REVIEW 4 major objections 5 minor 61 references
Reflection positivity in Euclidean formulations of relativistic quantum mechanics of particles
T0 review · 4 major / 5 minor · reviewed 2026-08-06 · deepseek-v4-flash
Pith's one-line read Relaxing locality produces Euclidean relativistic quantum models with a Hilbert space, cluster properties, and a spectral condition, all without analytic continuation.
desk verdict The two-point construction is clean and the structural idea is interesting, but the connected four-point reflection-positivity proof has a genuine gap that needs fixing before the general claims hold. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The machinery is the quasi-Schwinger function: a Euclidean covariant distribution indexed by separate initial and final Euclidean coordinates, replacing one symmetric Schwinger function. Connected quasi-Schwinger functions are built from the assumed intermediate-state form, a convolution of initial and final Euclidean-invariant vertex functions $S_{n,a}(X-x_i; p_e)$ around a propagator $D^s(p_e\cdot\sigma_e)/(p_e^2+m^2)$ with a non-negative spectral weight $\rho(m)$. Reflecting the initial Euclidean time turns the time integral into a contour integral whose only pole is at $p_e^0=-i\omega_m(p)$; after the residue is taken, the kernel becomes a positive matrix built from the spin-$s$ representation matrices $D^s(p_m\cdot\sigma_m)/2\omega_m(p)$, which are squares of Hermitian matrices. A one-variable Laplace-representation theorem [53] supplies the prototype for turning reflection positivity into a spectral representation, and a formal linked-cluster expansion converts sums of connected kernels into quasi-Schwinger functions with cluster properties.
What would settle it
Take any proposed non-negative spectral density and Euclidean-invariant vertex functions that are analytic in $p_e$ and decay in coordinate separations, evaluate the connected four-point kernel (92) on reflected-time test functions, and check numerically that the resulting inner-product matrix is positive semidefinite; a counterexample distribution that is reflection positive and Euclidean covariant but cannot be written in this convolution form would likewise show that the claimed general structure is not exhaustive.
Extended reading notes
Core claim
The central discovery is that the $N$-point functions of a local Euclidean field theory, constrained by symmetry, can be replaced in the nonlocal setting by $N-1$ independent distributions with $m$ initial and $k=N-m$ final points, and that this split relaxes reflection positivity into a workable condition while preserving the structures needed for physics. The paper constructs connected versions of these quasi-Schwinger functions from intermediate-state propagators with positive spectral weight and Euclidean-invariant vertex functions, proves that they satisfy Euclidean covariance and reflection positivity, and assembles them through a linked-cluster expansion into distributions satisfying cluster properties. The resulting Hilbert-space inner product is non-negative by construction, and the Euclidean generators become self-adjoint Poincaré generators with a Hamiltonian that is bounded from below.
Load-bearing premise
The load-bearing premise is that every connected quasi-Schwinger function can be written as the assumed intermediate-state convolution of Euclidean-invariant vertex functions around a positive propagator with a non-negative spectral weight, with the vertex functions analytic in the momentum variable and decaying in coordinate separations, and that an acceptable spectral density exists; the paper labels this structure as assumed rather than derived.
Editorial extensions
If this is right
- Cluster-separable relativistic few-body models can be written directly in Euclidean space, bypassing the recursive unitary constructions needed in direct-interaction relativistic quantum mechanics.
- Quantum-mechanical inner products and expectation values are computable from the Euclidean distributions themselves, so analytic continuation is not required for practical calculations.
- Local Euclidean field theories fit inside the construction, since their symmetric Schwinger functions satisfy all of the reflection-positivity conditions imposed on quasi-Schwinger functions.
- The dynamical problem separates from the structural one: any future dynamical principle that supplies an acceptable spectral density and vertex functions automatically yields a well-defined Euclidean representation with the required physical properties.
Reading between the lines
- If the vertex-function ansatz is in fact exhaustive, reflection positivity plus Euclidean covariance for connected distributions would reduce to a spectral condition, turning the construction into a classification scheme; the paper proves sufficiency in one direction but not this converse.
- A natural next step, not taken in the paper, would be to generate quasi-Schwinger functions from an approximate dynamical input such as lattice data or truncated Euclidean integral equations; the paper fixes the structural constraints such an input would have to satisfy.
