papers

Publications (167)

astro-ph.CO2026

Euclid preparation. Galaxy power spectrum modelling in redshift space

Euclid Collaboration, B. Camacho Quevedo, M. Crocce +292

Accurate modelling of redshift-space distortions (RSD) is essential for maximizing the cosmological information extracted from large galaxy redshift surveys. In preparation for the…

astro-ph.GA2025

Euclid preparation. Spatially resolved stellar populations of local galaxies with Euclid: a proof of concept using synthetic images with the TNG50 simulation

Euclid Collaboration, Abdurro'uf, C. Tortora +286

The European Space Agency's Euclid mission will observe approximately 14,000 of the extragalactic sky and deliver high-quality imaging for many galaxies. The depth a…

astro-ph.CO2024

Euclid preparation: XLVIII. The pre-launch Science Ground Segment simulation framework

Euclid Collaboration, S. Serrano, P. Hudelot +274

The European Space Agency's Euclid mission is one of the upcoming generation of large-scale cosmology surveys, which will map the large-scale structure in the Universe with unprece…

astro-ph.CO2025

Euclid preparation. Cosmology Likelihood for Observables in Euclid (CLOE). 4: Validation and Performance

Euclid Collaboration, M. Martinelli, A. Pezzotta +334

The Euclid satellite will provide data on the clustering of galaxies and on the distortion of their measured shapes, which can be used to constrain and test the cosmological model.…

astro-ph.GA2025

Euclid preparation. Estimating galaxy physical properties using CatBoost chained regressors with attention

Euclid Collaboration, A. Humphrey, P. A. C. Cunha +232

Euclid will image ~14000 deg^2 of the extragalactic sky at visible and NIR wavelengths, providing a dataset of unprecedented size and richness that will facilitate a multitude of s…

astro-ph.IM2023

Euclid preparation. XXIX. Water ice in spacecraft part I: The physics of ice formation and contamination

Euclid Collaboration, M. Schirmer, K. Thürmer +218

Molecular contamination is a well-known problem in space flight. Water is the most common contaminant and alters numerous properties of a cryogenic optical system. Too much ice mea…

astro-ph.HE2025

Euclid Quick Data Release (Q1). The active galaxies of Euclid

Euclid Collaboration, T. Matamoro Zatarain, S. Fotopoulou +355

We present a catalogue of candidate active galactic nuclei (AGN) in the Quick Release (Q1) fields. For each source we collect multi-wavelength photometry and spec…

astro-ph.CO2026

Euclid preparation. XCVIII. Cosmology Likelihood for Observables in Euclid (CLOE). 5: Extensions beyond the standard modelling of theoretical probes and systematic effects

Euclid Collaboration, L. W. K. Goh, A. Nouri-Zonoz +301

Euclid is expected to establish new state-of-the-art constraints on extensions beyond the standard LCDM cosmological model by measuring the positions and shapes of billions of gala…

astro-ph.CO2026

Euclid preparation. Three-dimensional galaxy clustering in configuration space: Three-point correlation function estimation

Euclid Collaboration, A. Veropalumbo, M. Moresco +303

Higher-order correlation functions are firmly established as a fundamental tool for the statistical analysis of clustering in modern galaxy surveys. It was demonstrated that they g…

astro-ph.GA2024

Euclid preparation. The Cosmic Dawn Survey (DAWN) of the Euclid Deep and Auxiliary Fields

Euclid Collaboration, C. J. R. McPartland, L. Zalesky +288

Euclid will provide deep NIR imaging to 26.5 AB magnitude over 59 deg in its deep and auxiliary fields. The Cosmic DAWN survey complements the deep Euclid data with…

astro-ph.CO2025

Euclid preparation. LXVII. Deep learning true galaxy morphologies for weak lensing shear bias calibration

Euclid Collaboration, B. Csizi, T. Schrabback +259

To date, galaxy image simulations for weak lensing surveys usually approximate the light profiles of all galaxies as a single or double Sérsic profile, neglecting the influence of…

astro-ph.IM2025

Euclid Structural-Thermal-Optical Performance

Euclid Collaboration, A. Anselmi, R. Laureijs +290

The Euclid system performance is defined in terms of image quality metrics tuned to the weak gravitational lensing (WL) cosmological probe. WL induces stringent requirements on the…

astro-ph.CO2026

Euclid preparation. XCII. Controlling angular systematics in the Euclid spectroscopic galaxy sample

