{"id":"4749802c-2cab-45af-a72a-e4b5aa0f3f4b","arxiv_id":"2507.13698","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":4.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":1,"one_line_summary":"No significant GeV-neutrino excess was found in a +/-500 s window around 178 compact binary mergers observed by LIGO/Virgo/KAGRA, so new upper limits on the neutrino flux were set.","lead":"Scientists searched for very low-energy neutrinos from 178 gravitational-wave-detected black hole and neutron star mergers using IceCube's DeepCore array. They found no signal and set new upper limits on how many GeV neutrinos these mergers could emit.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The null detection is plausible, but the quantitative upper limits rest on an unstated background model and a companion reference whose arXiv ID (2105.13160) is inconsistent with a 2025 O4a paper; the limits cannot be verified as submitted.","rationale":"I read the paper as a proceedings summary of a null search. The headline result—no statistically significant excess and upper limits—is internally consistent: the best pre-trial p-value of 0.25% with 178 trials yields a 40% post-trial p-value, and the binomial subpopulation test has p=81%. Nothing in the text suggests a computational error. The weakest point is that every quantitative output (p-values and limits) depends on the ELOWEN background expectation, and the paper neither presents a background model nor a systematic uncertainty. The single pointer to these details is reference [8], whose arXiv ID (2105.13160) is inconsistent with the stated 2025 publication and with an analysis covering O4a data. This is not an ad hominem or a disagreement with consensus; it is a verifiability gap. A null result with large post-trial p-values is robust to modest background errors, so I do not think the non-detection is threatened. However, the upper limits in Figure 1 are a quantitative scientific claim, and if the background normalization or its time variation is wrong by more than the quoted range, those limits would be systematically shifted. The reader's verdict of CONDITIONAL is therefore appropriate: the paper should be accepted only with either a corrected, accessible companion citation or a brief summary of the background treatment. My stress-test does not require a different verdict, hence UNCHANGED.","tokens_in":8468,"tokens_out":7723,"duration_ms":87957,"concrete_test":"Retrieve the companion paper at arXiv:2105.13160 and verify that it actually presents the ELOWEN O1-O4a analysis, including the background model, time-variation/systematics, and the exact limit calculation used in Figure 1. If the reference is correct, recompute the best pre-trial p-value and the Figure 1 limits using off-time ELOWEN data in 1000-s windows displaced from each GW time; require that the result reproduces the quoted numbers and that the limits shift by less than the 20% background spread before endorsing the limits.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim is a non-detection with upper limits. For that claim to stand, the ELOWEN background rate of about 20-25 mHz must be correct and stable over the full 2015-2024 dataset, and the limit calculation must use a defensible background model. The paper gives only the rate, no model or time-variation study, and defers all details to reference [8]. That reference is cited as 'arXiv (2025) [2105.13160]'; an ID of 2105.xxxxx corresponds to a May 2021 submission, which cannot be a 2025 paper describing O4a results. If [8] is an older or unrelated paper, the O4a analysis is effectively unavailable, and the quoted pre-trial p-value (0.25%) and the Figure 1 90% CL limits cannot be checked. Because background systematics propagate directly into both the post-trial p-values and the flux limits, the 'about 20-25 mHz' spread alone implies at least a 20% normalization uncertainty, and no study is shown to rule out larger time-dependent variations over nine observing years. This does not overturn the null result (post-trial p=40% is far from significant), but it leaves the quantitative upper limits unsupported by the submitted text.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This proceedings contribution reports a search for GeV neutrinos from compact binary mergers using the IceCube-DeepCore ELOWEN event selection. The search covers 178 mergers from LIGO/Virgo/KAGRA O1 through O4a, using ±500 s windows around each gravitational-wave time and an additional [t_GW, t_GW+3 s] window for mergers involving neutron stars. The authors report no statistically significant excess: the best pre-trial p-value is 0.25% (S230707ai), the post-trial p-value is 40%, and a binomial subpopulation test yields 81%. They present 90% upper limits on the all-flavour neutrino flux for E^-2, E^-2.5, and E^-3 spectra, with the E^-2 limits shown in Figure 1 against GRECO and