Euclid preparation
Year: 2026
Type: article
Abstract: Context. The Euclid mission of the European Space Agency will deliver galaxy and cosmic shear surveys, which will be used to constrain initial conditions and statistics of primordial fluctuations. Aims. We present highlights for the Euclid scientific capability to test initial conditions beyond Λ cold dark matter with the three-dimensional galaxy clustering from the spectroscopic survey, the tomographic approach to 3 × 2pt statistics from photometric galaxy survey, and their combination. We then present how these Euclid results can be enhanced when combined with current and future measurements of the cosmic microwave background (CMB) anisotropies. Methods. We provide Fisher forecasts from the combination of Euclid spectroscopic and photometric surveys for spatial curvature, running of the spectral index of the power spectrum of curvature perturbations, isocurvature perturbations, and primordial features. For the parameters of these models, we also provide the combination of Euclid forecasts (pessimistic and optimistic) with three different CMB specifications, i.e. Planck , the Simons Observatory (SO), and CMB-S4. We provide Fisher forecasts for how the power spectrum and bispectrum from the Euclid spectroscopic survey will constrain the local, equilateral, and orthogonal shapes of primordial non-Gaussianity. We also review how Bayesian field-level inference of primordial non-Gaussianity can constrain local primordial non-Gaussianity. Results. We find that the combination of the Euclid main probes will provide an uncertainty of σ (Ω K ) = 0.0044 (0.003) at a 68% confidence level (CL) in pessimistic (optimistic) settings, assuming flat spatial sections as fiducial cosmology. We also find that the combination of the Euclid main probes can detect the running of the scalar spectral index for the fiducial value α s = −0.01 with approximately 2 σ (4 σ ) uncertainty and provide the uncertainty of σ ( α s ) = 0.004 (0.0015) for the fiducial value α s = −0.001 at a 68% CL, always with pessimistic (optimistic) settings. We show how Euclid will have the capability to provide constraints on isocurvature perturbations with a blue spectral index that are one order of magnitude tighter than current bounds. For primordial non-Gaussianity, the combined power spectrum and bispectrum Fisher forecast for the Euclid spectroscopic survey leads to σ ( f NL local ) = 2.2, σ ( f NL equil ) = 108, and σ ( f NL ortho ) = 33 by assuming k max = 0.15 h Mpc −1 and universality for the halo mass function. We show how Bayesian field-level inference can reach the combined power spectrum and bispectrum Fisher forecast uncertainty on f NL local at these large scales, although it is more conservative as it is based on more realistic three-dimensional mock data and masks. For the Euclid main probes, we find relative errors on the amplitude of primordial oscillations (with a fiducial value of 0.01), of 21% (18%) for linear frequency and of 22% (18%) for logarithmic frequency at a 68% CL in the pessimistic (optimistic) case. These uncertainties can be further improved by adding the information from the bispectrum and the non-linear reconstruction. Conclusions. We show how Euclid , with its unique combination of three-dimensional galaxy clustering from the spectroscopic survey and 3 × 2pt statistics from the photometric survey, will provide the tightest constraints on low redshift to date. By targeting a markedly different range in redshift and scale, Euclid ’s expected uncertainties are complementary to those obtained by CMB primary anisotropy, returning the tightest combined constraints on the physics of the early Universe.
Source: Astronomy and Astrophysics
Authors: F. Finelli, Y. Akrami, A. Andrews, M. Ballardini, S. Casas, D. Karagiannis, Z. Sakr, J. Valiviita, G. Alestas, N. Bartolo, J. R. Bermejo-Climent, S. Nesseris, D. Paoletti, D. Sapone, I. Tutusaus, A. Achúcarro, G. Cañas-Herrera, J. Jasche, G. Lavaux, N. Aghanim, B. Altieri, A. Amara, L. Amendola, S. Andreon, N. Auricchio, C. Baccigalupi, D. Bagot, M. Baldi, S. Bardelli, P. Battaglia, A. Biviano, E. Branchini, M. Brescia, S. Camera, V. Capobianco, C. Carbone, J. Carretero, M. Castellano, G. Castignani, S. Cavuoti, K. C. Chambers, A. Cimatti, C. Colodro-Conde, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, F. Courbin, H. M. Courtois, M. Cropper, A. Da