- The same split of one N-point object into several initial-final distributions might soften reflection-positivity obstructions in other nonlocal Euclidean settings, such as effective hadronic models or open quantum systems, wherever locality is not available.
Signed reviews
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper develops a Euclidean formulation of relativistic quantum mechanics for finite numbers of degrees of freedom by dropping the locality axiom and replacing a single N-point Schwinger function with N−1 quasi-Schwinger functions distinguished by the number of initial and final coordinates. The two-point functions are explicitly constructed from positive-mass, positive-energy irreducible representations of the Poincaré group, and the paper claims that connected multi-point functions built from an assumed intermediate-state ansatz satisfy Euclidean covariance and reflection positivity, thereby defining a physical Hilbert space inner product with self-adjoint Poincaré generators, cluster properties, and a spectral condition. Section VIII provides a cluster expansion using a formal linked-cluster generating functional. The conclusion acknowledges that the spectral density is an assumption rather than a derived dynamical input.
Significance. If the construction is correct, it offers an interesting route to non-local relativistic quantum mechanical models in which physical inner products and scattering calculations can be performed without analytic continuation. The explicit two-point construction in Section V is a clean demonstration of how Lorentz-covariant inner products emerge from reflection-positive Euclidean kernels, and the paper's honest statement that the spectral density is dynamical input is a useful clarification of the method's scope. The proposal to replace one N-point function by N−1 reflection-positive distributions with different initial/final splits is a genuinely new structural feature that could simplify positivity conditions in non-local models. However, the central existence claim for connected multi-point functions is not yet rigorously established because the reflection-positivity proof contains a load-bearing gap.
major comments (4)
- [Section VII, Eqs. (103)-(104)] The reflection-positivity proof uses the identity θ(xe1−xe2)·pe = ((xe1−xe2)·pe)*, which is false for real Euclidean momenta pe. The identity holds only at the pole p0 = −iωλ(p), and even there it requires a reality condition on the vertex function, such as S_2 being real for real Euclidean arguments, so that Euclidean invariance yields S_2(θx, p_e) = (S_2(x, p_e))*. No such reality condition is stated in the assumptions on S^{s1s2:s}_2 (Eqs. (92)-(93)) or on the general S_{n,a} (Eq. (106)). As written, the replacement of S*_2(θ(x1−x2), pe) by (S_2(x1−x2, pe))* in passing from (103) to (104) is unjustified, so the non-negativity of the quadratic form (102) is not established.
- [Section VII, after Eq. (106)] The paper asserts that the proof of Euclidean covariance and reflection positivity for the general connected quasi-Schwinger functions 'follows the proof in the four-point case.' Since the four-point proof has the gap described above, the reflection positivity of the general class in Eq. (106) is not proven. A repaired argument would need either an explicit reality/positive-definiteness condition on the vertex functions S_{n,a} or an alternative derivation that does not rely on the false identity.
- [Section VII, Eq. (92) versus Eqs. (103)-(105)] The intermediate-state mass is denoted m in Eq. (92) but λ in Eqs. (103)-(105), and the residue calculation in (105) uses ωλ(p). This inconsistency makes it unclear which mass parameter appears in the spectral decomposition and in the assumed ρ(m) of Eq. (107). The notation should be unified, and the role of ρ(m) in the connected four-point function should be made explicit.
- [Section VII, Eqs. (92) and (106)] The paper explicitly assumes that every connected quasi-Schwinger function has the intermediate-state convolution form (92)/(106), with Euclidean-invariant, p_e-analytic vertex functions that vanish at large coordinate separations. No proof is given that all reflection-positive Euclidean covariant distributions admit such a decomposition, so the claim to characterize the 'general structure' of such distributions is stronger than what is established. This is a scope limitation that should be clearly stated in the introduction and conclusion.
minor comments (5)
- [Section V, Eq. (105)] In the displayed expression after the residue integration, the spatial Fourier phases e^{±ip·x} appear to be missing inside the brackets, and the factor e^{−ω(x0_e1+x0_e2)} is placed outside the integral. This makes the expression ambiguous; please move the exponential inside the integral and include the spatial phases so that the Fourier transform structure is explicit.
- [Section IV, paragraph after Eq. (19)] There is a duplicated phrase 'are are' in the sentence beginning 'Dot superscripts are are used...'.
- [References] Reference [53] contains a typo: 'Succicient' should be 'Sufficient'. Also, the citation 'see of [53]' in Section III should give a specific page or theorem number.