GFU results. All methodological details are deferred to a related publication [8].","tokens_in":8717,"tokens_out":4285,"duration_ms":43355,"significance":"If the quoted numbers are correct, this is a useful null measurement in an unexplored energy regime: it places GeV-range constraints on neutrino emission from compact binary mergers and complements higher-energy IceCube searches. The paper's strengths are its clearly stated p-values and limits, its use of external gravitational-wave catalogs (no circularity), and the explicit comparison of complementary event selections in Figure 1. Its main limitation is that none of the statistical machinery—background model, trial factors, limit construction, or systematics—is present in the submitted text, and the reference that is supposed to supply these details is cited with an internally inconsistent arXiv identifier. The central null result (post-trial p-value 40%) is plausible, but the quantitative upper limits cannot be verified as submitted.","major_comments":[{"comment":"All statistical details are deferred to reference [8], cited as 'arXiv (2025) [2105.13160]'. An arXiv identifier of the form 2105.xxxxx corresponds to a May 2021 submission, which cannot be a 2025 paper describing O4a results (O4a ends January 2024). Because the paper contains no other description of the background model, trial correction, or limit-setting procedure, the quoted pre-trial/post-trial p-values (0.25%, 40%, 81%) and the 90% limits in Figure 1 cannot be checked from the submitted manuscript. The reference must be corrected and, if it is indeed a different paper, the methods must be summarized in this manuscript or the analysis must be made available.","section":"References, ref. [8]"},{"comment":"The only background information given is that ELOWEN has a 'background rate of about 20−25 mHz'. Both the p-values and the upper limits scale directly with this rate, yet no background model, time-variation study, or systematic uncertainty is presented. Over the 2015–2024 span of O1–O4a, detector conditions and noise can change substantially; the stated 20–25 mHz spread alone implies an approximate 20% normalization uncertainty. The manuscript should either report how this uncertainty propagates into the final limits or provide a verifiable reference to a background model.","section":"Analysis, ELOWEN background rate"},{"comment":"The text reports the best pre-trial p-value (0.25%) and the corresponding post-trial p-value (40%) but does not define the test statistic, the background-only distribution, or the trial factor. Similarly, the binomial subpopulation test yielding 81% is not defined. These definitions are needed to interpret the central null claim; if they are only in reference [8], the proceedings should at least state the test statistic and the number of trials.","section":"Analysis, p-value procedure"}],"minor_comments":[{"comment":"The energy range is written as '0.5-–5 GeV' in the abstract and introduction; this appears to contain a stray extra dash and should be '0.5–5 GeV'.","section":"Abstract and Introduction"},{"comment":"The phrase 'the GRECO Astronomy [3]' should read 'the GRECO analysis [3]' or 'the GRECO sample [3]'; GRECO is the name of the event sample, not an astronomical facility.","section":"Analysis"},{"comment":"The axis label 'E2F(E)' should use a superscript for the squared energy, e.g., \\(E^2 F(E)\\), and the caption's 'all−flavour' contains a minus sign where a hyphen is intended.","section":"Figure 1 caption"},{"comment":"The text states upper limits are at '90% credible level' but elsewhere uses 'upper limits'; the Bayesian versus frequentist nature of the interval should be clarified, or the terminology aligned.","section":"Analysis"}],"recommendation":"major_revision","confidential_remarks":"The inconsistent arXiv identifier in [8] is a red flag that must be resolved by the editors before publication. This is a proceedings paper, so the absence of full methods is not surprising, but the companion reference is the only route to verification, and it is currently not a valid citation. I recommend requesting the corrected reference and a brief statistical description (test statistic, background model, trial factor) in the text."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"This is a null-result proceedings from IceCube: no GeV neutrinos from 178 compact binary mergers, with 90% upper limits in a new 0.5–5 GeV window. That is a legitimate, modest step for multi-messenger astronomy, and the numbers in the text are internally consistent.\n\nWhat's new is straightforward: they apply the ELOWEN DeepCore selection to O1–O4a GW events, add the O4a sample, and report limits for E^-2, E^-2.5, and E^-3 spectra. The best single event has a pre-trial p-value of 0.25%, a post-trial p-value of 40%, and a binomial test gives 81%. No evidence, and that is believable and matches the figure.