Silva, H. Degaudenzi, S. de la Torre, G. De Lucia, A. M. Di Giorgio, H. Dole, M. Douspis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, S. Escoffier, M. Farina, R. Farinelli, F. Faustini, S. Ferriol, P. Fosalba, M. Frailis, E. Franceschi, M. Fumana, S. Galeotta, K. George, B. Gillis, C. Giocoli, J. Gracia-Carpio, A. Grazian, F. Grupp, S. V. H. Haugan, W. Holmes, I. M. Hook, F. Hormuth, A. Hornstrup, K. Jahnke, M. Jhabvala, B. Joachimi, E. Keihänen, S. Kermiche, A. Kiessling, B. Kubik, M. Kümmel, M. Kunz, H. Kurki-Suonio, A. M. C. Le Brun, S. Ligori, P. B. Lilje, V. Lindholm, I. Lloro, G. Mainetti, D. Maino, E. Maiorano, O. Mansutti, S. Marcin, O. Marggraf, M. Martinelli, N. Martinet, F. Marulli, R. J. Massey, E. Medinaceli, S. Mei, Y. Mellier, M. Meneghetti, E. Merlin, G. Meylan, A. Mora, M. Moresco, L. Moscardini, C. Neissner, S.-M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, S. Pires, G. Polenta, M. Poncet, L. A. Popa, L. Pozzetti, F. Raison, R. Rebolo, A. Renzi, J. Rhodes, G. Riccio, E. Romelli, M. Roncarelli, C. Rosset, R. Saglia, B. Sartoris, M. Schirmer, T. Schrabback, A. Secroun, E. Sefusatti, G. Seidel, M. Seiffert, S. Serrano, P. Simon, C. Sirignano, G. Sirri, A. Spurio Mancini, L. Stanco, J. Steinwagner, P. Tallada-Crespí, D. Tavagnacco, A. N. Taylor, I. Tereno, N. Tessore, S. Toft, R. Toledo-Moreo, F. Torradeflot, L. Valenziano, T. Vassallo, G. Verdoes Kleijn, A. Veropalumbo, Y. Wang, J. Weller, A. Zacchei, G. Zamorani, F. M. Zerbi, E. Zucca, V. Allevato, E. Bozzo, C. Burigana, R. Cabanac, M. Calabrese, A. Cappi, D. Di Ferdinando, J. A. Escartin Vigo, L. Gabarra, J. Martín-Fleitas, S. Matthew, N. Mauri, R. B. Metcalf, A. A. Nucita, A. Pezzotta, M. Pöntinen, C. Porciani, I. Risso, V. Scottez, M. Sereno, M. Tenti, M. Viel, M. Wiesmann, I. T. Andika, M. Archidiacono, F. Atrio-Barandela, S. Avila, A. Balaguera-Antolinez, D. Bertacca, M. Bethermin, A. Blanchard, L. Blot, H. Böhringer, S. Borgani, M. L. Brown, S. Bruton, A. Calabro, B. Camacho Quevedo, F. Caro, C. S. Carvalho, T. Castro, F. Cogato, S. Conseil, A. R. Cooray, S. Davini, F. De Paolis, G. Desprez, A. Díaz-Sánchez, J. J. Diaz, S. Di Domizio, J. M. Diego, P. Dimauro, A. Enia, Y. Fang, A. G. Ferrari, A. Finoguenov, A. Fontana, A. Franco, K. Ganga, J. García-Bellido, T. Gasparetto, V. Gautard, E. Gaztanaga, F. Giacomini, F. Gianotti, G. Gozaliasl, A. Gruppuso, M. Guidi, C. M. Gutierrez, S. Hemmati, C. Hernández-Monteagudo, H. Hildebrandt, J. Hjorth, S. Joudaki, J. J. E. Kajava, Y. Kang, V. Kansal, K. Kiiveri, C. C. Kirkpatrick, S. Kruk, M. Lattanzi, V. Le Brun, J. Le Graet, L. Legrand, M. Lembo, F. Lepori, G. Leroy, G. F. Lesci, J. Lesgourgues, L. Leuzzi, T. I. Liaudat, J. Macias-Perez, G. Maggio, M. Magliocchetti, F. Mannucci, R. Maoli, C. J. A. P. Martins, L. Maurin, M. Migliaccio, M. Miluzio, P. Monaco, C. Moretti, G. Morgante, S. Nadathur, K. Naidoo, A. Navarro-Alsina, L. Pagano, F. Passalacqua, K. Paterson, L. Patrizii, A. Pisani, D. Potter, S. Quai, M. Radovich, P. Reimberg, P.-F. Rocci, G. Rodighiero, S. Sacquegna, M. Sahlén, D. B. Sanders, E. Sarpa, A. Schneider, D. Sciotti, E. Sellentin, L. C. Smith, K. Tanidis, C. Tao, G. Testera, R. Teyssier, S. Tosi, A. Troja, M. Tucci, C. Valieri, A. Venhola, D. Vergani, F. Vernizzi, G. Verza, P. Vielzeuf, N. A. Walton
Institutions: Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Osservatorio di Astrofisica e Scienza dello Spazio, National Institute for Astrophysics, Consejo Superior de Investigaciones Científicas, Instituto de Física Teórica, Case Western Reserve University, University of Ferrara, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, RWTH Aachen University, University of the Western Cape, Centre National de la Recherche Scientifique, Université Toulouse III - Paul Sabatier, Saint Joseph University, Heidelberg University, Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, Helsinki Institute of Physics, University of Padua, Istituto Nazionale di Fisica Nucleare, Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Osservatorio Astronomico di Padova, Universidad de La Laguna, Instituto de Astrofísica de Canarias, University of Chile, Leiden University, University of the Basque Country, European Space Agency, Leiden Observatory, European Space Research and Technology Centre, Stockholm University, Institut d'Astrophysique de Paris, Sorbonne Université, Université Paris-Saclay, Institut d'Astrophysique