Symbolic Emulators for Cosmology: Accelerating Cosmological Analyses Without Sacrificing Precision
This work addresses the need for faster and more efficient cosmological inference for researchers, though it is incremental as it builds on existing symbolic emulator methods.
The paper tackled the problem of accelerating cosmological analyses by expanding symbolic emulators to cover broader parameter ranges, achieving accuracies of better than 0.001% and 0.05% for key functions and showing consistent cosmological constraints in a Dark Energy Survey-like analysis.
In cosmology, emulators play a crucial role by providing fast and accurate predictions of complex physical models, enabling efficient exploration of high-dimensional parameter spaces that would be computationally prohibitive with direct numerical simulations. Symbolic emulators have emerged as promising alternatives to numerical approaches, delivering comparable accuracy with significantly faster evaluation times. While previous symbolic emulators were limited to relatively narrow prior ranges, we expand these to cover the parameter space relevant for current cosmological analyses. We introduce approximations to hypergeometric functions used for the $Λ$CDM comoving distance and linear growth factor which are accurate to better than 0.001% and 0.05%, respectively, for all redshifts and for $Ω_{\rm m} \in [0.1, 0.5]$. We show that integrating symbolic emulators into a Dark Energy Survey-like $3\times2$pt analysis produces cosmological constraints consistent with those obtained using standard numerical methods. Our symbolic emulators offer substantial improvements in speed and memory usage, demonstrating their practical potential for scalable, likelihood-based inference.