OmniCosmos: Transferring Particle Physics Knowledge Across the Cosmos
Vinicius Mikuni, Ibrahim Elsharkawy, Benjamin Nachman
TL;DR
The paper addresses transferring knowledge from collider-based foundation models to cosmology to improve parameter inference and halo velocity predictions from point-cloud data. It introduces OmniCosmos, a cosmology-adapted continuation of the OmniLearned model, with input-representation changes, geometry-aware pairwise features, and a carefully tuned fine-tuning regime (≈$2$ million parameters across $8$ transformer blocks) to handle up to ~5000 halos. Empirically, OmniCosmos delivers strong, data-efficient performance on CosmoBench tasks, surpassing scratch-trained baselines and matching or exceeding benchmarks on CAMELS-SAM and QUIJOTE with substantially fewer simulations. The work demonstrates cross-domain transferability of collider-pretrained foundation models to cosmology and points to future directions, including alternative adaptation strategies and generative capabilities for fast, high-fidelity cosmological surrogates.
Abstract
Foundation models build an effective representations of data that can be deployed on diverse downstream tasks. Previous research developed the OmniLearned foundation model for collider physics and showed that it could significantly advance discovery potential across collider experiments. In this paper we go beyond collider physics and show that Foundation Models trained on collider data can help improve the prediction of cosmological parameters and to predict halo and galaxy velocities in different datasets from CosmoBench. This is the first time a collider physics model is shown to generalize across scientific fields.
