{"id":"aa71be33-f7dd-48ba-ab65-bcc2a2e9be16","arxiv_id":"2606.13383","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":5.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"In a 2D gravitational collapse model, late-time multi-time correlations in Hawking radiation depend on pre-collapse parameters and are not reproduced by the Unruh vacuum.","lead":"This paper shows that multi-time quantum field correlations during black hole evaporation retain explicit dependence on the pre-collapse state in a 2D model, even as single-time radiation remains thermal. A smart generalist might read it to understand whether the information paradox requires rethinking observables beyond single-time measurements.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.3","headline":"Two-dimensional model sufficiency for generalizing multi-time correlation results to realistic 4D black hole physics","rationale":"The reader's weakest assumption directly identifies the same load-bearing point. The abstract-only review correctly flags the 2D-to-realistic extrapolation as the key unverified step; the full-text calculation, while presumably internally consistent within 2D, does not alter this gap. No other internal inconsistency (e.g., in the definition of multi-time correlators or Unruh comparison) is evident from the provided claim structure.","tokens_in":1635,"tokens_out":335,"duration_ms":14083,"concrete_test":"Extract the explicit form of the late-time multi-time correlator from the 2D calculation (e.g., the term depending on pre-collapse parameters) and recompute its analogue in a 4D semiclassical setup with the same initial state parameters; if the extra-dimensional contributions cancel the pre-collapse dependence, the claim does not generalize.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim is that late-time multi-time correlations contain explicit pre-collapse state dependence not captured by the Unruh vacuum, shown via a 2D gravitational collapse/evaporation model. This is used to argue that single-time observables are insufficient for the information paradox. The load-bearing step is the implicit assumption that the 2D result (likely in a CGHS-type or dilaton model) captures the relevant correlation structure without being altered by 4D-specific features such as angular modes, grey-body factors, or backreaction details that could restore effective thermality in multi-time functions at late times.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript claims that in a two-dimensional model of gravitational collapse and evaporation, late-time multi-time quantum-field correlations are not fully reproduced by the Unruh vacuum. In particular, they contain an explicit contribution depending on parameters of the pre-collapse state, despite the thermal character of the asymptotic radiation. This is used to argue that single-time observables are insufficient to formulate the black hole information paradox.","tokens_in":1724,"tokens_out":269,"duration_ms":21027,"significance":"If substantiated by the derivation in the 2D model, the result would identify multi-time correlations as a concrete mechanism for pre-collapse information survival in Hawking radiation. This could require reformulating the information paradox to account for temporal quantum correlations beyond thermality constraints on single-time observables.","major_comments":[{"comment":"The load-bearing step is the implicit assumption that the two-dimensional model (CGHS-type or dilaton gravity) captures the relevant multi-time correlation structure without alteration by four-dimensional features. The manuscript does not analyze how angular modes, grey-body factors, or backreaction details might restore effective thermality in multi-time functions at late times. This directly affects the generalization to realistic black hole physics.","section":null}],"minor_comments":[],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for their careful reading of the manuscript and for raising this important point about the scope of our two-dimensional model. We address the comment below and will revise the manuscript to strengthen the discussion of its limitations.","responses":[{"response":"We agree that the manuscript performs its explicit calculations in a two-dimensional dilaton-gravity model and does not contain an analysis of four-dimensional corrections such as angular modes, grey-body factors, or detailed backreaction effects on multi-time correlators. The central claim is therefore limited to the 2D setting: within this controlled model, late-time multi-time correlations retain an explicit dependence on pre-collapse parameters even though the single-time radiation is thermal. Two-dimensional models have long been used to isolate mechanisms relevant to the information paradox, and our result identifies one such mechanism. We do not assert that the quantitative structure is identical in 4D. In the revised manuscript we will add a new paragraph in the discussion section that explicitly acknowledges these limitations, states that 4D features could in principle modify the multi-time functions, and clarifies that the qualitative conclusion—that thermality of single-time observables does not preclude information-carrying temporal correlations—remains a point worth investigating beyond 2D. This constitutes a partial revision focused on improved caveats rather than new calculations.","revision_made":"partial","referee_comment":"The load-bearing step is the implicit assumption that the two-dimensional model (CGHS-type or dilaton gravity) captures the relevant multi-time correlation structure without alteration by four-dimensional features. The manuscript does not analyze how angular modes, grey-body factors, or backreaction details might restore effective thermality in multi-time functions at late times. This directly affects the generalization to realistic black hole physics."}],"tokens_in":1189,"tokens_out":375,"duration_ms":20312,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The paper shows that in a two-dimensional model of gravitational collapse, late-time multi-time field correlations contain a term that depends on parameters of the pre-collapse state even though the asymptotic radiation remains thermal at single times. This is the concrete claim.