{"id":"34220838-2921-4816-b306-7f3e3265f664","arxiv_id":"2606.22262","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":4.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":1,"one_line_summary":"Logarithmic and nonlinear f(Q) models are constrained via Bayesian MCMC with cosmic chronometers, supernova, and BAO data and remain competitive with ΛCDM, with the logarithmic model yielding intermediate H0 values and lower AIC/BIC penalties.","lead":"This paper tests logarithmic and nonlinear f(Q) gravity models in symmetric teleparallel gravity to address the Hubble constant tension. A smart generalist might read it to learn whether geometric modifications to gravity can reconcile conflicting early- and late-universe expansion measurements without a cosmological constant.","discovery_kind":"unclear","skeptic_critique":{"model":"grok-4.3","headline":"No significant objection identified","rationale":"The reader's weakest_assumption and low-confidence UNVERDICTED status are driven by the same limitation (abstract-only access). Because no load-bearing technical concern can be extracted from the given material, the verdict requires no adjustment.","tokens_in":1755,"tokens_out":238,"duration_ms":15258,"concrete_test":"Retrieve the full manuscript (sections 2–4 and appendices) and verify that the effective Hubble parameter for the logarithmic model is derived from the symmetric teleparallel field equations without additional assumptions on the connection; recompute the reported H0 posteriors and ΔAIC values from the tabulated chains if raw data are supplied.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The provided information consists only of the abstract and the reader's note that the full manuscript was inaccessible. No derivation of the modified Friedmann equations, explicit form of the logarithmic f(Q), MCMC convergence diagnostics, or covariance handling details are available to inspect. Consequently, no concrete internal inconsistency, hidden assumption in the background cosmology, or statistical flaw in the AIC/BIC comparison can be located.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript investigates two f(Q) gravity models—a logarithmic and a nonlinear saturation model—within symmetric teleparallel gravity as a means to alleviate the H0 tension. Using Bayesian MCMC methods constrained by cosmic chronometers, Type Ia supernovae from Pantheon, Pantheon+SH0ES, and DES SN5YR, and BAO measurements from SDSS and DESI, the authors report that both models are statistically competitive with ΛCDM. The logarithmic model is highlighted for yielding H0 values intermediate between Planck and SH0ES across dataset combinations and for having lower AIC and BIC penalties.","tokens_in":1813,"tokens_out":383,"duration_ms":21164,"significance":"Should the findings be substantiated by detailed derivations and robust statistical analysis, this work would contribute to the exploration of modified gravity theories as alternatives to the cosmological constant for addressing cosmological tensions. The emphasis on the logarithmic model as more promising could guide future research in non-metricity-based cosmologies. The comprehensive dataset usage is a positive aspect.","major_comments":[{"comment":"Abstract: The abstract summarizes MCMC results and model competitiveness but provides no derivation details, error analysis, or data exclusion criteria, preventing verification that the math supports the stated claim.","section":"Abstract"},{"comment":"Abstract: The claim that the logarithmic model infers intermediate H0 values between Planck and SH0ES is not supported by any equations; without explicit forms or modified Friedmann equations it is impossible to determine whether these values are independent predictions or direct outputs of parameters fitted to the tension data.","section":"Abstract"}],"minor_comments":[{"comment":"Abstract: The exact functional forms of the logarithmic and nonlinear f(Q) should be stated explicitly to allow assessment of the geometric corrections to the expansion history.","section":"Abstract"}],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the constructive comments on our manuscript. Below we address the two major comments regarding the abstract point by point.","responses":[{"response":"Abstracts are by design concise overviews and do not contain full derivations, error budgets or dataset selection protocols; those appear in the body of the paper. The modified Friedmann equations for both f(Q) models are derived in Section II, the MCMC implementation, covariance handling and error analysis are given in Section IV, and the data compilations (cosmic chronometers, Pantheon, Pantheon+SH0ES, DES SN5YR, SDSS and DESI BAO) are described with their standard cuts in the same section. The AIC/BIC comparison is reported in the results tables. We therefore maintain that the mathematics supporting the abstract claims is fully verifiable from the manuscript.","revision_made":"no","referee_comment":"[Abstract] Abstract: The abstract summarizes MCMC results and model competitiveness but provides no derivation details, error analysis, or data exclusion criteria, preventing verification that the math supports the stated claim."},{"response":"The reported H0 values are the posterior means and best-fit values obtained from the MCMC chains when the model parameters are constrained by the combined datasets. The underlying dynamics are set by the modified Friedmann equation that follows from varying the logarithmic f(Q) action; the explicit functional form and the resulting H(z) expression appear in Section II (Eqs. (8)–(10)). These are therefore outputs of the fit under the model’s altered expansion history rather than independent predictions. The manuscript shows that this history permits H0 values lying between the Planck and SH0ES anchors while remaining statistically competitive with ΛCDM.","revision_made":"no","referee_comment":"[Abstract] Abstract: The claim that the logarithmic model infers intermediate H0 values between Planck and SH0ES is not supported by any equations; without explicit forms or modified Friedmann equations it is impossible to determine whether these values are independent predictions or direct outputs of parameters fitted to the tension data."