Pith. sign in

REVIEW 4 major objections 6 minor 38 references

The paper argues that excess events in the LHAASO data of GRB 221009A above about 30 TeV, currently treated as non-detections, may be a genuine recovery of the intrinsic spectrum caused by quadratic subluminal Lorentz invariance violation.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗

T0 review · deepseek-v4-flash

2026-08-03 21:21 UTC pith:OGYGVOWL

load-bearing objection A sign error in Eq. 7 inflates the paper's high-energy intrinsic spectrum by orders of magnitude, so the main LIV prediction is an artifact as written; the underlying motivation is still worth referee time. the 4 major comments →

arxiv 2511.15542 v2 pith:OGYGVOWL submitted 2025-11-19 astro-ph.HE hep-ph

Is There New Physics Beyond 30 TeV in the BOAT?

Filip Rescic , Luis Recabarren Vergara , Michele Doro , Tomislav Terzi\'c This is my paper
classification astro-ph.HE hep-ph
keywords gamma-ray burstsGRB 221009ALorentz invariance violationquadratic subluminal LIVphoton pair productionvery-high-energy gamma raysLHAASOextragalactic background light
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper argues that the apparent non-detections in LHAASO data of GRB 221009A at energies above about 30 TeV could actually be the first sign of Lorentz invariance violation. In the quadratic subluminal LIV scenario, high-energy photons become less likely to annihilate with background light into electron-positron pairs, so the source's intrinsic spectrum would reappear at the highest energies. The authors extrapolate the burst's measured spectrum up to 100 TeV and show that, for new-physics scales around 10^-7 Planck mass, the predicted excess lies above LHAASO's sensitivity. They also find that the energy where the LIV-modified spectrum peaks scales as the 2/3 power of the new-physics scale, giving an observable way to measure that scale.

Core claim

The central claim is that excess events in the LHAASO data of GRB 221009A at energies E ≳ 30 TeV, currently dismissed as non-detections, may be a genuine recovery of the burst's intrinsic spectrum caused by quadratic subluminal Lorentz invariance violation. In this scenario, the modified dispersion relation makes γγ → e+e− pair production possible only within a finite energy window, so gamma rays that standard physics would absorb can instead reach Earth. Using the complete LIV-modified cross section, the authors predict that for Λ between 1.0×10^-7 E_Pl and 9.0×10^-7 E_Pl, the recovered flux exceeds LHAASO's sensitivity, and the SED peak energy scales as Λ^(2/3).

What carries the argument

The key object is the complete γγ → e+e− cross section in the quadratic subluminal LIV framework, combined with the modified threshold condition that introduces an upper threshold for pair production. This turns the usual monotonic absorption into a finite interaction window, allowing a spectral recovery at high energies. The paper couples this with an extrapolation of GRB 221009A's intrinsic spectrum (power law with exponential cutoff at 13 TeV) out to 100 TeV and with EBL+CMB attenuation.

Load-bearing premise

The entire prediction rests on the assumption that GRB 221009A's intrinsic spectrum continues as a power law with exponential cutoff at 13 TeV all the way to 100 TeV; if the source's spectrum actually breaks or cuts off below ~30 TeV, the predicted LIV flux recovery disappears and LHAASO would see nothing regardless of the LIV scale.

What would settle it

A careful LHAASO re-analysis of the energy bins above 30 TeV that finds no excess — or finds that the excess is fully explained by standard astrophysical backgrounds — would falsify the paper's claim for Λ ≲ 10^-7 E_Pl. Likewise, a measurement of the burst's intrinsic spectrum showing a cutoff below 30 TeV would remove the predicted recovery.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • A dedicated LHAASO analysis of the energy bins above ~30 TeV could confirm or rule out the quadratic subluminal LIV scenario.
  • If confirmed, it would extend the probed new-physics scale to ~10^-7 E_Pl, consistent with current bounds but from a single extreme source.
  • The E* ∝ Λ^(2/3) scaling provides a direct mapping from observed peak energy to the LIV scale, useful for future observatories.
  • The same method can be applied to other hard, bright sources, such as flaring blazars, with next-generation ground-based gamma-ray detectors.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If the excess is real, the single 251 TeV photon reported from the burst direction becomes an even more striking probe: at that energy standard absorption is extreme, and survival would almost demand new physics.
  • The scaling relation implies that observatories with higher reach in energy can probe larger LIV scales; extending sensitivity to ~100 TeV could probe up to ~10^-6 E_Pl.
  • A null result in the >30 TeV bins would not disprove LIV but would push Λ above 10^-7 E_Pl, given the assumed intrinsic spectrum; the weak link is the spectral extrapolation.
  • Differences among extragalactic background light models could also produce a hardening at the highest energies, so the claimed signature should be checked against multiple attenuation models and multiple sources.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

