{"id":"9c037adb-f04f-4d7b-8933-f9ccd316d6a7","arxiv_id":"2502.09404","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"A clustering-based galaxy-halo model predicts galaxy-galaxy lensing signals that agree with HSC, DES, and KiDS data, weakening the 'Lensing is Low' tension.","lead":"The authors use a clustering-based model of where BOSS galaxies live inside dark matter halos to predict how much they should bend light from background galaxies, then compare with lensing data from HSC, DES, and KiDS. They find the predicted signal agrees with the observations, suggesting the long-standing 'Lensing is Low' discrepancy may come from inaccurate galaxy-halo modeling rather than new physics.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"No-tension claim rests on error-free model lines; without propagating SHMR/completeness uncertainties the comparison cannot support the conclusion.","rationale":"Good-faith reading: the paper is a forward-model test. It takes a clustering-calibrated SHAM model from Paper IV and asks whether it predicts the observed GGL. That is a legitimate external test, and the paper deserves credit for using an independent observable and for being transparent that the S8 fit is approximate. The concern is not that the model is necessarily wrong, but that the paper does not provide the information needed to decide whether the model's agreement with lensing data is a meaningful falsification of the Lensing-is-Low interpretation. The predicted ΔΣ is a deterministic function of SHMR parameters and completeness; those inputs have posterior distributions, but the output is shown only as a line. If the output distribution is narrow and still lies below the data at small scales, the claim is strong; if the output distribution is broad, the claim reduces to the observation that some model in the posterior matches the data. The same issue infects the S8 fit in Table 2: the reported uncertainties come from the lensing covariance only and explicitly ignore the model covariance, so the 0.8267 ± 0.0108 value is not yet a cosmological constraint. The reader's weakest-assumption statement, regarding SHMR/completeness accuracy, is the correct root cause; this stress-test concern is the methodological consequence that the paper's central claim cannot be falsified as presented. A posterior-propagation check would settle this: if the model band is tight and still agrees with all three surveys, the result would be a strong external validation of the PAC galaxy-halo connection; if the model band is broad or inconsistent with the data, the conclusion should be weakened to 'there exists a PAC-calibrated model consistent with the data.' The LOWZ redshift mismatch is secondary because the no-tension conclusion is already stated for BOSS generally, and the CMASS S8 fit is the quantitative claim. On this reading, the reader's CONDITIONAL verdict remains appropriate, so no verdict change is recommended.","tokens_in":14722,"tokens_out":9150,"duration_ms":89006,"concrete_test":"Draw ~200 SHMR parameter vectors from the Table 1 posterior for the Planck CMASS fit; for each vector, regenerate the mock catalog using the same pipeline (SHAM + Table D2 completeness interpolated into 0.54–0.70) and compute ΔΣ(rp) exactly as in §3.2. Plot the 16–84% model band against the HSC/DES/KiDS data in Figure 3. If the band excludes the data at rp < 1 h^-1 Mpc, the no-tension claim fails; if the band is wide enough to include all datasets, the claim is vacuous. Repeat once with the completeness shifted by its (currently unpublished) uncertainty to see whether the conclusion survives.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim, that the Lensing-is-Low discrepancy disappears in both WMAP and Planck cosmologies, is carried entirely by the single predicted ΔΣ curves in Figures 3–5, which have no model error band. In §4.2 the authors state that the S8 fit is based on the best-fit SHMR and completeness and that the quoted errors are underestimated; the same is true of the no-tension statement. The predicted amplitude depends on (i) the SHMR parameters in Table 1, (ii) the stellar-mass completeness from Paper IV Table D2, interpolated in §4.2 for the 0.54–0.70 CMASS bin, and (iii) the SHAM assumption that galaxies trace subhalo mass in the N-body simulation. The reported MCMC posteriors are tight, but they are marginalized over PAC measurements, not over the GGL prediction; a small shift in log M0 or σ can move the small-scale one-halo term by more than the observed error bars. Without propagating these uncertainties, 'no significant tension' cannot be distinguished from 'the model space is flexible enough to accommodate any dataset.' The LOWZ comparison is additionally approximate (§4.2 admits 0.2–0.3/0.3–0.4 bins are used for observations at 0.15–0.31/0.31–0.43), but the CMASS S8 claim is the load-bearing part.