{"id":"72b2666c-e6ac-40d1-910c-35cc69800b25","arxiv_id":"2412.04405","paper_version":1,"verdict":"REJECT","confidence":"MODERATE","novelty_score":3.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":4,"one_line_summary":"The authors fit the galaxy power spectrum of BOSS (0.3<z<0.65) and eBOSS (0.6<z<1.0) samples to obtain BAO dilation-scale parameters α, finding BOSS more precise than eBOSS and 1σ agreement with DESI III.","lead":"This paper reviews how astronomers detect the Baryon Acoustic Oscillation (BAO) scale in galaxy surveys and adds new measurements of the BAO distance scale from BOSS and eBOSS galaxy samples. It reports that the BOSS measurement is more precise than eBOSS and agrees with DESI BAO results, but the central numbers appear only in figures and the comparison may be affected by different survey assumptions.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Claimed DESI III 1σ agreement rests on comparing α values defined against different fiducial cosmologies; the paper's Table 1 fiducial is itself inconsistent with Planck 2018, so the comparison must be redone on a common distance basis.","rationale":"The paper is best read as a review plus a new application of Anderson et al. (2014) to BOSS/eBOSS subsets. Its central claim is quantitative: α from this work agrees with DESI III within 1σ and varies with z in an unexplained way. For that claim to be true, the α values in Fig. 8 must be commensurable. They are not, because α is a ratio to each survey's own DV_fid (Eq. 29). The manuscript itself flags the fiducial dependence in Sec. 7.2, yet it does not list the fiducial cosmologies of the other surveys or renormalize them. The internal inconsistency of Table 1 (Ωm≈0.212 vs Planck 2018's ≈0.315) makes the own-fiducial issue concrete and testable: correcting it will shift the BOSS/eBOSS α by percent-level amounts, likely comparable to the shown error bars. This is not a disagreement with consensus; it is an internal comparability problem in the key figure. The secondary concerns raised by the reader (no numerical α values, 500-mock covariance, χ²/dof≈93/50, the erroneous P(k) scaling sentence in Sec. 7.1) are real and reinforce the rejection, but they are less directly load-bearing: poor χ² by itself could be a conservative covariance issue, and the P(k) scaling remark does not enter the α extraction. I therefore agree with the reader's identification and recommend that the verdict remain rejected until the comparison is re-expressed on a common distance basis.","tokens_in":15799,"tokens_out":7748,"duration_ms":74513,"concrete_test":"Redo Fig. 8 on a common distance measure: for each survey (DESI III, DES Y6, WiggleZ, and this work) take the published α and the survey's stated fiducial cosmology, convert to DV/rs (or to α relative to one reference flat ΛCDM), and recompute the offsets. In the same revision, tabulate the BOSS and eBOSS best-fit α with 1σ errors. If any point shifts by more than 0.5σ after conversion, the claimed 1σ agreement is not robust.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central new claim (abstract; Sec. 7.2; Fig. 8) is that the fitted BAO dilation parameter α for this BOSS subsample agrees with DESI III within 1σ and that the α−z modulation is physically interesting. This claim is only interpretable if the α values being compared are defined on the same fiducial cosmology, because Eq. 29 defines α = DV(z)/DV_fid(z), with DV_fid computed from the fiducial model used to convert redshifts to distances. The paper never states the fiducial models of DESI, DES Y6, or WiggleZ, and it never converts their α values to a common reference, e.g. DV/rs. Its own Table 1 is also internally suspicious: with ΩCDM=0.179 and Ωb=0.033 it has Ωm=0.212, whereas the Planck 2018 cosmology it cites has Ωm≈0.315. At z≈0.5 this changes H(z) by about 8 percent, and the corresponding shift in DV/DV_fid is comparable to or larger than the error bars in Fig. 8. If BOSS and eBOSS α were computed with this fiducial, the apparent 1σ agreement with DESI and the reported 1σ tension of BOSS with α=1 may both be artifacts. The authors' own remark in Sec. 7.2 that using α is \"not as independent as it should be\" makes this the load-bearing weakness of the paper's central result. Secondary issues (missing numerical α values, χ²/dof≈93/50, and the incorrect statement that P(k) ∝ 1 − 1/(1+z)^6 in Sec. 7.1) compound the problem but are not the main logical failure.