Cited by 3Quantum Mechanics and ApplicationsQuantum and Classical ElectrodynamicsAtomic and Molecular Physics

Interferometry with relativistic electrons

Open access
Marzlin, K.-P., Lee, T.·2014·Physical Review A

Abstract

We propose an experiment to test the influence of Lorentz contraction on the interference pattern of a beam of electrons. The electron beam is split and recombined by two pairs of bichromatic laser pulses, using a variation of the Kapitza-Dirac effect. Between the pairs, the electrons are accelerated to relativistic speed. We show that Lorentz contraction of the distance between two partial beams will then lead to a reduction of fringe visibility. The connection of the proposal to Bell's spaceship paradox is discussed.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper proposes an electron interferometer in which two partial beams are split and recombined by bi-chromatic laser pulses via a Kapitza-Dirac effect, then accelerated to relativistic speed. Lorentz contraction causes the beams to miss each other by \(\Delta z(\gamma-1)\), reducing fringe visibility, and the setup is closely related to Bell’s spaceship paradox.

Key findings

  • The proposed experiment uses two pairs of bi-chromatic laser pulses to split and recombine an electron beam; between the pairs the electrons are accelerated to relativistic speed \(v=\beta c\).
  • Lorentz contraction of the beam separation \(\Delta z\) leads to a spatial mismatch \(\Delta z'-\Delta z=(\gamma-1)\Delta z\) in the electron rest frame, reducing fringe visibility.
  • A numerical simulation with fourth-order harmonic generation (\(n=4\), \(\beta=3/5\)) gives a beam separation of about \(15\,\mu\text{m}\), using \(T=50\,\text{ns}\), \(T'=12.5\,\text{ns}\), and \(\tilde T=31\,\text{ns}\), with an electric potential difference of \(127.75\,\text{kV}\).
  • The estimated photon-emission probability during acceleration is less than \(5\%\) for cutoff parameter \(u>10^{-4}\), so photon emission is not expected to pose a problem.

Methods

  • Theoretical proposal and analysis based on the Dirac equation, extending a non-relativistic Ramsey-Bordé electron interferometer to the relativistic regime.
  • Numerical simulation in momentum space using a 10,000-point grid for Fourier transformation; the last two laser pulses are treated by Lorentz transforming the wavefunction into the mean rest frame of beam B.
  • The Kapitza-Dirac beam splitter is modeled by resonant coupling between momenta separated by \(2\hbar k_L\), with pulse duration \(t_L=\pi/(4g_1g_2)=1.56\,\text{ns}\).

Limitations

  • The paper states that the analysis assumes a homogeneous electric field, laser pulses switched on and off at specific times, and a one-dimensional treatment that ignores forces in the \(x\)- and \(y\)-directions.
  • The paper notes that the proposed experiment is not strictly an interference experiment: the measured quantity is a displacement between two partial beams, though fringe visibility can provide information about the displacement if the beams partially overlap.
  • The beam splitting process is velocity-selective, so only electrons within a specific velocity range are split or recombined; this increases the number of experimental runs needed, and detection may require time-of-flight measurement or deceleration after the last laser pulse.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1103/physreva.89.062103

Cites

44 of 44 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

2 of 17 cited sources checked · 1 supported · 0 flagged · accuracy not yet measured

  • Premisecitation
    § IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4

    Rule (iv) provides a reasonable approximation for the evolution of the electron state inside a bi-chromatic laser pulse if the resonance condition is fulfilled.

    “It was shown in Ref. [13] that rule (iv) provides a reasonable approximation for the evolution of the electron state inside a bi-chromatic laser pulse if the resonance condition”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [13] K.-P. Marzlin, Phys. Rev. A 88 , 043621 (2013), URL http://arxiv.org/abs/1307.4020 . source

      In the Kapitza–Dirac beam-splitter discussion (page unavailable), the paper derives a simplified evolution for a resonant electron state and says Eq. (10) remains an excellent approximation under specified conditions. Resonance alone is not sufficient in its account: it also requires weak coupling and a sufficiently narrow momentum distribution. The copy does not identify the citing paper’s ‘rule (iv)’ by that name. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
  • Findingreasoning
    § IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4

    The Lorentz transformation of the vector potential results in the same form (19) except that the frequencies are replaced by ω~1=(1−β)γω1 and ω~2=(1+β)γω2.