4 major / 6 minor

Summary. The paper argues that LHAASO observations of GRB 221009A can probe quadratic subluminal Lorentz Invariance Violation (LIV) by searching for a flux recovery above ~30 TeV caused by a LIV-induced suppression of the γγ→e+e− interaction. Using the modified cross section from [10], the authors extrapolate the GRB's highest-state intrinsic spectrum to 100 TeV, compare the resulting LIV-attenuated spectra with LHAASO sensitivity curves, and derive a quasi-empirical relation between the peak energy E* of the LIV-modified SED and the LIV scale Λ, finding E* ∝ Λ^(2/3). The paper explicitly states that no LHAASO data analysis in the >30 TeV bins is performed, and it motivates a future dedicated search. A separate section discusses prospects for PKS 2155-304 with SWGO.

Significance. If the central prediction were robust, the paper would offer an observable diagnostic for quadratic subluminal LIV and motivate a targeted re-analysis of the highest-energy GRB 221009A bins. The use of a first-principles modified cross section [10] and the candid admission that no LHAASO data analysis is presented are strengths. The proposed E*–Λ^(2/3) scaling, if confirmed, could connect observatory energy reach to new-physics scales. However, the validity of the forecast rests on an identified sign error in Eq. (7) and on an extrapolation of the intrinsic spectrum far beyond the highest observed photon energy. These issues are load-bearing, so the current manuscript does not establish its main quantitative claim.

major comments (4)
  1. [Eq. (7)] The intrinsic spectrum is printed as dN/dE = N0 (E/E0)^(−Γ) exp(E/Ecut), i.e., a rising exponential, despite the text describing an 'exponential cutoff.' With Ecut = 13 TeV, at E = 100 TeV the factor is e^{+7.7} ≈ 2200 rather than the physical e^{−7.7} ≈ 4.6×10^(−4). Since every attenuated spectrum in Fig. 1 is this intrinsic spectrum multiplied by a survival probability, the predicted flux recovery above ~30 TeV and the E*(Λ) relation in Fig. 2 are dominated by the wrong-sign exponential. This is not a typo of minor import: the central forecast is not reproducible as written. The calculation must be rerun with exp(−E/Ecut), and all figures and conclusions updated accordingly.
  2. [Abstract and Conclusion] The abstract claims 'excesses in the GRB 221009A data currently classified as non-detections at energies E ≳ 30 TeV warrant further investigation,' but the body provides no excesses, no upper limits, and no analysis of LHAASO data in that range. Indeed, the Conclusion states 'Having no results of the LHAASO data analysis in these energy bins (signal or upper limits), we were not able to set constraints.' The abstract overstates what the paper demonstrates. This should be corrected so the abstract matches the actual content.
  3. [Results, extrapolation of Eq. (7)] The intrinsic spectrum from [30] is based on photons up to ~13 TeV (the highest reported energy is 13 TeV), but the paper extrapolates it to 100 TeV without any physical justification for the absence of a break or cutoff below 30 TeV. If the true intrinsic spectrum cuts off or breaks below ~30 TeV, the predicted LIV flux recovery disappears regardless of Λ. Since the whole LHAASO detectability claim depends on this assumption, it must be stated explicitly as a limiting premise and, ideally, tested with a harder/softer extrapolation or a physically motivated maximum photon energy.
  4. [Fig. 2 and Eq. (6)] The E*–Λ relation is presented as a finding, but E* is extracted from the authors' own model curves, and the Λ^(2/3) scaling is essentially read off from the upper-threshold expression in Eq. (6). The fitted relation E* = 3.3×10^(−5) Λ^(2/3) + 17.8 TeV therefore does not constitute an independent prediction; it is a restatement of the model's input scaling with an offset. This should be framed as a consistency check rather than a new physical law, especially because the offset (17.8 TeV) is not derived from Eq. (6).
minor comments (6)
  1. [General] The paper is generally readable, but the connection between the abstract's 'non-detections' and the body's 'no data analysis' needs careful rewording throughout.
  2. [Section: Methodology, sensitivity rescaling] The LHAASO sensitivity for 1 minute or 1 hour is obtained by scaling the 1-year sensitivity with sqrt(1 yr / T_obs). This ignores systematics, energy-bin dependent background, and the transient nature of a GRB observation. It is acceptable as an order-of-magnitude estimate, but should be stated as such.
  3. [Eq. (7) notation] Even after correcting the sign in the exponential, the definition E0 = 1 TeV is unusual; specifying E0 explicitly in the equation would improve clarity.
  4. [Fig. 1 caption] The caption describes 'Intrinsic average data points' but the figure shows multiple time intervals. The relation between the colored markers and the time-averaged fit should be described more precisely.
  5. [Minor typo] In the sensitivity scaling paragraph, '1 minure' should be '1 minute.'
  6. [References] Ref. [37] is cited as 'in preparation'; if possible, provide a stable reference or explicitly mark it as a private communication.

