Straightening the Ruler: Field-Level Inference of the BAO Scale with LEFTfield

التفاصيل البيبلوغرافية
العنوان: Straightening the Ruler: Field-Level Inference of the BAO Scale with LEFTfield
المؤلفون: Babić, Ivana, Schmidt, Fabian, Tucci, Beatriz
سنة النشر: 2024
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
الوصف: Current inferences of the BAO scale from galaxy clustering employ a reconstruction technique at fixed cosmology and bias parameters. Here, we present the first consistent joint Bayesian inference of the isotropic BAO scale, jointly varying the initial conditions as well as all bias coefficients, based on the EFT-based field-level forward model $\texttt{LEFTfield}$. We apply this analysis to mock data generated with a much higher cutoff (resolution), resulting in a significant model mismatch between mock data and the model used in the inference. We demonstrate that the remaining systematic bias in the BAO scale is below 2% for all data considered and below 1% when Eulerian bias is used for inference. Furthermore, we find that the inferred error on the BAO scale is up to 1.6 times smaller compared to that from a replication of the standard power-spectrum reconstruction approach, using the same scales as in the field-level inference, with the improvement growing towards smaller scales (higher $k$). Thus, a field-level approach to BAO not only allows for a consistent inference of the BAO scale, but promises to achieve more precise measurements on the same data as well.
Comment: 25 pages, 15 figures
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2407.01524
رقم الأكسشن: edsarx.2407.01524
قاعدة البيانات: arXiv