Euclid Collaboration, P. Monaco, M. Y. Elkhashab +298

We present the strategy used to identify and mitigate potential sources of angular systematics in the \textit{Euclid} spectroscopic galaxy survey, and we quantify their impact on g…

astro-ph.CO2025

Euclid Quick Data Release (Q1). The first catalogue of strong-lensing galaxy clusters

Euclid Collaboration, P. Bergamini, M. Meneghetti +375

We present the first catalogue of strong lensing galaxy clusters identified in the Euclid Quick Release 1 observations (covering ). This catalogue is the resu…

astro-ph.IM2025

Euclid VI. NISP-P optical ghosts

Euclid Collaboration, K. Paterson, M. Schirmer +309

The Near-Infrared Spectrometer and Photometer (NISP) onboard Euclid includes several optical elements in its path, which introduce artefacts into the data from non-nominal light pa…

astro-ph.CO2025

Euclid preparation: Expected constraints on initial conditions

Euclid Collaboration, F. Finelli, Y. Akrami +307

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 fluctu…

astro-ph.GA2025

Euclid Quick Data Release (Q1). A first view of the star-forming main sequence in the Euclid Deep Fields

Euclid Collaboration, A. Enia, L. Pozzetti +348

The star-forming main sequence (SFMS) is a tight relation observed between stellar masses and star formation rates (SFR) in a population of galaxies. This relation is observed at d…

astro-ph.CO2025

Tracing cosmic voids with fast simulations

M. D. Lepinzan, C. T. Davies, T. Castro +3

Context. Cosmic voids are vast underdense regions in the cosmic web that encode crucial information about structure formation, the composition of the Universe, and its expansion hi…

astro-ph.CO2026

Euclid preparation. Galaxy 2-point correlation function modelling in redshift space

Euclid Collaboration, M. Kärcher, M. -A. Breton +309

The Euclid satellite will measure spectroscopic redshifts for tens of millions of emission-line galaxies. In the context of Stage-IV surveys, the 3-dimensional clustering of galaxi…

astro-ph.GA2025

Euclid Quick Data Release (Q1). The Strong Lensing Discovery Engine D -- Double-source-plane lens candidates

Euclid Collaboration, T. Li, T. E. Collett +335

Strong gravitational lensing systems with multiple source planes are powerful tools for probing the density profiles and dark matter substructure of the galaxies. The ratio of Eins…

astro-ph.IM2025

Euclid preparation: The NISP spectroscopy channel, on ground performance and calibration

Euclid Collaboration, W. Gillard, T. Maciaszek +356

ESA's Euclid cosmology mission relies on the very sensitive and accurately calibrated spectroscopy channel of the Near-Infrared Spectrometer and Photometer (NISP). With three opera…

astro-ph.CO2026

\textit{Euclid} preparation. Baryon acoustic oscillations extraction techniques: comparison and optimisation

Euclid Collaboration, E. Sarpa, A. Veropalumbo +296

We present the first end-to-end validation of the Euclid baryon acoustic oscillation (BAO) analysis pipeline, encompassing density-field reconstruction, two-point correlation funct…

astro-ph.CO2026

Euclid Quick Data Release (Q1). The role of cosmic connectivity in shaping galaxy clusters

Euclid Collaboration, C. Gouin, C. Laigle +337

The matter distribution around galaxy clusters is distributed over several filaments, reflecting their positions as nodes in the large-scale cosmic web. The number of filaments con…

astro-ph.IM2026

OpenGadget3 GPU solver tests

A. Ragagnin, G. S. Karademir, F. Groth +6

We present an in-depth evaluation of the scalability and accuracy of the GPU porting of the N-body code for hydrodynamic cosmological simulations \og. While technical details of ou…

astro-ph.CO2024

Euclid preparation. Modelling spectroscopic clustering on mildly nonlinear scales in beyond-CDM models

Euclid Collaboration, B. Bose, P. Carrilho +229

We investigate the approximations needed to efficiently predict the large-scale clustering of matter and dark matter halos in beyond-CDM scenarios. We examine the normal branch…

astro-ph.GA2026

Euclid Quick Data Release (Q1). The Strong Lensing Discovery Engine F -- Bright and low-redshift strong lenses