\n\nThe soft spot is that this proceedings gives almost no statistical machinery. The ELOWEN background rate is \"about 20–25 mHz\" with no model or time-variation study, and the paper explicitly defers methods to reference [8]. That reference is cited as arXiv (2025) [2105.13160], which cannot be right: 2105 is May 2021. So the quantitative upper limits in Figure 1 are not verifiable from the submitted text. The null result itself is robust—even a 20% background normalization error would not turn post-trial p=40% into a discovery—but the limits would shift, and the reader cannot check them.\n\nI do not see circularity: they use external GW catalogs and a fixed event selection; the limits come from counts. The citation error needs fixing, and the companion paper needs to exist and be referenced correctly. For a proceedings, deferring details is normal, but the reference mismatch is sloppy.\n\nWho is this for? People tracking neutrino–GW multi-messenger limits, especially the GeV gap between GRECO and GFU. It is a useful data point, not a breakthrough. I would accept it for peer review because the underlying search is serious and the result is worth having, but the authors must correct the reference and make the companion paper available.","headline":"A believable null result for GeV neutrinos from binary mergers, but the proceedings text lacks the statistical detail to verify the quoted limits, and the companion reference is mis-cited.","tokens_in":9308,"tokens_out":2218,"would_cite":true,"duration_ms":24963,"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":"The paper searches for GeV neutrinos in 500-second windows around 178 compact binary mergers and finds no excess, setting 90% upper limits on the all-flavour flux.","keywords":["neutrino astronomy","compact binary mergers","gravitational waves","GeV neutrinos","IceCube-DeepCore","ELOWEN","upper limits","multi-messenger astronomy"],"falsifier":"Run the same ELOWEN search on the next set of gravitational-wave detections with the background rate measured independently in adjacent off-source windows; an event whose post-trial p-value is below 1% after the full trial correction, or a measured background drift outside the quoted 20–25 mHz range, would contradict the paper's claim of no excess.","tokens_in":8313,"feed_emoji":"🔭","tokens_out":10706,"duration_ms":115591,"temperature":0.7,"pith_summary":"Compact binary mergers detected in gravitational waves are candidate sources of GeV neutrinos, which could be produced when protons and neutrons collide in the merger environment. The paper searches for such neutrinos with the ELOWEN sample, a low-energy event selection from the dense central part of the IceCube detector, checking for an excess in a ±500-second window around each of 178 mergers detected from 2015 through January 2024. It finds no statistically significant excess: the most promising event, S230707ai, has a 0.25% pre-trial p-value that becomes 40% after accounting for trials, and a binomial test for a subpopulation of neutrino-emitting mergers returns 81%. With no signal, the paper sets 90% upper limits on the all-flavour neutrino flux for $E^{-\\gamma}$ spectra with $\\gamma = 2$, 2.5, and 3. If the result stands, the GeV neutrino emission from these mergers is too faint to be seen by this selection.","feed_headline":"No GeV neutrino excess from 178 binary mergers","feed_subtitle":"A 500-second search around gravitational-wave detections finds only background; new 90% flux limits follow.","key_machinery":"The central object is the Extremely-LOW-ENergy (ELOWEN) sample: clusters of hits in DeepCore, the dense inner sub-volume of the IceCube Neutrino Observatory, selected with a background rate of about 20–25 mHz and primary sensitivity to neutrinos in the 0.5–5 GeV range. The search counts ELOWEN events in $\\pm 500$ s windows centred on each gravitational-wave time $t_{\\rm GW}$, with an additional window $[t_{\\rm GW}, t_{\\rm GW}+3\\,{\\rm s}]$ for mergers involving at least one neutron star, motivated by the observed delay between GW170817 and GRB 170817A. Significance is judged by pre-trial and trial-corrected post-trial p-values for the most promising window, and limits are computed as 90% credible upper bounds on the flux normalisation $\\phi$ in $F(E)=\\phi (E/{\\rm GeV})^{-\\gamma}$.","core_discovery":"On the paper's own terms, the central result is a null measurement: in the ELOWEN sample, none of the 178 compact binary mergers observed by the gravitational-wave detectors between O1 and O4a shows a GeV neutrino excess above the expected background. The best single-event candidate, S230707ai, has a pre-trial p-value of 0.25%, but the post-trial p-value is 40%, so the candidate is consistent with background. The subpopulation search, a binomial test, gives a post-trial p-value of 81%. The paper therefore reports 90% credible upper