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Amartya Sanyal

@amartyasanyal.bsky.social
983 followers 147 following 18 posts

Assistant Professor @Dept. Of Computer Science, University of Copenhagen, Ex Postdoc @MPI-IS, ETHZ, PhD @University of Oxford, B.Tech @CSE,IITK.

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Reposted by Amartya Sanyal
Omri Ben-Dov @omribendov.bsky.social · 22/08/2025
In our new work we ask: Can end-users make a platform’s ML models fairer? Firm-side fair learning often reduces accuracy, discouraging firms from using it. But if a platform relies on user data, can minority users collectively change the data to induce fairness? (1/4)
A classifier has an error of 0.15 and unfairness violation of 0.13, while the same classifier, on data with 6 relabeled samples, have the the same error but 0.03 fairness violation.
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Differential Privacy Papers @dppapers.bsky.social · 15/08/2025
An Iterative Algorithm for Differentially Private $k$-PCA with Adaptive Noise Johanna Düngler, Amartya Sanyal arxiv.org/abs/2508.10879
An Iterative Algorithm for Differentially Private $k$-PCA with Adaptive Noise

Johanna Düngler, Amartya Sanyal

http://arxiv.org/abs/2508.10879

Given $n$ i.i.d. random matrices $A_i \in \mathbb{R}^{d \times d}$ that share
a common expectation $\Sigma$, the objective of Differentially Private
Stochastic PCA is to identify a subspace of dimension $k$ that captures the
largest variance directions of $\Sigma$, while preserving differential privacy
(DP) of each individual $A_i$. Existing methods either (i) require the sample
size $n$ to scale super-linearly with dimension $d$, even under Gaussian
assumptions on the $A_i$, or (ii) introduce excessive noise for DP even when
the intrinsic randomness within $A_i$ is small. Liu et al. (2022a) addressed
these issues for sub-Gaussian data but only for estimating the top eigenvector
($k=1$) using their algorithm DP-PCA. We propose the first algorithm capable of
estimating the top $k$ eigenvectors for arbitrary $k \leq d$, whilst overcoming
both limitations above. For $k=1$ our algorithm matches the utility guarantees
of DP-PCA, achieving near-optimal statistical error even when $n =
\tilde{\!O}(d)$. We further provide a lower bound for general $k > 1$, matching
our upper bound up to a factor of $k$, and experimentally demonstrate the
advantages of our algorithm over comparable baselines.
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Amartya Sanyal @amartyasanyal.bsky.social · 15/05/2025
🚨New Paper: Online Learning and Unlearning 🚨 We look at learning and unlearning in the online setting where both learning and unlearning requests arrive continuously over time. Lead by @yaxihu.bsky.social and joint work with Bernhard Schölkopf arxiv.org/abs/2505.08557
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UKP Lab @ukplab.bsky.social · 23/04/2025
𝗖𝗮𝗻 𝘄𝗲 𝗮𝗹𝗶𝗴𝗻 𝗟𝗟𝗠𝘀 𝘁𝗼𝘄𝗮𝗿𝗱𝘀 𝗮 𝗱𝗲𝘀𝗶𝗿𝗲𝗱 𝗯𝗲𝗵𝗮𝘃𝗶𝗼𝘂𝗿 𝘄𝗵𝗶𝗹𝗲 𝗺𝗮𝗶𝗻𝘁𝗮𝗶𝗻𝗶𝗻𝗴 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁𝗶𝗮𝗹 𝗽𝗿𝗶𝘃𝗮𝗰𝘆 𝗴𝘂𝗮𝗿𝗮𝗻𝘁𝗲𝗲𝘀? We answer this in our #ICLR2025 paper. Tl;dr: We propose, evaluate and audit a novel differentially private activation steering algorithm for aligning LLMs. (1/🧵)
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Amartya Sanyal @amartyasanyal.bsky.social · 27/03/2025
Open postdoc position in learning theory/ privacy/ robustness/ unlearning or any related topics with me and others in University of Copenhagen, Denmark. If you think you would be a good candidate, send me an email amartya18x.github.io/hiring/ #postdoc
amartya18x.github.io
Vacancies
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Reposted by Amartya Sanyal
Konrad Rieck 🌈 @rieck.mlsec.org · 03/03/2025
No plans for April 9–11 yet? — Why not spend an amazing week in beautiful Copenhagen 🇩🇰, exploring cutting-edge research on trustworthy machine learning. Join us at SaTML 2025, the premier conference on AI security, AI privacy, and AI fairness! 👉 satml.org/attend @satml.org
IEEE Conference on Secure and Trustworthy Machine Learning (SaTML), April 9-11, 2025, Copenhagen.
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Amartya Sanyal @amartyasanyal.bsky.social · 25/02/2025
Very shortly at @realaaai.bsky.social, @alext2.bsky.social and I will be giving a Tutorial on the impact of Quality and availability of labels and data for Privacy, Fairness, and Robustness of ML algorithms See here amartya18x.github.io/files/Tutori... @ucph.bsky.social
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Reposted by Amartya Sanyal
Pioneer Centre for AI @aicentre.dk · 22/02/2025
3rd IEEE Conference on Secure and Trustworthy Machine Learning University of Copenhagen, Denmark, April 9-11, 2025 - registration is open. satml.org @amartyasanyal.bsky.social
satml.org
IEEE SaTML
IEEE Conference on Secure and Trustworthy Machine Learning
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Reposted by Amartya Sanyal
Differential Privacy Papers @dppapers.bsky.social · 31/01/2025
Differentially Private Steering for Large Language Model Alignment Anmol Goel, Yaxi Hu, Iryna Gurevych, Amartya Sanyal arxiv.org/abs/2501.18532
Differentially Private Steering for Large Language Model Alignment
Anmol Goel, Yaxi Hu, Iryna Gurevych, Amartya Sanyal
http://arxiv.org/abs/2501.18532
Aligning Large Language Models (LLMs) with human values and away from
undesirable behaviors (such as hallucination) has become increasingly
important. Recently, steering LLMs towards a desired behavior via activation
editing has emerged as an effective method to mitigate harmful generations at
inference-time. Activation editing modifies LLM representations by preserving