Euclid Collaboration, L. R. Ecker, M. Fabricius +346

We present 72 additional galaxy-galaxy strong lenses that complement the sample discovered in the Euclid Quick Release 1 data (63.1 deg^2) of the Strong Lens Discovery Engine (SLDE…

astro-ph.CO2025

Euclid preparation. Constraining parameterised models of modifications of gravity with the spectroscopic and photometric primary probes

Euclid Collaboration, I. S. Albuquerque, N. Frusciante +285

The Euclid mission has the potential to understand the fundamental physical nature of late-time cosmic acceleration and, as such, of deviations from the standard cosmological model…

astro-ph.GA2025

Euclid Quick Data Release (Q1): Hunting for luminous z > 6 galaxies in the Euclid Deep Fields -- forecasts and first bright detections

Euclid Collaboration, N. Allen, P. A. Oesch +309

The evolution of the rest-frame ultraviolet luminosity function (UV LF) is a powerful probe of early star formation and stellar mass build-up. At z > 6, its bright end (MUV < -21)…

astro-ph.CO2024

Euclid preparation. LIX. Angular power spectra from discrete observations

Euclid Collaboration, N. Tessore, B. Joachimi +266

We present the framework for measuring angular power spectra in the Euclid mission. The observables in galaxy surveys, such as galaxy clustering and cosmic shear, are not continuou…

astro-ph.GA2024

Euclid preparation. LVIII. Detecting globular clusters in the Euclid survey

Euclid Collaboration, K. Voggel, A. Lançon +270

Extragalactic globular clusters (EGCs) are an abundant and powerful tracer of galaxy dynamics and formation, and their own formation and evolution is also a matter of extensive deb…

astro-ph.GA2026

Euclid preparation. Probing galaxy evolution within cosmic voids in Euclid-like simulations

Euclid Collaboration, G. Papini, O. Cucciati +294

The evolution of galaxies is profoundly influenced by the environment in which they reside. Cosmic voids serve as pristine laboratories for studying galaxy evolution in the relativ…

astro-ph.GA2026

Euclid Quick Data Release (Q1): The geometry of dark matter halos from extragalactic streams

Euclid Collaboration, N. Starkman, J. Nibauer +295

Wide-field surveys like Euclid mark a new era of extragalactic stellar stream studies. With a large number of streams, it is now possible to constrain the dark matter halos of gala…

astro-ph.GA2025

Euclid Quick Data Release (Q1): The Strong Lensing Discovery Engine A -- System overview and lens catalogue

Euclid Collaboration, M. Walmsley, P. Holloway +372

We present a catalogue of 497 galaxy-galaxy strong lenses in the Euclid Quick Release 1 data (63 deg). In the initial 0.45\% of Euclid's surveys, we double the total number of…

astro-ph.GA2025

Euclid Quick Data Release (Q1). First Euclid statistical study of galaxy mergers and their connection to active galactic nuclei

Euclid Collaboration, A. La Marca, L. Wang +334

Galaxy major mergers are a key pathway to trigger AGN. We present the first detection of major mergers in the Euclid Deep Fields and analyse their connection with AGN. We construct…

astro-ph.IM2024

Euclid. IV. The NISP Calibration Unit

Euclid Collaboration, F. Hormuth, K. Jahnke +332

The near-infrared calibration unit (NI-CU) on board Euclid's Near-Infrared Spectrometer and Photometer (NISP) is the first astronomical calibration lamp based on light-emitting dio…

astro-ph.GA2025

Euclid preparation: LXXXI. The impact of nonparametric star formation histories on spatially resolved galaxy property estimation using synthetic Euclid images

Euclid Collaboration, A. Nersesian, Abdurro'uf +283

We analyzed the spatially resolved and global star formation histories (SFHs) for a sample of 25 TNG50-SKIRT Atlas galaxies to assess the feasibility of reconstructing accurate SFH…

astro-ph.GA2025

Euclid preparation LXX. Forecasting detection limits for intracluster light in the Euclid Wide Survey

Euclid Collaboration, C. Bellhouse, J. B. Golden-Marx +292

The intracluster light (ICL) permeating galaxy clusters is a tracer of the cluster's assembly history, and potentially a tracer of their dark matter structure. In this work we expl…

astro-ph.GA2025

Euclid Quick Data Release (Q1). The Strong Lensing Discovery Engine C: Finding lenses with machine learning