    “Consequently, the vector potential still has the form (19) except that in the exponentials we have to make the replacements ω 1 → ˜ ω 1 ≡ (1 -β ) γω 1 and ω 2 → ˜ ω 2 ≡ (1+ β ) γω 2 .”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Despite the relativistic mean electron velocity, the velocity spread of the electron beam is still non-relativistic.
  • Findingreasoning
    § IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4

    If the final electron velocity is β=(n−1)/(n+1), then the resonance condition can be fulfilled by choosing δω=∓2ħ√n k_22/m.

    “If the final velocity of the electrons takes the value β = ( n -1) / ( n + 1) then these relations simplify to ∆˜ ω = √ nδω and ˜ k L ≈ √ nω 2 /c = √ nk 2 . The resonance condition can then easily be fulfilled by choosing δω = ∓ 2 ℏ √ nk 2 2 /m”
    Quote in the paperSubstantial claim
  • Findingnone given
    § VIII. CONCLUSION · p. 7

    Two partial beams, which would be perfectly overlapping for non-relativistic electrons, will miss each other by an amount ∆z(γ-1), with ∆z the beam separation in the interferometer.

    “Two partial beams, which would be perfectly overlapping for non-relativistic electrons, will miss each other by an amount ∆ z ( γ -1), with ∆ z the beam separation in the interferometer.”
    Quote in the paperNot a substantial claim
  • Findingown data
    § V. NUMERICAL RESULTS · p. 4

    In the numerical simulation, the distance between wavepackets A and B is about 15 μm, corresponding to the spatial mismatch induced by Lorentz contraction.

    “The distance between wavepackets A and B of about 15 µ m corresponds to the spatial mismatch induced by Lorentz contraction.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: For the chosen pulse duration, the laser intensities are so low that coupling to other momenta is very weak and can be neglected except when the resonance condition is fulfilled.
  • May combine two claims. 19
  • Classified as probably not a substantial claim. 7
  • The quote only partly states this claim. 1
  • May combine two claims.

    Premisecitation
    § IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4

    For non-relativistic velocities, the Dirac equation can be solved using a Foldy-Wouthuysen transformation, and the analysis of Ref. [13] can therefore be applied to the first two laser pulses.

    “For non-relativistic velocities the Dirac equation can be solved using a Foldy-Wouthuysen transformation [15]. The large components of the Dirac spinor are then of the form ψ = exp( -imc 2 t/ ℏ ) ˜ ψ , where ˜ ψ is a solution to the Schr¨ odinger equation with the same vector potential. The analysis of Ref. [13] can therefore be applied to the first two laser pulses.”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [15] J. D. Bjorken and S. D. Drell, Relativistic quantum mechanics (McGraw-Hill, 1998).

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [13] K.-P. Marzlin, Phys. Rev. A 88 , 043621 (2013), URL http://arxiv.org/abs/1307.4020 . source
  • May combine two claims.

    Findingreasoning
    § V. NUMERICAL RESULTS · p. 5

    The distance between wavepackets A and B in Fig. 2 is not exactly equal to the shift (γ-1)∆z derived in Sec. II, but is given by Eq. (25), because Eq. (25) accounts for the finite laser pulse duration t_L while the discussion in Secs. II and III assumes instantaneous momentum change.

    “We remark that the distance between wavepackets A and B in Fig. 2 is not exactly equal to the shift ( γ -1)∆ z derived in Sec. II, but is rather given by”
    • Also stated in: § V. NUMERICAL RESULTS · p. 5 · plain
      “The reason is that Eq. (25) takes into account the finite duration t L of the laser pulses, while the discussion in Secs. II and III assumes that the momentum of the electrons changes instantaneously.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: The momentum of the electrons changes instantaneously (as assumed in Secs. II and III).
  • May combine two claims.

    Findingown data
    § VII. DISCUSSION · p. 6

    For the parameters used in Sec. V, the total photon emission probability P_em(u) varies very slowly with u and is less than 5% for u > 10^-4.

