{"id":"cca1169a-07bf-47ec-8d8d-1bf727bf260e","arxiv_id":"2506.19589","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":5,"one_line_summary":"At redshifts 2 to 7, black holes in massive elliptical hosts show no sign of the cosmological growth needed to make black holes the dark energy, with k=0.13 +/- 0.27 instead of k=3.","lead":"Using 12 very distant galaxies seen by JWST, this paper tests the idea that black holes grow as the universe expands and could be the dark energy. The black holes in these galaxies show no such growth, leading the authors to claim black holes are not dark energy and to link the galaxies to earlier compact objects called little red dots.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Eq. (3)'s selection-free likelihood, combined with k=3 predicted BH masses 1.7-2.9 dex below the observed sample, means the 11-sigma rejection could be a flux-limited selection artifact; no selection function is modeled.","rationale":"The reader's weakest_assumption already identifies the unmodeled selection function and the fact that k=3 predicts black holes well below detection threshold. My independent reading of Eqs. (2)-(4) and Table I confirms this is the most load-bearing issue: the numerical gap between the k=3 prediction and the observed masses (1.7 to 2.9 dex) is so large that any luminosity-based selection could fully account for the reported offset, and the paper's own choice of 'bright, high stellar mass quasars' makes that selection explicit. The abstract's '>10 sigma' language is therefore not supported by the current statistical treatment. The paper's qualitative direction is consistent with other constraints, and the LRD evolution scenario is illustrative rather than decisive, so a revised version that models the selection function, propagates systematic virial-mass uncertainties, and softens the significance claim could be a useful contribution. This matches the reader's CONDITIONAL verdict, so no verdict change is needed; the stress-test sharpens the specific mechanism by which the selection bias can produce a spurious k near zero.","tokens_in":10972,"tokens_out":6574,"duration_ms":78608,"concrete_test":"Forward-model the survey selection: (1) draw 10^4 mock sources at the redshifts and Mstar values of Table I; assign MBH from Eq. (1) scaled by (1+z)^(-k) with k=3 and 0.5 dex intrinsic scatter; (2) assign Eddington ratios from the distribution of the real sources, compute broad-line luminosities, and retain only mocks above the actual detection limits of the surveys in Refs. [47-51, 54]; (3) run the Eq. (3) MCMC on the selected mocks. If the recovered k peaks near 0 and excludes 3 at high significance, the headline result is a selection artifact. A cheaper check: add a truncation term to the likelihood at the observed minimum MBH (log MBH ~ 7.3) and see how much the k posterior shifts; if it moves by several sigma, selection is not negligible.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central statistical claim rests on Eq. (3), a complete-data likelihood that treats the 12 measured (Mstar, MBH) pairs as random draws from the underlying Mstar-MBH relation with only measurement scatter. This is not valid for a flux-limited sample of luminous broad-line AGNs. Under k=3, Eq. (2) predicts log MBH ~ 5.8-6.2 for the stellar masses and redshifts in Table I (e.g., GN-9994014: predicted 5.84 vs observed 7.55; J2236+0032: predicted 6.21 vs observed 9.13). The authors explicitly select 'bright, high stellar mass quasars observed by JWST' to avoid low-luminosity populations; that is a selection on luminosity, hence on MBH at a given Eddington ratio. If the true population follows k=3, only the high-mass tail of the MBH distribution is detectable, and that tail would produce exactly the offset seen in Figure 1. No selection probability, detection threshold, or luminosity limit enters Eq. (3)-(4), so the resulting k=0.13±0.27 and the ~11-sigma exclusion of k=3 measure the conditional distribution of detected objects, not the underlying coupling strength. A secondary concern is host classification: Table I lists SFR values up to ~300-500 M_sun/yr, making 'red-sequence elliptical with constant stellar mass' questionable for some sources, but the selection-bias issue alone suffices to undercut the headline significance.