IOP Copyright PoliciesHannu Kurki-SuonioMario ZannoniV. LindholmM. TomasiCarole TuckerFrançois R. BouchetSebastian GrandisDiego MolinariGianluca PolentaGiampaolo PisanoClive DickinsonSebastien ClesseAnthony LasenbyMiguel QuartinBruno MaffeiGiuseppe D'AlessandroFabio FinelliMassimiliano LattanziGemma LuzziJens ChlubaAlessio NotariA. TartariA. PolloZhen-Yi CaiI. ColantoniJose M. DiegoVincent VenninAlessandro CoppolecchiaCarlo BuriganaMartina GerbinoMario BallardiniMartin KunzC. Hervias-CaimapoJussi ValiviitaC. S. CarvalhoE. Di ValentinoCarlos MartinsM. BonatoNicola VittorioR. Fernandez-CobosPeter A. R. AdeMathieu RemazeillesAlessandro PaiellaTiziana TrombettiM. López-CaniegoP. VielvaAnthony ChallinorDaniela PaolettiE. HivonWill HandleyMatthew HillsMario ZannoniJulien LesgourguesJ. BorrillDiego MolinariAnna BonaldiD. McCarthyB. Van TentM. AshdownJosquin ErrardR. AllisonAna AchúcarroM. BucherJacques DelabrouilleE. Martínez-GonzálezKarl YoungMartin CrookR. BanerjiMichele LiguoriF. BoulangerIngunn Kathrine WehusCarlo BaccigalupiAntony LewisSimone FerraroS. HagstotzFrancesco ForastieriAlessandro BuzzelliShaul HananyJames G. BartlettLaura SalvatiM. RomanLuca LamagnaMartino CalvoN. TrappeG. de GasperisA. J. BandaySilvia MasiStephen M. FeeneyThomas D. KitchingL. PolastriCarlo BuriganaThejs BrinckmannS. MatarreseAlessandro MonfardiniD. TramontePaolo NatoliMario BallardiniK. KiiveriM. PiatE. Di ValentinoG. de ZottiC. Hernández-MonteagudoAlessandro MelchiorriM. BonatoJ. GreensladeVivian PoulinJose Alberto Rubino-MartinMattia NegrelloDaniel BaumannP. de BernardisJean-Baptiste MelinH. K. EriksenMarco BersanelliTheodore KisnerRicardo Genova-SantosTiziana TrombettiU. FuskelandNicola BartoloG. CastellanoR. Van de WeijgaertJ. González-NuevoS. GalliS. BasakG. Patanchon2025-06-162025-06-162018-04-051475-751610.1088/1475-7516/2018/04/02310.48550/arxiv.1704.04501https://ror.circle-u.eu/handle/123456789/588701We demonstrate that, for the baseline design of the CORE satellite mission, the polarized foregrounds can be controlled at the level required to allow the detection of the primordial cosmic microwave background (CMB) $B$-mode polarization with the desired accuracy at both reionization and recombination scales, for tensor-to-scalar ratio values of ${r\gtrsim 5\times 10^{-3}}$. We consider detailed sky simulations based on state-of-the-art CMB observations that consist of CMB polarization with $��=0.055$ and tensor-to-scalar values ranging from $r=10^{-2}$ to $10^{-3}$, Galactic synchrotron, and thermal dust polarization with variable spectral indices over the sky, polarized anomalous microwave emission, polarized infrared and radio sources, and gravitational lensing effects. Using both parametric and blind approaches, we perform full component separation and likelihood analysis of the simulations, allowing us to quantify both uncertainties and biases on the reconstructed primordial $B$-modes. Under the assumption of perfect control of lensing effects, CORE would measure an unbiased estimate of $r=\left(5 \pm 0.4\right)\times 10^{-3}$ after foreground cleaning. In the presence of both gravitational lensing effects and astrophysical foregrounds, the significance of the detection is lowered, with CORE achieving a $4��$-measurement of $r=5\times 10^{-3}$ after foreground cleaning and $60$% delensing. For lower tensor-to-scalar ratios ($r=10^{-3}$) the overall uncertainty on $r$ is dominated by foreground residuals, not by the 40% residual of lensing cosmic variance. Moreover, the residual contribution of unprocessed polarized point-sources can be the dominant foreground contamination to primordial B-modes at this $r$ level, even on relatively large angular scales, $\ell \sim 50$. Finally, we report two sources of potential bias for the detection of the primordial $B$-modes.[abridged]OPENcosmic background radiation: polarizationcosmic background radiationAtomicB-mode: primordialthermalParticle and Plasma PhysicsCMBR experiments; cosmological parameters from CMBR; gravitational waves and CMBR polarization; inflation; Astronomy and AstrophysicsPolarizationCMBR experimentsCMB POLARIZATIONQCQBPhysicsastro-ph.CO; astro-ph.CO; astro-ph.GA; astro-ph.IMCosmology: observationscosmological parameters from CMBRNuclear & Particles Physics520gravitational waves and CMBR polarization; CMBR experiments; cosmological parameters from CMBR; inflationINTERNAL LINEAR COMBINATIONPhysical Sciencesinfraredastro-ph.COGALACTIC SYNCHROTRON EMISSIONAstrophysics - Instrumentation and Methods for AstrophysicsAstronomical and Space SciencesAstrophysics - Cosmology and Nongalactic AstrophysicsRADIO-SOURCESsatellite: PlanckCosmology and Nongalactic Astrophysics (astro-ph.CO)ANGULAR POWER SPECTRUMastro-ph.GAParticles & Fieldshydrogen: recombinationFOS: Physical sciencesparametricSettore FIS/05 - ASTRONOMIA E ASTROFISICAAstronomy & Astrophysics530cosmic background radiation: B-modegravitation: lensionizationsynchrotronSTAR-FORMING GALAXIESNuclear[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]inflationInstrumentation and Methods for Astrophysics (astro-ph.IM)AstrophysiqueScience & Technology500MolecularPOINT-SOURCE DETECTIONmethods: data analysisAstrophysics - Astrophysics of Galaxiesdiffuse radiation[PHYS.PHYS.PHYS-INS-DET] Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]Astrophysics of Galaxies (astro-ph.GA)PROBE WMAP OBSERVATIONSSTATISTICAL PROPERTIESmicrowaves: emissionspectralgalaxy[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph][PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]gravitational waves and CMBR polarizationMICROWAVE BACKGROUND POLARIZATIONastro-ph.IMpublication01 natural sciences0103 physical sciences13. Climate actiondoi_dedup___http://arxiv.org/abs/1704.0450110651/4891011245.1/4fb183ba-506e-4110-a568-7e463637502610852/6772320.500.14243/4278752434/57015111577/32700532108/18824011573/112152711392/24014042013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/317578