| phenomenon | cosmic microwave background anisotropies— “Since their discovery (Smoot et al. 1992), temperature anisotropies in the cosmic microwave background (CMB) have become one of the most powerful ways of studying cosmology and the physics of the early Universe.” |
| claim-type | existence— “We find good consistency with the standard spatially-flat 6-parameter ΛCDM cosmology having a power-law spectrum of adiabatic scalar perturbations (denoted “base ΛCDM” in this paper), from polarization, temperature, and lensing, separately and in combination.” |
| method — evidence | — “We present cosmological parameter results from the final full-mission Planck measurements of the cosmic microwave background (CMB) anisotropies, combining information from the temperature and polarization maps and the lensing reconstruction.” |
| transfer | from statistics / computational statistics (Bayesian inference, MCMC): Bayesian inference via Markov chain Monte Carlo used to estimate cosmological parameters from the cosmic microwave background— “sampled, along with cosmological parameters, during Markov chain Monte Carlo (MCMC) exploration of the likelihood” | transfers[0] |
| mechanism | THE MODEL EVERY NUMBER IN THE PAPER IS QUOTED AGAINST IS INTRODUCED AS A QUOTED LABEL, WITH A PARAMETER COUNT AND A SCOPE: we refer to this model, WHICH CAN BE SPECIFIED BY SIX PARAMETERS, as “base” ΛCDM IN THIS PAPER. The scare quotes and the words `in this paper` are both the collaboration's: the label is declared local to the document, and what it denotes is fixed by a count of parameters rather than by a description— “We refer to this model, which can be specified by six parameters, as “base” ΛCDM in this paper.” | mechanisms[0] |
| mechanism | WHICH PARAMETERS ARE PRIMITIVE IS STATED AS A CHOICE, NOT AS A FACT ABOUT THE UNIVERSE: the first six parameters are THE ONES ON WHICH WE IMPOSE FLAT PRIORS AND USE AS SAMPLING PARAMETERS; the remaining parameters ARE DERIVED FROM THE FIRST SIX. The same physics could be parameterised the other way round, and the paper says which way it chose— “The first six parameters here are the ones on which we impose flat priors and use as sampling parameters; the remaining parameters are derived from the first six.” | mechanisms[1] |
| mechanism | AN ENTIRE CLASS OF PARAMETERS IS NAMED “nuisance” IN SCARE QUOTES - AND THE QUOTES COME OFF IN THE NEXT SENTENCE, WHERE THEY ARE SAMPLED ON THE SAME FOOTING AS THE COSMOLOGICAL ONES: a physically motivated parametric model containing “nuisance” parameters; these nuisance parameters ARE SAMPLED, ALONG WITH COSMOLOGICAL PARAMETERS, during MCMC exploration of the likelihood. The hedge is dropped one sentence after it is made, and the objects it hedged about are treated as first-class— “a physically motivated parametric model containing “nuisance” parameters. These nuisance parameters are sampled, along with cosmological parameters, during Markov chain Monte Carlo (MCMC) exploration of the likelihood.” | mechanisms[2] |
| mechanism | A CEILING ON THE PAPER'S OWN INTERPRETATION, STATED BY THE PAPER: a total systematic uncertainty of around half a sigma MAY BE MORE REALISTIC, and VALUES SHOULD NOT BE OVERINTERPRETED BEYOND THIS LEVEL. Not a limitation of the data but an instruction to the reader about how far the numbers may be read - issued by the people who produced them— “A total systematic uncertainty of around 0.5σ may be more realistic, and values should not be overinterpreted beyond this level.” | mechanisms[3] |
| mechanism | TWO WAYS OF DOING ONE CORRECTION ARE NAMED IN A SINGLE SENTENCE, BY CONTRAST WITH EACH OTHER: adopting the estimates from one spectrum for both (we call this the “map-based” APPROACH); or applying independent estimates from each (the “spectrum-based” APPROACH). Neither name would mean anything without the other; the pair is defined by the difference between two procedures— “We have investigated ways of correcting for effective polarization efficiencies: adopting the estimates from EE (which are about a factor of 2 more precise than T E) for both the T E and EE spectra (we call this the “map-based” approach); or applying independent estimates from T E and EE (the “spectrum-based” approach).” | mechanisms[4] |
