The spin–statistics connection is obtained for classical particles. The connection holds within pseudomechanics, a theory of particle motion that extends classical physics to include anticommuting Grassmann variables, and that exhibits classical analogs of both spin and statistics. Classical realizations of Lie groups are constructed in a canonical formalism generalized to include Grassmann variables. The theory of irreducible canonical realizations of the Poincaré group is developed in this framework, with particular emphasis on the rotation subgroup. The behavior of irreducible realizations under time inversion and charge conjugation is obtained. The requirement that the Lagrangian retain its form under the combined operation of charge conjugation and time reversal leads directly to the spin–statistics connection by an adaptation of Schwinger’s 1951 proof to irreducible canonical realizations of the Poincaré group of spin j: Generalized spin coordinates and momenta satisfy fundamental Poisson bracket relations for 2j even, and fundamental Poisson antibracket relations for 2j odd.

1.
W.
Pauli
, “
The connection between spin and statistics
,”
Phys. Rev.
58
,
722
(
1940
).
2.
W.
Pauli
, “
The connection between spin and statistics
,”
Phys. Rev.
58
,
716
722
(
1940
).
3.
W. Pauli, “Exclusion principle and quantum mechanics,” in Nobel Lectures-Physics: 1942–62 (Elsevier, New York, 1964) pp. 27–43.
4.
W.
Pauli
, “
On the connection between spin and statistics
,”
Prog. Theor. Phys.
5
,
526
543
(
1950
).
5.
H. J.
Bhabha
, “
On the postulational basis of the theory of elementary particles
,”
Rev. Mod. Phys.
21
,
451
462
(
1949
).
6.
Julian
Schwinger
, “
Theory of quantized fields I
,”
Phys. Rev.
82
,
914
927
(
1951
).
7.
N.
Burgoyne
, “
On the connection of spin and statistics
,”
Nuovo Cimento
8
,
607
609
(
1958
).
8.
Gerhard
Lüders
and
Bruno
Zumino
, “
Connection between spin and statistics
,”
Phys. Rev.
110
,
1450
1453
(
1958
).
9.
R. F. Streater and A. S. Wightman, PCT, Spin and Statistics, and All That (Benjamin, New York, 1964).
10.
G. F.
Dell’Antonio
, “
On the connection between spin and statistics
,”
Ann. Phys. (N.Y.)
16
,
153
157
(
1961
).
11.
Julian
Schwinger
, “
Spin, statistics, and the TCP theorem
,”
Proc. Natl. Acad. Sci. U.S.A.
44
,
223
228
(
1958
).
12.
Julian Schwinger, Particles and Sources (Gordon and Breach, New York, 1969), pp. 25–27.
13.
L.
Brown
and
J.
Schwinger
, “
Spin and statistics
,”
Prog. Theor. Phys.
26
,
917
926
(
1961
).
14.
Steven
Weinberg
, “
Feynman rules for any spin
,”
Phys. Rev.
133B
,
1318
1332
(
1964
).
15.
Steven
Weinberg
, “
Feynman rules for any spin. II. Massless particles
,”
Phys. Rev.
134B
,
882
896
(
1964
).
16.
Steven
Weinberg
, “
Feynman Rules for any spin. III
,”
Phys. Rev.
181
,
1893
1899
(
1969
).
17.
C. L.
Hammer
and
R. H.
Good
, “
Quantization process for massless particles
,”
Phys. Rev.
111
,
342
345
(
1958
).
18.
R. H. Good, “Theory of particles with zero rest-mass,” in Lectures in Theoretical Physics, Summer Institute of Theoretical Physics, University of Colorado, Boulder, edited by W. E. Brittin and L. G. Dunham (Interscience, New York, 1958).
19.
Ian Duck and E. C. G. Sudarshan, Pauli and the Spin-Statistics Theorem (World Scientific, Singapore, 1997).
20.
