Data di Pubblicazione:
2023
Citazione:
BeyondPlanck. IV. Simulations and validation / M. Brilenkov, K.S.F. Fornazier, L.T. Hergt, G.A. Hoerning, A. Marins, T. Murokoshi, F. Rahman, N.-. Stutzer, Y. Zhou, F.B. Abdalla, K.J. Andersen, R. Aurlien, R. Banerji, A. Basyrov, A. Battista, M. Bersanelli, S. Bertocco, S. Bollanos, L.P.L. Colombo, H.K. Eriksen, J.R. Eskilt, M.K. Foss, C. Franceschet, U. Fuskeland, S. Galeotta, M. Galloway, S. Gerakakis, E. Gjerløw, B. Hensle, D. Herman, T.D. Hoang, M. Ieronymaki, H.T. Ihle, J.B. Jewell, A. Karakci, E. Keihänen, R. Keskitalo, G. Maggio, D. Maino, M. Maris, S. Paradiso, B. Partridge, M. Reinecke, A.-. Suur-Uski, T.L. Svalheim, D. Tavagnacco, H. Thommesen, M. Tomasi, D.J. Watts, I.K. Wehus, A. Zacchei. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - 675:(2023 Jun 28), pp. A4.1-A4.15. [10.1051/0004-6361/202244958]
Abstract:
End-to-end simulations play a key role in the analysis of any high-sensitivity CMB experiment, providing high-fidelity systematic
error propagation capabilities unmatched by any other means. In this paper, we address an important issue regarding such simula-
tions, namely how to define the inputs in terms of sky model and instrument parameters. These may either be taken as a constrained
realization derived from the data, or as a random realization independent from the data. We refer to these as Bayesian and fre-
quentist simulations, respectively. We show that the two options lead to significantly different correlation structures, as frequentist
simulations, contrary to Bayesian simulations, effectively include cosmic variance, but exclude realization-specific correlations from
non-linear degeneracies. Consequently, they quantify fundamentally different types of uncertainties, and we argue that they therefore
also have different and complementary scientific uses, even if this dichotomy is not absolute; Bayesian simulations are in general
more convenient for parameter estimation studies, while frequentist simulations are in general more convenient for model testing.
Before BeyondPlanck, most pipelines have used a mix of constrained and random inputs, and used the same hybrid simulations for
all applications, even though the statistical justification for this is not always evident. BeyondPlanck represents the first end-to-end
CMB simulation framework that is able to generate both types of simulations, and these new capabilities have brought this topic to
the forefront. The Bayesian BeyondPlanck simulations and their uses are described extensively in a suite of companion papers. In this
paper we consider one important applications of the corresponding frequentist simulations, namely code validation. That is, we gener-
ate a set of 1-year LFI 30 GHz frequentist simulations with known inputs, and use these to validate the core low-level BeyondPlanck
algorithms; gain estimation, correlated noise estimation, and mapmaking.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Cosmology: observations; cosmic microwave background; diffuse radiation
Elenco autori:
M. Brilenkov, K.S.F. Fornazier, L.T. Hergt, G.A. Hoerning, A. Marins, T. Murokoshi, F. Rahman, N.-. Stutzer, Y. Zhou, F.B. Abdalla, K.J. Andersen, R. Aurlien, R. Banerji, A. Basyrov, A. Battista, M. Bersanelli, S. Bertocco, S. Bollanos, L.P.L. Colombo, H.K. Eriksen, J.R. Eskilt, M.K. Foss, C. Franceschet, U. Fuskeland, S. Galeotta, M. Galloway, S. Gerakakis, E. Gjerløw, B. Hensle, D. Herman, T.D. Hoang, M. Ieronymaki, H.T. Ihle, J.B. Jewell, A. Karakci, E. Keihänen, R. Keskitalo, G. Maggio, D. Maino, M. Maris, S. Paradiso, B. Partridge, M. Reinecke, A.-. Suur-Uski, T.L. Svalheim, D. Tavagnacco, H. Thommesen, M. Tomasi, D.J. Watts, I.K. Wehus, A. Zacchei
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