| mechanism | THE NULL EXPLANATION IS DECLARED THE BASELINE ASSUMPTION, IN THOSE WORDS: alternatively, it could just be a statistical fluctuation, WHICH IS OUR BASELINE ASSUMPTION. Which of the competing accounts gets the default is a choice, and it is named as one rather than argued for— “Alternatively, it could just be a statistical fluctuation, which is our baseline assumption.” | mechanisms[5] |
| mechanism | EVIDENCE IS GRANTED AND THE CLAIM IS DECLINED IN THE SAME SENTENCE: although both likelihoods CLEARLY SHOW A PREFERENCE for a lensing amplitude above one, THIS CANNOT BE CLAIMED TO BE A ROBUST DETECTION at much over two sigma. `Clearly show` and `cannot be claimed` are asserted of the same result, and the line between them is a number— “Although both likelihoods clearly show a preference for AL > 1, this cannot be claimed to be a robust detection at much over 2σ” | mechanisms[6] |
| mechanism | THE COLLABORATION CALLS A PERSISTENT ANOMALY IN ITS OWN DATA A CURIOUS FEATURE: the preference for a lensing amplitude above one within the model IS A CURIOUS FEATURE OF THE PLANCK CMB POWER SPECTRUM DATA, and has already been discussed extensively in three earlier papers, ALTHOUGH IT IS NOW SLIGHTLY MORE SIGNIFICANT. A result that has survived three releases, growing, and the standing description of it is an adjective— “The preference for AL > 1 within the ΛCDM model is a curious feature of the Planck CMB power spectrum data, and has already been discussed extensively in PCP13, PCP15, and Planck Collaboration Int. LI (2017), although it is now slightly more significant.” | mechanisms[7] |
| mechanism | THE AUTHORS CHARACTERISE THEIR OWN REVISION AS LARGELY COSMETIC: it is important to emphasize that these changes to the likelihood ARE LARGELY COSMETIC AND HAVE VERY LITTLE IMPACT ON COSMOLOGICAL PARAMETERS. The word measures a methodological change by its effect on the outputs rather than by what was changed— “It is important to emphasize that these changes to the 2018 CamSpec TT likelihood are largely cosmetic and have very little impact on cosmological parameters.” | mechanisms[8] |
| mechanism | A METHOD CHANGE BETWEEN RELEASES IS STATED AS A DIFFERENCE FROM THE PREVIOUS PAPER, WITH THE OLD PROCEDURE DESCRIBED: THIS DIFFERS FROM THE APPROACH ADOPTED IN 2015, which used a Galactic dust template WITH THE SAME SHAPE AT ALL FREQUENCIES. The superseded choice is named, so the two releases' numbers can be read as answers to slightly different questions— “This differs from the approach adopted in 2015, which used a Galactic dust template with the same shape at all frequencies.” | mechanisms[9] |
| mechanism | A COINED ACRONYM IS MINTED FOR OBJECTS THE ANALYSIS ITSELF PRODUCES, AND THE RULE THAT DECIDES HOW MANY OF THEM COUNT IS LEFT UNNAMED: the rotation diagonalizing the Fisher inverse **DEFINES** the eigenmodes; truncation of the hierarchy, to determine the number used for parameter estimation, is performed ACCORDING TO SOME SUITABLY CHOSEN SELECTION CRITERION - AND WE REFER TO THESE MODES AS “eXeMs”. One sentence defines the objects, the next leaves the rule for counting them to be chosen suitably, and the third gives them a name— “The rotation diagonalizing the Fisher inverse defines the xe eigenmodes. Truncation of the eigenmode hierarchy to determine the number of xe modes used for parameter estimation is performed according to some suitably chosen selection criterion. We refer to these modes as “eXeMs”” | mechanisms[10] |
| mechanism | A DISAGREEMENT IS LEFT OPEN WITH ITS THREE POSSIBLE MEANINGS ENUMERATED AND NONE CHOSEN: further work is needed to assess whether the discrepancy IS A STATISTICAL FLUCTUATION, IS CAUSED BY SMALL SYSTEMATIC ERRORS, OR IS A SIGNATURE OF NEW PHYSICS. Noise, error, and discovery are offered as the alternatives, in that order, and the paper declines to rank them— “Further work is needed to assess whether the discrepancy between Planck and the Ly α BAO results is a statistical fluctuation, is caused by small systematic errors, or is a signature of new physics.” | mechanisms[11] |