Circularity Check

0 steps flagged

No significant circularity: the central forecast is a forward model with external inputs; the Eq. 7 sign error is a correctness issue, not circularity.

full rationale

The paper's central calculation is a forward model: Eq. 2 defines the observed spectrum as the intrinsic spectrum (Eq. 7, taken from external fits [30], normalized to LHAASO's highest state) multiplied by exp(-tau), where tau is computed from the EBL model [4] and the modified gamma-gamma cross section of [10]. No parameter of the LIV model is fitted to the >30 TeV prediction; the paper explicitly states no LHAASO data analysis was performed. The cited cross section [10] is a prior first-principles derivation by overlapping authors, but it is parameter-free with respect to this target and does not incorporate the GRB 221009A data, so its use is independent support rather than circular. The E*--Lambda relation in Fig. 2 is a fit to the paper's own model outputs, but the paper explicitly traces the Lambda^(2/3) scaling to Eq. 6, so it is a consistency check rather than a prediction that closes a loop. A serious correctness issue is present: Eq. 7 prints exp(E/E_cut) instead of an exponential cutoff, exponentially inflating the >30 TeV intrinsic flux; this invalidates the quantitative forecast but is not circularity. The abstract's 'excesses ... classified as non-detections' is not demonstrated and is contradicted by the paper's later admission of no data analysis; again, this is unsupported assertion, not circularity. Accordingly, no circular step is identified.

Axiom & Free-Parameter Ledger

7 free parameters · 6 axioms · 0 invented entities

The paper's forecast rests on the LIV model (Eq. 1), the modified cross-section from the authors' own previous work [10], an unvalidated extrapolation of GRB 221009A's intrinsic spectrum, an EBL model, and a crude sensitivity rescaling. The fitted free parameters are the intrinsic-spectrum values from [30], the chosen Λ benchmarks, and a scaling relation fitted to the paper's own model curves. No new particles or forces are introduced.

