Siddharth Choudhary

Research Scientist · Luma AI

I am a Research Scientist at Luma AI, where I currently focus on robot foundation models. Before this, I was a Principal Applied Scientist at Amazon AGI, where I was tech-lead for multimodal pre-training of the Amazon Nova foundation models.

Prior to Amazon, I was a Principal Computer Vision Researcher at Magic Leap. I finished my Ph.D. from the School of Interactive Computing at Georgia Institute of Technology. I was advised by Professor Henrik I. Christensen and Professor Frank Dellaert. I completed my Bachelors and Masters in Computer Science from IIIT Hyderabad where I was advised by Prof. P J Narayanan.

Siddharth Choudhary

Key Projects

Illustration: OPAL Lab & Robot Foundation Models
Luma AI · Current

OPAL Lab & Robot Foundation Models

Current work

Building robot foundation models at Luma’s Open Science Physical AI Lab (OPAL), which researches methods for generalization in physical AI and world models that understand and act in the physical world — the Perceive → Imagine → Act loop, applied to robots.

Illustration: Amazon Nova
Amazon AGI · 2024–2025

Amazon Nova

Tech-lead · Multimodal pre-training

Tech-lead for multimodal pre-training of Amazon’s foundation models. Designed the multimodal architecture and pre-training data mix for Nova 2.0 Lite, built the unified architecture behind Nova 2.0 Omni’s native image generation, and developed the image/video pre-training recipes for Nova Pro, Lite and Micro.

Illustration: Multimodal LLM
Amazon · 2024–2026

Multimodal LLM

Transferring LLM knowledge to image generation with Mixture-of-Transformers, grounding vision-language models to curb hallucination, and retrieval-augmented multimodal learning.

Illustration: Augmented Reality
Magic Leap · 2020

Augmented Reality

Shipped on Magic Leap One

Multiuser, scalable 3D object detection in the AR cloud using distributed data association and fusion, so many headsets share one semantic map.

Illustration: Structure from Motion
IIIT Hyderabad · 2012

Structure from Motion

Visibility probabilities between points and cameras in SfM datasets for faster, more accurate localization and triangulation.

All Works

Amazon Nova2

Illustration: Amazon Nova 2: Multimodal Reasoning and Generation Models

Amazon Nova 2: Multimodal Reasoning and Generation Models

AWS re:Invent, 2025Tech-lead on multimodal pre-training team

Tech-lead for Nova 2.0 Lite: Core-team member focused on designing MM architecture and finalized pretraining data mix and recipe integrating vision, speech and language understanding at scale. Achieves state-of-the-art performance on 13 out of 15 benchmarks vs Claude Haiku 4.5.

Nova 2.0 Omni pre-training: I developed unified multimodal architecture integrating native image generation with text, vision, and speech understanding. Designed pre-training recipe that enable generative capabilities while preserving performance across all input modalities. Checkout the models at nova.amazon.com/chat.

Illustration: Amazon Nova Foundation Models

Amazon Nova Foundation Models

AWS re:Invent, 2024Tech-lead on multimodal pre-training team

Tech-lead on multimodal pre-training team responsible for developing image/video pretraining recipes for Amazon Nova foundation models. Achieved state-of-the-art performance on multimodal understanding benchmarks against Claude 3 Haiku and Gemini 1.5 Pro. The family includes Nova Pro, Nova Lite, Nova Micro, Nova Canvas, and Nova Reel.

Multimodal LLM3

Illustration: Mural: Transferring LLM Knowledge to Image Generation via Mixture-of-Transformers

Mural: Transferring LLM Knowledge to Image Generation via Mixture-of-Transformers

Achin Jain, Jie An, Siddharth Choudhary, Davide Modolo
arXiv, 2026

Mural integrates frozen large language models with diffusion-based image generators through shared attention (Mixture-of-Transformers), transferring LLM knowledge using only standard text-image pairs. It reaches 0.85 on GenEval, 86.75 on DPG-Bench, and 0.66 on WISE with inference-time reasoning, and exhibits emergent capabilities absent from training data such as cross-lingual generation, color-guided composition, and world-knowledge-directed synthesis.

3D Human Reconstruction and Health CVML4

Illustration: Development and Validation of an Accurate Smartphone Application for Measuring Waist-to-Hip Circumference Ratio

Development and Validation of an Accurate Smartphone Application for Measuring Waist-to-Hip Circumference Ratio

Nature Digital Medicine, 2023Shipped with Amazon Halo Body

Propose a CNN based model called MeasureNet for accurately and reliably predicting body measurements and waist-hip ratio. Model is trained using realistic synthetic dataset.

Augmented Reality1

Distributed Semantic SLAM9

Illustration: Distributed Mapping with Privacy and Communication Constraints: Lightweight Algorithms and Object-based Models

Distributed Mapping with Privacy and Communication Constraints: Lightweight Algorithms and Object-based Models

IJRR, 2017

Propose a distributed implementation of the two-stage pose graph optimization, using Successive Over-Relaxation (SOR) and the Jacobi Over-Relaxation (JOR) as workhorses to split the computation among the robots. Extends it to work with object-based map models.

Structure from Motion3

GPU Computing2

Illustration: CPU and/or GPU: Revisiting the GPU Vs. CPU Myth

CPU and/or GPU: Revisiting the GPU Vs. CPU Myth

Kishore Kothapalli, Dip Sankar Banerjee, P. J. Narayanan, Surinder Sood, Aman Kumar Bahl, Shashank Sharma, Shrenik Lad, Krishna Kumar Singh, Kiran Matam, Sivaramakrishna Bharadwaj, Rohit Nigam, Parikshit Sakurikar, Aditya Deshpande, Ishan Misra, Siddharth Choudhary, Shubham Gupta
arXiv, 2013

Side Projects

Notes & Reviews