| mechanism | AN ASSUMPTION IS JUSTIFIED BY WHAT THE SIMPLEST MODELS PREDICT, WITH THE PRECISION CAVEAT IN A PARENTHESIS: the base model assumes that the spatial hypersurfaces are flat, SUCH AS WOULD BE PREDICTED (TO WITHIN MEASURABLE PRECISION) BY THE SIMPLEST INFLATIONARY MODELS. The warrant for the assumption is the simplicity of a theory, and the hedge is about what an instrument could see— “The base-ΛCDM model assumes that the spatial hypersurfaces are flat, such as would be predicted (to within measurable precision) by the simplest inflationary models.” | mechanisms[12] |
| mechanism | A FEATURE THAT PULLS PARAMETERS AWAY FROM THE MODEL IS REPORTED AND REBUTTED IN THE SAME SENTENCE, BY NAMING THE PROBES THAT DO NOT SEE IT: a feature which pulls some parameters that affect the lensing amplitude away from the model; HOWEVER, THIS IS NOT SUPPORTED BY THE LENSING RECONSTRUCTION OR (in models that also change the background geometry) **BAO DATA**. The anomaly's own paper supplies the evidence against it— “which pulls some parameters that affect the lensing amplitude away from the ΛCDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data.” | mechanisms[13] |
| builds-on | Markov chain Monte Carlo (Bayesian inference, statistics)— “Markov chain Monte Carlo (MCMC) exploration of the likelihood” | claim_relations[0] |
| builds-on | earlier Planck cosmological-parameter papers PCP13 (Planck Collaboration XVI 2014) and PCP15 (Planck Collaboration XIII 2016)— “The definitions, methodology, and notation used in this paper largely follow those adopted in the earlier Planck Collaboration papers dealing with cosmological parameters (PCP13, PCP15).” | claim_relations[1] |
| contradicts | Riess et al. (2019) distance-ladder measurement of the Hubble constant— “The latest measurement from Riess et al. (2019) is discrepant with the Planck base- ΛCDM value for H0 at about the 4.4σ level.” | claim_relations[2] |
| sense | late-Universe parameter - a quantity the paper marks parenthetically as MODEL-DEPENDENT, inferred by assuming base-LambdaCDM rather than measured directly— “Assuming the base-ΛCDM cosmology, the inferred (model-dependent) late-Universe parameters are: Hubble constant H0 = (67.4 ± 0.5) km s−1 Mpc−1; matter density parameter Ωm = 0.315 ± 0.007; and matter fluctuation amplitude” | senses[0] |
| sense | base LambdaCDM - the six-parameter spatially-flat model with a power-law spectrum of adiabatic scalar perturbations, named for use in this paper— “We find good consistency with the standard spatially-flat 6-parameter ΛCDM cosmology having a power-law spectrum of adiabatic scalar perturbations (denoted “base ΛCDM” in this paper), from polarization, temperature, and lensing, separately and in combination.” | senses[1] |
| sense | fiducial model - a model adopted in order to build the covariance matrices and likelihood, rather than one being tested— “we need to adopt a fiducial model. For the 2018 analysis, we adopted the best-fit CamSpec base-ΛCDM model from PCP15 to construct a likelihood from the 2018 temperature maps.” | senses[2] |
| sense | polarization efficiencies - AS CALIBRATED: by a procedure the paper itself calls model-dependent, and then BOUNDS rather than defends - the fit is restricted to multipoles where the TT spectra are cosmic-variance limited, which is the reason given for the calibration being insensitive to small changes in the cosmology— “This is clearly a model-dependent procedure, but given that we fit over a restricted range of multipoles, where the T T spectra are measured to cosmic variance, the resulting polarization calibrations are insensitive to small changes in the underlying cosmological model.” | senses[3] |