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The manuscript compiles a sample of 12 JWST-detected broad-line AGNs at redshifts z≈2–7 whose hosts are classified as red-sequence elliptical galaxies with stellar masses above 4×10^10 M_sun. Assuming the local Mstar–MBH fundamental plane (Eq. 1) evolves only through a cosmological coupling factor (1+z)^{-k}, the authors fit k = 0.13 ± 0.27 (68% CI) and claim that the cosmologically coupled black-hole dark-energy hypothesis (k = 3) is rejected at about 11σ. In a second part, the paper simulates the evolution of little red dots (LRDs) from z≈6 to z≈1.61 and z≈0.85 and argues that they can evolve into the red-sequence elliptical hosts without cosmological coupling.","tokens_in":11272,"tokens_out":9943,"duration_ms":107035,"significance":"If the central claim were correct, this would be a decisive observational disproof of a prominent and actively discussed dark-energy hypothesis, and the paper would also provide a plausible evolutionary link between JWST-discovered LRDs and lower-redshift red-sequence ellipticals. The compilation of high-redshift AGN host properties in Table I is useful, the MCMC implementation is straightforward, and the posterior for k is transparently presented. However, the headline significance is not supported: the likelihood ignores the strong luminosity selection of the sample, and the inference assumes no intrinsic redshift evolution of the Mstar–MBH relation. The LRD simulation is an interesting illustrative model but is not an independent test. The manuscript's main quantitative conclusion is therefore not established.","major_comments":[{"comment":"The likelihood in Eq. (3) treats the 12 observed (Mstar, MBH) pairs as random draws from the underlying Mstar–MBH relation with only measurement scatter and intrinsic scatter. This is not valid for a flux-limited, luminosity-selected sample. The authors explicitly select 'bright, high stellar mass quasars observed by JWST' and impose Mstar > 4×10^10 M_sun and E(B-V) < 0.5; detection of a broad-line AGN depends on luminosity, hence on MBH at a given Eddington ratio. Under k = 3, Eq. (2) predicts log MBH roughly 5.8–7.2 for the stellar masses and redshifts in Table I, whereas the observed values are 7.3–10.0. A survey with a luminosity threshold would then only detect the high-mass tail of the k = 3 population, producing exactly the offset shown in Figure 1. The fitted k = 0.13 ± 0.27 and the quoted ~11σ exclusion therefore characterize the conditional distribution of detectable objects, not the coupling strength of the underlying population. The paper must include a selection function P(det | Mstar, MBH, z, survey limits) or otherwise demonstrate that the strong selection on AGN luminosity does not bias the inference; without this, the headline claim is unsupported.","section":"Eqs. (2)–(4), Methods"},{"comment":"The classification of several hosts as red-sequence ellipticals with constant stellar mass is not secure. Table I lists SFR values up to 543.8 M_sun/yr (J1030+0524), 311.1 M_sun/yr (J1148+5251), and other sources with SFR > 100 M_sun/yr, and some E(B-V) values near the 0.5 threshold. At z~5–7, rest-frame optical morphology and SED fitting give limited constraints on quiescence, and broad-line AGN light can contaminate host photometry. If the stellar mass is not constant over the redshift baseline, or if the host stellar mass is overestimated, then the constant-Mstar assumption entering Eq. (2) biases k. The authors should show, for each source, the quantitative offset from the adopted SFR–Mstar main sequence and address host-light decomposition systematics.","section":"Table I and Data"},{"comment":"The inference assumes that the local Mstar–MBH fundamental plane (Eq. 1) is universal up to the (1+z)^{-k} factor. However, there is independent evidence that the Mstar–MBH relation evolves with redshift and that high-redshift quasars can host overmassive black holes; moreover, the authors' own LRD simulation includes stellar mass growth and BH accretion that would move objects relative to the local relation without any cosmological coupling. The analysis must either model this intrinsic evolution or argue quantitatively that it is negligible; otherwise the fitted k conflates astrophysical evolution of the relation with the cosmological coupling signal.","section":"Eq. (1) and Result"},{"comment":"The LRD evolution simulation is calibrated to the observed LRD population and adopts, without physical derivation, constant SFR and constant BH accretion rates from z~6 to z~1.61 and then SFR = 0 with continued accretion. The good match in Figure 3 is therefore an illustration that the assumed tracks can connect the two populations, not an independent test of