- [Section VIII, first paragraph] The statement that 'reflection positivity is preserved under addition and tensor products' is standard but should be either proven in a line or accompanied by a reference, since it is a key ingredient in the cluster-expansion argument.
- [Section VII, Eq. (103)] The Clebsch-Gordan coefficient ⟨s1, µ1, s2, µ2|s, µ⟩ is real, but the transition from (103) to (104) applies a complex conjugate to this factor; the reality should be stated explicitly to avoid confusion.
Circularity Check
No circularity: the quasi-Schwinger construction is a self-contained sufficiency construction; the reflection-positivity proof has a non-circular technical gap.
full rationale
The derivation is not circular. The two-point quasi-Schwinger function in Eq. (71) is explicitly built from the known positive-energy irreducible representation, and its reflection positivity is verified by reducing the Euclidean bilinear form to the manifestly positive Lorentz-covariant inner product (78), which is a consistency check, not a circular reduction. The connected four-point and multi-point forms (92) and (106) are introduced as explicit 'assumed' ansätze, with the paper stating that the spectral density is 'dynamical information that should be calculated rather than assumed'; the existence claim is therefore a sufficiency construction, not a prediction extracted from data or from the target conclusion. No fitted parameters are used, and no uniqueness theorem is invoked. The citation to [5] for the Poincaré generators is a conditional construction that assumes distributions of the type constructed here, so it does not supply the existence claim; the present construction is what supplies it. The main mathematical concern is not circularity: the step between Eqs. (103) and (104) uses the identity θx·p = (x·p)*, which is false for real Euclidean p and needs an unstated reality condition or a pole-contour qualification; this is a correctness gap in the reflection-positivity proof, not a reduction of the conclusion to the inputs. The acknowledged assumptions about the vertex functions and spectral weight are explicit limitations, not circular inputs.
Assumptions & free parameters
free parameters (2)
- spectral density ρ(m) =
unspecified nonnegative measure
- intermediate-state mass λ and spin (s,0) =
arbitrary
assumptions (7)
- standard math Widder's theorem: continuous reflection-positive kernels k(t) have the Laplace representation k(t)=∫ e^{-λ t} dρ(λ)
- standard math Unitary representations of the Poincaré group decompose into direct integrals of positive-mass positive-energy irreducible representations
- standard math Wigner D functions are entire functions of rotation angles, so their SL(2,C) extension is analytic and Clebsch-Gordan decompositions persist
- ad hoc to paper The general connected quasi-Schwinger function has the assumed intermediate-state ansatz (Eqs. 92, 106) with Euclidean invariant, p_e-analytic vertex functions S_{n,a}
- ad hoc to paper An acceptable spectral density ρ(m) exists and is part of the dynamical input
- domain assumption Self-adjointness and cluster properties of the Poincaré generators on the constructed Hilbert space follow from prior work [5]
- domain assumption Test functions have Euclidean time support, enabling residue-theorem evaluation of Euclidean momentum integrals
Cite this review
Pith. "Pith review of Reflection positivity in Euclidean formulations of relativistic quantum mechanics of particles." pith.science (2026). https://pith.science/paper/SZ2RIR3N
@misc{pith2026250620526,
author = {Pith},
title = {Pith review of: Reflection positivity in Euclidean formulations of relativistic quantum mechanics of particles},
year = {2026},
howpublished = {\url{https://pith.science/paper/SZ2RIR3N}},
note = {Machine review of arXiv:2506.20526}
}
read the original abstract
This paper discusses the general structure of reflection positive Euclidean covariant distributions that can be used to construct Euclidean representations of relativistic quantum mechanical models of systems of a finite number of degrees of freedom. Because quantum systems of a finite number of degrees of freedom are not local, reflection positivity is not as restrictive as it is in a local field theory. The motivation for the Euclidean approach is that it is straightforward to construct exactly Poincar\'e invariant quantum models of finite number of degrees of freedom systems that satisfy cluster properties and a spectral condition. In addition the quantum mechanical inner product can be computed without requiring an analytic continuation. Whether these distributions can be generated by a dynamical principle remains to be determined, but understanding the general structure of the Euclidean covariant distributions is an important first step.