Spatiale, European Space Astronomy Centre, University of Surrey, Brera Astronomical Observatory, Scuola Internazionale Superiore di Studi Avanzati, Trieste Astronomical Observatory, Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Institute for Fundamental Physics of the Universe, Centre National d'Études Spatiales, University of Bologna, Istituto Nazionale di Fisica Nucleare, Sezione di Genova, University of Genoa, Astronomical Observatory of Capodimonte, University of Naples Federico II, Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Osservatorio Astrofisico di Torino, University of Turin, Universitat Autònoma de Barcelona, Port d'Informació Científica, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Astronomical Observatory of Rome, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, University of Hawaiʻi at Mānoa, University of Hawaii System, Royal Observatory, University of Edinburgh, University of Manchester, European Space Research Institute, Lyon 1 Université, Institut National de Physique Nucléaire et de Physique des Particules, Institut de Physique des 2 Infinis de Lyon, Institució Catalana de Recerca i Estudis Avançats, Institut de Ciències del Cosmos, Universitat de Barcelona, University College London, University of Lisbon, Institute of Astrophysics and Space Sciences, University of Geneva, Aix-Marseille Université, Institute for Space Astrophysics and Planetology, Centre de physique des particules de Marseille, Agenzia Spaziale Italiana, Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Universitat Politècnica de Catalunya, Ludwig-Maximilians-Universität München, Max Planck Institute for Extraterrestrial Physics, University of Oslo, Jet Propulsion Laboratory, Lancaster University, Technical University of Denmark, Max Planck Institute for Astronomy, Goddard Space Flight Center, Université Paris Sciences et Lettres, Observatoire de Paris, Laboratoire d'Étude de l'Univers et des Phénomènes Extrêmes, SKA Observatory, Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules, University of Milan, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, FHNW University of Applied Sciences and Arts Northwestern Switzerland, University of Bonn, Istituto Nazionale di Fisica Nucleare, Sezione di Roma I, Durham University, Université Paris Cité, Centre Pierre Binétruy, University of California, Berkeley, École Polytechnique Fédérale de Lausanne, Institute for High Energy Physics, Barcelona Institute of Science and Technology, University of Copenhagen, University of Waterloo, Perimeter Institute, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Astrophysique, Instrumentation et Modélisation, Universität Innsbruck, University of London, Royal Holloway University of London, Universidad Politécnica de Cartagena, University of Groningen, California Institute of Technology, Infrared Processing and Analysis Center, Istituto di Radioastronomia di Bologna, Osservatorio Astronomico della Regione Autonoma Valle d'Aosta, Regione Autonoma Valle d'Aosta, Université Côte d'Azur, Lagrange Laboratory, Observatoire de la Côte d’Azur, University of Oxford, University of Salento, Istituto Nazionale di Fisica Nucleare, Sezione di Lecce, Université Catholique de Lille, Fondazione ICSC Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Max Planck Institute for Astrophysics, Technical University of Munich, Universidad de Salamanca, Observatoire astronomique de Strasbourg, Université de Strasbourg, Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo, Max Planck Institute for Physics, University of Trieste, University of California, Irvine, Instituto de Física de Cantabria, National Observatory, CEA Paris-Saclay - Etablissement de Saclay, CEA Paris-Saclay, Institut de Recherche sur les Lois Fondamentales de l'Univers, University of Portsmouth, Aalto University, Ruhr University Bochum, ARC Centre of Excellence for Dark Matter Particle Physics, Swinburne University of Technology, University of Cambridge, University of Zurich, Institut polytechnique de Grenoble, Arcetri Astrophysical Observatory, Sapienza University of Rome, Universidade do Porto, Centro de Astrofísica da Universidade do Porto, University of Rome Tor Vergata, Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata, Uppsala University, Princeton University, University of Oulu, Institut de Physique Théorique, Flatiron Institute
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7160238166