Ph.D. student @KhouryCollege, working to make LLMs interpretable

Boston, MA
Joined September 2022
How can a language model find the veggies in a menu? New pre-print where we investigate the internal mechanisms of LLMs when filtering on a list of options. Spoiler: turns out LLMs use strategies surprisingly similar to functional programming (think "filter" from python)! ๐Ÿงต
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Arnab Sen Sharma retweeted
New COLM paper: Identifying Introspection From the Inside When an LLM tells us about its decisions, does it ๐˜ฌ๐˜ฏ๐˜ฐ๐˜ธ what drives its choicesโ€”or is it guessing? In our setting, we find that faithful models decide and report with the same layers. Unfaithful ones don't. ๐Ÿงต
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A builtin sub-circuit (attn heads) in VLMs that encodes image segments to language concepts! And, the model uses these encodings for downstream behavior. Checkout this cool work from @sheridan_feucht et al.
[New preprint] How do images in VLMs align with words? In this work, we found a set of attention heads responsible for OCR. But to our surprise, these heads were actually able to verbalize much more than just text. So, we used them to create a simple logit lens for image tokens!
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Arnab Sen Sharma retweeted
Excited to kickstart this effort with @glnmario and a star-studded advisory team! ๐Ÿš€ Also, we're hiring for 2 MTS and 1 Ops manager! Come build the future of white-box audits with us: parallx.ai/careers
Introducing Parallax ๐Ÿ” We're a new UK/EU-based nonprofit research lab building scalable methods and infrastructure to audit the beliefs, goals, and plans that shape model behaviours in long-horizon agentic evaluations. parallx.ai โ€” Thread ๐Ÿงต 1/
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Arnab Sen Sharma retweeted
๐Ÿง ๐Ÿค– The 2026 New England Mechanistic Interpretability (NEMI) Workshop will be Aug. 14 at Boston University! Help spread the word and join the New England mech interp community! Registration and submission info in thread:๐Ÿ‘‡
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Arnab Sen Sharma retweeted
Can you tell when an AI model is lying? Announcing Aletheia's Quest, an AI lie detection challenge running this summer, organized by @cadenza_labs and @ndif_team. Multiple model organisms to interrogate and probe, $50K prize pool, no local GPU required.
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Super excited to be attending @iclr_conf in Rio. Stop by our poster tomorrow morning (10:30am - 1:00pm) in Pavilion 4 (P4-#4001) to know about list-processing mechanisms in LMs. DMs are open. Please reach out if you want to meet up!
How can a language model find the veggies in a menu? New pre-print where we investigate the internal mechanisms of LLMs when filtering on a list of options. Spoiler: turns out LLMs use strategies surprisingly similar to functional programming (think "filter" from python)! ๐Ÿงต
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Arnab Sen Sharma retweeted
Can you solve this algebra puzzle? ๐Ÿงฉ cb=c, ac=b, ab=? A small transformer can learn to solve problems like this! And since the letters don't have inherent meaning, this lets us study how context alone imparts meaning. Here's what we found:๐Ÿงตโฌ‡๏ธ
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Arnab Sen Sharma retweeted
Can models understand each other's reasoning? ๐Ÿค” When Model A explains its Chain-of-Thought (CoT) , do Models B, C, and D interpret it the same way? Our new preprint with @davidbau and @csinva explores CoT generalizability ๐Ÿงต๐Ÿ‘‡ (1/7)
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Arnab Sen Sharma retweeted
At the #Neurips2025 mechanistic interpretability workshop I gave a brief talk about Venetian glassmaking, since I think we face a similar moment in AI research today. Here is a blog post summarizing the talk: davidbau.com/archives/2025/1โ€ฆ
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Arnab Sen Sharma retweeted
I am very excited to share that our paper, "One-Step is Enough: Sparse Autoencoders for Text-to-Image Diffusion Models" will be presented at #NeurIPS2025! @ViaSurkov is presenting it at #MexIPS2025: ๐Ÿ“๐ˆ๐Ÿ ๐ฒ๐จ๐ฎ ๐š๐ซ๐ž ๐š๐ญ๐ญ๐ž๐ง๐๐ข๐ง๐  ๐๐ž๐ฎ๐ซ๐ˆ๐๐’ ๐ข๐ง ๐Œ๐ž๐ฑ๐ข๐œ๐จ ๐‚๐ข๐ญ๐ฒ, ๐ฉ๐ฅ๐ž๐š๐ฌ๐ž ๐ฌ๐ญ๐จ๐ฉ ๐›๐ฒ! Date: Thursday, Dec 4, 2025 Time: 11:00 AM โ€“ 2:00 PM PST Location: Foyer (Mexico City Poster Session) Come visit @ViaSurkov it's his first conference and he will be happy to explain his amazing work. Sadly, #NeurIPS2025 does not allow for parallel presentation in San Diego. However, I am in San Diego and happy to meet up / chat. Please don't hesitate to reach out here or via [email protected]. Once again, a big shout out to our brilliant students Viacheslav Surkov and Antonio Mari who did phenomenal work here and pushed this work (that started as a class project more than a year ago) all the way to pass the high threshold of #NeurIPS2025. Also, I want to thank manifund.org/ (@andyarditi and @ryan_kidd44 in particular) for helping us to finance Viacheslav Surkov's conference trip. Please find more information about our work below. We have so many amazing interactive materials (e.g., 3x huggingface demo spaces) for you to check out. Most of our implementations are open-sourced (RIEBench on FLUX, which we added to our appendix during the NeurIPS rebuttal is currently missing but we plan to add it ASAP). Me demoing the demo attached.
How do diffusion models create images and can we control that process? We are excited to release a update to our SDXL Turbo sparse autoencoder paper. New title: One Step is Enough: Sparse Autoencoders for Text-to-Image Diffusion Models Spoiler: We have FLUX SAEs now :)
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A key challenge for interpretability agents is knowing when theyโ€™ve understood enough to stop experimenting. Our @NeurIPSConf paper introduces a self-reflective agent that measures the reliability of its own explanations and stops once its understanding of models has converged.
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The fact that the neural mechanisms implemented in transformer architecture align with human-designed symbolic strategies suggests that certain computational patterns rise naturally from task demands rather than specific architectural constraints.
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Thanks to my collaborators @giordanoprogers , @NatalieShapira, and @davidbau. Checkout our paper for more details: ๐Ÿ“œ arxiv.org/pdf/2510.26784 ๐Ÿ’ป github.com/arnab-api/filter ๐ŸŒ filter.baulab.info
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