1. 
 Ade, P. A. R., et al.
(författare)

Planck 2015 results XIX. Constraints on primordial magnetic fields
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 594

Tidskriftsartikel (refereegranskat)abstract
 We compute and investigate four types of imprint of a stochastic background of primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) anisotropies: the impact of PMFs on the CMB temperature and polarization spectra, which is related to their contribution to cosmological perturbations; the effect on CMB polarization induced by Faraday rotation; the impact of PMFs on the ionization history; magneticallyinduced nonGaussianities and related nonzero bispectra; and the magneticallyinduced breaking of statistical isotropy. We present constraints on the amplitude of PMFs that are derived from different Planck data products, depending on the specific effect that is being analysed. Overall, Planck data constrain the amplitude of PMFs to less than a few nanoGauss, with different bounds that depend on the considered model. In particular, individual limits coming from the analysis of the CMB angular power spectra, using the Planck likelihood, are B1 (Mpc) < 4.4 nG (where B1 Mpc is the comoving field amplitude at a scale of 1 Mpc) at 95% confidence level, assuming zero helicity. By considering the Planck likelihood, based only on parityeven angular power spectra, we obtain B1 (Mpc) < 5.6 nG for a maximally helical field. For nearly scaleinvariant PMFs we obtain B1 (Mpc) < 2.0 nG and B1 (Mpc) < 0.9 nG if the impact of PMFs on the ionization history of the Universe is included in the analysis. From the analysis of magneticallyinduced nonGaussianity, we obtain three different values, corresponding to three applied methods, all below 5 nG. The constraint from the magneticallyinduced passivetensor bispectrum is B1 (Mpc) < 2.8 nG. A search for preferred directions in the magneticallyinduced passive bispectrum yields B1 (Mpc) < 4.5 nG, whereas the compensatedscalar bispectrum gives B1 (Mpc) < 3 nG. The analysis of the Faraday rotation of CMB polarization by PMFs uses the Planck power spectra in EE and BB at 70 GHz and gives B1 (Mpc) < 1380 nG. In our final analysis, we consider the harmonicspace correlations produced by Alfven waves, finding no significant evidence for the presence of these waves. Together, these results comprise a comprehensive set of constraints on possible PMFs with Planck data.


2. 
 Aghanim, N., et al.
(författare)

Planck 2018 results VI. Cosmological parameters
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 We present cosmological parameter results from the final fullmission Planck measurements of the cosmic microwave background (CMB) anisotropies, combining information from the temperature and polarization maps and the lensing reconstruction. Compared to the 2015 results, improved measurements of largescale polarization allow the reionization optical depth to be measured with higher precision, leading to significant gains in the precision of other correlated parameters. Improved modelling of the smallscale polarization leads to more robust constraints on many parameters, with residual modelling uncertainties estimated to affect them only at the 0.5 sigma level. We find good consistency with the standard spatiallyflat 6parameter Lambda CDM cosmology having a powerlaw spectrum of adiabatic scalar perturbations (denoted base Lambda CDM in this paper), from polarization, temperature, and lensing, separately and in combination. A combined analysis gives dark matter density Omega (c)h(2)=0.120 +/ 0.001, baryon density Omega (b)h(2)=0.0224 +/ 0.0001, scalar spectral index n(s)=0.965 +/ 0.004, and optical depth tau =0.054 +/ 0.007 (in this abstract we quote 68% confidence regions on measured parameters and 95% on upper limits). The angular acoustic scale is measured to 0.03% precision, with 100 theta (*)=1.0411 +/ 0.0003. These results are only weakly dependent on the cosmological model and remain stable, with somewhat increased errors, in many commonly considered extensions. Assuming the baseLambda CDM cosmology, the inferred (modeldependent) lateUniverse parameters are: Hubble constant H0=(67.4 +/ 0.5) km s(1) Mpc(1); matter density parameter Omega (m)=0.315 +/ 0.007; and matter fluctuation amplitude sigma (8)=0.811 +/ 0.006. We find no compelling evidence for extensions to the baseLambda CDM model. Combining with baryon acoustic oscillation (BAO) measurements (and considering singleparameter extensions) we constrain the effective extra relativistic degrees of freedom to be Neff=2.99 +/ 0.17, in agreement with the Standard Model prediction Neff=3.046, and find that the neutrino mass is tightly constrained to Sigma m(nu)< 0.12 eV. The CMB spectra continue to prefer higher lensing amplitudes than predicted in base CDM at over 2 sigma, which pulls some parameters that affect the lensing amplitude away from the Lambda CDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data. The joint constraint with BAO measurements on spatial curvature is consistent with a flat universe, Omega (K)=0.001 +/ 0.002. Also combining with Type Ia supernovae (SNe), the darkenergy equation of state parameter is measured to be w(0)=1.03 +/ 0.03, consistent with a cosmological constant. We find no evidence for deviations from a purely powerlaw primordial spectrum, and combining with data from BAO, BICEP2, and Keck Array data, we place a limit on the tensortoscalar ratio r(0.002)< 0.06. Standard bigbang nucleosynthesis predictions for the helium and deuterium abundances for the baseCDM cosmology are in excellent agreement with observations. The Planck baseLambda CDM results are in good agreement with BAO, SNe, and some galaxy lensing observations, but in slight tension with the Dark Energy Survey's combinedprobe results including galaxy clustering (which prefers lower fluctuation amplitudes or matter density parameters), and in significant, 3.6 sigma, tension with local measurements of the Hubble constant (which prefer a higher value). Simple model extensions that can partially resolve these tensions are not favoured by the Planck data.