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper revisits the \"Lensing is Low\" tension by predicting galaxy-galaxy lensing (GGL) signals around BOSS LOWZ and CMASS galaxies using the galaxy-halo connection derived in Paper IV from Photometric objects Around Cosmic webs (PAC) measurements. The authors generate mock catalogs via subhalo abundance matching in two N-body simulations with WMAP (CosmicGrowth) and Planck (Jiutian) cosmologies, then compare the predicted ΔΣ(rp) profiles against HSC Y1, DES Y3, and KiDS-1000 GGL measurements. They report no significant tension between predictions and observations in either cosmology, and they fit S8 = 0.8294 ± 0.0110 (HSC), 0.8073 ± 0.0372 (DES), and 0.8189 ± 0.0440 (KiDS) for CMASS, with a combined value of 0.8267 ± 0.0108. The paper concludes that imprecise galaxy-halo connection modeling in earlier work is the primary cause of the apparent discrepancy, and that strong baryon feedback is not required to match small-scale GGL data.","tokens_in":15040,"tokens_out":2952,"duration_ms":29604,"significance":"If the predicted GGL curves are robust, this result would substantially reframe the \"Lensing is Low\" discussion by showing that an accurate galaxy-halo connection, constrained without using lensing information, can reproduce the observed amplitudes and scale dependence in both WMAP and Planck cosmologies. The PAC-based SHAM constraints are a genuine independent input, and the comparison to multiple lensing surveys is a strength. The paper also makes a concrete falsifiable prediction: the small-scale GGL signal around BOSS galaxies should follow the presented curves, and future data with smaller errors can discriminate between cosmologies. The claim that baryon feedback is unnecessary is provocative but is only a corollary of the no-tension claim, so its robustness depends on the same error analysis. The work is clearly relevant to the journal's scope in observational cosmology.","major_comments":[{"comment":"The predicted ΔΣ curves are shown as single lines with no uncertainty bands, yet the paper's central conclusion is that \"there is no significant tension\" between these curves and the observed GGL measurements. The SHMR parameters in Table 1 have MCMC posteriors, and the stellar mass completeness from Table D2 of Paper IV is an inferred quantity, but none of these uncertainties are propagated into the predicted GGL profiles. Without error bands, the statement of no tension is only a visual judgment and cannot be distinguished from the alternative that the model space is flexible enough to accommodate the data. To make the central claim quantitative, the authors should propagate the SHMR posterior and completeness uncertainties into the predicted profiles and report a tension statistic (e.g., chi-square or probability-to-exceed) for each survey and cosmology.","section":"§4.2, Figures 3–5"},{"comment":"The reported S8 values are obtained by fitting the amplitude of the observed GGL signals under the assumption that the predicted amplitude scales as S8^2 at fixed galaxy-halo connection. These constraints are therefore not independent predictions of S8; they are a re-parameterization of the observed GGL amplitude. The abstract and conclusions present these S8 values alongside the \"no tension\" claim, which risks conflating an a posteriori fit with an a priori prediction. The paper should clearly separate the two statements: the SHMR-derived curves are the independent predictions, while the S8 values are fitted parameters whose only role is to show consistency with the WMAP and Planck cosmologies under the adopted scaling law.","section":"§4.2, Table 2, Conclusions"},{"comment":"For the LOWZ comparison, the predicted signals are computed for redshift bins 0.2–0.3 and 0.3–0.4, while the observed measurements are for 0.15–0.31 and 0.31–0.43. The text acknowledges this is \"an approximation for reference,\" yet the subsequent sentences state that the predictions \"exhibit a higher degree of consistency\" and that \"no significant tension exists\" at large scales for LOWZ. Because the lens sample selection differs between prediction and observation, this comparison cannot support the no-tension claim as stated. The authors should either recompute the predictions for the exact observed redshift bins using the completeness interpolation, or explicitly mark the LOWZ comparison as illustrative and exclude it from the quantitative conclusions.","section":"§4.2, Figure 4"},{"comment":"The strong redshift dependence of the predicted GGL signals shown in Figure 2 is driven by the stellar mass completeness, and the CMASS 0.54–0.70 predictions rely on interpolating completeness from Table D2 of Paper IV. The paper does not test the sensitivity of the predicted ΔΣ profiles to plausible variations in this completeness interpolation. Given that a small shift in completeness can change the effective lens redshift distribution