| sense | `dark energy` / `modified gravity` - TWO NAMES FOR ONE OBSERVATION, CHOSEN BY WHICH MECHANISM YOU ASSUME: `Such dynamics is usually associated with a fluid (a scalar field) which we refer to as “dark energy” (DE), or with modifications of GR, which we refer to as “modified gravity” (MG).` NOT A RENAMING AND NOT A DISAGREEMENT ABOUT A WORD. The measurement is identical either way; the two names record two rival explanations of it, and the sentence assigns a name to each branch before either is established.— “Such dynamics is usually associated with a fluid (a scalar field) which we refer to as “dark energy” (DE), or with modifications of GR, which we refer to as “modified gravity” (MG).” | senses[4] |
| sense | `conservative BBN prior` - A TERM DEFINED BY BEING WIDE ENOUGH NOT TO CHOOSE: `we refer to a “conservative BBN prior,” wb = 0.0222 +/- 0.0005 (68% CL), set to be compatible with each of these three predictions.` The word `conservative` is doing definitional work: the interval is not an estimate of the quantity but a construction that survives three competing determinations. SAME SHAPE AS `brown2020`'s vocabulary built to REMAIN AGNOSTIC on a live question (typology mechanism 26) - here it is a NUMBER built not to decide one.— “In several places in this work and in PL2018, we refer to a “conservative BBN prior,” ωb = 0.0222 ± 0.0005 (68% CL), set to be compatible with each of these three predictions.” | senses[5] |
| sense | A REPORTING CONVENTION STATED IN THE ABSTRACT AND BINDING ON EVERY NUMBER IN IT: `in this abstract we quote 68% confidence regions on measured parameters and 95% on upper limits`. TWO DIFFERENT INTERVALS UNDER ONE `+/-` NOTATION, distinguished only by whether the quantity was measured or bounded. A reader lifting a figure out of this abstract without the convention has a number whose coverage they cannot state.— “in this abstract we quote 68% confidence regions on measured parameters and 95% on upper limits).” | senses[6] |
| sense | `base ΛCDM` - A NAME THAT MEANS `THIS PAPER'S SIX-PARAMETER VERSION`, NOT `THE STANDARD MODEL`. `We refer to this model, which can be specified by six parameters, as “base” ΛCDM in this paper.` The qualifier `in this paper` is doing real work: `ΛCDM` names a family, and `base` picks out one member by a parameter COUNT. A citing author who writes `ΛCDM` and one who writes `base ΛCDM` are not necessarily referring to the same model, and this sentence is the only thing that fixes which.— “We refer to this model, which can be specified by six parameters, as “base” ΛCDM in this paper.” | senses[7] |
| sense | `As` IS NOT A NUMBER UNTIL A SCALE IS CHOSEN. `the primordial comoving curvature power spectrum amplitude As (which we define at the pivot scale k0 = 0.05 Mpc−1)`. The amplitude is scale-dependent, so the quoted value carries an unstated convention with it. A parameter defined at a chosen pivot is a quantity plus a convention, and only one of the two travels with the symbol.— “the primordial comoving curvature power spectrum amplitude As (which we define at the pivot scale k0 = 0.05 Mpc−1)” | senses[8] |
| control | the likelihood built from HALF-MISSION CROSS-spectra rather than auto-spectra — held — rules out noise bias - an auto-spectrum correlates a map's noise with itself and adds a positive term to the power, while two independent halves of the mission have uncorrelated noise that averages away— “The likelihood is built using half-mission crossspectra to avoid noise biases from auto-spectra.” | controls[0] |
| control | different multipole cuts applied per cross-spectrum — held — rules out the multipole ranges where the beam's limited resolution lets noise dominate, so those scales cannot drive the fit— “with different multipole cuts to avoid multipole regions where noise dominates due to the limited resolution of the beams” | controls[1] |
| outcome (stated by the tagger, no quotation) | control — held | controls[0] |
| outcome (stated by the tagger, no quotation) | control — held | controls[1] |
| for which use | limitation — the lensing-amplitude parameters specifically: a >2-sigma feature PULLS SOME PARAMETERS THAT AFFECT THE LENSING AMPLITUDE AWAY FROM THE [model], unsupported by other probes— “which pulls some parameters that affect the lensing amplitude away from the ΛCDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data.” | limitations[0] |