3. 
 Delabrouille, J., et al.
(författare)

Exploring cosmic origins with CORE : Survey requirements and mission design
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :4

Tidskriftsartikel (refereegranskat)abstract
 Future observations of cosmic microwave background (CMB) polarisation have the potential to answer some of the most fundamental questions of modern physics and cosmology, including: what physical process gave birth to the Universe we see today? What are the dark matter and dark energy that seem to constitute 95% of the energy density of the Universe? Do we need extensions to the standard model of particle physics and fundamental interactions? Is the ACDM cosmological scenario correct, or are we missing an essential piece of the puzzle? In this paper, we list the requirements for a future CMB polarisation survey addressing these scientific objectives, and discuss the design drivers of the CORE space mission proposed to ESA in answer to the M5 call for a mediumsized mission. The rationale and options, and the methodologies used to assess the mission's performance, are of interest to other future CMB mission design studies. CORE has 19 frequency channels, distributed over a broad frequency range, spanning the 60600 GHz interval, to control astrophysical foreground emission. The angular resolution ranges from 2' to 18', and the aggregate CMB sensitivity is about 2 mu K.arcmin. The observations are made with a single integrated focalplane instrument, consisting of an array of 2100 cryogenicallycooled, linearlypolarised detectors at the focus of a 1.2m aperture crossDragone telescope. The mission is designed to minimise all sources of systematic effects, which must be controlled so that no more than 10(4) of the intensity leaks into polarisation maps, and no more than about 1% of Etype polarisation leaks into Btype modes. CORE observes the sky from a large Lissajous orbit around the SunEarth L2 point on an orbit that offers stable observing conditions and avoids contamination from sidelobe pickup of stray radiation originating from the Sun, Earth, and Moon. The entire sky is observed repeatedly during four years of continuous scanning, with a combination of three rotations of the spacecraft over different timescales. With about 50% of the sky covered every few days, this scan strategy provides the mitigation of systematic effects and the internal redundancy that are needed to convincingly extract the primordial Bmode signal on large angular scales, and check with adequate sensitivity the consistency of the observations in several independent data subsets. CORE is designed as a nearultimate CMB polarisation mission which, for optimal complementarity with groundbased observations, will perform the observations that are known to be essential to CMB polarisation science and cannot be obtained by any other means than a dedicated space mission. It will provide wellcharacterised, highlyredundant multifrequency observations of polarisation at all the scales where foreground emission and cosmic variance dominate the final uncertainty for obtaining precision CMB science, as well as 2' angular resolution maps of highfrequency foreground emission in the 300600 GHz frequency range, essential for complementarity with future groundbased observations with large telescopes that can observe the CMB with the same beamsize.