and the one-halo term, the authors should include a completeness-variation test (e.g., using the upper and lower edges of the completeness curves or an alternate interpolation scheme) to demonstrate that the no-tension conclusion is robust to this input.","section":"§3.1, §4.2, Figure 2"}],"minor_comments":[{"comment":"The phrase \"unless the the GGL observation\" contains a duplicated \"the\"; please correct.","section":"Abstract"},{"comment":"The word \"Compassion\" in \"Compassion between predicted GGL signals\" should be \"Comparison\".","section":"§5, Figure 5 caption"},{"comment":"The text defines Macc as \"the viral mass of the halo\" — \"viral\" should be \"virial\".","section":"§3.1, Eq. (1)"},{"comment":"The text introduces rmax_pi = 50 Mpc/h but the integration variable in Eq. (3) is r_pi; please make the notation consistent and define the line-of-sight integration limits explicitly.","section":"§3.2"},{"comment":"The phrase \"we only consider the best-fit value of the SHMR and stellar mass completeness\" is important and appears only in the S8 fitting discussion; it should be stated earlier and repeated in the conclusions, since it directly limits the strength of the no-tension claim.","section":"§4.2"}],"recommendation":"major_revision","confidential_remarks":"The central idea of the paper is interesting and the PAC-based SHAM approach is a valuable independent input to the GGL comparison. However, the paper's headline conclusion — that the \"Lensing is Low\" problem does not exist — is currently supported only by visual agreement of error-free prediction lines. The missing error propagation and the conflation of fitted S8 values with independent predictions are load-bearing issues that require a major revision. If the authors add uncertainty bands and a quantitative tension assessment, the paper could become a solid contribution. I also note that the paper relies heavily on the authors' own Paper IV for the SHMR and completeness; this is appropriate given the series format, but the sensitivity tests should reference those inputs explicitly. The typographical issues are minor and easily fixed."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Colleague,\n\nThe thing to know: this paper turns the 'Lensing is Low' story on its head by using a clustering-calibrated SHAM model—not a standard HOD—to predict BOSS galaxy-galaxy lensing. The predicted ΔΣ curves track HSC, DES, and KiDS measurements down to 0.2 Mpc/h, in both WMAP and Planck cosmologies. If that holds, a big piece of the S8 tension is a modeling artifact, not new physics.\n\nWhat's new: the application. The PAC method and SHMR were built in earlier papers (I, IV). Here they are used to generate mock catalogs and predict GGL, and the lensing comparison is genuinely external—the SHMR was fit to clustering, not to lensing. That is real credit. Their Figure 5 comparison with Amon et al.'s HOD is also useful: it shows where standard HODs put too much mass in large halos.\n\nThe soft spots are real but not fatal. The predicted curves have no error bands. SHMR posterior and stellar-mass completeness uncertainties are not propagated into ΔΣ. The authors are honest about this—they say the S8 errors are underestimated—but the headline 'no significant tension' is therefore a visual statement, not a statistical one. A small shift in log M0 or scatter can move the one-halo term by more than the observed error bars. So the stress-test framing is right: the model space is flexible, and without propagated uncertainties the central claim is underdetermined. The LOWZ comparison is also approximate (redshift bins don't match), and the CMASS S8 values are fitted to the GGL amplitudes, so they are not independent predictions. No code or data is released, which makes independent checks harder.\n\nNone of this kills the paper. The central argument—that a more flexible, clustering-calibrated galaxy-halo connection removes the tension—is plausible and consistent with what's shown. What's missing is the quantitative piece.\n\nWho this is for: anyone working on galaxy-galaxy lensing, HOD/SHAM, or the S8 tension. It deserves a serious referee, but the referee should push for uncertainty propagation, proper LOWZ binning, and code/data release. I'd probably not cite it as a settled result until the error bars appear.