    “For the parameters used in Sec. V, P em ( u ) varies very slowly with u and is less than 5% for u > 10 -4 .”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingreasoning
    § III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3

    For constant η and E(p), the maximal transition probability between positive- and negative-energy solutions is ħ2η2/(E(p)2+ħ2η2), significant only for accelerations a≈10^30 m/s2 or larger.

    “For constant values of η and E ( p ) we find that the maximal transition probability is given by ℏ 2 η 2 / ( E ( p ) 2 + ℏ 2 η 2 ), which is only significant for extreme accelerations of a ≈ 10 30 m/s 2 or larger.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning
    § VII. DISCUSSION · p. 6

    The loss of coherence from photon emission is not a fundamental problem for the proposed experiment, but the associated change in electron momentum may nevertheless affect the displacement between partial beams A and B.

    “While point (i) implies that this loss of coherence is not a fundamental problem, the associated change in the electron momentum may nevertheless affect the displacement between partial beams A and B.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given
    § VII. DISCUSSION · p. 6

    The theoretical analysis is based on simplifying assumptions including a homogeneous electric field, laser pulses switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x- and y-direction.

    “The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The electric field is homogeneous.
    • The authors state this as an assumption: The laser pulses are switched on and off at specific times.
    • The authors state this as an assumption: The analysis is one-dimensional and ignores forces in the x- and y-direction.
  • May combine two claims.

    Interpretationreasoning
    § VII. DISCUSSION · p. 7

    A disadvantage of velocity-selection is that runs in which an electron has the wrong velocity will not contribute to the measurement, so the total number of experimental runs needed will be increased.

    “A disadvantage of velocity-selection is that runs in which an electron has the wrong velocity will not contribute to the measurement. The total number of experimental runs needed will therefore be increased.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning
    § II. SKETCH OF PROPOSED EXPERIMENT · p. 2

    Once electrons move at speed v, the proper distance ∆z′ in their rest frame is γ∆z, where γ=1/√(1−β2), because ∆z is the Lorentz contraction of ∆z′.

    “We then have ∆ z ′ = γ ∆ z > ∆ z , where γ = 1 / √ 1 -β 2 , because ∆ z is the Lorentz contraction of ∆ z ′ .”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given
    § VII. DISCUSSION · p. 7

    Temporal fluctuations in the electric field could significantly change the electron dynamics between different runs and thus make it impossible to measure the beam displacement.

    “Temporal fluctuations in the electric field could significantly change the dynamics of the electrons between different runs and thus make it impossible to measure the beam displacement.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning
    § VII. DISCUSSION · p. 6

    If the two partial beams are partially overlapping, the fringe visibility can provide information about the displacement; coherence is therefore helpful but not essential.

    “However, if the two partial beams are partially overlapping, the fringe visibility can provide information about the displacement. Coherence is therefore helpful but not essential.”
    Quote in the paperNot a substantial claim
  • May combine two claims. The quote only partly states this claim.

    Interpretationreasoning
    § VII. DISCUSSION · p. 7

    The resonant interaction with laser pulses selects those electrons which have obtained the proper velocity and position to contribute to the measured observable, overcoming the problem of temporal field fluctuations.

    “Thus, the resonant interaction with laser pulses selects those electrons which have obtained the proper velocity and position to contribute to the measured observable.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning
    § VII. DISCUSSION · p. 6

    The measured observable is a relative displacement of two partial beams along the direction of the laser pulses; effects on motion in other directions (such as x- or y-forces) do not affect the result, and z-forces affecting both partial beams equally do not affect the displacement.

    “(ii) The measured observable is a relative displacement of two partial beams along the direction of the laser pulses. Any effects that affect the motion in other directions, such as forces in the x - or y -direction, do therefore not affect the result. Similarly, forces in the z -direction that affect both partial beams in the same way will not affect the displacement.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Study design and conductnone given
    § V. NUMERICAL RESULTS · p. 4

    For the acceleration considered, rule (iii) provides an excellent approximation and can be evaluated directly.

    “For the acceleration of 1 . 8 × 10 16 m/s 2 that we considered, rule (iii) provides an excellent approximation and can also be evaluated directly.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation
    § I. INTRODUCTION · p. 1

    Lorentz contraction has generally only been confirmed indirectly, for instance through the compressed charge distribution in high-energy ion collisions and the wavelength of free-electron lasers.