\n\nThey do a clean job separating the single-time thermality constraint from the structure of temporal correlations. The abstract states the distinction plainly and frames the multi-time functions as a possible information carrier, which is a reasonable way to look at the problem.\n\nThe soft spot is the two-dimensional restriction. The stress-test note is on target: four-dimensional physics brings angular modes, grey-body factors, and different back-reaction details that could change or erase the extra dependence in the multi-time functions. The paper does not show that the 2D result is robust under those additions, so the step from the model to the information paradox in real black holes remains an assumption.\n\nThe work is for people already thinking about quantum field theory on dynamical backgrounds and the information paradox. A reader who wants to see an explicit calculation that multi-time observables can carry extra data will find something usable here. It deserves a serious referee because the central distinction is coherent and the 2D demonstration can be checked on its own terms even if the four-dimensional extension needs separate work.","headline":"In their 2D collapse model the multi-time correlations pick up explicit pre-collapse dependence that the Unruh vacuum misses, but whether this survives in 4D is left open.","tokens_in":2219,"tokens_out":343,"would_cite":false,"duration_ms":13139,"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":"Late-time multi-time correlations in black hole radiation retain explicit dependence on the pre-collapse state.","keywords":["black hole information paradox","Hawking radiation","multi-time correlations","Unruh vacuum","gravitational collapse","two-dimensional models","quantum field theory in curved spacetime"],"falsifier":"An explicit computation of the same multi-time correlation functions in a four-dimensional evaporating black hole that shows complete agreement with Unruh-vacuum predictions and no residual dependence on pre-collapse parameters would falsify the central claim.","tokens_in":2533,"feed_emoji":"","tokens_out":604,"duration_ms":18057,"temperature":0.7,"pith_summary":"In a two-dimensional model of gravitational collapse and evaporation the asymptotic radiation is thermal for any observable defined at a single time. Multi-time correlation functions, however, contain an additional contribution that depends directly on parameters of the collapsing matter. This structure shows that information about the initial state survives in the temporal relations among successive measurements of the radiation. The finding indicates that standard statements of the information paradox, which rely only on single-time thermality, do not capture the full content of the outgoing field.","feed_headline":"Multi-time correlations carry pre-collapse information in Hawking radiation","feed_subtitle":"In a 2D model, late-time radiation correlations depend explicitly on initial-state parameters even though single-time observables remain the","key_machinery":"Multi-time correlation functions of the quantum field computed in the two-dimensional collapse spacetime, which are compared against the Unruh vacuum predictions.","core_discovery":"Using a two-dimensional model of gravitational collapse and evaporation, late-time multi-time quantum-field correlations are not fully reproduced by the Unruh vacuum. These correlations contain a contribution that depends explicitly on parameters characterizing the pre-collapse state, even though the asymptotic radiation remains thermal for single-time observables.","pith_inferences":["The same distinction between single-time and multi-time observables could be examined in four-dimensional models to test whether the dependence on initial data persists.","Laboratory analogues of black hole evaporation that allow time-resolved measurements might detect analogous correlation signatures.","The result suggests that any complete resolution of the information paradox must incorporate the full temporal structure of the radiation rather than its spectrum alone."],"forward_implications":["Multi-time observables serve as concrete carriers of information in Hawking radiation.","Thermality of single-time quantities does not imply that all information about the collapsing matter is lost.","Formulations of the black hole information paradox that rest solely on single-time observables are incomplete.","Measurable multi-time correlations provide a direct channel for information to reappear in the radiation."],"fun_headline_variants":["Multi-time correlations retain pre-collapse info in radiation","Black hole multi-time correlations depend on initial state","Late-time correlations exceed Unruh vacuum in 2D model","Pre-collapse state affects multi-time radiation correlations"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"The two-dimensional model of collapse and evaporation is sufficient to demonstrate that multi-time correlations carry pre-collapse information in realistic black hole physics.","fun_headline_variants_meta":{"raw":{"variants":["Multi-time correlations retain pre-collapse info in radiation","Black hole multi-time correlations depend on initial state","Late-time correlations exceed Unruh vacuum in 2D model","Pre-collapse state affects multi-time radiation correlations"]},"model":"grok-4.3","cost_usd":0.004142,"raw_usage":{"total_tokens":2049,"prompt_tokens":569,"num_sources_used":0,"completion_tokens":53,"cost_in_usd_ticks":41424500,"prompt_tokens_details":{"text_tokens":569,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":1427,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":569,"tokens_out":53,"duration_ms":7671,"temperature":1.0,"reasoning_tokens":1427,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-06-27T06:56:37.818927+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"An explicit computation of the same multi-time correlation functions in a four-dimensional evaporating black hole that shows complete agreement with Unruh-vacuum predictions and no residual dependence on pre-collapse parameters would falsify the central claim.","supporting_citations":[],"review_version":1}