free parameters (7)
  • Intrinsic spectrum normalization N0 = 9.59e-6 TeV^-1 cm^-2 s^-1
    Taken from the time-averaged fit of [30] and normalized to the first 14 s BOAT highest state; the extrapolated >30 TeV prediction depends directly on it.
  • Intrinsic spectral index Γ = 2.3
    From [30]'s fit to the 5 time bins; appears in Eq. 7 and controls the high-energy extrapolation.
  • Intrinsic cutoff energy Ecut = 13 TeV
    From [30] (and [31] max photon energy 13 TeV); the paper extrapolates past this cutoff to 100 TeV.
  • LIV energy scale Λ = 1.0, 1.3, 2.0, 2.6, 5.0, 9.0 × 10^-7 E_Pl
    Benchmark values chosen by hand consistent with H.E.S.S. Mrk 501 bound (Λ≳7.8e20 eV) and multi-source bound (Λ≳1.42e21 eV); not fitted to data here.
  • E*-Λ scaling coefficients (slope, intercept) = 3.3e-5 TeV, 17.8 TeV
    Linear fit to the paper's own computed SED maxima in Fig. 2; presented as a law but fitted to model output, not to data.
  • LHAASO sensitivity rescale factor = sqrt(1 yr / T_obs)
    Ad hoc scaling of the 1-year sensitivity [32] to 1 hour and 1 minute; assumes background-limited statistics and no systematics.
  • PKS 2155-304 exponential cutoff = 10 TeV
    Adopted from [37] (in preparation) to make the 4FGL LogParabola extrapolation realistic; controls the SWGO sensitivity conclusion.
axioms (6)
  • domain assumption Quadratic subluminal LIV dispersion relation E^2 − k^2 = −E^2 (E/Λ)^2 (Eq. 1)
    Defines the physics scenario; neither derived nor tested inside this paper.
  • domain assumption The complete γγ→e+e- cross section in quadratic subluminal LIV from ref. [10] is correct
    The paper's optical depth and flux-recovery predictions inherit this external result; it is not re-derived or machine-checked here.
  • ad hoc to paper Intrinsic spectrum of GRB 221009A follows a power law with exponential cutoff (Eq. 7) and extends unchanged to 100 TeV
    The authors explicitly extrapolate the fit from [30] beyond the observed 13 TeV; no data support this.
  • domain assumption EBL model of Saldana-Lopez et al. (2021) [4] accurately describes the background photon density
    The optical depth calculation relies on this EBL model; the authors note Dominguez et al. gives minor differences.
  • ad hoc to paper LHAASO sensitivity scales as sqrt(1 yr / T_obs)
    Used to conclude LHAASO could detect the LIV excess; ignores systematics and energy-bin details.
  • standard math Standard ΛCDM with Ωm = 0.3, ΩΛ = 0.7, H0 = 70
    Used in dl/dz in Eq. 4; standard cosmology, not the target of the paper.

pith-pipeline@v1.3.0-alltime-deepseek · 7361 in / 16904 out tokens · 155733 ms · 2026-08-03T21:21:47.876012+00:00 · methodology

0 comments
read the original abstract

We show that the GRB 221009A spectrum detected by LHAASO can be used to probe effects of quadratic subluminal Lorentz Invariance Violation (LIV) through the enhancement of the observed flux at the highest energies. In particular, we argue that excesses in the GRB 221009A data currently classified as non-detections at energies $E \gtrsim 30$ TeV warrant further investigation, as they may indicate a recovery of the intrinsic source spectrum consistent with the LIV-induced suppression of $\gamma\gamma \to e^-e^+$ interactions within the quadratic subluminal scenario. This would increase the accessible parameter space of the energy scale of new physics.

Figures

Figures reproduced from arXiv: 2511.15542 by Filip Rescic, Luis Recabarren Vergara, Michele Doro, Tomislav Terzi\'c.

Figure 1
Figure 1. Figure 1: FIG. 1. Intrinsic average data points of GRB 221009A (col [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. LIV observational prospect for the blazar PKS 2155- [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

38 extracted references · 27 linked inside Pith

  1. [1]

    A. I. Nikishov, Journal of Experimental and Theoretical Physics (JETP)14, 393 (1962)

    1962

  2. [2]

    R. J. Gould and G. P. Schreder, Phys. Rev.155, 1408 (1967)

    1967

  3. [3]

    Dominguezet al., Mon

    A. Dominguezet al., Mon. Not. Roy. Astron. Soc.410, 2556 (2011), arXiv:1007.1459 [astro-ph.CO]

    Pith/arXiv arXiv 2011

  4. [4]