O. W.
Greenberg
, “
Spin-statistics, spin-locality, and TCP: Three distinct theorems
,”
Phys. Lett. B
416
,
144
149
(
1998
).
21.
Julio
Finkelstein
and
David
Rubinstein
, “
Connection between spin, statistics, and kinks
,”
J. Math. Phys.
9
,
1762
1779
(
1968
).
22.
Ralf D.
Tscheuschner
, “
Topological spin-statistics relation in quantum field theory
,”
Int. J. Theor. Phys.
28
,
1269
1310
(
1989
).
23.
Ralf D.
Tscheuschner
, “
Coinciding versus noncoinciding: Is the topological spin-statistics theorem already proven in quantum mechanics?
,”
J. Math. Phys.
32
,
749
752
(
1990
).
24.
A. P.
Balachandran
,
A.
Daughton
,
Z.-C.
Gu
,
G.
Marmo
,
R. D.
Sorkin
, and
A. M.
Srivastava
, “
A topological spin-statistics theorem or a use of the antiparticle
,”
Mod. Phys. Lett. A
5
,
1575
1585
(
1990
).
25.
A. P.
Balachandran
,
R. D.
Sorkin
,
W. D.
McGlinn
,
L.
O’Raifeartaigh
, and
S.
Sen
, “
The spin-statistics connection from homology groups of configuration space and an anyon Wess-Zumino term
,”
Int. J. Mod. Phys. A
7
,
6887
6906
(
1992
).
26.
A. P.
Balachandran
,
A.
Daughton
,
Z.-C.
Gu
,
R. D.
Sorkin
,
G.
Marmo
, and
A. M.
Srivastava
, “
Spin-statistics theorems without relativity or field theory
,”
Int. J. Mod. Phys. A
8
,
2993
3044
(
1993
).
27.
A. P.
Balachandran
,
W. D.
McGlinn
,
L.
O’Raifeartaigh
,
S.
Sen
,
R. D.
Sorkin
, and
A. M.
Srivastava
, “
Topological spin-statistics theorems for strings
,”
Mod. Phys. Lett. A
7
,
1427
1442
(
1992
).
28.
A. P.
Balachandran
,
T.
Einarsson
,
T. R.
Govindarajan
, and
R.
Ramachandran
, “
Statistics and spin on two-dimensional surfaces
,”
Mod. Phys. Lett. A
6
,
2801
2810
(
1991
).
29.
In fact, no relation between spin and statistics holds for topological geons in canonical quantum gravity, in which topology change, and thus the existence of anti-geons, is forbidden. See
H. F.
Dowker
and
R. D.
Sorkin
, “
Spin and statistics in quantum gravity,” arXiv:
gr-qc/0101042.
30.
I could not locate the origin of this formulation, but Finkelstein and Rubinstein state the theorem for kinks using almost exactly these words in Sec. V.4 of their 1968 paper, Ref. 21.
31.
R. P.
Feynman
, “
The theory of positrons
,”
Phys. Rev.
76
,
749
759
(
1949
).
32.
R. P. Feynman, R. B. Leighton, and M. Sands, The Feynman Lectures on Physics (Addison–Wesley, Reading, MA, 1965), Vol. III, Chap. 4.
33.
R. P. Feynman, “The reason for antiparticles,” in R. P. Feynman and S. Weinberg, Elementary Particles and the Laws of Physics (Cambridge U.P., Cambridge, 1987).
34.
D. E.
Neuenschwander
, “
Question #7. The spin-statistics theorem
,”
Am. J. Phys.
62
,
972
(
1994
).
35.
Ian
Duck
and
E. C. G.
Sudarshan
, “
Toward an understanding of the spin-statistics theorem
,”
Am. J. Phys.
66
,
284
303
(
1998
).
36.
M. V.
Berry
and
J. M.
Robbins
, “
Indistinguishability for quantum particles: Spin, statistics, and the geometric phase
,”
Proc. R. Soc. London, Ser. A
453
,
1771
1790
(
1997
).
37.