information from positive demonstrations (e.g., truthful) and minimising
information from negative demonstrations (e.g., hallucinations). When these
demonstrations come from a private dataset, the aligned LLM may leak private
information contained in those private samples. In this work, we present the
first study of aligning LLM behavior with private datasets. Our work proposes
the \textit{\underline{P}rivate \underline{S}teering for LLM
\underline{A}lignment (PSA)} algorithm to edit LLM activations with
differential privacy (DP) guarantees. We conduct extensive experiments on seven
different benchmarks with open-source LLMs of different sizes (0.5B to 7B) and
model families (LlaMa, Qwen, Mistral and Gemma). Our results show that PSA
achieves DP guarantees for LLM alignment with minimal loss in performance,
including alignment metrics, open-ended text generation quality, and
general-purpose reasoning. We also develop the first Membership Inference
Attack (MIA) for evaluating and auditing the empirical privacy for the problem
of LLM steering via activation editing. Our attack is tailored for activation
editing and relies solely on the generated texts without their associated
probabilities. Our experiments support the theoretical guarantees by showing
improved guarantees for our \textit{PSA} algorithm compared to several existing
non-private techniques.
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Amartya Sanyal @amartyasanyal.bsky.social · 28/01/2025
PhD call in Denmark. Applications open!
ddsa.dk
DDSA PhD Fellowship Call 2025 | DDSA
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UKP Lab @ukplab.bsky.social · 27/01/2025
#ICLR »Differentially Private Steering for Large Language Model Alignment« by @anmolgoel.bsky.social, Yaxi Hu, Iryna Gurevych (@igurevych.bsky.social) & Amartya Sanyal (@amartyasanyal.bsky.social) (2/🧵)
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Amartya Sanyal @amartyasanyal.bsky.social · 24/01/2025
I was very lucky and happy to be awarded the Villum Young Investigator grant yesterday villumfonden.dk/en/news/mill... Looking forward to the resulting research in unlearning, privacy, and online learning supported by the Villum foundation. (Hiring motivated PhDs and postdocs, especially postdocs)
villumfonden.dk
Millions in funding for young researchers
Nineteen promising researchers working within the technical and natural sciences have received funding of DKK 150 million for their research projects.
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Reposted by Amartya Sanyal
Mahdi Haghifam @mahdihaghifam.bsky.social · 11/12/2024
I’ll be at #NeurIPS2024 this week! Looking forward to presenting my joint work with Thomas Steinke(@stein.ke) and Jon Ullman(@thejonullman.bsky.social) NeurIPS page with video: neurips.cc/virtual/2024... Link to arxiv: arxiv.org/abs/2406.07407
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Reposted by Amartya Sanyal
Daniil Dmitriev @ddmitriev.bsky.social · 10/12/2024
Excited to present at #NeurIPS2024 our work on robust mixture learning! How hard is mixture learning when (a lot of) outliers are present? We show that it's easier than it seems! Join us at the poster session (Wed, 16:30 PT, West Ballroom A-D #5710).
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Reposted by Amartya Sanyal
Rasmus Pagh @rasmuspagh.net · 03/12/2024
Graduating with a PhD related to privacy and robustness in machine learning? Apply to this post-doc opening by @amartyasanyal.bsky.social: employment.ku.dk/faculty/?sho...
employment.ku.dk
Postdoc in Privacy and Robustness of Machine Learning Algorithms
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Amartya Sanyal @amartyasanyal.bsky.social · 02/12/2024
Two weeks remaining to apply to this position. I'll also be at NeurIPS, if you want to chat you can DM or email me. :)
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Amartya Sanyal @amartyasanyal.bsky.social · 27/11/2024
Three long research meetings throughout the day with four brilliant collaborators. It was a good day.
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Reposted by Amartya Sanyal
Clément Canonne @ccanonne.github.io · 25/11/2024
On the TCS job market: Hao Wu! Hao Wu's research interests focus on both the theoretical and practical aspects of differentially private data analysis. He is actively pursuing opportunities in academia and industry. 1/2 #TCSSky #AcademicJobMarket
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Reposted by Amartya Sanyal
Nando Fioretto @nandofioretto.bsky.social · 23/11/2024
🆘Help needed! Are you working on Privacy (from a Technical (e.g., Differential Privacy), Policy, or Law perspective)? Please give your availability to review for PPAI (ppai-workshop.github.io) if you can! We'd highly appreciate it! 🙏 forms.gle/dqjVsBsR2y81...
ppai-workshop.github.io
Sixth AAAI Workshop on Privacy-Preserving Artificial Intelligence
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Amartya Sanyal @amartyasanyal.bsky.social · 21/11/2024
I made a starter pack for european researchers interested in some aspects of learning theory. The list is clearly inexhaustive. So please enter your suggestions in comments. go.bsky.app/5o5uVnr
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Amartya Sanyal @amartyasanyal.bsky.social · 19/11/2024
Open Postdoctoral position in Privacy, unlearning, and Robustness in Machine Learning in University of Copenhagen to work with me! Deadline: December 15th If you want to spend a couple of years working on these exciting topics in beautiful Copenhagen, Apply here employment.ku.dk/all-vacancies/…
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