4. 
 Abdalla, E., et al.
(författare)

Cosmology intertwined : A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies
 2022

Ingår i: Journal of High Energy Astrophysics.  : Elsevier BV.  22144048 . 22144056. ; 34, s. 49211

Tidskriftsartikel (refereegranskat)abstract
 The standard Λ Cold Dark Matter (ΛCDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to a more realistic scenario yet to be found. In this paper, we list a few important goals that need to be addressed in the next decade, taking into account the current discordances between the different cosmological probes, such as the disagreement in the value of the Hubble constant H0, the σ8–S8 tension, and other less statistically significant anomalies. While these discordances can still be in part the result of systematic errors, their persistence after several years of accurate analysis strongly hints at cracks in the standard cosmological scenario and the necessity for new physics or generalisations beyond the standard model. In this paper, we focus on the 5.0σ tension between the Planck CMB estimate of the Hubble constant H0 and the SH0ES collaboration measurements. After showing the H0 evaluations made from different teams using different methods and geometric calibrations, we list a few interesting new physics models that could alleviate this tension and discuss how the next decade's experiments will be crucial. Moreover, we focus on the tension of the Planck CMB data with weak lensing measurements and redshift surveys, about the value of the matter energy density Ωm, and the amplitude or rate of the growth of structure (σ8,fσ8). We list a few interesting models proposed for alleviating this tension, and we discuss the importance of trying to fit a full array of data with a single model and not just one parameter at a time. Additionally, we present a wide range of other less discussed anomalies at a statistical significance level lower than the H0–S8 tensions which may also constitute hints towards new physics, and we discuss possible generic theoretical approaches that can collectively explain the nonstandard nature of these signals. Finally, we give an overview of upgraded experiments and nextgeneration space missions and facilities on Earth that will be of crucial importance to address all these open questions.


5. 
 Finelli, F., et al.
(författare)

Exploring cosmic origins with CORE : Inflation
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; 2018:4

Tidskriftsartikel (refereegranskat)abstract
 We forecast the scientific capabilities to improve our understanding of cosmic inflation of CORE, a proposed CMB space satellite submitted in response to the ESA fifth call for a mediumsize mission opportunity. The CORE satellite will map the CMB anisotropies in temperature and polarization in 19 frequency channels spanning the range 60600 GHz. CORE will have an aggregate noise sensitivity of 1.7 mu K.arcmin and an angular resolution of 5' at 200 GHz. We explore the impact of telescope size and noise sensitivity on the inflation science return by making forecasts for several instrumental configurations. This study assumes that the lower and higher frequency channels suffice to remove foreground contaminations and complements other related studies of component separation and systematic effects, which will be reported in other papers of the series Exploring Cosmic Origins with CORE. We forecast the capability to determine key inflationary parameters, to lower the detection limit for the tensortoscalar ratio down to the 10(3) level, to chart the landscape of single field slowroll inflationary models, to constrain the epoch of reheating, thus connecting inflation to the standard radiationmatter dominated Big Bang era, to reconstruct the primordial power spectrum, to constrain the contribution from isocurvature perturbations to the 10(3) level, to improve constraints on the cosmic string tension to a level below the presumptive GUT scale, and to improve the current measurements of primordial nonGaussianities down to the f(NL)(local) < 1 level. For all the models explored, CORE alone will improve significantly on the present constraints on the physics of inflation. Its capabilities will be further enhanced by combining with complementary future cosmological observations.