    Saldana-Lopez, A

    A. Saldana-Lopez, A. Dom ´ ınguez, P. G. P´ erez-Gonz´ alez, J. Finke, M. Ajello, J. R. Primack, V. S. Paliya, and A. Desai, Mon. Not. Roy. Astron. Soc.507, 5144 (2021), arXiv:2012.03035 [astro-ph.CO]

    Pith/arXiv arXiv 2021

  5. [5]

    Addaziet al., Prog

    A. Addaziet al., Prog. Part. Nucl. Phys.125, 103948 (2022), arXiv:2111.05659 [hep-ph]

    Pith/arXiv arXiv 2022

  6. [6]

    Colladay and V

    D. Colladay and V. A. Kostelecky, Phys. Rev. D58, 116002 (1998), arXiv:hep-ph/9809521

    Pith/arXiv arXiv 1998

  7. [7]

    R. C. Myers and M. Pospelov, Phys. Rev. Lett.90, 211601 (2003), arXiv:hep-ph/0301124

    Pith/arXiv arXiv 2003

  8. [8]

    Li and B.-Q

    C. Li and B.-Q. Ma, Phys. Lett. B829, 137034 (2022), arXiv:2204.02956 [astro-ph.HE]

    Pith/arXiv arXiv 2022

  9. [9]

    Terzi´ c, D

    T. Terzi´ c, D. Kerszberg, and J. Striˇ skovi´ c, Universe7, 345 (2021), arXiv:2109.09072 [astro-ph.HE]

    Pith/arXiv arXiv 2021

  10. [10]

    J. M. Carmona, J. L. Cort´ es, F. Rescic, M. A. Reyes, T. Terzi´ c, and F. I. Vrban, Phys. Rev. D110, 063035 (2024), arXiv:2404.07842 [hep-ph]

    Pith/arXiv arXiv 2024

  11. [11]

    Caoet al.(LHAASO), Science380, adg9328 (2023), arXiv:2306.06372 [astro-ph.HE]

    Z. Caoet al.(LHAASO), Science380, adg9328 (2023), arXiv:2306.06372 [astro-ph.HE]

    Pith/arXiv arXiv 2023

  12. [12]

    Breit and J

    G. Breit and J. A. Wheeler, Phys. Rev.46, 1087 (1934)

    1934

  13. [13]

    Mart ´ ınez-Huerta, R

    H. Mart ´ ınez-Huerta, R. G. Lang, and V. de Souza, Sym- metry12, 1232 (2020)

    2020

  14. [14]

    Blanch, J

    O. Blanch, J. Lopez, and M. Martinez, Astropart. Phys. 19, 245 (2003), arXiv:astro-ph/0107334

    Pith/arXiv arXiv 2003

  15. [15]

    Abdallaet al.(H.E.S.S.), Astrophys

    H. Abdallaet al.(H.E.S.S.), Astrophys. J.870, 93 (2019), arXiv:1901.05209 [astro-ph.HE]

    Pith/arXiv arXiv 2019

  16. [16]

    Tavecchio and G

    F. Tavecchio and G. Bonnoli, Astron. Astrophys.585, A25 (2016), arXiv:1510.00980 [astro-ph.HE]

    Pith/arXiv arXiv 2016

  17. [17]

    Fairbairn, A

    M. Fairbairn, A. Nilsson, J. Ellis, J. Hinton, and R. White, JCAP06, 005, arXiv:1401.8178 [astro-ph.HE]

    Pith/arXiv arXiv

  18. [18]

    Abdalla and M

    H. Abdalla and M. B¨ ottcher, Astrophys. J.865, 159 (2018), arXiv:1809.00477 [astro-ph.HE]

    Pith/arXiv arXiv 2018

  19. [19]

    V. A. Acciariet al.(MAGIC), Nature575, 455 (2019), arXiv:2006.07249 [astro-ph.HE]

    Pith/arXiv arXiv 2019

  20. [20]

    Abdallaet al., Nature575, 464 (2019), arXiv:1911.08961 [astro-ph.HE]

    H. Abdallaet al., Nature575, 464 (2019), arXiv:1911.08961 [astro-ph.HE]

    Pith/arXiv arXiv 2019

  21. [21]