Reference graph
Works this paper leans on
-
[1]
The connected four point function can be replaced by a square matrix of m + n-point connected distributions with the same “intermediate states”
-
[2]
The spinors of rank ( s, 0) can be replaced by spinors of rank ( sr, sl) or direct sums of rank ( s, 0) ⊕ (0, s)
-
[3]
A single “intermediate state” of mass, λ >0, and spin ( sr, sl) can be replaced by linear superpositions of states with different λ’s and spins with a positive weight
-
[4]
It isstraightforward to construct Sn,a with these properties
The initial and final distributions S s1s2:s 2 ( 1 2 (y1 − y2), pe)⟨s1, ν1, s2, ν2|s, ν,⟩ are replaced sums of products of invariant distributions and constant coupling coefficients of the form X a S (sr1,sl1)···(srn,sln);(sr,sl) n,a (Xe − xe1 · · ·Xe − xen−1; pc e)C (sr1,sl1),···(srn,sln);(srsl) (µr1,µl1)···(µrn,µln);(µr,µl)(a) (106) where X = 1 n (xe1 +...
-
[5]
G. S. Samad and W. N. Polyzou, Euclidean formulation of relativistic quantum mechanics of n particles, Phys. Rev. C 103, 025203 (2021)
work page 2021
-
[6]
P. Kopp and W. N. Polyzou, A Euclidean formulation of relativistic quantum mechanics, Phys. Rev. D85, 016004 (2012), arXiv:1106.4086 [nucl-th]
arXiv 2012
-
[7]
W. N. Polyzou, Scattering and reflection positivity in relativistic Euclidean quantum mechanics, Phys. Rev. D89, 076008 (2014), arXiv:1312.3585 [math-ph]
arXiv 2014
-
[8]
W. N. Polyzou, Representations of relativistic particles of arbitrary spin in Poincar´ e, Lorentz, and Euclidean covariant formulations of relativistic quantum mechanics, Phys. Rev. C99, 025202 (2019), arXiv:1809.09717 [math-ph]
arXiv 2019
Show all 61 references
-
[9]
G. J. Aiello and W. N. Polyzou, Scattering asymptotic conditions in Euclidean relativistic quantum theory, Phys. Rev. D93, 056003 (2016), arXiv:1512.03651 [hep-th]. 21
2016 arXiv
-
[10]
Bakamjian and L
B. Bakamjian and L. H. Thomas, Relativistic particle dynamics. 2, Phys. Rev. 92, 1300 (1953)
1953
-
[11]
R. F. Streater and A. S. Wightman, PCT, Spin and Statistics, and All That (Princeton Landmarks in Physics, 1980) pp. 168–170
1980
-
[12]
Haag and D
R. Haag and D. Kastler, An Algebraic approach to quantum field theory, J. Math. Phys. 5, 848 (1964)
1964
-
[13]
Osterwalder and R
K. Osterwalder and R. Schrader, Axioms for Euclidean Green’s functions, Commun. Math. Phys. 31, 83 (1973)
1973
-
[14]
Osterwalder and R
K. Osterwalder and R. Schrader, Axioms for Euclidean Green’s Functions II, Commun. Math. Phys. 42, 281 (1975)
1975
-
[15]
Glockle, T
W. Glockle, T. S. H. Lee, and F. Coester, Relativistic effects in three-body bound states, Phys. Rev. C33, 709 (1986)
1986
-
[16]
Coester, Scattering theory for relativistic particles, Helv
F. Coester, Scattering theory for relativistic particles, Helv. Phys. Acta 38, 7 (1965)
1965
-
[17]
B. L. G. Bakker, L. A. Kondratyuk, and M. V. Terentev, ON THE FORMULATION OF TWO-BODY AND THREE- BODY RELATIVISTIC EQUATIONS EMPLOYING LIGHT FRONT DYNAMICS, Nucl. Phys. B158, 497 (1979)
1979
-
[18]
S. N. Sokolov, Relativistic Addition of Direct Interactions in the Point Form of Dynamics, Theor. Math. Phys. 36, 682 (1979)
1979
-
[19]
rotationless
[20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42]. These phenomenological models can be constructed so they satisfy most of the axioms of a quantum field theory, however they are not local, since they are formula...
