{"id":"786e7f9c-7479-4e10-8f92-4b0c9f081fdb","arxiv_id":"2607.27819","paper_version":1,"verdict":"REJECT","confidence":"MODERATE","novelty_score":4.0,"correctness_risk":"high","formal_verification":"none","parameter_count":5,"one_line_summary":"In a Vicsek-type model with two non-overlapping heading cones, narrowing the lateral field of view suppresses global order, while front/back asymmetric cones switch flocking between dense bands and homogeneous flow.","lead":"The paper simulates a modified Vicsek model where particles align only with neighbors whose headings fall inside two angular cones, and maps the phase diagram in aperture and orientation. It reports that limiting lateral vision destabilizes global order, forward-facing vision forms dense 'follow-the-leader' bands, and backward-facing vision produces a more homogeneous flock.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Eq. (4) filters on heading differences/sums, not on spatial cone positions; as written it is symmetric, so the claimed non-reciprocal 'partial vision' mechanisms and phase interpretations do not follow from the implemented model.","rationale":"Reader's weakest_assumption identifies the same issue I find load-bearing. Eq. (4) is the only neighbor matrix in the paper, and every conclusion—shifted η_c, dense bands, cross-sea, follow-the-leader, backward-suppressed fluctuations—is interpreted as a consequence of spatial blind spots. The equation's condition on |θ_i±θ_j| instead of on the neighbor displacement angle means the simulated interaction is a heading-similarity filter; it is also symmetric, contradicting the non-reciprocity narrative. The paper includes no code or data deposit, so one cannot determine whether the actual CUDA implementation used Eq. (4) or a spatial rule; but as a scientific text, the claims rest on the stated model. Secondary issues (scalar angle average in Eq. (1), volume-exclusion comparison at different N, no error bars) strengthen the case for rejection but are not needed for it. Because the central mechanism is mis-specified, the REJECT verdict stands. I would keep the verdict unchanged.","tokens_in":14066,"tokens_out":4583,"duration_ms":39766,"concrete_test":"Implement both neighbor rules for the same parameters: (i) Eq. (4) exactly; (ii) the intended spatial-cone rule, e.g. n_ij=1 iff |x_i−x_j|≤R0 and (angle(x_j−x_i)−θ_i mod 2π) lies in [β−α/2,β+α/2] or [π+β−α/2,π+β+α/2]. Run the α=90°, β=45°, η=0.20 case and the α=30°, β=90°, η=0.45 case, comparing polar order ψ(η), density fluctuations σ_ρ^2, and snapshots for the band/cross-sea phases. A cheap analytic check is to verify Eq. (4) gives n_ij=n_ji, which already rules out the claimed non-reciprocal mechanism; if the two rules produce different phases at these points, the paper's central mechanism is the heading filter, not the advertised vision cones.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper's central claim is that two non-overlapping spatial vision cones—lateral blind spots, forward/backward bias—produce the reported phases (cross sea, ultra-dense bands, low-fluctuation flock). The only neighbor rule stated in the manuscript, Eq. (4), does not implement spatial cones. It accepts j as neighbor of i if |x_i−x_j|≤R0 and either |θ_i−θ_j|∈I or |θ_i+θ_j|∈I, with I=[|β−α/2|,|β+α/2|]. This is a filter on heading differences and sums, not on the angle of the displacement vector x_j−x_i relative to θ_i. A genuine spatial cone would require that angle to lie in [β−α/2,β+α/2] or in the opposite sector (shifted by π), for example. Moreover, Eq. (4) is manifestly symmetric under i↔j, so n_ij=n_ji; the paper repeatedly states the interaction matrix is 'not necessary symmetric' and attributes the β-dependent phases to non-reciprocity. As written, no non-reciprocity exists. If the simulations actually used the spatial-cone rule, Eq. (4) is a critical mis-specification; if they used Eq. (4), the biological motivation and the spatial interpretations ('follow-the-leader', backward-biased homogeneous flock) do not follow. Either way the central claim is not supported by the stated model.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper introduces a 'blind spot Vicsek model' with two angular vision cones, parametrized by aperture α and orientation β, and reports extensive simulations showing that restricted lateral vision destabilizes order, produces dense traveling bands, and that forward/backward-biased cones lead to distinct collective phases via claimed non-reciprocal interactions. The authors also study the effect of volume exclusion. The central novelty is the claim that non-overlapping spatial vision cones produce a rich phase diagram, including a cross-sea phase and a low-fluctuation homogeneous flock.","tokens_in":14355,"tokens_out":3850,"duration_ms":36747,"significance":"If the model were implemented as described, the