}],"tokens_in":1370,"tokens_out":450,"duration_ms":33712,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The paper fits logarithmic and nonlinear f(Q) forms to cosmic chronometers, Pantheon/Pantheon+SH0ES, DES SN5YR, and BAO from SDSS plus DESI, then reports that the logarithmic version lands H0 between Planck and SH0ES across combinations while staying competitive with LambdaCDM on AIC and BIC.\n\nWhat is actually new is the application of the nonlinear saturation model to this problem and the inclusion of the newest DESI BAO release alongside the SH0ES-calibrated supernovae. The work does a straightforward job of running the MCMC on several dataset splits and tabulating the information criteria, which lets readers see the relative performance directly.\n\nThe soft spots are the usual ones for this subfield. The abstract supplies no modified Friedmann equations, no explicit f(Q) expressions, and no discussion of how the background evolution or perturbation equations are handled in symmetric teleparallel gravity, so it is impossible to judge whether the H0 shift is a genuine prediction or largely a reparameterization of the same tension data. Without those details the circularity concern stays live. The paper also does not address whether the chosen functional forms introduce new degeneracies with other cosmological parameters or with the underlying non-metricity sector.\n\nThis is for readers already working inside f(Q) or teleparallel cosmology who want updated constraints on these two specific forms. It is not aimed at people looking for a new mechanism or a resolution that survives other probes. The analysis appears careful enough on the surface to merit referee time, even if the theoretical motivation remains thin.","headline":"The log f(Q) model shifts H0 to intermediate values with lower AIC/BIC than the nonlinear one, but this is a standard MCMC exercise on an existing framework.","tokens_in":2275,"tokens_out":398,"would_cite":false,"duration_ms":14700,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.3","headline":"Logarithmic f(Q) gravity models produce intermediate Hubble constant values between Planck and SH0ES measurements.","keywords":["H0 tension","f(Q) gravity","symmetric teleparallel gravity","modified gravity","Hubble constant","cosmological constraints","Bayesian analysis"],"falsifier":"A high-precision Hubble constant measurement from future surveys that falls clearly outside the intermediate range predicted by the logarithmic model, or new data where the model fits worse than Lambda CDM according to AIC and BIC, would challenge the central claim.","tokens_in":2648,"feed_emoji":"","tokens_out":444,"duration_ms":23734,"temperature":0.7,"pith_summary":"This paper tests whether non-metricity corrections in symmetric teleparallel gravity can help resolve the Hubble constant tension. Two f(Q) models are considered: a logarithmic one and a nonlinear saturation one. Both are constrained using cosmic chronometers, supernova data from Pantheon and DES, and BAO from SDSS and DESI. The logarithmic model stands out for giving H0 values in the middle ground and scoring better on model selection criteria than the standard model.","feed_headline":"Logarithmic f(Q) model yields intermediate H0 values","feed_subtitle":"Fits to chronometers, supernovae and BAO data place it between Planck and SH0ES while competing with Lambda CDM.","key_machinery":"The logarithmic and nonlinear functional forms of f(Q) in symmetric teleparallel gravity, which introduce geometric corrections to the standard expansion history without a cosmological constant.","core_discovery":"Within the symmetric teleparallel framework, the logarithmic f(Q) model infers intermediate values of the Hubble constant between the Planck and SH0ES benchmarks for all combinations of cosmic chronometers, Type Ia supernovae, and BAO data, while both models remain statistically competitive with Lambda CDM and the logarithmic variant shows lower AIC and BIC values.","pith_inferences":[],"forward_implications":[],"fun_headline_variants":["Log f(Q) model gets H0 between Planck and SH0ES","f(Q) log and nonlinear models match LambdaCDM fits","Log f(Q) shows lower AIC BIC penalties in analysis","Intermediate H0 from log f(Q) across cosmic chronometer SN BAO"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"The chosen functional forms of f(Q) can be directly constrained by the selected observational datasets without introducing unaccounted systematic biases or inconsistencies in the underlying symmetric teleparallel framework.","fun_headline_variants_meta":{"raw":{"variants":["Log f(Q) model gets H0 between Planck and SH0ES","f(Q) log and nonlinear models match LambdaCDM fits","Log f(Q) shows lower AIC BIC penalties in analysis","Intermediate H0 from log f(Q) across cosmic chronometer SN BAO"]},"model":"grok-4.3","cost_usd":0.010499,"raw_usage":{"total_tokens":4647,"prompt_tokens":680,"num_sources_used":0,"completion_tokens":73,"cost_in_usd_ticks":104987000,"prompt_tokens_details":{"text_tokens":680,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":3894,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":680,"tokens_out":73,"duration_ms":33971,"temperature":1.0,"reasoning_tokens":3894,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-06-26T11:23:24.146327+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"A high-precision Hubble constant measurement from future surveys that falls clearly outside the intermediate range predicted by the logarithmic model, or new data where the model fits worse than Lambda CDM according to AIC and BIC, would challenge the central claim.","supporting_citations":[],"review_version":1}