-
[20]
Coester and W
F. Coester and W. N. Polyzou, Relativistic quantum mechanics of particles with direct interactions, Phys. Rev. D26, 1348 (1982)
1982
-
[21]
P. L. Chung, F. Coester, and W. N. Polyzou, Charge Form-Factors of Quark Model Pions, Phys. Lett. B205, 545 (1988)
1988
-
[22]
P. L. Chung, W. N. Polyzou, F. Coester, and B. D. Keister, Hamiltonian Light Front Dynamics of Elastic electron Deuteron Scattering, Phys. Rev. C37, 2000 (1988)
1988
-
[23]
B. D. Keister, Front-form Hamiltonian dynamics of deuteron electrodisintegration, Phys. Rev. C37, 1765 (1988)
1988
-
[24]
W. N. Polyzou, Relativistic Two-Body Models, Ann. Phys. 193, 367 (1989)
1989
-
[25]
P. L. Chung and F. Coester, Relativistic constituent quark model of nucleon form-factors, Phys. Rev. D44, 229 (1991)
1991
-
[26]
B. D. Keister and W. N. Polyzou, Relativistic Hamiltonian dynamics in nuclear and particle physics, Adv. Nucl. Phys. 20, 225 (1991)
1991
-
[27]
Cardarelli, E
F. Cardarelli, E. Pace, G. Salme, and S. Simula, Nucleon and pion electromagnetic form-factors in a light front constituent quark model, Phys. Lett. B357, 267 (1995), arXiv:nucl-th/9507037
1995 arXiv
-
[28]
W. H. Klink and W. N. Polyzou, Relativistic N-body models, Phys. Rev. C54, 1189 (1996)
1996
-
[29]
W. N. Polyzou and W. Gl¨ ockle, Scaling for deuteron structure functions in a relativistic light front model, Phys. Rev.C53, 3111 (1996)
1996
-
[30]
A. F. Krutov, Electroweak properties of light mesons in the relativistic model of constituent quarks, Phys. Atom. Nucl. 60, 1305 (1997)
1997
-
[31]
Coester and D
F. Coester and D. O. Riska, Poincare covariant quark models of baryon form-factors, Few Body Syst. 25, 29 (1998), arXiv:hep-ph/9707388 [hep-ph]
1998 arXiv
-
[32]
T. W. Allen, W. H. Klink, and W. N. Polyzou, Point-Form Analysis of Elastic Deuteron Form Factors, Phys. Rev. C63, 034002 (2001), arXiv:nucl-th/0005050
2001 arXiv
-
[33]
Julia-Diaz, D
B. Julia-Diaz, D. O. Riska, and F. Coester, Baryon Form Factors of Relativistic Constituent-Quark Models, Phys. Rev. C69, 035212 (2004), arXiv:hep-ph/0312169
2004 arXiv
-
[34]
Coester and W
F. Coester and W. N. Polyzou, Charge form factors of quark-model pions, Phys. Rev. C71, 028202 (2005)
2005
-
[35]
T. Lin, C. Elster, W. N. Polyzou, and W. Glockle, Relativistic Effects in Exclusive pd Breakup Scattering at Intermediate Energies, Phys. Lett. B660, 345 (2008), arXiv:0710.4056 [nucl-th]
2008 arXiv
-
[36]
J. P. B. C. de Melo, T. Frederico, E. Pace, S. Pisano, and G. Salme, Time- and Spacelike Nucleon Electromagnetic Form Factors beyond Relativistic Constituent Quark Models, Phys. Lett. B671, 153 (2009), arXiv:0804.1511 [hep-ph]
2009 arXiv
-
[37]
T. Lin, C. Elster, W. N. Polyzou, H. Witala, and W. Glockle, Poincar´ e Invariant Three-Body Scattering at Intermediate Energies, Phys. Rev. C78, 024002 (2008), arXiv:0801.3210 [nucl-th]
2008 arXiv
-
[38]
Witala et al
H. Witala et al. , Relativity and the low energy nd Ay puzzle, Phys. Rev. C77, 034004 (2008), arXiv:0801.0367 [nucl-th]
2008 arXiv
-
[39]
Witala et al
H. Witala et al. , Relativistic effects in 3N reactions, Mod. Phys. Lett. A24, 871 (2009)
2009
-
[40]
E. P. Biernat, W. Schweiger, K. Fuchsberger, and W. H. Klink, Electromagnetic meson form factor from a relativistic coupled-channel approach, Phys. Rev. C79, 055203 (2009), arXiv:0902.2348 [nucl-th]
2009 arXiv
-
[41]