limits on the all-flavour time-integrated flux at Earth for power-law spectra with spectral indices 2, 2.5, and 3, and displays the $\\gamma=2$ limits together with the higher-energy GRECO and GFU searches.","pith_inferences":["One inference the authors do not draw is that the two highlighted binary neutron star mergers, GW170817 and GW190425, are the natural benchmarks for future GeV-neutrino searches because their nearby distances make them the most promising targets.","A stacked search that sums ELOWEN counts over all neutron-star mergers, rather than testing each event individually, would likely improve sensitivity and could expose a weak cumulative signal that the current per-event analysis treats as background.","If the ELOWEN background rate at 20–25 mHz is representative, a single merger would need to produce a large prompt neutrino flare to be seen, so the null result suggests that any prompt GeV emission is either rare or below the current trigger threshold, a statement that can be compared with theoretical models of proton–proton emission."],"forward_implications":["The 90% credible upper limits bound the all-flavour neutrino flux at Earth under $E^{-2}$, $E^{-2.5}$, and $E^{-3}$ power-law spectra, constraining hadronic GeV emission from compact binary mergers.","The null result extends merger-neutrino searches into the 0.5–5 GeV band, complementing the GRECO and GFU searches at higher energies.","The binomial subpopulation test finding a post-trial p-value of 81% leaves no evidence that a particular class of the analysed mergers is a regular GeV neutrino emitter.","As the paper notes, combining ELOWEN with other IceCube samples in joint analyses would tighten constraints on the neutrino energy distribution and could reveal production mechanisms that single-band searches miss."],"supporting_citations":[{"why":"Defines DeepCore, the dense inner sub-volume whose hit-cluster selection yields the ELOWEN sample.","marker":"[6]"},{"why":"Describes the IceCube detector and online systems used to record the neutrino candidates.","marker":"[7]"},{"why":"The related paper holding the full method, background model, and detailed results referenced by this contribution.","marker":"[8]"},{"why":"GWTC-1 catalogue providing the O1 and O2 merger events used in the search.","marker":"[9]"},{"why":"GWTC-2 catalogue providing the first half of O3 merger events.","marker":"[10]"},{"why":"GWTC-2.1 catalogue refining the O3a event list.","marker":"[11]"},{"why":"GWTC-3 catalogue providing the second part of O3 merger events.","marker":"[12]"},{"why":"Multi-messenger observations of GW170817 that motivate the short 3-second window for neutron-star mergers.","marker":"[13]"},{"why":"GRECO GeV–TeV search whose upper limits are compared with the ELOWEN limits in Figure 1.","marker":"[3]"},{"why":"GFU TeV–PeV search whose upper limits complement the ELOWEN energy range in Figure 1.","marker":"[14]"}],"fun_headline_variants":["IceCube finds no GeV neutrinos from 178 binary mergers","Null result: no GeV neutrino burst from compact binary mergers","178 compact binary mergers show no GeV neutrino excess","GeV neutrino search around mergers yields only background","Upper limits set on GeV neutrinos from 178 mergers"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The calculation assumes the ELOWEN background rate, stated as about 20–25 mHz, is stable and correctly known across the full 2015–2024 observing period; if the rate drifts with detector conditions, the p-values and upper limits move with it.","fun_headline_variants_meta":{"raw":{"variants":["IceCube finds no GeV neutrinos from 178 binary mergers","Null result: no GeV neutrino burst from compact binary mergers","178 compact binary mergers show no GeV neutrino excess","GeV neutrino search around mergers yields only background","Upper limits set on GeV neutrinos from 178 mergers"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.00023,"raw_usage":{"total_tokens":1455,"prompt_tokens":893,"completion_tokens":562,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":509,"completion_tokens_details":{"reasoning_tokens":484}},"tokens_in":509,"tokens_out":562,"duration_ms":6309,"temperature":1.0,"reasoning_tokens":484,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-06T16:18:16.479462+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Run the same ELOWEN search on the next set of gravitational-wave detections with the background rate measured independently in adjacent off-source windows; an event whose post-trial p-value is below 1% after the full trial correction, or a measured background drift outside the quoted 20–25 mHz range, would contradict the paper's claim of no excess.","supporting_citations":[{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Defines DeepCore, the dense inner sub-volume whose hit-cluster selection yields the ELOWEN sample."}],"review_version":1}