    “Lorentz contraction generally has only been confirmed indirectly, for instance through the compressed charge distribution in high-energy ion collisions [3] and the wavelength of free-electron lasers [4].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [3]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [4]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation
    § VI. BELL'S SPACESHIP PARADOX · p. 5

    Most authors who addressed whether Lorentz contraction causes stress in the string concluded that the string in Bell's paradox would break.

    “Most authors came to the conclusion that the string would break.”
    Quote in the paperNot a substantial claim0 of 8 sources checked
    • cites [25] J. S. Bell, Speakable and unspeakable in quantum mechanics (Cambridge University Press, 2004). source
    • cites [26] E. Dewan and M. Beran, Am. J. Phys. 27 , 517 (1959), URL http://link.aip.org/link/?AJP/27/517/1 .

      Not checked in the free run.

    • cites [31] P. J. Nawrocki, Am. J. Phys. 30 , 771 (1962), URL http: //link.aip.org/link/?AJP/30/771/1 .

      Not checked in the free run.

    • cites [32] E. M. Dewan, Am. J. Phys. 31 , 383 (1963), URL http: //link.aip.org/link/?AJP/31/383/1 .

      Not checked in the free run.

    • cites [33] D. T. Cornwell, Europhys. Lett. 71 , 699 (2005), URL http://stacks.iop.org/0295-5075/71/i=5/a=699 .

      Not checked in the free run.

    • cites [34] J. Franklin, European Journal of Physics 31 , 291 (2010), URL http://stacks.iop.org/0143-0807/31/i= 2/a=006 .

      Not checked in the free run.

    • cites [35] A. Tartaglia and M. L. Ruggiero, Europ. J. Phys. 24 , 215 (2003), URL http://stacks.iop.org/0143-0807/24/i= 2/a=361 .

      Not checked in the free run.

    • cites [36] D. F. Styer, Am. J. Phys. 75 , 805 (2007), URL http: //link.aip.org/link/?AJP/75/805/1 .

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning
    § VI. BELL'S SPACESHIP PARADOX · p. 5

    In both Bell's paradox and the proposed experiment, it is Lorentz contraction of the final separation ∆z′ that is responsible for a physical effect: the mismatch between the final positions of beams A and B in the interferometer, and the breaking of the string in Bell's paradox.

    “In both cases, it is Lorentz contraction of the final separation ∆ z ′ that is responsible for a physical effect: the mismatch between the final positions of beam A and B in the electron interferometer, and the breaking of the string in Bell's paradox.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning
    § VII. DISCUSSION · p. 6

    Spatial homogeneity of the electric field is not a critical assumption, because it only matters that both partial beams achieve the same Lorentz factor γ at the end of the acceleration phase.

    “Spatial homogeneity is not a critical assumption because it only matters that both partial beams achieve the same Lorentz factor γ at the end of the acceleration phase.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning
    § VII. DISCUSSION · p. 6

    Because both partial beams essentially follow the same path and are separated only along the z-axis, they undergo the same (non-constant) acceleration before recombination; hence field fluctuations along the z-axis would not affect the experimental outcome.

    “Because both partial beams essentially follow the same path and are only separated along the z -axis, both beams would undergo the same (non-constant) acceleration before they are recombined. Hence, field fluctuations along the z -axis would not affect the experimental outcome.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning
    § VII. DISCUSSION · p. 6

    In the proposed setup, pulse timing is not a problem because only partial beam A actually interacts with the pulses, while partial beam B does not obtain a momentum transfer.

    “In the proposed setup this is not a problem because only partial beam A actually interacts with the pulses, while partial beam B does not obtain a momentum transfer.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data
    § V. NUMERICAL RESULTS · p. 5

    The numerical results were checked by verifying that the wavefunction is normalized and that the mean position of all partial beams agrees with the position (in the rest frame of beam B) of a classical relativistic point particle receiving a specific momentum kick at each laser pulse.