Euclid Collaboration, N. E. P. Lines, T. E. Collett +350

Strong gravitational lensing has the potential to provide a powerful probe of astrophysics and cosmology, but fewer than 1000 strong lenses have been confirmed so far. With a 0.16'…

astro-ph.GA2023

Euclid preparation. XXVII. A UV-NIR spectral atlas of compact planetary nebulae for wavelength calibration

Euclid Collaboration, K. Paterson, M. Schirmer +201

The Euclid mission will conduct an extragalactic survey over 15000 deg of the extragalactic sky. The spectroscopic channel of the Near-Infrared Spectrometer and Photometer (NIS…

astro-ph.IM2026

Euclid Quick Data Release (Q1). AstroVink: A vision transformer approach to find strong gravitational lens systems

Euclid Collaboration, S. H. Vincken, K. Rojas +302

We present AstroVink, a vision transformer classifier designed for automated identification of strong lens candidates in Euclid imaging. We build upon the DINOv2 encoder, fine tune…

astro-ph.GA2025

Euclid Quick Data Release (Q1) The Strong Lensing Discovery Engine B -- Early strong lens candidates from visual inspection of high velocity dispersion galaxies

Euclid Collaboration, K. Rojas, T. E. Collett +336

We present a search for strong gravitational lenses in Euclid imaging with high stellar velocity dispersion ( km/s) reported by SDSS and DESI. We performed expert visua…

astro-ph.CO2025

Euclid: Exploring observational systematics in cluster cosmology -- a comprehensive analysis of cluster counts and clustering

A. Fumagalli, M. Costanzi, T. Castro +168

This study explores the impact of observational and modelling systematic effects on cluster number counts and cluster clustering and provides model prescriptions for their joint an…

astro-ph.GA2025

Euclid Quick Data Release (Q1) -- Data release overview

Euclid Collaboration, H. Aussel, I. Tereno +407

The first Euclid Quick Data Release, Q1, comprises 63.1 sq deg of the Euclid Deep Fields (EDFs) to nominal wide-survey depth. It encompasses visible and near-infrared space-based i…

astro-ph.CO2026

Euclid preparation. First investigation of the impact of cross-contamination on spectroscopic redshift measurements with pixel-level simulations

Euclid Collaboration, F. Passalacqua, S. Anselmi +299

We present a study on simulated data focused on understanding the performance of the spectroscopic redshift measurements with the Near-Infrared Spectrometer and Photometer (NISP) i…

astro-ph.CO2025

Euclid preparation. LXXIV. Euclidised observations of Hubble Frontier Fields and CLASH galaxy clusters

Euclid Collaboration, P. Bergamini, M. Meneghetti +263

We present HST2EUCLID, a novel Python code to generate Euclid realistic mock images in the , , , and photometric bands based on panchro…

astro-ph.GA2025

Euclid Quick Data Release (Q1). An investigation of optically faint, red objects in the Euclid Deep Fields

Euclid Collaboration, G. Girardi, G. Rodighiero +326

Our understanding of cosmic star-formation at used to largely rely on rest-frame UV observations. However, these observations overlook dusty and massive sources, resulting in…

astro-ph.GA2024

Euclid preparation. XLIX. Selecting active galactic nuclei using observed colours

Euclid Collaboration, L. Bisigello, M. Massimo +244

Euclid will cover over 14000 with two optical and near-infrared spectro-photometric instruments, and is expected to detect around ten million active galactic nuclei (AGN)…

astro-ph.CO2026

Euclid: The linear-construction covariance and cosmology

V. Lindholm, E. Sihvola, J. Valiviita +137

We study the properties of galaxy cluster 2-point correlation function covariance matrices estimated using the linear-construction (LC) method, which is computationally up to 20 ti…

astro-ph.GA2025

Euclid Quick Data Release (Q1). Extending the quest for little red dots to z<4

Euclid Collaboration, L. Bisigello, G. Rodighiero +348

Recent James Webb Space Telescope (JWST) observations have revealed a population of sources with a compact morphology and a characteristic `v-shaped' continuum, namely blue at rest…

astro-ph.GA2025

Euclid Quick Data Release (Q1). First Euclid statistical study of the active galactic nuclei contribution fraction

Euclid Collaboration, B. Margalef-Bentabol, L. Wang +331

Active galactic nuclei (AGN) play a key role in galaxy evolution but are challenging to identify due to their varied observational signatures. Furthermore, understanding their impa…

astro-ph.CO2026

Euclid: Galaxy SED reconstruction in the PHZ processing function: impact on the PSF and the role of medium-band filters