\n\nRecommendation: send to peer review, conditionally. The claim is important enough that a desk reject would be wrong.","headline":"Clustering-calibrated SHAM predicts BOSS GGL without tension, but missing model error bars make the no-tension claim conditional.","tokens_in":15617,"tokens_out":2551,"would_cite":true,"duration_ms":23380,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"Calibrating BOSS galaxies' stellar-to-halo mass relation with PAC clustering measurements yields galaxy-galaxy lensing predictions that agree with HSC, DES, and KiDS, so the 'lensing is low' discrepancy is a modeling artifact, not new…","keywords":["galaxy-galaxy lensing","lensing is low","galaxy-halo connection","subhalo abundance matching","stellar-to-halo mass relation","BOSS galaxies","S8 tension","PAC method"],"falsifier":"A decisive check is to measure BOSS CMASS halo masses independently of the PAC clustering data, for instance by stacking satellite kinematics or using a lensing source catalog with fully independent photometric redshifts, and compare with the PAC stellar-to-halo mass relation; if the independently inferred halo masses are systematically higher at fixed stellar mass, the predicted ΔΣ would be too low and the claimed agreement would be coincidental.","tokens_in":14492,"feed_emoji":"🔭","tokens_out":11543,"duration_ms":101289,"temperature":0.7,"pith_summary":"This paper argues that the well-known 'lensing is low' tension, in which observed galaxy-galaxy lensing around BOSS galaxies falls 20-30% below predictions based on Planck cosmology, is largely an artifact of how previous models connected galaxies to dark matter halos. Using PAC measurements, which count photometric galaxies around spectroscopic BOSS galaxies in stellar-mass bins, the authors calibrate a subhalo abundance-matching model with a tightly constrained stellar-to-halo mass relation and stellar mass completeness. Predicted galaxy-galaxy lensing for BOSS CMASS and LOWZ matches measured signals from HSC Y1, DES Y3, and KiDS-1000 down to 0.2 Mpc/h in both WMAP and Planck universes. The best-fit S8 from CMASS lensing is 0.8267 ± 0.0108 combined, leaving Planck and WMAP both viable. The practical upshot is that accurate modeling of the lens population, not baryonic feedback or a lowered S8, removes the small-scale deficit, except for a KiDS small-scale LOWZ offset that the authors flag as needing confirmation.","feed_headline":"A better halo map erases the 'lensing is low' deficit","feed_subtitle":"Stellar-to-halo masses fixed by PAC cross-correlations reproduce BOSS shear without baryon tweaks.","key_machinery":"The load-bearing object is the PAC-calibrated galaxy-halo connection: the excess surface density n̄2 wp(rp) of photometric galaxies with given stellar masses around BOSS spectroscopic galaxies (42 LOWZ and 33 CMASS measurements), fitted by subhalo abundance matching to a double-power-law stellar-to-halo mass relation M* = 2k / [(Macc/M0)^−α + (Macc/M0)^−β] with log-normal scatter. Combined with the stellar mass completeness of LOWZ and CMASS as a function of redshift (Table D2 of Paper IV), this maps every BOSS galaxy to a central or satellite subhalo in N-body simulations. Predicted lensing is obtained by projecting the galaxy-matter cross-correlation ξgm to get ΔΣ(rp) = Σ(<rp) − Σ(rp), the quantity compared with observed galaxy-galaxy lensing. The SHMR plus completeness, not a tuned HOD, supplies the correct one-halo contribution at rp < 1 Mpc/h, which is the regime where the 'lensing is low' deficit appeared.","core_discovery":"The paper's central claim is that the 'lensing is low' discrepancy disappears once the galaxy-halo connection of BOSS galaxies is built from PAC cross-correlation measurements rather than from standard HOD fits. In Paper IV, 42 LOWZ and 33 CMASS excess surface density measurements in stellar-mass bins were modeled by subhalo abundance matching with a double-power-law stellar-to-halo mass relation with scatter, giving percent-level parameter constraints. Here the authors apply that relation plus the stellar mass completeness of the BOSS samples to N-body mock catalogs in CosmicGrowth (WMAP, S8 = 0.785) and Jiutian (Planck 2018, S8 = 0.825), compute the galaxy-galaxy lensing signal ΔΣ(rp) from the galaxy-matter cross-correlation, and compare with measurements from HSC Y1, DES Y3, and KiDS-1000. They find no scale range in which the predicted CMASS signal exceeds the observations, and the LOWZ predictions agree with HSC and DES at rp < 0.6 h−1 Mpc. They conclude that no significant baryon feedback is required to suppress small-scale clustering and that earlier reports of low lensing stem from insufficiently flexible or inaccurate galaxy-halo modeling.","pith_inferences":["An implication left implicit is that joint analyses of clustering and lensing that marginalize over standard HOD parameters may systematically underestimate the small-scale one-halo lensing signal; using PAC-style n̄2 wp observables in stellar-mass bins should reduce that bias in future S8 constraints.","A natural extension is to apply the same PAC-calibrated abundance matching to the newer DESI lens samples; the paper's logic predicts the 'lensing is low' deficit should also disappear there, which is directly testable with upcoming DESI lensing data.","The survey-to-survey spread in fitted S8 suggests that the combined constraint leans heavily on HSC's small error bars; if HSC's shear calibration carries an unknown