paper would provide a useful exploration of anisotropic perception in Vicsek-type active matter, with large-scale simulations (N≈2×10^5) and systematic phase diagrams. The authors are also appropriately cautious about the tentative hyperuniformity signature and make an effort to connect to experimental realizations. However, the paper's central claim is not supported by the stated model: Eq. (4) does not implement spatial vision cones, and the interaction matrix is symmetric, contradicting the paper's repeated non-reciprocity interpretation. The core mechanisms invoked in the abstract and Sections IV A and IV B therefore do not follow from the equations as written. This is a load-bearing flaw, not a presentation issue.","major_comments":[{"comment":"Eq. (4) defines n_ij using |θ_i − θ_j| ∈ I or |θ_i + θ_j| ∈ I, i.e., conditions on the particles' heading differences and sums. This is not a spatial vision cone rule, which would require the angle of the displacement vector x_j − x_i relative to θ_i to lie in the cone interval. As written, neighbors are selected by heading similarity, not by position in physical space. The entire interpretation in Section IV A (lateral blind spots) and Section IV B (forward- vs backward-biased vision) is therefore not supported by the stated model. Moreover, the condition is symmetric under i↔j, so n_ij = n_ji for every pair; the claim that the interaction matrix is 'intrinsically non-symmetric' (Section II A and repeated throughout) is false as written. This invalidates the mechanism for the β-dependent phases and the 'follow-the-leader' / 'negative feedback' explanations.","section":"II A, Eq. (4)"},{"comment":"The orientation update is a scalar average of angles, θ_i(t+Δt) = (1/N) ∑_j n_ij θ_j(t) + noise, not the vectorial Vicsek alignment θ_i → arg(∑_j e^{iθ_j}) + noise. The scalar average is ill-defined for periodic angles near ±π and introduces an artificial dependence on the total particle number N rather than on the number of neighbors. If this equation was actually implemented, it is a nonstandard variant whose quantitative phase diagram (critical noise, Binder cumulant, density fluctuations) cannot be directly compared with the standard Vicsek results invoked throughout the paper. The authors do not justify this choice or discuss its consequences.","section":"II A, Eq. (1)"},{"comment":"Because Eq. (4) does not implement spatial vision cones, the specific claims that reducing α leads to lateral-only vision and that varying β breaks front-back symmetry are not consequences of the stated model. The 'cross sea' phase in Fig. 2(a) (α=30°, η=0.45) is attributed to 'purely lateral, narrow vision cones,' but the model actually implements a heading-similarity filter. The link to Kürsten & Ihle (Ref. 41) is therefore not established. Similarly, the non-reciprocal chase mechanism described in Section IV B is absent from the symmetric matrix of Eq. (4). These are not minor interpretive overstatements; they are the paper's main conclusions.","section":"IV A, IV B"}],"minor_comments":[{"comment":"Eq. (12) defines ρ_v = ⟨N_v⟩/(2αR_0^2), while the figure captions for Fig. 3(h) and Fig. 5(h) state ρ_v = N_v/(αR_0^2). The factor of 2 is inconsistent and should be clarified.","section":"Eq. (12) and Fig. 3(h), 5(h) captions"},{"comment":"There are numerous typographical errors: 'symmertic' (Sec. II A), 'studding' and 'studiend' (Sec. IV B), 'significanly' in Sec. IV C, and inconsistent reference spellings. A careful proofreading pass is needed.","section":"General"},{"comment":"Several references are duplicated (e.g., Refs. 28/42, 41/55, 1? etc.) and the bibliography contains many redundant entries. Also, Ref. 5 lists 'G. Volpe' twice.","section":"Bibliography"},{"comment":"The phrase 'cross-eye angle β' is unclear; consider using 'cone orientation' or 'cone center angle' consistently.","section":"Sec. II A"}],"recommendation":"reject","confidential_remarks":"The paper's central claim is undermined by the inconsistency between the stated neighbor rule and the spatial vision-cone picture that motivates the entire study. The skeptic's concern is fully confirmed by inspection of Eq. (4). The scalar angle update in Eq. (1) is an additional major deviation from the standard Vicsek model that is not addressed. These are not fixable by local edits; either the model definition must be corrected (and all results re-examined) or the interpretations must be substantially changed. The manuscript in its current form does not support its stated conclusions."