Euclid Collaboration, F. Tarsitano, C. Schreiber +301

Weak lensing surveys require accurate correction for the point spread function (PSF) when measuring galaxy shapes. For a diffraction-limited PSF, as arises in space-based missions,…

astro-ph.CO2026

Euclid preparation. LXXXV. Toward a DR1 application of higher-order weak lensing statistics

Euclid Collaboration, S. Vinciguerra, F. Bouchè +284

This is the second paper in the HOWLS (higher-order weak lensing statistics) series exploring the usage of non-Gaussian statistics for cosmology inference within Euclid. With respe…

astro-ph.IM2025

Euclid Quick Data Release (Q1): From images to multiwavelength catalogues: the Euclid MERge Processing Function

Euclid Collaboration, E. Romelli, M. Kümmel +345

The Euclid satellite is an ESA mission that was launched in July 2023. \Euclid is working in its regular observing mode with the target of observing an area of $14\,000~\text{deg}^…

astro-ph.CO2025

Euclid preparation: The flat-sky approximation for the clustering of Euclid's photometric galaxies

Euclid Collaboration, W. L. Matthewson, R. Durrer +277

We compare the performance of the flat-sky approximation and Limber approximation for the clustering analysis of the photometric galaxy catalogue of Euclid. We study a 6 bin config…

astro-ph.GA2026

Euclid Quick Data Release (Q1): The evolution of the passive-density and morphology-density relations between and

Euclid Collaboration, C. Cleland, S. Mei +320

The extent to which the environment affects galaxy evolution has been under scrutiny by researchers for decades. With the first data from Euclid, we can begin to systematically stu…

astro-ph.CO2026

Testing template-fitting models for the multipoles of the two-point clustering of galaxy clusters

Euclid Collaboration, E. Tsaprazi, A. Fumagalli +274

The \textit{Euclid} satellite will deliver a catalogue of optically-selected galaxy clusters spanning from around deg in Data Release (DR) 1 to around deg

astro-ph.GA2025

The impact of assembly history on the X-ray detectability of halos. From galaxy groups to galaxy clusters

I. Marini, P. Popesso, K. Dolag +15

Galaxy groups represent a significant fraction of the halo population, playing a crucial role in galaxy formation and evolution. However, their detection in X-rays remains challeng…

astro-ph.GA2024

Euclid Preparation XXXIII. Characterization of convolutional neural networks for the identification of galaxy-galaxy strong lensing events

Euclid Collaboration, L. Leuzzi, M. Meneghetti +216

Forthcoming imaging surveys will potentially increase the number of known galaxy-scale strong lenses by several orders of magnitude. For this to happen, images of tens of millions…

astro-ph.GA2025

Euclid Quick Data Release (Q1). Optical and near-infrared identification and classification of point-like X-ray selected sources

Euclid Collaboration, W. Roster, M. Salvato +316

To better understand the role of active galactic nuclei (AGN) in galaxy evolution, it is crucial to achieve a complete and pure AGN census. X-ray surveys are key to this, but ident…

astro-ph.CO2024

Euclid preparation: TBD. The impact of line-of-sight projections on the covariance between galaxy cluster multi-wavelength observable properties -- insights from hydrodynamic simulations

Euclid Collaboration, A. Ragagnin, A. Saro +240

Cluster cosmology can benefit from combining multi-wavelength studies, which can benefit from characterising the correlation coefficients between different mass-observable relation…

astro-ph.CO2025

Euclid preparation. Methodology for validating the Euclid Catalogue of Galaxy Clusters using external data

Euclid Collaboration, J. -B. Melin, S. A. Stanford +315

We present our methodology for identifying known clusters as counterparts to objects in the Euclid Catalogue of Galaxy Clusters (ECGC). Euclid is expected to detect a large number…

astro-ph.CO2024

Euclid Preparation. XXXVII. Galaxy colour selections with Euclid and ground photometry for cluster weak-lensing analyses

Euclid Collaboration, G. F. Lesci, M. Sereno +238

We derived galaxy colour selections from Euclid and ground-based photometry, aiming to accurately define background galaxy samples in cluster weak-lensing analyses. Given any set o…

astro-ph.GA2026

Euclid Quick Data Release (Q1). Quenching precedes bulge formation in dense environments but follows it in the field

