.CL2025★ 1 cited

Differentially Private Steering for Large Language Model Alignment

Anmol Goel, Yaxi Hu, Iryna Gurevych +1

Aligning Large Language Models (LLMs) with human values and away from undesirable behaviors (such as hallucination) has become increasingly important. Recently, steering LLMs towar…

cs.LG2024★ 3 cited

What Makes and Breaks Safety Fine-tuning? A Mechanistic Study

Samyak Jain, Ekdeep Singh Lubana, Kemal Oksuz +4

Safety fine-tuning helps align Large Language Models (LLMs) with human preferences for their safe deployment. To better understand the underlying factors that make models safe via…

cs.LG2024

Robust Mixture Learning when Outliers Overwhelm Small Groups

Daniil Dmitriev, Rares-Darius Buhai, Stefan Tiegel +5

We study the problem of estimating the means of well-separated mixtures when an adversary may add arbitrary outliers. While strong guarantees are available when the outlier fractio…

cs.LG2024★ 1 cited

Accuracy on the wrong line: On the pitfalls of noisy data for out-of-distribution generalisation

Amartya Sanyal, Yaxi Hu, Yaodong Yu +3

"Accuracy-on-the-line" is a widely observed phenomenon in machine learning, where a model's accuracy on in-distribution (ID) and out-of-distribution (OOD) data is positively correl…

cs.CR2024

Provable Privacy with Non-Private Pre-Processing

Yaxi Hu, Amartya Sanyal, Bernhard Schölkopf

When analysing Differentially Private (DP) machine learning pipelines, the potential privacy cost of data-dependent pre-processing is frequently overlooked in privacy accounting. I…

cs.LG2024

On the Growth of Mistakes in Differentially Private Online Learning: A Lower Bound Perspective

Daniil Dmitriev, Kristóf Szabó, Amartya Sanyal

In this paper, we provide lower bounds for Differentially Private (DP) Online Learning algorithms. Our result shows that, for a broad class of -DP online algorithm…

cs.LG2023

Can semi-supervised learning use all the data effectively? A lower bound perspective

Alexandru Ţifrea, Gizem Yüce, Amartya Sanyal +1

Prior works have shown that semi-supervised learning algorithms can leverage unlabeled data to improve over the labeled sample complexity of supervised learning (SL) algorithms. Ho…

cs.LG2023

How robust accuracy suffers from certified training with convex relaxations

Piersilvio De Bartolomeis, Jacob Clarysse, Amartya Sanyal +1

Adversarial attacks pose significant threats to deploying state-of-the-art classifiers in safety-critical applications. Two classes of methods have emerged to address this issue: e…

cs.LG2023★ 1 cited

PILLAR: How to make semi-private learning more effective

Francesco Pinto, Yaxi Hu, Fanny Yang +1

In Semi-Supervised Semi-Private (SP) learning, the learner has access to both public unlabelled and private labelled data. We propose a computationally efficient algorithm that, un…

cs.LG2023

Certifying Ensembles: A General Certification Theory with S-Lipschitzness

Aleksandar Petrov, Francisco Eiras, Amartya Sanyal +2

Improving and guaranteeing the robustness of deep learning models has been a topic of intense research. Ensembling, which combines several classifiers to provide a better model, ha…

cs.CR2023

Certified private data release for sparse Lipschitz functions

Konstantin Donhauser, Johan Lokna, Amartya Sanyal +3

As machine learning has become more relevant for everyday applications, a natural requirement is the protection of the privacy of the training data. When the relevant learning ques…

cs.LG2022

Do you pay for Privacy in Online learning?

Amartya Sanyal, Giorgia Ramponi

Online learning, in the mistake bound model, is one of the most fundamental concepts in learning theory. Differential privacy, instead, is the most widely used statistical concept…

stat.ML2022

A law of adversarial risk, interpolation, and label noise

Daniel Paleka, Amartya Sanyal

In supervised learning, it has been shown that label noise in the data can be interpolated without penalties on test accuracy. We show that interpolating label noise induces advers…

cs.LG2022★ 6 cited

How Robust is Unsupervised Representation Learning to Distribution Shift?

Yuge Shi, Imant Daunhawer, Julia E. Vogt +2

The robustness of machine learning algorithms to distributions shift is primarily discussed in the context of supervised learning (SL). As such, there is a lack of insight on the r…

cs.LG2022★ 1 cited

Catastrophic overfitting can be induced with discriminative non-robust features

Guillermo Ortiz-Jiménez, Pau de Jorge, Amartya Sanyal +5

Adversarial training (AT) is the de facto method for building robust neural networks, but it can be computationally expensive. To mitigate this, fast single-step attacks can be use…

cs.LG2022★ 2 cited

How unfair is private learning ?

Amartya Sanyal, Yaxi Hu, Fanny Yang

As machine learning algorithms are deployed on sensitive data in critical decision making processes, it is becoming increasingly important that they are also private and fair. In t…

cs.LG2022★ 31 cited

Make Some Noise: Reliable and Efficient Single-Step Adversarial Training

Pau de Jorge, Adel Bibi, Riccardo Volpi +4

Recently, Wong et al. showed that adversarial training with single-step FGSM leads to a characteristic failure mode named Catastrophic Overfitting (CO), in which a model becomes su…

cs.LG2022★ 2 cited

Towards Adversarial Evaluations for Inexact Machine Unlearning

Shashwat Goel, Ameya Prabhu, Amartya Sanyal +3

Machine Learning models face increased concerns regarding the storage of personal user data and adverse impacts of corrupted data like backdoors or systematic bias. Machine Unlearn…

cs.LG2021

Identifying and Exploiting Structures for Reliable Deep Learning

Amartya Sanyal

Deep learning research has recently witnessed an impressively fast-paced progress in a wide range of tasks including computer vision, natural language processing, and reinforcement…