the no-coupling hypothesis. The text should present it as such, and the abstract's claim that LRDs 'naturally evolve' into the red-sequence ellipticals should be softened accordingly.","section":"Result and discussion, Figure 3"}],"minor_comments":[{"comment":"The word 'Remanants' should be 'Remnants'.","section":"Title"},{"comment":"Equation (4) defines sigma_tot, but Eq. (3) uses sigma_i; state explicitly that sigma_i = sigma_tot,i.","section":"Eqs. (3)–(4)"},{"comment":"The caption does not label the grey region representing the intrinsic scatter of the local relation.","section":"Figure 1"},{"comment":"The sentence claiming that the impact of observational biases is 'relatively small' for hosts with Mstar > 4×10^10 M_sun requires quantitative support or should be deleted.","section":"Data section"},{"comment":"Several references are still arXiv preprints (e.g., [48]–[50]); update to published versions where available.","section":"References"}],"recommendation":"reject","confidential_remarks":"The paper contains a useful data compilation and a suggestive LRD evolutionary scenario, but the central 11σ rejection of cosmological coupling is invalid because the likelihood in Eq. (3) ignores the luminosity selection of the AGN sample. In my view this cannot be repaired within the current sample, since the objects are selected on AGN brightness and hence on black-hole mass. A future paper focusing on the LRD evolutionary scenario, with the statistical claim removed or heavily caveated, or a new analysis based on a sample selected purely by host-galaxy properties, could be reconsidered."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Colleague,\n\nThis paper applies the same basic test as Lei et al. 2024 to a larger JWST sample of 12 broad-line AGNs at z=2-7 in supposedly red-sequence elliptical hosts, fits the coupling parameter k against the local M*-MBH relation, gets k=0.13±0.27, and claims an ~11-sigma rejection of the k=3 cosmologically coupled black hole dark energy scenario. It also forward-simulates little red dots evolving into the Farrah et al. sample at z~0.7-2.5.\n\nThe direction of the result is credible and consistent with other independent constraints. The sample compilation is careful: blue AGNs, E(B-V)<0.5, stellar masses above 4e10, SFR below the main sequence. The LRD simulation is a nice illustrative scenario, clearly labeled as an evolutionary calculation with assumptions. The paper is honest about many of its choices.\n\nBut the headline significance is not supported as stated. The likelihood in Eq. (3) treats the 12 measured pairs as complete draws from the underlying relation, with no selection function. The sample is explicitly selected to be bright, high-stellar-mass quasars. Under k=3, Eq. (2) predicts log MBH ~5.8-6.2 for these hosts, well below the observed ~7.3-10. A flux-limited AGN sample preferentially detects overmassive BHs at a given host mass, and that selection alone can produce exactly the offset seen in Figure 1. The stress-test note is right: the ~11 sigma is a statement about the conditional distribution of detected objects, not about k.\n\nThere's also a host classification problem. Several sources in Table I have SFRs of 300-500 Msun/yr. Calling those \"red-sequence ellipticals with constant stellar mass\" is a stretch, and it matters because the whole test assumes the host stellar mass is the appropriate anchor. The error budget also omits systematic offsets in virial BH mass estimators, which are known to be significant at high redshift.\n\nThe LRD simulation is not a falsifiable prediction; it's a scenario with parameters chosen to match the target. That said, it does show plausibility and the conclusion doesn't depend on it.\n\nAll told: the paper deserves a serious referee, but the 11-sigma claim should be softened, the selection function modeled or at least bounded, and the host classification discussed more honestly. If those are fixed, it's a solid contribution to the debate.","headline":"A useful, plausible test of cosmologically coupled black holes whose headline 11-sigma exclusion is undermined by unmodeled selection effects and host misclassification.","tokens_in":11922,"tokens_out":1964,"would_cite":false,"duration_ms":19762,"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":"JWST data on twelve high-redshift quiescent ellipticals reject black holes as a dark energy source at about 11 sigma and identify little red dots as their progenitors.","keywords":["dark energy","cosmologically coupled black