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper is partly a review of BAO theory, estimators, and survey techniques, and partly a new analysis. The authors use nbodykit to compute P(k) for a BOSS DR12 LOWZ+CMASS sample (0.3<z<0.65) and an eBOSS LRG sample (0.6<z<1.0), then fit the Anderson et al. (2014) BAO template with an MCMC to obtain the dilation parameter α, the damping scale Σ_nl, and a constant bias. They report that the BOSS α has smaller error bars than the eBOSS α, that BOSS is in tension with α=1 while eBOSS is not, and that the BOSS α agrees with DESI III within 1σ. The paper also highlights an unexplained redshift modulation of α.","tokens_in":16154,"tokens_out":4327,"duration_ms":41460,"significance":"If the measurements were correctly calibrated, additional BAO α determinations at z≈0.5-0.8 would provide a modest but useful cross-check of DESI and eBOSS results. The review sections could be useful for students entering the field, and the use of public data, mocks, and open-source software is commendable. However, the central quantitative claims are currently not supported because the cross-survey comparison is made in terms of α values defined against different fiducial cosmologies, and the fitted values are not reported numerically. The paper therefore does not yet meet the standard for publication as a research article.","major_comments":[{"comment":"The central comparison of α across surveys is not meaningful because α is defined relative to each survey's own fiducial cosmology (α = DV/DV_fid). The paper never states the fiducial models used by DESI III, DES Y6, or WiggleZ, nor does it convert their results to a common distance measure such as DV/rs. Moreover, the fiducial model in Table 1 is not the Planck 2018 cosmology cited: with ΩCDM=0.179 and Ωb=0.033, Ωm=0.212, whereas Planck 2018 has Ωm≈0.315; at z≈0.5 this changes H(z) by roughly 8 percent, shifting α by an amount comparable to the error bars in Fig. 8. The claimed 1σ agreement with DESI III and the apparent tension of BOSS with α=1 may therefore be artifacts of the fiducial choice. The comparison should be redone by converting all measurements to a common distance variable (e.g., DV/rs) or by explicitly matching fiducial cosmologies.","section":"Sec. 7.2, Eq. (29), Fig. 8, Table 1"},{"comment":"The numerical best-fit values of α and their uncertainties are never reported for either sample. The abstract and text claim that the BOSS α has smaller error bars than the eBOSS α and that DESI III agrees within 1σ, but without the fitted values and errors these claims cannot be checked. A table listing α, Σ_nl, b, and χ²/dof for both samples should be added.","section":"Sec. 7.2 and Fig. 8"},{"comment":"The reported fit quality for BOSS is poor, χ²/dof ≃ 93/50 for the combined caps, while the covariance matrix is estimated from only 500 mocks (Sec. 6.4) compared with the 2048 mocks used by the SDSS team ([56]). The paper attributes the high χ² to coarse k-binning and mesh size, but a fit with χ²/dof ≈ 1.9 indicates that the model or covariance is inadequate, so the quoted uncertainties on α may be unreliable. This needs to be addressed before the BOSS error-bar claim can be accepted.","section":"Sec. 7.1 and Sec. 6.4"}],"minor_comments":[{"comment":"The statement that 'P(k) ∝ 1 − 1/(1+z)^6' is incorrect: the linear matter power spectrum does not scale with redshift in this way, and the expression appears to be a confusion with a different quantity. Please correct or remove this sentence.","section":"Sec. 7.1"},{"comment":"The notation '$e^{-ir·k}$' mixes a vector dot product with a scalar-looking variable; use '$e^{-i\\mathbf{r}\\cdot\\mathbf{k}}$' for clarity.","section":"Sec. 3.2, Eq. (16)"},{"comment":"The phrase 'Landy-Szalay estimator estimator' contains a duplicated word; please fix.","section":"Sec. 3.1"},{"comment":"References [19] and [20] refer to the same Eisenstein et al. paper; one duplicate should be removed.","section":"References"},{"comment":"The sound horizon formula in Eq. (10) uses R_eq without a clear definition in the text; please define all symbols and provide a citation for the integral result.","section":"Sec. 