Raghav Singhal

I'm currently an AI PhD student in the Computer Science department at EPFL. I am fortunate to be advised by the amazing Prof. Robert West and am a contributor to the Apertus project (the biggest fully open and compliant training run & LLM to date).

Previously, I was a researcher at Massachusetts Institute of Technology and Mohamed bin Zayed University of Artificial Intelligence (MBZUAI), where I worked with Prof. Praneeth Vepakomma. Prior to this, I graduated from IIT Bombay with a Bachelor's in EE and a Master's in AI/ML.


For EPFL students: If you are interested in a project, please feel free to reach out via mail. I'm very happy to supervise motivated students!

Email  /  Scholar  /  Twitter  /  LinkedIn  /  Github

profile photo

Research

My research interests currently revolve around pretraining, data, and robust alignment of language models.

Some of the projects I am currently working on include:

  • Developing effective pretraining methods that instill safety (alignment) from token 0, rather than relying on the superficial post-training-only approaches used today.
  • Moving toward (almost) fully synthetic data pretraining, for even more robust alignment, while ensuring there is no diversity collapse.
  • Understanding and improving how rephrasals and repetitions should be used effectively in data-constrained settings.
  • Feedback- (or metadata-) conditioned pretraining, with the aim of moving toward more on-policy updates during pretraining itself.

Check out my Google Scholar for a complete list of publications. * denotes equal contribution. Selected projects are highlighted.

SPP Synthetic Persona Pretraining: Alignment from Token Zero
Julian Minder*, Viktor Moskvoretskii*, Raghav Singhal*, Difan Jiao, Kartik Bali, Yiderigun Borjigin, Shaobo Cui, Stefan Krsteski, Ashton Anderson, Roland Aydin, Robert West
Blogpost, 2026
blog post / X thread

We propose Synthetic Persona Pretraining (SPP): append value-laden reflections to pretraining documents (10% annotated) to install the desired persona during pretraining rather than hope that it will emerge organically. SPP is very simple and purely a pretraining data intervention. Our results demonstrate that SPP models are consistently safer and more aligned than a range of baselines.

Apertus Apertus: Democratizing Open and Compliant LLMs for Global Language Environments
Project Apertus
arXiv / Hugging Face / Pretrain Code / Pretrain Data / Posttrain Code / Posttrain Data / Evals

The biggest fully open and compliant training run & LLM to date.

8B and 70B fully pretrained open-data open-weights models, multilingual in >1000 languages. Performance equivalent or better than corresponding Llama 3 sizes.

PontTuset Safety Subspaces are Not Linearly Distinct: A Fine-Tuning Case Study
Kaustubh Ponkshe*, Shaan Shah*, Raghav Singhal*, Praneeth Vepakomma
ICLR 2026
code / arXiv

We show that safety alignment in LLMs is not confined to distinct subspaces (but rather, highly entangled with general ability directions), thus fundamentally challenging the foundation of subspace-based defenses.

PontTuset FedEx-LoRA: Exact Aggregation for Federated and Efficient Fine-Tuning of Foundation Models
Raghav Singhal*, Kaustubh Ponkshe*, Praneeth Vepakomma
ACL 2025 - Oral (Top 2.2% of submitted papers)
code / arXiv

We achieve exact aggregation in distributed fine-tuning of LLMs, consistently improving over SOTA.

PontTuset ABBA: Highly Expressive Hadamard Product Adaptation for Large Language Models
Raghav Singhal*, Kaustubh Ponkshe*, Rohit Vartak*, Praneeth Vepakomma
ICLR 2026
Abridged at ES-FOMO @ ICML 2025 - Spotlight (Top 9.5% of accepted papers)
code / arXiv

We introduce ABBA, a PEFT method that enhances expressivity by decoupling low-rank updates from pre-trained weights via a Hadamard product, consistently improving over SOTA methods.

PontTuset Fed-SB: A Silver Bullet for Extreme Communication Efficiency and Performance in (Private) Federated LoRA Fine-Tuning
Raghav Singhal*, Kaustubh Ponkshe*, Rohit Vartak, Lav Varshney, Praneeth Vepakomma
NeurIPS 2026 | TMLR - J2C Certification (Top 10% of accepted papers)
code / arXiv

We set a new Pareto frontier for distributed fine-tuning of LLMs, achieving SOTA performance, stronger privacy guarantees, and up to 230x lower communication costs.

PontTuset Initialization using Update Approximation is a Silver Bullet for Extremely Efficient Low-Rank Fine-Tuning
Kaustubh Ponkshe*, Raghav Singhal*, Eduard Gorbunov, Alexey Tumanov, Samuel Horvath, Praneeth Vepakomma
Abridged at SCOPE @ ICLR 2025
code / arXiv

We provably achieve the best approximation of full fine-tuning in low-rank spaces solely through clever initialization, outperforming LoRA while using up to 90x fewer parameters.

PontTuset M3CoL: Harnessing Shared Relations via Multimodal Mixup Contrastive Learning for Multimodal Classification
Raja Kumar*, Raghav Singhal*, Pranamya Kulkarni, Deval Mehta, Kshitij Jadhav
TMLR
code / arXiv

We introduce a multimodal mixup-based contrastive learning framework that effectively captures shared relations across modalities, enabling robust multimodal representation learning.


Source code taken from Jon Barron's website.