| for which use | limitation — every quoted uncertainty in the paper: WE THEREFORE DO NOT EXPLICITLY MODEL AN INCREASE IN ERROR BARS DUE TO THESE RESIDUAL SYSTEMATIC ERRORS - a known error source is excluded by decision— “In this paper we therefore do not explicitly model an increase in error bars due to these residual systematic errors – any such characterization would inevitably be incomplete, and it would also be impossible to give the necessary probabilistic characterization required for meaningful quantitative error bars.” | limitations[1] |
| for which use | limitation — the polarization results in particular: INACCURACIES IN THE CORRECTIONS FOR EFFECTIVE POLARIZATION EFFICIENCIES AND TEMPERATURE-TO-POLARIZATION LEAKAGE ARE THE MAIN CONTRIBUTORS TO SYSTEMATIC ERRORS— “Inaccuracies in the corrections for effective polarization efficiencies and temperature-to-polarization leakage are the main contributors to systematic errors in the Planck polarization spectra at high multipoles.” | limitations[2] |
| for which use | limitation — the Planck-versus-Lyman-alpha comparison: FURTHER WORK IS NEEDED TO ASSESS WHETHER THE DISCREPANCY ... IS A STATISTICAL FLUCTUATION, IS CAUSED BY SMALL SYSTEMATIC ERRORS, OR IS A SIGNATURE OF new physics— “Further work is needed to assess whether the discrepancy between Planck and the Ly α BAO results is a statistical fluctuation, is caused by small systematic errors, or is a signature of new physics.” | limitations[3] |
| for which use | limitation — the small-scale polarization constraints: RESIDUAL MODELLING UNCERTAINTIES ESTIMATED TO AFFECT THEM ONLY AT THE 0.5 SIGMA L[evel] - estimated, not eliminated— “Improved modelling of the small-scale polarization leads to more robust constraints on many parameters, with residual modelling uncertainties estimated to affect them only at the 0.5σ level.” | limitations[4] |
| for which use | limitation — the external-data selection as a purely evidential choice: the paper gives as its second reason that its primary purpose is to present and emphasize the Planck results— “Secondly, the primary purpose of this paper is to present and emphasize the Planck results. We therefore make minimal use of external” | limitations[5] |
| for which use | limitation — the 2018 parameter constraints as independent of the 2015 analysis: the likelihood was constructed using a fiducial model adopted from PCP15— “we need to adopt a fiducial model. For the 2018 analysis, we adopted the best-fit CamSpec base-ΛCDM model from PCP15 to construct a likelihood from the 2018 temperature maps.” | limitations[6] |
| for which use | limitation — these constraints as incorporating cluster counts: they are deliberately excluded from the main parameter grid— “Given the uncertainties in these calibrations, we do not use cluster counts in our main parameter grid.” | limitations[7] |
| evidence status note | mechanism — Three sentences later the same term is spelled without its hyphen - “map-based” in the naming sentence, “mapbased” where the approach is adopted. A lost line-break hyphen and an inconsistency by the authors look identical in an extracted PDF, so this records the observation without claiming which it is.— “We have investigated ways of correcting for effective polarization efficiencies: adopting the estimates from EE (which are about a factor of 2 more precise than T E) for both the T E and EE spectra (we call this the “map-based” approach); or applying independent estimates from T E and EE (the “spectrum-based” approach).” | mechanisms[4] |
| evidence status note | mechanism — The record's limitations[0] quotes this passage and had to stop at “away from the”, one word short of the model's name; its tag says “[model]” in brackets to mark the gap. This span reaches the name and the rebuttal that follows it.— “which pulls some parameters that affect the lensing amplitude away from the ΛCDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data.” | mechanisms[13] |
| replication | untested |