2, Eq. (10)"},{"comment":"Some non-English phrases remain, such as 'Endereço de correspondência' in the footnote; these should be translated or removed.","section":"Author footnote"}],"recommendation":"major_revision","confidential_remarks":"The paper mixes a review with a new measurement. The review portion is adequate for a pedagogical venue, but the new quantitative results are not currently publishable because the cross-survey α comparison ignores fiducial-cosmology differences and the fitted values are not reported. If the authors redo the comparison on a common distance basis and report the numbers, the paper could become acceptable. If they decline to do so, I would recommend rejection."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Quick take: this is a review-plus-measurement paper where the measurement is not actually presented. The authors apply the Anderson et al. (2014) BAO fitting pipeline to a combined BOSS LOWZ+CMASS sample (0.3<z<0.65) and an eBOSS LRG sample (0.6<z<1.0), and claim to measure α that agrees with DESI III within 1σ. The α values themselves never appear in the text or tables—only in triangular and scatter plots—so the central result is not checkable.\n\nWhat is new: applying the existing pipeline to a differently binned public sample. That is incremental but legitimate. The review sections are serviceable and the authors are transparent about some limitations: they note the covariance from 500 mocks is noisy, they report the poor chi-square for BOSS, and they explicitly admit that α is not as fiducial-independent as it should be.\n\nThe soft spots are load-bearing. First, the fiducial cosmology in Table 1 is internally inconsistent with the cited Planck 2018 model: with ΩCDM=0.179 and Ωb=0.033, Ωm≈0.212, whereas Planck 2018 has Ωm≈0.315. If distances were computed with this fiducial, H(z) at z≈0.5 is off by about 8%, which is larger than the error bars in Figure 8. Second, the paper compares α from DESI III, DES Y6, and WiggleZ without converting to a common distance measure like DV/rs, even though α is defined relative to each survey's own fiducial. Their own remark in Sec. 7.2 admits this, but they proceed anyway. The claimed 1σ agreement with DESI III therefore may be an artifact. Third, the assertion in Sec. 7.1 that P(k) ∝ 1 − 1/(1+z)^6 is simply wrong; the amplitude of P(k) does scale with the growth factor squared, but not with that expression.\n\nThere is also the poor fit for BOSS (χ²/dof≈93/50), which the authors attribute to coarse binning and mock count, but it still raises questions about the model's validity in this regime.\n\nWho is this for? A student or someone new to BAO might get a useful overview of the estimators, but they will need to double-check the physical statements. The measurement itself is not ready for publication in its current form. My recommendation: reject, but tell the authors that a revised version that reports α numerically, converts all comparisons to a common distance basis, and corrects the P(k) scaling error could be reconsidered.","headline":"A review paper with a new BAO measurement that is not presented in checkable form; the headline agreement with DESI III rests on an unverified fiducial-cosmology comparison.","tokens_in":16736,"tokens_out":4686,"would_cite":false,"duration_ms":92073,"reading_group":"no","serious_thinker":"yes","would_accept_peer_review":false},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"The paper applies a standard power-spectrum template fit to BOSS and eBOSS galaxy samples, measures the BAO dilation parameter α, and reports that BOSS's α has smaller error bars than eBOSS's and that both agree with DESI III within 1σ.","keywords":["baryon acoustic oscillations","BAO","galaxy surveys","power spectrum","dilation scale","BOSS","eBOSS","large-scale structure"],"falsifier":"Compute $D_{V,\\mathrm{fid}}(z)$ from each survey's stated fiducial cosmology, convert every published $\\alpha$ into $D_V/r_s$, and check whether the values still agree within $1\\sigma$; if they do not, the paper's agreement claim rests on fiducial choices rather than on the distance scale.","tokens_in":15582,"feed_emoji":"🌌","tokens_out":9805,"duration_ms":80915,"temperature":0.7,"pith_summary":"This paper pairs a review of baryon acoustic oscillation (BAO) methods with new