6. 
 Di Valentino, E., et al.
(författare)

Exploring cosmic origins with CORE : Cosmological parameters
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :4

Tidskriftsartikel (refereegranskat)abstract
 We forecast the main cosmological parameter constraints achievable with the CORE space mission which is dedicated to mapping the polarisation of the Cosmic Microwave Background (CMB). CORE was recently submitted in response to ESA's fifth call for mediumsized mission proposals (M5). Here we report the results from our presubmission study of the impact of various instrumental options, in particular the telescope size and sensitivity level, and review the great, transformative potential of the mission as proposed. Specifically, we assess the impact on a broad range of fundamental parameters of our Universe as a function of the expected CMB characteristics, with other papers in the series focusing on controlling astrophysical and instrumental residual systematics. In this paper, we assume that only a few central CORE frequency channels are usable for our purpose, all others being devoted to the cleaning of astrophysical contaminants. On the theoretical side, we assume ACDM as our general framework and quantify the improvement provided by CORE over the current constraints from the Planck 2015 release. We also study the joint sensitivity of CORE and of future Baryon Acoustic Oscillation and Large Scale Structure experiments like DESI and Euclid. Specific constraints on the physics of inflation are presented in another paper of the series. In addition to the six parameters of the base ACDM, which describe the matter content of a spatially flat universe with adiabatic and scalar primordial fluctuations from inflation, we derive the precision achievable on parameters like those describing curvature, neutrino physics, extra light relics, primordial helium abundance, dark matter annihilation, recombination physics, variation of fundamental constants, dark energy, modified gravity, reionization and cosmic birefringence. In addition to assessing the improvement on the precision of individual parameters, we also forecast the postCORE overall reduction of the allowed parameter space with figures of merit for various models increasing by as much as similar to 10(7) as compared to Planck 2015, and 10(5) with respect to Planck 2015 + future BAO measurements.


7. 
 Challinor, A., et al.
(författare)

Exploring cosmic origins with CORE : Gravitational lensing of the CMB
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :4

Tidskriftsartikel (refereegranskat)abstract
 Lensing of the cosmic microwave background (CMB) is now a welldeveloped probe of the clustering of the largescale mass distribution over a broad range of redshifts. By exploiting the nonGaussian imprints of lensing in the polarization of the CMB, the CORE mission will allow production of a clean map of the lensing deflections over nearly the fullsky. The number of highSAN modes in this map will exceed current CMB lensing maps by a factor of 40, and the measurement will be samplevariance limited on all scales where linear theory is valid. Here, we summarise this mission product and discuss the science that will follow from its power spectrum and the crosscorrelation with other clustering data. For example, the summed mass of neutrinos will be determined to an accuracy of 17 meV combining CORE lensing and CMB twopoint information with contemporaneous measurements of the baryon acoustic oscillation feature in the clustering of galaxies, three times smaller than the minimum total mass allowed by neutrino oscillation measurements. Lensing has applications across many other science goals of CORE, including the search for Bmode polarization from primordial gravitational waves. Here, lensinduced Bmodes will dominate over instrument noise, limiting constraints on the power spectrum amplitude of primordial gravitational waves. With lensing reconstructed by CORE, one can delens the observed polarization internally, reducing the lensing Bmode power by 60 %. This can be improved to 70 % by combining lensing and measurements of the cosmic infrared background from CORE, leading to an improvement of a factor of 2.5 in the error on the amplitude of primordial gravitational waves compared to no delensing (in the null hypothesis of no primordial Bmodes). Lensing measurements from CORE will allow calibration of the halo masses of the tens of thousands of galaxy clusters that it will find, with constraints dominated by the clean polarizationbased estimators. The 19 frequency channels proposed for CORE will allow accurate removal of Galactic emission from CMB maps. We present initial findings that show that residual Galactic foreground contamination will not be a significant source of bias for lensing power spectrum measurements with CORE.


8. 
 Burigana, C., et al.
(författare)

Exploring cosmic origins with CORE : Effects of observer peculiar motion
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :4