| no type for this | polarization angles → efficiencies — THE TWO CANNOT BE SEPARATED IN THIS STUDY - the DESIGN form of the negative relation / No edge type can express it: all eight assert that a relation HOLDS. Recorded here because a confounding statement BOUNDS WHAT THE PAPER'S OWN RESULTS CAN MEAN, and it lives in a methods paragraph where nothing downstream will find it. States the mechanism of the inseparability in one word - DEGENERATE - which is the physics term for exactly the relation we cannot express.— “The SRoll mapmaking algorithm assumes the ground-based measurements of polarization angles and efficiencies, which cannot be separated because they are degenerate with each other.” | unhoused_relations[0] |
| limitation | a >2-sigma feature pulls some lensing-amplitude parameters away from the model, not supported by other probes— “which pulls some parameters that affect the lensing amplitude away from the ΛCDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data.” | limitations[0] |
| limitation | Residual systematic errors in the polarization spectra are not folded into the quoted error bars, because the authors judge any such characterisation would be incomplete and could not be given a proper probabilistic form.— “In this paper we therefore do not explicitly model an increase in error bars due to these residual systematic errors – any such characterization would inevitably be incomplete, and it would also be impossible to give the necessary probabilistic characterization required for meaningful quantitative error bars.” | limitations[1] |
| limitation | Imperfect corrections for polarization efficiency and temperature-to-polarization leakage remain the dominant systematic error in the high-multipole polarization spectra.— “Inaccuracies in the corrections for effective polarization efficiencies and temperature-to-polarization leakage are the main contributors to systematic errors in the Planck polarization spectra at high multipoles.” | limitations[2] |
| limitation | The origin of the disagreement between Planck and the Lyman-alpha BAO measurements is left unresolved.— “Further work is needed to assess whether the discrepancy between Planck and the Ly α BAO results is a statistical fluctuation, is caused by small systematic errors, or is a signature of new physics.” | limitations[3] |
| limitation | Residual modelling uncertainty in the small-scale polarization is estimated, not eliminated, and is stated to shift parameters at the half-sigma level.— “Improved modelling of the small-scale polarization leads to more robust constraints on many parameters, with residual modelling uncertainties estimated to affect them only at the 0.5σ level.” | limitations[4] |
| limitation | The choice of which external data to combine with is justified partly by a presentational aim, not only an evidential one.— “Secondly, the primary purpose of this paper is to present and emphasize the Planck results. We therefore make minimal use of external” | limitations[5] |
| limitation | The likelihood used for the 2018 analysis was built on a fiducial model taken from the previous data release.— “we need to adopt a fiducial model. For the 2018 analysis, we adopted the best-fit CamSpec base-ΛCDM model from PCP15 to construct a likelihood from the 2018 temperature maps.” | limitations[6] |
| limitation | Cluster counts are excluded from the main parameter grid because their mass calibrations are uncertain.— “Given the uncertainties in these calibrations, we do not use cluster counts in our main parameter grid.” | limitations[7] |
| limitation | The headline late-Universe parameters are marked model-dependent in a single parenthesis - 'the inferred (model-dependent) late-Universe parameters are: Hubble constant H0 = ...' - while the angular acoustic scale in the preceding sentence is described as only weakly model-dependent. Two classes of number sit in one abstract with very different warrants, separated by one bracketed word that does not survive being quoted.— “Assuming the base-ΛCDM cosmology, the inferred (model-dependent) late-Universe parameters are: Hubble constant H0 = (67.4 ± 0.5) km s−1 Mpc−1; matter density parameter Ωm = 0.315 ± 0.007; and matter fluctuation amplitude σ8 = 0.811 ± 0.006.” | limitations[8] |