measurements from two spectroscopic galaxy samples: a BOSS sample at redshifts $0.3<z<0.65$ and an eBOSS sample at $0.6<z<1.0$. The authors fit a standard power-spectrum template to each sample's monopole and extract the BAO dilation parameter $\\alpha$, the ratio of the measured isotropic BAO distance to the distance in a chosen fiducial cosmology. They report that the BOSS fit yields smaller error bars than eBOSS, because the BOSS sample contains many more galaxies, and that both values agree with the DESI III results within $1\\sigma$. The paper also notes that the residual variation of $\\alpha$ with redshift is a known, unresolved feature seen in both 3D and angular analyses.","feed_headline":"New BAO distances from BOSS and eBOSS line up with DESI III","feed_subtitle":"Applying a standard template fit to two samples yields a tight alpha for BOSS and a 1-sigma match to DESI III.","key_machinery":"The object that carries the measurement is the dilation parameter $\\alpha = D_V(z)/D_{V,\\mathrm{fid}}(z)$, the ratio of the true isotropic BAO distance to the distance predicted by the fiducial flat $\\Lambda$CDM cosmology used when converting redshifts to comoving coordinates. It is estimated by fitting the monopole power spectrum with the template $P_{\\rm fit}(k) = P_{\\rm sm}(k)\\left[1 + (O_{\\rm sc\\,lin}(k/\\alpha) - 1)\\,e^{-k^2 \\Sigma_{\\rm nl}^2/2}\\right]$, where $P_{\\rm sm}$ combines a smooth no-wiggle power spectrum [18] with five polynomial nuisance terms (four for eBOSS), and $O_{\\rm sc\\,lin}$ is the purely oscillatory part of the linear power spectrum. The fit uses flat priors on $\\alpha$ and the damping scale $\\Sigma_{\\rm nl}$, a linear bias $b$, and MCMC sampling, with the covariance matrix built from 500 mock catalogs.","core_discovery":"The central claim is that applying the same template fit used in earlier BOSS analyses to a new combined LOWZ+CMASS sample ($0.3<z<0.65$) and an eBOSS LRG sample ($0.6<z<1.0$) gives clean BAO detections with dilation parameters $\\alpha$ that agree with DESI III within $1\\sigma$, and with the BOSS $\\alpha$ considerably more precise than the eBOSS $\\alpha$. The precision difference is attributed to the much larger number of galaxies in the BOSS sample rather than to redshift-dependent physics. As a corollary, the paper shows that photometric surveys (DES Y6, WiggleZ) produce larger $\\alpha$ errors, and it highlights the unexplained modulation of $\\alpha$ with redshift as an open problem common to 3D and angular tomographic BAO measurements.","pith_inferences":["A direct reproducibility check would be to run the same template fit on the exact BOSS DR12 and eBOSS LRG samples and publish the full $\\alpha$ covariance; without the numerical values, the claimed $1\\sigma$ agreement cannot be verified independently.","Converting all $\\alpha$ values to $D_V/r_s$ using each survey's fiducial cosmology would settle whether the $\\alpha$ modulation is cosmic or an artifact of differing fiducial assumptions.","Splitting the BOSS sample into finer redshift bins and fitting each bin separately would test whether the reported precision advantage of BOSS holds at all redshifts or only for the combined $0.3<z<0.65$ window.","The paper's choice to drop one polynomial term for eBOSS suggests a redshift-dependent nuisance model; testing whether keeping the full polynomial changes the eBOSS $\\alpha$ would quantify the systematic impact of this modeling choice."],"forward_implications":["A larger, lower-redshift spectroscopic sample gives a more precise BAO distance than a smaller higher-redshift one, so future surveys should prioritize sample size for $\\alpha$ measurements.","The $1\\sigma$ agreement with DESI III, if real, supports the current $\\Lambda$CDM-informed BAO distance scale at $z\\lesssim1$ and suggests the template method is robust across surveys.","The unresolved $\\alpha$ modulation with redshift persists in both 3D and angular analyses, so it likely reflects a property of the fitting framework or the data rather than a single survey's artifact.","Photometric surveys' larger $\\alpha$ errors align with expectations from photo-$z$ smearing, confirming that precision BAO distances need spectroscopic redshifts."],"supporting_citations":[{"why":"Supplies the smooth-plus-oscillation template fit and the