holes","JWST AGN sample","red-sequence elliptical galaxies","little red dots","black hole-host galaxy scaling relation","MCMC likelihood","high-redshift quasars"],"falsifier":"A complete sample of quiescent ellipticals at z>2 selected by host stellar mass rather than AGN luminosity, with black-hole masses measured from rest-frame optical lines, should show whether the M_star–M_BH relation tracks k=3 once selection is accounted for. If the inferred coupling returns to about k=3 under that selection function, the 11-sigma rejection fails; if it stays near k=0, the claim stands.","tokens_in":10645,"feed_emoji":"🕳️","tokens_out":9320,"duration_ms":86971,"temperature":0.7,"pith_summary":"This paper tests whether black holes gain mass as the universe expands and thereby act as dark energy. Using 12 bright JWST-detected AGNs hosted by red-sequence elliptical galaxies at redshifts 2.0 to 7, it compares their black hole masses with the local $M_{\\star}$–$M_{\\rm BH}$ relation. The fit gives a cosmological coupling strength $k=0.13\\pm0.27$, consistent with no coupling and incompatible with the $k=3$ needed for dark energy at about 11 $\\sigma$. The paper also simulates the evolution of little red dots and finds they naturally become the red-sequence ellipticals with low-mass black holes seen at $z\\sim0.7$–$2.5$. If right, the dark-energy origin of black holes is dead, and these high-redshift systems have an ordinary astrophysical explanation.","feed_headline":"JWST black holes kill dark-energy coupling at 11 sigma","feed_subtitle":"Twelve high-redshift elliptical hosts show black holes that do not grow with the universe; little red dots fill their ancestry.","key_machinery":"The load-bearing object is the local black-hole-mass versus stellar-mass fundamental plane for red-sequence ellipticals, $\\log_{10}(M_{\\rm BH}/M_\\odot)=8.66+1.32\\,\\log_{10}(M_{\\star}/10^{11}M_\\odot)$, used as a no-coupling baseline, together with a Gaussian likelihood that puts a redshift-dependent $k\\log(1+z)$ term into the expected black-hole mass. The second mechanism is a Monte Carlo evolution simulation: mock little red dots drawn from JWST-observed stellar masses, black-hole masses, star-formation rates, and accretion rates are grown from $z\\sim6$ to $z\\sim0.85$ with quenched star formation and constant low accretion, reproducing the observed samples at $z\\approx1.61$ and $z\\approx0.85$.","core_discovery":"The central claim is that black holes in massive, quiescent elliptical galaxies have not grown with cosmic expansion: the coupling strength is $k=0.13\\pm0.27$, i.e., consistent with $k=0$ and rejected at about $11\\sigma$ relative to the $k=3$ required for a dark-energy source. The evidence is the location of 12 AGN host galaxies at $z=2.09$–$6.77$ on the local black-hole-mass versus stellar-mass plane; under $k=3$ their black holes should sit far below the observed masses. A Monte Carlo likelihood using the local fundamental plane with intrinsic scatter yields the bound. In a second step, the paper argues that little red dots—compact, red, low-accretion-rate AGNs at $z\\sim5$–$8$—can grow, quench, and accrete slowly into exactly the red-sequence ellipticals with relatively low-mass black holes previously used to claim $k\\approx3$, so no cosmological coupling is needed.","pith_inferences":["The quoted $11\\sigma$ assumes the 12 detected AGNs are an unbiased sample of all massive red-sequence ellipticals at these redshifts; a flux-limited selection could in principle reject $k=3$ even if the coupling were real, because $k=3$ predicts black holes fainter than the detection threshold.","A testable extension is to model the survey selection function and redo the likelihood; if the selection correction moves $k$ upward, the decisive constraint could weaken.","The little-red-dot simulation keeps accretion rates roughly constant and quenches star formation after $z\\approx1.6$; X-ray stacking of the presumed descendants at $z\\approx1$ could check whether that accretion assumption holds.","The same data could constrain other redshift-dependent growth laws, like Eddington-limited accretion histories, separating ordinary accretion from cosmological coupling."],"forward_implications":["At $k=0.13\\pm0.27$, cosmologically coupled stellar-remnant black holes cannot supply the measured dark-energy density; another mechanism must drive cosmic acceleration.","The apparent growth of black holes in the earlier red-sequence sample is reinterpreted as an evolutionary track from little red dots