    “To check the numerical results we have verified that the wavefunction is normalized and the mean position of all partial beams agrees with the position (in the rest frame of beam B) of a classical relativistic point particle that receives a specific momentum kick at each laser pulse.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationown data
    § VI. BELL'S SPACESHIP PARADOX · p. 5

    Bell's spaceship paradox and the proposed interference experiment are closely related; except for the parts in which electron beams A and B are split and recombined, the two space-time diagrams coincide.

    “Comparing Figs. 1b) and 3 one can see that Bell's paradox and the proposed interference experiment are closely related. Except for the parts in which electron beam A and B are split and recombined, the two space-time diagrams coincide.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given
    § V. NUMERICAL RESULTS · p. 4

    Rules (i) and (ii) can be evaluated exactly in momentum space.

    “Rules (i) and (ii) can be evaluated exactly in momentum space.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationnone given
    § VII. DISCUSSION · p. 6

    Strictly speaking, the proposed experiment is not an interference experiment; the measured quantity is a displacement between two partial beams, which would also be produced for incoherent electron beams.

    “(i) Strictly speaking, the proposed experiment is not an interference experiment. The measured quantity is a displacement between to partial beams, which would also be produced for incoherent electron beams.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given
    § VII. DISCUSSION · p. 6

    The beam splitting process is velocity-selective: the electron beam is only split or recombined for electrons within a specific velocity range.

    “(iii) The beam splitting process is velocity-selective, i.e., the electron beam is only split or recombined for electrons within a specific velocity range.”
    Quote in the paperNot a substantial claim
24 of 24
  • The authors state this as an assumption.

    The beam intensity is low enough that space-charge effects can be neglected.

    “It is assumed that the beam intensity is low enough so that space-charge effects can be neglected [14].”
  • The paper relies on this without support.

    Despite the relativistic mean electron velocity, the velocity spread of the electron beam is still non-relativistic.

    “To describe the last two laser pulses we can exploit that, despite the relativistic mean electron velocity, the velocity spread is still non-relativistic.”
  • The paper relies on this without support.

    The momentum width of the wavepackets is still small after the acceleration.

    “In the relativistic case we can obtain an approximate solution by exploiting that the momentum width of the wavepackets is still small after the acceleration.”
  • The paper relies on this without support.

    For the chosen pulse duration, the laser intensities are so low that coupling to other momenta is very weak and can be neglected except when the resonance condition is fulfilled.

    “However, for a pulse duration of t L = π/ (4 g 1 g 2 ) = 1 . 56 ns, where g i is defined in Eq. (7) of Ref. [13], the laser intensities are so low that this coupling is very weak and can be neglected except when resonance condition (22) (or Eq. (12) of Ref. [13] for non-relativistic electrons) is fulfilled.”
  • The authors state this as an assumption.

    The electric field is homogeneous.

    “The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
  • The authors state this as an assumption.

    The laser pulses are switched on and off at specific times.

    “The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
  • The authors state this as an assumption.

    The analysis is one-dimensional and ignores forces in the x- and y-direction.

    “The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
  • The authors state this as an assumption.

    The momentum of the electrons changes instantaneously (as assumed in Secs. II and III).

    “The reason is that Eq. (25) takes into account the finite duration t L of the laser pulses, while the discussion in Secs. II and III assumes that the momentum of the electrons changes instantaneously.”
8 of 8

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. T. Matsuda, 2004, AAPPS Bull., 14, 3

Cited by

Sorted by citations

Authors
Marzlin, K.-P., & Lee, T.
Affiliations
  • University of Calgary (CA)
  • St. Francis Xavier University (CA)
Venue
Physical Review A
Published
2014-06-04
Volume
89
Issue
6
ISSN
  • 0556-2791 (ISSN-L)
  • 1050-2947
  • 1094-1622
OpenAlex
W2079823567
Cited by
3
References
42
Citations by year
2024: 1 · 2018: 1 · 2017: 1
FWCI
0.17
Type
journal article
Language
en
Open access
Locations
  • Physical Review A (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
  • arXiv (Cornell University)
Topics
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum Mechanics and Applications
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum and Classical Electrodynamics
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Atomic and Molecular Physics
Keywords
electron interferometry, length contraction, Kapitza-Dirac effect, relativistic electrons, fringe visibility, special relativity

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-23.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-23.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review