It may be that electron–hole pairs would suffice in condensed matter applications.
38.
R.
Mickelsson
, “
Geometry of spin and statistics in classical and quantum mechanics
,”
Phys. Rev. D
30
,
1843
1845
(
1984
).
39.
H. C.
Corben
, “
Spin in classical and quantum theory
,”
Phys. Rev.
121
,
1833
1839
(
1961
).
40.
Ralph
Schiller
, “
Quasi-classical theory of the spinning electron
,”
Phys. Rev.
125
,
1116
1123
(
1962
).
41.
Ralph
Schiller
, “
Quasi-classical theory of a relativistic spinning electron
,”
Phys. Rev.
128
,
1402
1412
(
1962
).
42.
A. J.
Hanson
and
T.
Regge
, “
The relativistic spherical top
,”
Ann. Phys. (N.Y.)
87
,
498
566
(
1974
).
43.
Patrick L.
Nash
, “
A Lagrangian theory of the classical spinning electron
,”
J. Math. Phys.
25
,
2104
2108
(
1984
).
44.
Jin-Ho
Cho
and
Jae-Kwan
Kim
, “
Derivation of the classical Lagrangian for the relativistic spinning particle
,”
Phys. Lett. B
332
,
118
122
(
1994
).
45.
F. A.
Berezin
and
M.
Marinov
, “
Particle spin dynamics as the Grassmann variant of classical mechanics
,”
Ann. Phys. (N.Y.)
104
,
336
(
1977
).
46.
Carlos A. P.
Galvao
and
Claudio
Teitelboim
, “
Classical supersymmetric particles
,”
J. Math. Phys.
21
,
1863
1880
(
1980
).
47.
Robert Geroch, Mathematical Physics (University of Chicago Press, Chicago, 1985), Chap. 19.
48.
W.-K. Tung, Group Theory in Physics (World Scientific, Singapore, 1985), Chaps. 7–10.
49.
E. C. G. Sudarshan, and N. Mukunda, Classical Dynamics: A Modern Perspective (Wiley, New York, 1974), pp. 391, 454–466.
50.
F. A. Berezin, The Method of Second Quantization (Academic, New York, 1966).
51.
M. S. Swanson, Path Integrals and Quantum Processes (Academic, New York, 1992), Chap. 5.
52.
Reference 51, p. 120.
53.
The result to be proven concerns symmetries of Poisson brackets for dynamical variables of a single massive particle; there is no need to examine what is meant by “identical” particles in the present discussion.
54.
R.
Casalbuoni
, “
On the quantization of systems with anticommuting variables
,”
Nuovo Cimento Soc. Ital. Fis., A
33
,
115
124
(
1976
).
55.
R.
Casalbuoni
, “
The classical mechanics for Bose-Fermi systems
,”
Nuovo Cimento Soc. Ital. Fis., A
33
,
389
431
(
1976
).
56.
F. A.
Berezin
and
G. I.
Kac
, “
Lie Groups with commuting and anticommuting parameters
,”
Math. USSR. Sb.
11
,
311
325
(
1970
).
57.
L.
Corwin
,
Y.
Ne’eman
, and
S.
Sternberg
, “
Graded Lie algebras in mathematics and physics (Bose-Fermi symmetry)
,”
Rev. Mod. Phys.
47
,
573
603
(
1975
).
58.
Steven Weinberg, The Quantum Theory of Fields III (Cambridge U.P., Cambridge, 2000), pp. 25–26.
59.
J.
Gomis
,
M.
Novell
,
A.
Poch
, and
K.
Rafanelli
, “
Pseudoclassical description of a relativistic spinning particle
,”
Phys. Rev. D
32
,
1985
1992
(
1985
).
60.
J.
Gomis
and
M.
Novell
, “
Pseudoclassical description for a nonrelativistic spinning particle. I. The Levy-Leblond equation
,”
Phys. Rev. D
33
,
2212
2219
(
1986
).
61.
J.
Gomis
,
M.