rather than cosmological coupling, so those data no longer support $k\\approx3$.","Future space-telescope samples of quiescent ellipticals at $z>2$ should continue to follow the no-coupling plane, with scatter dominated by intrinsic scatter rather than redshift evolution.","Little red dots at $z\\approx5$–$8$ become viable progenitors for the relatively low-mass black holes seen in massive ellipticals at $z\\approx0.7$–$2.5$, with growth driven by sustained low-level accretion."],"supporting_citations":[{"why":"Defines the red-sequence elliptical selection criteria and the mass-growth signal this paper reinterprets as little-red-dot evolution.","marker":"[16]"},{"why":"Introduces the cosmological coupling law with strength k and the k=3 dark-energy hypothesis being tested.","marker":"[17]"},{"why":"Provides the fundamental-plane relation, the likelihood function, and the earlier high-redshift JWST test that this work extends.","marker":"[37]"},{"why":"Supplies one of the highest-redshift quasar black-hole mass and host stellar mass measurements used in the fit.","marker":"[47]"},{"why":"Supplies the observed JWST little-red-dot stellar masses, black-hole masses, and accretion-rate relations used as initial conditions in the simulation.","marker":"[50]"},{"why":"Provides black-hole and host stellar masses for several z>5 quasars in the selected sample.","marker":"[51]"},{"why":"Provides a z about 4.1 AGN host stellar mass and black-hole mass used in the fit.","marker":"[54]"},{"why":"Provides black-hole and host stellar masses for several z about 6.5 quasars in the selected sample.","marker":"[58]"},{"why":"Supplies the z about 2.1 quasar COS-XQG1 measurement that anchors the lower-redshift end of the sample.","marker":"[59]"}],"fun_headline_variants":["Black holes do not grow with universe, 11 sigma","Dark energy from black holes ruled out at 11 sigma","JWST finds black holes static, not driving cosmic expansion","Little red dots evolve into massive ellipticals, no dark energy","Black hole coupling dead: 11 sigma kill shot"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the 12 JWST-selected AGNs fairly represent black holes in massive red-sequence ellipticals at these redshifts: that detection is not biased toward a particular black-hole mass range, the hosts are truly quiescent with constant stellar mass, and the virial black-hole masses carry no systematic offset relative to the local relation.","fun_headline_variants_meta":{"raw":{"variants":["Black holes do not grow with universe, 11 sigma","Dark energy from black holes ruled out at 11 sigma","JWST finds black holes static, not driving cosmic expansion","Little red dots evolve into massive ellipticals, no dark energy","Black hole coupling dead: 11 sigma kill shot"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000683,"raw_usage":{"total_tokens":3105,"prompt_tokens":953,"completion_tokens":2152,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":569,"completion_tokens_details":{"reasoning_tokens":2071}},"tokens_in":569,"tokens_out":2152,"duration_ms":14161,"temperature":1.0,"reasoning_tokens":2071,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-15T18:31:52.551167+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"A complete sample of quiescent ellipticals at z>2 selected by host stellar mass rather than AGN luminosity, with black-hole masses measured from rest-frame optical lines, should show whether the M_star–M_BH relation tracks k=3 once selection is accounted for. If the inferred coupling returns to about k=3 under that selection function, the 11-sigma rejection fails; if it stays near k=0, the claim stands.","supporting_citations":[{"cited_title":"A Preferential Growth Channel for Supermassive Black Holes in Elliptical Galaxies at z<2","cited_arxiv_id":"2212.06854","evidence_quote":"Defines the red-sequence elliptical selection criteria and the mass-growth signal this paper reinterprets as little-red-dot evolution."},{"cited_title":"The dashed contours in black, blue and red show our simulated LRDs redshiftz∼6,z∼1.61 and z∼0.85","cited_arxiv_id":null,"evidence_quote":"Introduces the cosmological coupling law with strength k and the k=3 dark-energy hypothesis being tested."},{"cited_title":"JWST observations constrain the time evolution of fine structure constants and dark energy - electromagnetic coupling","cited_arxiv_id":"2411.08774","evidence_quote":"Supplies one of the highest-redshift quasar black-hole mass and host stellar mass measurements used in the fit."}],"review_version":2}