systematic, the true S8 could be lower and the Planck-versus-WMAP question would remain open even with this model.","The present argument does not model baryonic gas explicitly; a hydrodynamical simulation with strong feedback could test whether the small-scale agreement hides a cancellation between baryonic suppression and residual uncertainty in the PAC stellar-to-halo mass relation."],"forward_implications":["The BOSS CMASS 'lensing is low' deficit disappears at all measured scales down to 0.2 h−1 Mpc once the PAC-calibrated abundance-matching model is used, so the anomaly does not require lowering S8 or adding baryonic suppression.","The inferred S8 values from CMASS lensing (0.8294 ± 0.0110 for HSC, 0.8073 ± 0.0372 for DES, 0.8189 ± 0.0440 for KiDS, and 0.8267 ± 0.0108 combined) are consistent with both WMAP and Planck cosmologies at current precision, so these data alone cannot discriminate between the two.","Because predicted lensing depends strongly on the redshift-dependent stellar mass completeness, future analyses of samples with rapidly varying completeness, such as CMASS, must model completeness bin by bin rather than for the full redshift range.","If the small-scale KiDS-1000 LOWZ measurement is confirmed, it would point to survey-specific systematics or to a genuine baryonic effect at rp < 0.6 h−1 Mpc that the PAC model does not need elsewhere; if not confirmed, the 'lensing is low' problem is fully explained by galaxy-halo modeling."],"supporting_citations":[{"why":"It supplies the PAC measurements of n̄2 wp, the SHMR fit, and the stellar mass completeness that define the galaxy-halo connection used for all predictions.","marker":"Xu et al. (2023)"},{"why":"It provides the GGL measurements around BOSS galaxies from HSC Y1, DES Y3, and KiDS-1000, with covariance matrices used in the comparison and S8 fit.","marker":"Leauthaud et al. (2022)"},{"why":"It provides the updated GGL measurements and the standard-HOD predictions whose 20-30% deficit defines the baseline that this paper argues against.","marker":"Amon et al. (2023)"},{"why":"It introduces the PAC method of measuring the excess surface density of photometric objects around spectroscopic galaxies.","marker":"Xu et al. (2022b)"},{"why":"It supplies the Planck 2018 cosmology with S8 = 0.825 used for the Jiutian simulation and as the high-S8 reference universe.","marker":"Planck Collaboration et al. (2020)"},{"why":"It supplies the WMAP cosmology with S8 = 0.785 used for the CosmicGrowth simulation and as the low-S8 reference universe.","marker":"Hinshaw et al. (2013)"},{"why":"It provides the CosmicGrowth N-body simulation suite used to build the WMAP-cosmology mock galaxy catalogs.","marker":"Jing (2019)"},{"why":"It provides the recipe for computing and projecting ξgm into ΔΣ, including the rπ,max = 50 Mpc/h cutoff and physical-unit conversions.","marker":"Leauthaud et al. (2011)"}],"fun_headline_variants":["Precise halo mapping kills the 'lensing is low' problem","PAC cross-correlations resolve BOSS lensing anomaly","No baryon feedback needed with accurate halo masses","Lensing is low? Not with PAC-based halo connection","BOSS lensing matches theory with PAC-informed halos"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the stellar-to-halo mass relation, its scatter, the satellite assignment, and the stellar mass completeness derived from the PAC clustering measurements are accurate for BOSS galaxies down to 0.2 Mpc/h; if any of these are wrong, the predicted lensing amplitude and shape shift and the agreement with the observed shear does not actually test the 'lensing is low' claim.","fun_headline_variants_meta":{"raw":{"variants":["Precise halo mapping kills the 'lensing is low' problem","PAC cross-correlations resolve BOSS lensing anomaly","No baryon feedback needed with accurate halo masses","Lensing is low? Not with PAC-based halo connection","BOSS lensing matches theory with PAC-informed halos"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000251,"raw_usage":{"total_tokens":1662,"prompt_tokens":1157,"completion_tokens":505,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":773,"completion_tokens_details":{"reasoning_tokens":425}},"tokens_in":773,"tokens_out":505,"duration_ms":5116,"temperature":1.0,"reasoning_tokens":425,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-07T21:36:34.036514+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"A decisive check is to measure BOSS CMASS halo masses independently of the PAC clustering data, for instance by stacking satellite kinematics or using a lensing source catalog with fully independent photometric redshifts, and compare with the PAC stellar-to-halo mass relation; if the independently inferred halo masses are systematically higher at fixed stellar mass, the predicted ΔΣ would be too low and the claimed agreement would be coincidental.","supporting_citations":[],"review_version":1}