Tidskriftsartikel (refereegranskat)abstract
 We discuss the effects on the cosmic microwave background (CMB), cosmic infrared background (CIB), and thermal SunyaevZeldovich effect due to the peculiar motion of an observer with respect to the CMB rest frame, which induces boosting effects. After a brief review of the current observational and theoretical status, we investigate the scientific perspectives opened by future CMB space missions, focussing on the Cosmic Origins Explorer (CORE) proposal. The improvements in sensitivity offered by a mission like CORE, together with its high resolution over a wide frequency range, will provide a more accurate estimate of the CMB dipole. The extension of boosting effects to polarization and crosscorrelations will enable a more robust determination of purely velocitydriven effects that are not degenerate with the intrinsic CMB dipole, allowing us to achieve an overall signaltonoise ratio of 13; this improves on the Planck detection and essentially equals that of an ideal cosmic variancelimited experiment up to a multipole l similar or equal to 2000. Precise interfrequency calibration will offer the opportunity to constrain or even detect CMB spectral distortions, particularly from the cosmological reionization epoch, because of the frequency dependence of the dipole spectrum, without resorting to precise absolute calibration. The expected improvement with respect to COBEFIRAS in the recovery of distortion parameters (which could in principle be a factor of several hundred for an ideal experiment with the CORE configuration) ranges from a factor of several up to about 50, depending on the quality of foreground removal and relative calibration. Even in the case of similar or equal to 1% accuracy in both foreground removal and relative calibration at an angular scale of 1 degrees, we find that dipole analyses for a mission like CORE will be able to improve the recovery of the CIB spectrum amplitude by a factor similar or equal to 17 in comparison with current results based on COBEFIRAS. In addition to the scientific potential of a mission like CORE for these analyses, synergies with other planned and ongoing projects are also discussed.


9. 
 De Zotti, G., et al.
(författare)

Exploring cosmic origins with CORE : Extragalactic sources in cosmic microwave background maps
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :4

Tidskriftsartikel (refereegranskat)abstract
 We discuss the potential of a next generation spaceborne Cosmic Microwave Background (CMB) experiment for studies of extragalactic sources. Our analysis has particular bearing on the definition of the future space project, CORE, that has been submitted in response to ESA's call for a Mediumsize mission opportunity as the successor of the Planck satellite. Even though the effective telescope size will be somewhat smaller than that of Planck, CORE will have a considerably better angular resolution at its highest frequencies, since, in contrast with Planck, it will be diffraction limited at all frequencies. The improved resolution implies a considerable decrease of the source confusion, i.e. substantially fainter detection limits. In particular, CORE will detect thousands of strongly lensed highz galaxies distributed over the full sky. The extreme brightness of these galaxies will make it possible to study them, via followup observations, in extraordinary detail. Also, the CORE resolution matches the typical sizes of highz galaxy protoclusters much better than the Planck resolution, resulting in a much higher detection efficiency; these objects will be caught in an evolutionary phase beyond the reach of surveys in other wavebands. Furthermore, CORE will provide unique information on the evolution of the star formation in virialized groups and clusters of galaxies up to the highest possible redshifts. Finally, thanks to its very high sensitivity, CORE will detect the polarized emission of thousands of radio sources and, for the first time, of dusty galaxies, at mm and submm wavelengths, respectively.


10. 
 Natoli, P., et al.
(författare)

Exploring cosmic origins with CORE : Mitigation of systematic effects
 2018

Ingår i: Journal of Cosmology and Astroparticle Physics.  : IOP Publishing.  14757516. ; :4

Tidskriftsartikel (refereegranskat)abstract
 We present an analysis of the main systematic effects that could impact the measurement of CMB polarization with the proposed CORE space mission. We employ timeline tomap simulations to verify that the CORE instrumental setup and scanning strategy allow us to measure sky polarization to a level of accuracy adequate to the mission science goals. We also show how the CORE observations can be processed to mitigate the level of contamination by potentially worrying systematics, including intensitytopolarization leakage due to bandpass mismatch, asymmetric main beams, pointing errors and correlated noise. We use analysis techniques that are well validated on data from current missions such as Planck to demonstrate how the residual contamination of the measurements by these effects can be brought to a level low enough not to hamper the scientific capability of the mission, nor significantly increase the overall error budget. We also present a prototype of the CORE photometric calibration pipeline, based on that used for Planck, and discuss its robustness to systematics, showing how CORE can achieve its calibration requirements. While a finegrained assessment of the impact of systematics requires a level of knowledge of the system that can only be achieved in a future study phase, the analysis presented here strongly suggests that the main areas of concern for the CORE mission can be addressed using existing knowledge, techniques and algorithms.