Euclid Collaboration, F. Gentile, E. Daddi +321

(Abridged) The bimodality between star-forming discs and quiescent spheroids requires the existence of two main processes: the galaxy quenching and the morphological transformation…

astro-ph.CO2025

Euclid preparation LX. The use of HST images as input for weak-lensing image simulations

Euclid Collaboration, D. Scognamiglio, T. Schrabback +245

Data from the Euclid space telescope will enable cosmic shear measurements with very small statistical errors, requiring corresponding systematic error control level. A common appr…

astro-ph.GA2024

Euclid preparation. Optical emission-line predictions of intermediate-z galaxy populations in GAEA for the Euclid Deep and Wide Surveys

Euclid Collaboration, L. Scharré, M. Hirschmann +239

In anticipation of the Euclid Wide and Deep Surveys, we present optical emission-line predictions at intermediate redshifts from 0.4 to 2.5. Our approach combines a mock light cone…

astro-ph.GA2024

Euclid preparation. XLIII. Measuring detailed galaxy morphologies for Euclid with machine learning

Euclid Collaboration, B. Aussel, S. Kruk +255

The Euclid mission is expected to image millions of galaxies with high resolution, providing an extensive dataset to study galaxy evolution. We investigate the application of deep…

astro-ph.CO2023

Euclid preparation: XXVIII. Modelling of the weak lensing angular power spectrum

Euclid Collaboration, A. C. Deshpande, T. Kitching +200

This work considers which higher-order effects in modelling the cosmic shear angular power spectra must be taken into account for Euclid. We identify which terms are of concern, an…

astro-ph.CO2024

Euclid preparation. Simulations and nonlinearities beyond CDM. 1. Numerical methods and validation

Euclid Collaboration, J. Adamek, B. Fiorini +268

To constrain models beyond CDM, the development of the Euclid analysis pipeline requires simulations that capture the nonlinear phenomenology of such models. We present an over…

astro-ph.GA2026

Euclid Quick Data Release (Q1). Searching for radio-selected \Euclid-dark galaxies in the EDF-N

Euclid Collaboration, M. Giulietti, I. Prandoni +308

We present and investigate the properties of a sample of radio-selected, Euclid-dark galaxies, identified from LOFAR HBA observations at 144 MHz within the Euclid Deep Field-North…

astro-ph.CO2022

The BEHOMO project: LTB -body simulations

V. Marra, T. Castro, D. Camarena +2

Our Universe may feature large-scale inhomogeneities and anisotropies which cannot be explained by the standard model of cosmology, that is, the homogeneous and isotropic FLRW metr…

astro-ph.CO2026

Euclid preparation: LXXXVII. Non-Gaussianity of 2-point statistics likelihood: Precise analysis of the matter power spectrum distribution

Euclid Collaboration, J. Bel, S. Gouyou Beauchamps +281

We investigate the non-Gaussian features in the distribution of the matter power spectrum multipoles. Using the COVMOS method, we generate 100\,000 mock realisations of dark matter…

astro-ph.CO2024

Euclid preparation. XXXIX. The effect of baryons on the Halo Mass Function

Euclid Collaboration, T. Castro, S. Borgani +220

The Euclid photometric survey of galaxy clusters stands as a powerful cosmological tool, with the capacity to significantly propel our understanding of the Universe. Despite being…

astro-ph.CO2025

Euclid preparation. Cosmology Likelihood for Observables in Euclid (CLOE). 6: Impact of systematic uncertainties on the cosmological analysis

Euclid Collaboration, L. Blot, K. Tanidis +309

Extracting cosmological information from the Euclid galaxy survey will require modelling numerous systematic effects during the inference process. This implies varying a large numb…

astro-ph.CO2026

Euclid preparation: Testing multi-field inflation with galaxy power spectrum and bispectrum

Euclid Collaboration, D. Linde, A. Moradinezhad Dizgah +281

Primordial non-Gaussianity (PNG) is a powerful probe of the origin of cosmic structure. Stage-IV surveys like \Euclid will measure galaxy - and -point clustering at high sign…

astro-ph.CO2024

Euclid preparation. Sensitivity to neutrino parameters

Euclid Collaboration, M. Archidiacono, J. Lesgourgues +246

The Euclid mission of the European Space Agency will deliver weak gravitational lensing and galaxy clustering surveys that can be used to constrain the standard cosmological model…

astro-ph.CO2024

Euclid preparation: 6x2 pt analysis of Euclid's spectroscopic and photometric data sets

