Euclid preparation

@article{sarpa2026euclid,
  title = {{Euclid preparation}},
  author = {Sarpa E. and Veropalumbo A. and Bonici M. and Kärcher M. and Crocce M. and Sefusatti E. and Maragliano E. and Branchini E. and Oliveri C. and Gambardella G. and Camacho Quevedo B. and Moretti C. and Monaco P. and Bautista J. and Viel M. and Percival W. J. and Nadathur S. and Pezzotta A. and Eggemeier A. and Sánchez A. G. and Bel J. and Carbone C. and Crespi A. and Radinović S. and Parimbelli G. and Farina A. and Risso I. and Guidi M. and Degni G. and Eisenstein D. and Beutler F. and García-García C. and Piccirilli G. and Sorce J. G. and Altieri B. and Andreon S. and Baccigalupi C. and Baldi M. and Bardelli S. and Battaglia P. and Biviano A. and Brescia M. and Camera S. and Cañas-Herrera G. and Capobianco V. and Carretero J. and Castander F. J. and Castellano M. and Castignani G. and Cavuoti S. and Chambers K. C. and Cimatti A. and Colodro-Conde C. and Congedo G. and Conversi L. and Copin Y. and Courbin F. and Courtois H. M. and Degaudenzi H. and de la Torre S.},
  journal = {Astronomy \& Astrophysics},
  year = {2026},
  month = nov,
  doi = {10.1051/0004-6361/202660781},
  url = {https://doi.org/10.1051/0004-6361/202660781},
  note = {CC BY},
}

TY  - JOUR
TI  - Euclid preparation
AU  - Sarpa E.
AU  - Veropalumbo A.
AU  - Bonici M.
AU  - Kärcher M.
AU  - Crocce M.
AU  - Sefusatti E.
AU  - Maragliano E.
AU  - Branchini E.
AU  - Oliveri C.
AU  - Gambardella G.
AU  - Camacho Quevedo B.
AU  - Moretti C.
AU  - Monaco P.
AU  - Bautista J.
AU  - Viel M.
AU  - Percival W. J.
AU  - Nadathur S.
AU  - Pezzotta A.
AU  - Eggemeier A.
AU  - Sánchez A. G.
AU  - Bel J.
AU  - Carbone C.
AU  - Crespi A.
AU  - Radinović S.
AU  - Parimbelli G.
AU  - Farina A.
AU  - Risso I.
AU  - Guidi M.
AU  - Degni G.
AU  - Eisenstein D.
AU  - Beutler F.
AU  - García-García C.
AU  - Piccirilli G.
AU  - Sorce J. G.
AU  - Altieri B.
AU  - Andreon S.
AU  - Baccigalupi C.
AU  - Baldi M.
AU  - Bardelli S.
AU  - Battaglia P.
AU  - Biviano A.
AU  - Brescia M.
AU  - Camera S.
AU  - Cañas-Herrera G.
AU  - Capobianco V.
AU  - Carretero J.
AU  - Castander F. J.
AU  - Castellano M.
AU  - Castignani G.
AU  - Cavuoti S.
AU  - Chambers K. C.
AU  - Cimatti A.
AU  - Colodro-Conde C.
AU  - Congedo G.
AU  - Conversi L.
AU  - Copin Y.
AU  - Courbin F.
AU  - Courtois H. M.
AU  - Degaudenzi H.
AU  - de la Torre S.
PY  - 2026
DA  - 2026/11/04
JO  - Astronomy & Astrophysics
DO  - 10.1051/0004-6361/202660781
UR  - https://doi.org/10.1051/0004-6361/202660781
AB  - We present the first end-to-end validation of the Euclid baryon acoustic oscillation (BAO) analysis pipeline, encompassing density-field reconstruction, two-point correlation function measurement, and cosmological parameter inference. Using eight Euclid-like mock catalogues extracted from each of the four snapshots of the Flagship 1 (FS1) simulation, which is designed to replicate the statistical properties of the first Euclid data release (DR1), we assessed the performance of the two standard BAO reconstruction methods based on the Zeldovich approximation, RECSYM and RECISO, in four redshift snapshots (0.9 ≤ z ≤ 1.8). The pipeline introduces several methodological advances: an emulator-based model evaluator (Bora.jl) combined with a Hamiltonian Monte Carlo sampler (NUTS), achieving a speed-up of more than 500 times relative to standard Monte Carlo Markov chains, and a semi-analytical covariance estimator (BeXiCov+WinCov) that enables robust error estimates with only eight mock realisations and remains stable under variations in the fiducial cosmology. Together, these components ensure computational efficiency while significantly reducing the risk of underestimating the parameter uncertainties. The two reconstruction schemes yield unbiased BAO measurements for all redshifts and user-defined choices, including the smoothing scale and fiducial cosmology. In each snapshot, reconstruction enhances the figure of merit for {Ωm, H0rs} by a factor of ∼3, which is equivalent to tripling the effective survey volume. When we combined the four redshift bins, the improvement remained substantial, with BAO-only constraints reaching ∼10% precision on Ωm and ∼3% on H0rs. The results from RECSYM and RECISO are consistent within the uncertainties, but we recommend RECSYM during testing because its sensitivity to covariance variations is lower. These findings establish the accuracy, robustness, and scalability of the Euclid BAO pipeline for DR1 and provide a solid foundation for future cosmological analyses.
SN  - 0004-6361
SN  - 1432-0746
ER  -