Novell
, and
K.
Rafanelli
, “
Pseudoclassical model of a particle with arbitrary spin
,”
Phys. Rev. D
34
,
1072
1075
(
1986
).
62.
P.
Di Vecchia
and
F.
Ravndal
, “
Supersymmetric Dirac particles
,”
Phys. Lett. A
73
,
371
373
(
1979
).
63.
F.
Ravndal
, “
Supersymmetric Dirac particles in external fields
,”
Phys. Rev. D
21
,
2823
2832
(
1980
).
64.
Steven Weinberg, The Quantum Theory of Fields I (Cambridge U.P., Cambridge, 1995), pp. 58–62.
65.
E.
Wigner
, “
On unitary representations of the inhomogeneous Lorentz group
,”
Ann. Math.
40
,
149
204
(
1939
).
66.
P. A. M.
Dirac
, “
Forms of relativistic dynamics
,”
Rev. Mod. Phys.
21
,
392
399
(
1949
).
67.
Steven Weinberg, Gravitation and Cosmology (Wiley, New York, 1972), pp. 58–61.
68.
M.
Pauri
and
G. M.
Prosperi
, “
Canonical realizations of the Poincare group. I. General theory
,”
J. Math. Phys.
16
,
1503
1521
(
1975
).
69.
Reference 48, pp. 103–105.
70.
A.
Loinger
, “
New concept of representation of a Lie algebra
,”
Ann. Phys. (N.Y.)
23
,
23
27
(
1963
).
71.
Reference 49, pp. 322–327.
72.
In the corresponding classical unitary representation, this result follows immediately from Schur’s lemma.
73.
P. A. M. Dirac, The Principles of Quantum Mechanics (Clarendon, New York, 1958), 4th ed., pp. 144–146.
74.
E. J. Saletan, and A. H. Cromer, Theoretical Mechanics (Wiley, New York, 1971), pp. 335–40.
75.
Reference 49, pp. 447–453.
76.
M.
Pauri
and
G. M.
Prosperi
, “
Canonical realizations of the rotation group
,”
J. Math. Phys.
8
,
2256
2267
(
1967
).
77.
V.
Bargmann
and
E. P.
Wigner
, “
Group theoretical discussion of relativistic wave equations
,”
Proc. Natl. Acad. Sci. U.S.A.
34
,
211
223
(
1948
).
78.
M.
Fierz
and
W.
Pauli
, “
On relativistic wave equations for particles of arbitrary spin in an electromagnetic field
,”
Proc. R. Soc. London, Ser. A
173
,
211
232
(
1939
).
79.
E. P. Wigner, Group Theory and its Application to the Quantum Mechanics of Atomic Spectra (Academic, New York, 1959), Chap. 26.
80.
Reference 64, pp. 78–79.
81.
A. R. Edmonds, Angular Momentum in Quantum Mechanics (Princeton U.P., Princeton, 1960), p. 72.
82.
U. Fano and G. Racah, Irreducible Tensorial Sets (Academic, New York), pp. 27–31.
83.
John P.
Costella
,
Bruce H. J.
McKellar
, and
Andrew A.
Rawlinson
, “
Classical antiparticles
,”
Am. J. Phys.
65
,
835
841
(
1997
).
84.
R. P.
Feynman
, “
A relativistic cut-off for classical electrodynamics
,”
Phys. Rev.
74
,
939
946
(
1948
).
85.
There is no loss of generality in this restriction, although the total Lagrangian in pseudoclassical models contains terms corresponding to more than one irreducible realization, see Eq. (20), and in general, contains a term that mixes vector and spinor variables.
86.
Schwinger’s original proof can be generalized by substituting flavor symmetry for CT invariance, see also Ref. 35.
87.
Reference 6, p. 927.
88.
M.
Pauri
and
G. M.
Prosperi
, “
Canonical realizations of Lie symmetry groups
,”
J. Math. Phys.
7
,
366
375
(
1966
).
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