fitting method used to extract $\\alpha$.","marker":"[6]"},{"why":"Provides the no-wiggle and oscillatory linear power spectra that define the template's smooth and oscillating pieces.","marker":"[18]"},{"why":"Power-spectrum estimator used with nbodykit to compute the galaxy monopole from the survey catalogs.","marker":"[21]"},{"why":"MCMC sampler used to obtain posterior distributions and parameter uncertainties.","marker":"[23]"},{"why":"MultiDark-Patchy mocks used to estimate the covariance matrix for the BOSS fit.","marker":"[29]"},{"why":"Companion mock catalogs used with [29] for the covariance estimate.","marker":"[42]"},{"why":"DESI III BAO results, the primary comparison for the paper's $1\\sigma$ agreement claim.","marker":"[3]"},{"why":"DES Y6 photometric BAO measurement, compared as a representative photometric survey.","marker":"[1]"},{"why":"WiggleZ BAO distance measurement, compared as a photometric survey with large error bars.","marker":"[28]"},{"why":"Defines the same BOSS sub-sample used here, providing the sample selection and a model-independent $\\alpha$ comparison.","marker":"[33]"}],"fun_headline_variants":["BAO from BOSS and eBOSS align with DESI III","Tight BAO in BOSS, eBOSS matches DESI III","New BAO fits confirm agreement with DESI III","BOSS and eBOSS BAO agree with DESI within 1σ","BAO from BOSS and eBOSS sync with DESI III"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The comparison of $\\alpha$ across surveys assumes each survey's $\\alpha$ is directly comparable even though $\\alpha$ is defined relative to that survey's own fiducial cosmology ($\\alpha = D_V/D_{V,\\mathrm{fid}}$); the paper does not state the fiducial models of WiggleZ, DES Y6, or DESI III, nor convert the measurements to a common distance like $D_V/r_s$, so the apparent $1\\sigma$ agreement with DESI III could be an artifact of differing fiducial assumptions.","fun_headline_variants_meta":{"raw":{"variants":["BAO from BOSS and eBOSS align with DESI III","Tight BAO in BOSS, eBOSS matches DESI III","New BAO fits confirm agreement with DESI III","BOSS and eBOSS BAO agree with DESI within 1σ","BAO from BOSS and eBOSS sync with DESI III"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000711,"raw_usage":{"total_tokens":3219,"prompt_tokens":980,"completion_tokens":2239,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":596,"completion_tokens_details":{"reasoning_tokens":2149}},"tokens_in":596,"tokens_out":2239,"duration_ms":16984,"temperature":1.0,"reasoning_tokens":2149,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-11T21:23:45.344798+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Compute $D_{V,\\mathrm{fid}}(z)$ from each survey's stated fiducial cosmology, convert every published $\\alpha$ into $D_V/r_s$, and check whether the values still agree within $1\\sigma$; if they do not, the paper's agreement claim rests on fiducial choices rather than on the distance scale.","supporting_citations":[{"cited_title":"The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: baryon acoustic oscillations in the Data Releases 10 and 11 Galaxy samples","cited_arxiv_id":null,"evidence_quote":"Supplies the smooth-plus-oscillation template fit and the fitting method used to extract $\\alpha$."},{"cited_title":"Baryonic features in the matter transfer function","cited_arxiv_id":null,"evidence_quote":"Provides the no-wiggle and oscillatory linear power spectra that define the template's smooth and oscillating pieces."},{"cited_title":"emcee: the MCMC hammer","cited_arxiv_id":null,"evidence_quote":"MCMC sampler used to obtain posterior distributions and parameter uncertainties."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Companion mock catalogs used with [29] for the covariance estimate."},{"cited_title":"The WiggleZ Dark Energy Survey: improved distance measurements toz = 1 with reconstruction of the baryonic acoustic feature","cited_arxiv_id":null,"evidence_quote":"WiggleZ BAO distance measurement, compared as a photometric survey with large error bars."},{"cited_title":"A first model-independent radial BAO constraint from the final BOSS sample","cited_arxiv_id":"1808.10695","evidence_quote":"Defines the same BOSS sub-sample used here, providing the sample selection and a model-independent $\\alpha$ comparison."}],"review_version":1}