cosmosage
Welcome to cosmosage—an advanced AI assistant designed for those curious about the universe we live in. cosmosage was trained on thousands of papers and books and will try its best to answer your questions about cosmology. However, while cosmosage is a powerful tool for brainstorming, expanding your knowledge, and exploring new ideas, keep in mind that it's still an LLM and may sometimes produce inaccurate responses.
Project status
Free inference for cosmosage and the arXiv paper recommender have both ended, and as of October 2026 the project is complete. Thanks to everyone who used it, and to Andrea Zonca for hosting the AstroSage-70B demo.
The model weights remain freely available at https://huggingface.co/AstroMLab/AstroSage-70B
About cosmosage
Learn more about the development and capabilities of cosmosage by reading the following papers.
cosmosage: A natural-language assistant for cosmology
Tijmen de Haan
Published in Astronomy and Computing, Volume 51 (2025).
Achieving GPT-4o level performance in astronomy with a specialized 8B-parameter large language model
Tijmen de Haan, Yuan-Sen Ting, Tirthankar Ghosal, Tuan Dung Nguyen, Alberto Accomazzi, Azton Wells, Nesar Ramachandra, Rui Pan, Zechang Sun
Published in Scientific Reports, Volume 15 (2025).
AstroMLab 4: Benchmark-Topping Performance in Astronomy Q&A with a 70B-Parameter Domain-Specialized Reasoning Model
Tijmen de Haan, Yuan-Sen Ting, Tirthankar Ghosal, Tuan Dung Nguyen, Alberto Accomazzi, Emily Herron, Vanessa Lama, Rui Pan, Azton Wells, and Nesar Ramachandra
arXiv:2505.17592 (2025), accepted contribution to Astro4ML (ICML 2025).