Smokescreen: A Python package for data vector blinding and encryption in cosmological analyses

arXiv (Cornell University)

Abstract

Smokescreen is an open-source Python library for data-vector concealment (blinding) in cosmological analyses. Data-vector blinding works by applying cosmology-dependent shifts to the observed data vector, moving it away from the true cosmological signal without affecting its statistical properties, so that analysts cannot infer the true result until the analysis is frozen and the blinding is lifted. The package computes these shifts using Firecrown likelihoods applied to data vectors stored in the SACC format, ensuring that the theoretical model used for blinding is identical to that used for inference whilst remaining agnostic to the specific observable being blinded. To prevent accidental unblinding, the original SACC file, containing the true cosmology, is encrypted. Although developed for the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), Smokescreen is applicable to any experiment using Firecrown likelihoods and the SACC data format.

Authors 13

1. Arthur Loureiro

   Stockholm University · Imperial College London

   Affiliation as printed

   Astrophysics Group , Blackett Laboratory , Imperial College London , London SW7 2AZ , UK

   Oskar Klein Centre for Cosmoparticle Physics , Department of Physics , Stockholm University , Stockholm , SE-106 91 , Sweden

2. J. Muir

   University of Cincinnati

   Affiliation as printed

   University of Cincinnati , Cincinnati , Ohio 45221 , USA

3. J. Blazek

   Northeastern University

   Affiliation as printed

   Department of Physics , Northeastern University , Boston , MA 02115 , USA

4. Nora Elisa Chisari Aachen Leiden Observatory

   Leiden University · Utrecht University · Leiden Observatory

   Affiliation as printed

   Institute for Theoretical Physics , Utrecht University , Princetonplein 5 , 3584 CC , Utrecht , the Netherlands

   Leiden Observatory , Leiden University , Niels Bohrweg 2 , 2333 CA , Leiden , the Netherlands

5. Pedro H. Costa Ribeiro

   Universidade Federal do Rio de Janeiro · Universidade Estadual de Londrina · Centro Universitário da Cidade

   Affiliation as printed

   Departamento de Física , Universidade Estadual de Londrina , Rod. Celso Garcia Cid , Km 380 , 86057 970 , Londrina , Paraná , Brazil

   Instituto de Física , Universidade Federal do Rio de Janeiro , Cidade Universitária , Rio de Janeiro , 21941-909 , Brazil

6. Christos Georgiou

   Institute for High Energy Physics · Barcelona Institute of Science and Technology

   Affiliation as printed

   Institut de Física d'Altes Energies (IFAE) , The Barcelona Institute of Science and Technology , Campus UAB , 08193 Bellaterra ( Barcelona ), Spain

7. C. Danielle Leonard
8. Bruno Moraes
9. M. Paterno
10. N. Šarčević

    Duke University

    Affiliation as printed

    Department of Physics , Duke University , Science Dr , Durham , NC 27710 , USA

11. Tilman Tröster

    ETH Zurich · Institute for Particle Physics and Astrophysics

    Affiliation as printed

    Institute for Particle Physics and Astrophysics , ETH Zurich , 8093 Zurich , Switzerland

12. Sandro D. P. Vitenti

    Universidade Estadual de Londrina

    Affiliation as printed

    Departamento de Física , Universidade Estadual de Londrina , Rod. Celso Garcia Cid , Km 380 , 86057 970 , Londrina , Paraná , Brazil

13. the LSST Dark Energy Science Collaboration