Desplanques, RQM description of the charge form factor of the pion and its asymptotic behavior, Eur
B. Desplanques, RQM description of the charge form factor of the pion and its asymptotic behavior, Eur. Phys. J. A42, 219 (2009), arXiv:0906.1889 [nucl-th]
2009 arXiv
-
[42]
M. G. Fuda and F. Bulut, Three-particle model of the pion-nucleon system, Phys. Rev. C80, 024002 (2009)
2009
-
[43]
Witala, J
H. Witala, J. Golak, R. Skibinski, W. Glockle, H. Kamada, and W. N. Polyzou, Three-nucleon force in relativis- tic three-nucleon Faddeev calculations, Phys. Rev. C83, 044001 (2011), [Erratum: Phys. Rev.C88,no.6,069904(2013)], arXiv:1101.4053 [nucl-th]
2011 arXiv
-
[44]
M. G. Fuda, Relativistic quantum mechanics and the quark-pair creation model, Phys. Rev. C86, 055205 (2012)
2012
-
[45]
M. R. Hadizadeh, C. Elster, and W. N. Polyzou, Relativistic three-body bound state in a 3D formulation, Phys. Rev. C90, 054002 (2014), arXiv:1409.1650 [nucl-th]
2014 arXiv
-
[46]
S. K. Kunhammed and W. N. Polyzou, Simple relativistic quark models, Phys. Rev. C 102, 065209 (2020)
2020
-
[47]
Grassi, J
A. Grassi, J. Golak, W. N. Polyzou, R. Skibi´ nski, H. Wita la, and H. Kamada, Electron and neutrino scattering off the deuteron in a relativistic framework, Phys. Rev. C 107, 024617 (2023)
2023
-
[48]
S. N. Sokolov, , Dokl. Akad. Nauk SSSR 233, 575 (1977)
1977
-
[49]
Gilmm and A
J. Gilmm and A. Jaffe, Quantum Physics - A functional Integral Point of View (Springer, 1981)
1981
-
[50]
Schwinger, On Angular Momentum (Dover, NY, 2015)
J. Schwinger, On Angular Momentum (Dover, NY, 2015)
2015
-
[51]
N. N. Bogoliubov and D. V. Shirkov, Introduction to the theory of quantized fields (Wiley-Interscience, 1959) p. 150. 22
1959
-
[52]
Epstein and V
H. Epstein and V. Glaser, The Role of locality in perturbation theory, Ann. Inst. H. Poincare A Phys. Theor. 19, 211 (1973)
1973
-
[53]
Grang´ e, J.-F
P. Grang´ e, J.-F. Mathiot, B. Mutet, and E. Werner, Taylor-lagrange renormalization scheme: Application to light-front dynamics, Phys. Rev. D 80, 105012 (2009)
2009
-
[54]
Scharf, Quantum gauge theories: A true ghost story (Wiley, New York, USA, 2001)
G. Scharf, Quantum gauge theories: A true ghost story (Wiley, New York, USA, 2001)
2001
-
[55]
Brenig and R
W. Brenig and R. Haag, General quantum theory of collision processes, Fort. der Physik 7, 183 (1959)
1959
-
[56]
Ruelle, , Helv
D. Ruelle, , Helv. Phys. Acta. 35, 147 (1962)
1962
-
[57]
Haag, Quantum field theories with composite particles and asymptotic conditions, Phys
R. Haag, Quantum field theories with composite particles and asymptotic conditions, Phys. Rev. 112, 669 (1958)
1958
-
[58]
D. V. Widder, Necessary and Succicient conditions for the representation of a function by a doubly infinite laplace integral, Bull. Amer. Math. Soc. 40, 321 (1934)
1934
-
[59]
E. P. Wigner, On Unitary Representations of the Inhomogeneous Lorentz Group, Annals Math. 40, 149 (1939)
1939
-
[60]
Reed and B
M. Reed and B. Simon, Methods of Modern mathematical Physics , Vol. III Scattering Theory (Academic Press, 1979) p. 317
1979
-
[61]
Carleman, Les fonctions quasi analytiques, Collection de Monographies sur la Th´ eorie des Fonctions (Gauthier–Villars, Paris, 1926)
T. Carleman, Les fonctions quasi analytiques, Collection de Monographies sur la Th´ eorie des Fonctions (Gauthier–Villars, Paris, 1926)
1926
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