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The paper is a systematic numerical study of a Vicsek variant with two angular sectors, and the phase diagrams look thorough. But there is a load-bearing problem: the neighbor rule in Eq. (4) does not actually implement spatial cones. It filters on heading differences and sums, not on the angle of the displacement vector relative to the focal particle's heading, and it is symmetric under i↔j. So the paper's central narrative about non-reciprocal 'follow-the-leader' alignment and backward-biased suppression does not follow from the equations. This is not a minor typo; the biological motivation, the phase interpretations, and the novelty claim all rest on the spatial cone picture.\n\nWhat is genuinely useful: the large-scale CUDA simulations, the systematic α–η and β–η phase maps, the connection of the cross-sea state to Kürsten & Ihle, and the volume-exclusion check. If the simulation code actually used a spatial-cone rule, the paper is a promising start. If it used Eq. (4), the results describe a different model—heading-similarity filtering—and need reinterpretation.\n\nOther soft spots: the scalar angle average in Eq. (1) is non-standard; the usual Vicsek update averages unit vectors, not angles, which can shift the transition. There are no error bars and no code/data deposit, so the phase diagrams are hard to verify. The volume-exclusion comparison mixes N≈2×10⁵ with N=192, a confound between particle size and system size. The abstract overclaims by calling the backward-biased state 'exceptionally homogeneous' when the text itself says it is 'less homogeneous than the symmetrical case.' Citation to the fore-aft asymmetric flocking work (ref 54) is present but not engaged with.\n\nAs written, the central claim is not supported. The paper needs a major revision: either correct Eq. (4) to a genuine spatial cone condition or resubmit as a study of orientation-difference filters with a different physical interpretation. I would still send it to a referee because the empirical phase diagram, if reproducible, could be a useful contribution to the active-matter subfield, but I would expect a clear request to fix the model–equation mismatch and provide code/data.","headline":"The paper's central equation does not implement the advertised spatial vision cones, so the claimed non-reciprocal mechanisms and phases are not supported as written.","tokens_in":14959,"tokens_out":2895,"would_cite":false,"duration_ms":26857,"reading_group":"maybe","serious_thinker":"no","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"A generalized Vicsek model with two non-overlapping vision cones shows that restricting lateral sight destabilizes global order and produces ultra-dense traveling bands, while forward- versus backward-biased vision drives either strong clus","keywords":["blind-spot Vicsek model","vision cones","non-reciprocal interactions","collective motion","active matter","traveling bands","cross-sea phase","density fluctuations"],"falsifier":"Replace Eq. (4)'s heading-based condition with a spatial-cone condition, e.g., require the angle of the displacement vector r_ij relative to the observer's heading to lie in two wedges of aperture alpha centered at ±beta, keeping everything else identical. If the cross-sea pattern, the follow-the-leader bands, and the backward homogeneous flock do not appear, the reported phenomena are due to the heading-similarity filter, not to partial spatial vision.","tokens_in":13823,"feed_emoji":"🐦","tokens_out":10351,"duration_ms":92458,"temperature":0.7,"pith_summary":"Using a generalized Vicsek model in which each particle aligns only with neighbors inside two non-overlapping angular vision cones, the authors ask how partial, direction-dependent perception reshapes collective motion. They establish three main results: narrowing the lateral cones (small aperture alpha) shifts the order-disorder transition to lower noise and promotes highly compressed traveling bands, including a grid-like 'cross sea' phase; orienting the cones forward (small beta) creates dense 'follow-the-leader' bands; orienting them backward (large beta) yields an exceptionally homogeneous ordered flock with suppressed density fluctuations. The work matters because it shows that non-reciprocal perception alone can select among qualitatively different flocking states, and that the total vision area, not its orientation, sets the critical noise. These are claims about a specific model; whether they survive a fully spatial implementation of the vision cones is a separate issue.","feed_headline":"Forward vision clusters flocks; backward vision calms them","feed_subtitle":"A two-cone Vicsek model shows partial perception decides between dense bands and calm flocks.","key_machinery":"The key object is the modified neighbor matrix of the 'blind spot Vicsek model': particle i interacts with particle j if they are within distance R0 and the headings satisfy |theta_i − theta_j| in I or |theta_i + theta_j| in I, where I = [|beta−alpha/2|, |beta+alpha/2|] is defined by cone aperture alpha and orientation beta. This rule replaces the isotropic metric neighborhood of the