Euclid Collaboration, L. Paganin, M. Bonici +252

We present cosmological parameter forecasts for the Euclid 6x2pt statistics, which include the galaxy clustering and weak lensing main probes together with previously neglected cro…

astro-ph.CO2026

Euclid preparation. CII. Non-Gaussianity of 2-pt statistics likelihood: Parameter inference with a non-Gaussian likelihood in Fourier and configuration space

Euclid Collaboration, S. Gouyou Beauchamps, J. Bel +277

In this work we account for this skewness in parameter inference by modelling the likelihood through an Edgeworth expansion which involves the complete skewness tensor, composed of…

astro-ph.CO2025

Euclid preparation. Simulating thousands of Euclid spectroscopic skies

Euclid Collaboration, P. Monaco, G. Parimbelli +303

We present two extensive sets of 3500+1000 simulations of dark matter haloes on the past light cone, and two corresponding sets of simulated (`mock') galaxy catalogues that represe…

astro-ph.CO2026

Euclid preparation. Testing analytic models of galaxy intrinsic alignments in the Euclid Flagship simulation

Euclid Collaboration, R. Paviot, B. Joachimi +293

We model intrinsic alignments (IA) in Euclid's Flagship simulation to investigate its impact on Euclid's weak lensing signal. Our IA implementation in the Flagship simulation takes…

astro-ph.IM2025

Euclid Quick Data Release (Q1). From simulations to sky: Advancing machine-learning lens detection with real Euclid data

Euclid Collaboration, N. E. P. Lines, T. E. Collett +301

In the era of large-scale surveys like Euclid, machine learning has become an essential tool for identifying rare yet scientifically valuable objects, such as strong gravitational…

astro-ph.GA2026

Euclid preparation. 3D reconstruction of the cosmic web with simulated Euclid Deep spectroscopic samples

Euclid Collaboration, K. Kraljic, C. Laigle +321

The ongoing Euclid mission aims to measure spectroscopic redshifts for approximately two million galaxies using the H line emission detected in near-infrared slitless spectros…

astro-ph.CO2025

Cosmology Likelihood for Observables in \Euclid (CLOE). 1. Theoretical recipe

Euclid Collaboration, V. F. Cardone, S. Joudaki +323

As the statistical precision of cosmological measurements increases, the accuracy of the theoretical description of these measurements needs to increase correspondingly in order to…

astro-ph.CO2024

Euclid preparation. The impact of relativistic redshift-space distortions on two-point clustering statistics from the Euclid wide spectroscopic survey

Euclid Collaboration, M. Y. Elkhashab, D. Bertacca +252

Measurements of galaxy clustering are affected by RSD. Peculiar velocities, gravitational lensing, and other light-cone projection effects modify the observed redshifts, fluxes, an…

astro-ph.GA2025

Euclid preparation. Predicting star-forming galaxy scaling relations with the spectral stacking code SpectraPyle

Euclid Collaboration, S. Quai, L. Pozzetti +309

We introduce SpectraPyle, a versatile spectral stacking pipeline developed for the Euclid mission's NISP spectroscopic surveys, aimed at extracting faint emission lines and spectra…

astro-ph.IM2024

Euclid. III. The NISP Instrument

Euclid Collaboration, K. Jahnke, W. Gillard +434

The Near-Infrared Spectrometer and Photometer (NISP) on board the Euclid satellite provides multiband photometry and R>=450 slitless grism spectroscopy in the 950-2020nm wavelength…

astro-ph.GA2025

Euclid Quick Data Release (Q1). Galaxy shapes and alignments in the cosmic web

Euclid Collaboration, C. Laigle, C. Gouin +341

Galaxy morphologies and shape orientations are expected to correlate with their large-scale environment, since they grow by accreting matter from the cosmic web and are subject to…

astro-ph.GA2025

Euclid Quick Data Release (Q1). Spectroscopic unveiling of highly ionised lines at z = 2.48-3.88

Euclid Collaboration, D. Vergani, S. Quai +316

This study explores a rare population of sources in a currently uncharted region of spectroscopic redshift space in the Euclid Quick Data Release (Q1), and is intended potentially…

astro-ph.GA2026

Euclid Quick Data Release (Q1): Euclid spectroscopy of quasars. 1. Identification and redshift determination of 3500 bright quasars