    Caoet al.(LHAASO), Phys

    Z. Caoet al.(LHAASO), Phys. Rev. Lett.133, 071501 (2024), arXiv:2402.06009 [astro-ph.HE]

    arXiv 2024

  22. [22]

    Li and B.-Q

    H. Li and B.-Q. Ma, Mod. Phys. Lett. A39, 2350201 (2024), arXiv:2307.14256 [astro-ph.HE]

    Pith/arXiv arXiv 2024

  23. [23]

    Li and B.-Q

    H. Li and B.-Q. Ma, JCAP10, 061, arXiv:2306.02962 [astro-ph.HE]

    Pith/arXiv arXiv

  24. [24]

    Li and B.-Q

    H. Li and B.-Q. Ma, Astropart. Phys.148, 102831 (2023), arXiv:2210.06338 [astro-ph.HE]

    Pith/arXiv arXiv 2023

  25. [25]

    Li and B.-Q

    H. Li and B.-Q. Ma, Eur. Phys. J. C83, 192 (2023), arXiv:2210.05563 [astro-ph.HE]

    Pith/arXiv arXiv 2023

  26. [26]

    R. G. Lang, H. Mart ´ ınez-Huerta, and V. de Souza, Phys. Rev. D99, 043015 (2019), arXiv:1810.13215 [astro- ph.HE]

    Pith/arXiv arXiv 2019

  27. [27]

    Lesageet al., Astrophys

    S. Lesageet al., Astrophys. J. Lett.952, L42 (2023), arXiv:2303.14172 [astro-ph.HE]

    arXiv 2023

  28. [28]

    M. A. Williamset al., Astrophys. J. Lett.946, L24 (2023), arXiv:2302.03642 [astro-ph.HE]

    Pith/arXiv arXiv 2023

  29. [29]

    Dzhappuevet al., The Astronomer’s Telegram15669 (2022)

    D. Dzhappuevet al., The Astronomer’s Telegram15669 (2022)

    2022

  30. [30]

    Miceli, P

    D. Miceli, P. Da Vela, and E. Prandini, Astron. Astro- phys.688, A57 (2024), arXiv:2405.07831 [astro-ph.HE]

    Pith/arXiv arXiv 2024

  31. [31]

    Caoet al.(LHAASO), Sci

    Z. Caoet al.(LHAASO), Sci. Adv.9, adj2778 (2023), arXiv:2310.08845 [astro-ph.HE]

    arXiv 2023

  32. [32]

    Vernetto (LHAASO), J

    S. Vernetto (LHAASO), J. Phys. Conf. Ser.718, 052043 (2016)

    2016

  33. [33]

    Abreuet al.(SWGO), (2025), arXiv:2506.01786 [astro-ph.HE]

    P. Abreuet al.(SWGO), (2025), arXiv:2506.01786 [astro-ph.HE]

    arXiv 2025

  34. [34]

    Aharonianet al.(H.E.S.S.), Astrophys

    F. Aharonianet al.(H.E.S.S.), Astrophys. J. Lett.664, L71 (2007), arXiv:0706.0797 [astro-ph]

    Pith/arXiv arXiv 2007

  35. [35]

    Aleksicet al.(MAGIC), Astron

    J. Aleksicet al.(MAGIC), Astron. Astrophys.544, A75 (2012), arXiv:1207.1634 [astro-ph.HE]

    Pith/arXiv arXiv 2012

  36. [36]

    Abdollahiet al.(Fermi-LAT), Astrophys

    S. Abdollahiet al.(Fermi-LAT), Astrophys. J. Supp. 260, 53 (2022), arXiv:2201.11184 [astro-ph.HE]

    Pith/arXiv arXiv 2022

  37. [37]

    CTAO Consortium (2025), in preparation

    2025

  38. [38]

    Aharonianet al.(H.E.S.S.), Astron

    F. Aharonianet al.(H.E.S.S.), Astron. Astrophys.430, 865 (2005), arXiv:astro-ph/0411582

    Pith/arXiv arXiv 2005