Vicsek model and makes the interaction matrix non-symmetric, since i may see j but not vice versa. The two parameters alpha and beta control the total field-of-view area (2*alpha*R0^2) and its front-back asymmetry, and the paper uses an auxiliary 'vision density' rho_v = <N_v>/(2*alpha*R0^2) to link local neighb","core_discovery":"The paper argues that replacing the isotropic circular neighborhood of the standard Vicsek model with two non-overlapping vision cones (angular width alpha, centered at angle beta from the heading) changes the emergent phases of aligning active particles. Narrowing symmetric lateral cones (beta=90°) lowers the critical noise, sharpens the order-disorder transition, and produces ultra-dense narrow traveling bands; at alpha=30° these form a perpendicular 'cross sea'. Breaking front-back symmetry at fixed alpha=90° makes interactions non-reciprocal: forward-biased vision (beta=45°) drives 'follow-the-leader' clustering into dense parallel bands, while backward-biased vision (beta=135°) stabiliz","pith_inferences":["The neighbor rule in Eq. (4) filters on heading differences or sums, not on the spatial angle of the line joining i and j; taken literally, the 'vision cones' are heading-similarity filters, and the biological interpretation and the reported phase labels depend on this implementation matching the intended spatial-cone picture.","A decisive test is to rerun the same model with a genuinely spatial cone rule: keep neighbors only if the angle of the displacement vector r_ij lies in two wedges of width alpha centered at ±beta relative to theta_i. If the cross-sea, follow-the-leader, and homogeneous-backward states do not reappear, the phenomena are artifacts of the heading filter.","The insensitivity of the global order transition to beta hints at a possible general principle: for local alignment rules of this kind, global order may depend only on the number of interaction partners, not their angular distribution. This is a testable hypothesis beyond the present model."],"forward_implications":["If correct, the phase diagram of the two-cone generalized Vicsek model contains, for the first time in a single minimal model, a cross-sea phase, ultra-dense narrow bands, and a low-fluctuation homogeneous flock, all tunable by cone aperture alpha and orientation beta.","Forward-biased vision produces 'follow-the-leader' bands that survive moderate volume exclusion, making them plausible targets for experiments with small robotic swarms or active granular matter.","Backward-biased vision suppresses density fluctuations; the paper's tentative near-hyperuniform exponent at beta=45° would be a notable finding if confirmed by finite-size scaling.","The invariance of critical noise with beta—while alpha is fixed—implies that the polar order transition is governed by the total field-of-view area, a prediction that can be tested in related non-reciprocal alignment models."],"fun_headline_variants":["Two vision cones flip flocking order","Blind spots steer active matter phases","Partial vision yields dense bands or calm flocks","Forward bias clusters, backward bias calms","Vision cones decide flocking fate"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The load-bearing premise is that Eq. (4) implements two non-overlapping angular vision cones in physical space; in fact, the condition selects neighbors by their heading difference (or sum) relative to the observer, not by the angle of the line connecting them, so the blind-spot interpretation and all associated phase interpretations rest on this mapping.","fun_headline_variants_meta":{"raw":{"variants":["Two vision cones flip flocking order","Blind spots steer active matter phases","Partial vision yields dense bands or calm flocks","Forward bias clusters, backward bias calms","Vision cones decide flocking fate"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000435,"raw_usage":{"total_tokens":2036,"prompt_tokens":717,"completion_tokens":1319,"prompt_tokens_details":{"cached_tokens":256},"prompt_cache_hit_tokens":256,"prompt_cache_miss_tokens":461,"completion_tokens_details":{"reasoning_tokens":1257}},"tokens_in":461,"tokens_out":1319,"duration_ms":9454,"temperature":1.0,"reasoning_tokens":1257,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-01T00:47:56.766916+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Replace Eq. (4)'s heading-based condition with a spatial-cone condition, e.g., require the angle of the displacement vector r_ij relative to the observer's heading to lie in two wedges of aperture alpha centered at ±beta, keeping everything else identical. If the cross-sea pattern, the follow-the-leader bands, and the backward homogeneous flock do not appear, the reported phenomena are due to the heading-similarity filter, not to partial spatial vision.","supporting_citations":[],"review_version":1}