Euclid Collaboration, Y. Fu, R. Bouwens +354

The slitless spectroscopy mode of the NISP onboard Euclid has enabled efficient spectroscopy of objects within a large FoV. We present a large and homogeneous sample of bright quas…

astro-ph.CO2024

Euclid preparation. Improving cosmological constraints using a new multi-tracer method with the spectroscopic and photometric samples

Euclid Collaboration, F. Dournac, A. Blanchard +240

Future data provided by the Euclid mission will allow us to better understand the cosmic history of the Universe. A metric of its performance is the figure-of-merit (FoM) of dark e…

astro-ph.CO2026

Euclid preparation. Impact of redshift distribution uncertainties on the joint analysis of photometric galaxy clustering and weak gravitational lensing

Euclid Collaboration, K. A. Bertmann, A. Porredon +290

One of the mission's key projects is the so-called 32pt analysis, that is, the combination of cosmic shear, photometric galaxy clustering, and galaxy-gala…

astro-ph.GA2025

Euclid preparation: TBD. Cosmic Dawn Survey: evolution of the galaxy stellar mass function across 0.2<z<6.5 measured over 10 square degrees

Euclid Collaboration, L. Zalesky, J. R. Weaver +304

The Cosmic Dawn Survey Pre-launch (PL) catalogues cover an effective 10.13 deg area with uniform deep Spitzer/IRAC data ( mag, 5), the largest area covered to th…

astro-ph.CO2024

Euclid preparation. LII. Forecast impact of super-sample covariance on 3x2pt analysis with Euclid

Euclid Collaboration, D. Sciotti, S. Gouyou Beauchamps +221

Deviations from Gaussianity in the distribution of the fields probed by large-scale structure surveys generate additional terms in the data covariance matrix, increasing the uncert…

astro-ph.CO2026

Euclid preparation. XCVI. Cosmology Likelihood for Observables in Euclid (CLOE). 3. Inference and Forecasts

Euclid Collaboration, G. Cañas-Herrera, L. W. K. Goh +337

The Euclid mission aims to measure the positions, shapes, and redshifts of over a billion galaxies to provide unprecedented constraints on the nature of dark matter and dark energy…

astro-ph.CO2026

Euclid preparation. LXXXIX. Accurate and precise data-driven angular power spectrum covariances

Euclid Collaboration, K. Naidoo, J. Ruiz-Zapatero +280

We develop techniques for generating accurate and precise internal covariances for measurements of clustering and weak-lensing angular power spectra. These methods have been design…

astro-ph.CO2025

Euclid preparation. XLI. Galaxy power spectrum modelling in real space

Euclid Collaboration, A. Pezzotta, C. Moretti +246

We investigate the accuracy of the perturbative galaxy bias expansion in view of the forthcoming analysis of the Euclid spectroscopic galaxy samples. We compare the performance of…

astro-ph.CO2025

Euclid preparation. BAO analysis of photometric galaxy clustering in configuration space

Euclid Collaboration, V. Duret, S. Escoffier +286

With about 1.5 billion galaxies expected to be observed, the very large number of objects in the Euclid photometric survey will allow for precise studies of galaxy clustering from…

astro-ph.CO2024

Euclid. I. Overview of the Euclid mission

Euclid Collaboration, Y. Mellier, Abdurro'uf +1134

The current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown. Eucl…

astro-ph.IM2025

Euclid preparation. Overview of Euclid infrared detector performance from ground tests

Euclid Collaboration, B. Kubik, R. Barbier +341

The paper describes the objectives, design and findings of the pre-launch ground characterisation campaigns of the Euclid infrared detectors. The pixel properties, including baseli…

astro-ph.CO2026

Euclid. Populating a dark universe with galaxies using SciPIC

Euclid Collaboration, E. J. Gonzalez, J. Carretero +305

High-fidelity galaxy mocks are crucial for validating analysis pipelines and for cosmological inference. In this context, the Science Pipeline at PIC (SciPIC) is a pipeline specifi…

astro-ph.CO2026

Euclid preparation. Galaxy power spectrum and bispectrum modelling

Euclid Collaboration, K. Pardede, A. Eggemeier +306

Higher-order correlation functions of the large-scale galaxy distribution offer access to information beyond that contained in standard 2-point statistics such as the power spectru…