We give a complete proof of the twisted duality property M(q)=Z̃M(q)Z̃* of the (self-dual) CAR-Algebra in any Fock representation. The proof is based on the natural Halmos decomposition of the (reference) Hilbert space when two suitable closed subspaces have been distinguished. We use modular theory and techniques developed by Kato concerning pairs of projections in some essential steps of the proof. As a byproduct of the proof we obtain an explicit and simple formula for the graph of the modular operator. This formula can be also applied to fermionic free nets, hence giving a formula of the modular operator for any double cone.

1.
Achieser, N. I. and Glasmann, I. M., Theorie der linearen Operatoren im Hilbert-Raum (Verlag Harri Deutsch, Thun, 1981).
2.
Araki
,
H.
, “
A lattice of von Neumann algebras associated with the quantum theory of a free bose field
,”
J. Math. Phys.
4
,
1343
1362
(
1963
).
3.
Araki
,
H.
, “
On quasifree states of CAR and Bogoliubov automorphisms
,”
Publ. RIMS, Kyoto Univ.
6
,
385
442
(
1970/71
).
4.
Araki, H., “Bogoljubov automorphisms and Fock representations of canonical anticommutation relations,” in Operator Algebras and Mathematical Physics (Proceedings of the summer conference held at the University of Iowa, 1985), edited by P. E. T. Jorgensen and P. S. Muhly (American Mathematical Society, Providence, RI, 1987).
5.
Avron
,
J.
,
Seiler
,
R.
, and
Simon
,
B.
, “
Charge deficiency, charge transport and comparison of dimensions
,”
Commun. Math. Phys.
159
,
399
422
(
1994
).
6.
Avron
,
J.
,
Seiler
,
R.
, and
Simon
,
B.
, “
The index of a air of projections
,”
J. Funct. Anal.
120
,
220
237
(
1994
).
7.
Baumgärtel, H., Operatoralgebraic Methods in Quantum Field Theory. A Series of Lectures (Akademie Verlag, Berlin, 1995).
8.
Baumgärtel
,
H.
,
Jurke
,
M.
, and
Lledó
,
F.
, “
On free nets over Minkowski space
,”
Rep. Math. Phys.
35
,
101
127
(
1995
).
9.
Baumgärtel, H. and Wollenberg, M., Causal Nets of Operator Algebras. Mathematical Aspects of Algebraic Quantum Field Theory (Akademie Verlag, Berlin, 1992).
10.
Bisognano
,
J. J.
and
Wichmann
,
E. H.
, “
On the duality condition for quantum fields
,”
J. Math. Phys.
17
,
303
321
(
1976
).
11.
Borac
,
S.
, “
On the algebra generated by two projections
,”
J. Math. Phys.
36
,
863
874
(
1995
).
12.
Bratteli, O. and Robinson, D. W., Operator Algebras and Quantum Statistical Mechanics 1 (Springer Verlag, Berlin, 1987).
13.
Davis
,
C.
, “
Separation of two linear subspaces
,”
Acta Sci. Math. Szeged
19
,
172
187
(
1958
).
14.
Dell’Antonio
,
G. F.
, “
Structure of the algebras of some free systems
,”
Commun. Math. Phys.
9
,
81
117
(
1968
).
15.
Dixmier
,
J.
, “
Position relative de deux variétés linéaires fermées dans un espace de Hilbert
,”
Rev. Sci.
86
,
387
399
(
1948
).
16.
Doplicher
,
S.
,
Haag
,
R.
, and
Roberts
,
J. E.
, “
Local observables and particle statistics I
,”
Commun. Math. Phys.
23
,
199
230
(
1971
).
17.
Doplicher
,
S.
,
Haag
,
R.
, and
Roberts
,
J. E.
, “
Local observables and particle statistics II
,”
Commun. Math. Phys.
35
,
49
85
(
1974
).
18.
Eckmann
,
J. P.
and
Osterwalder
,
K.
, “
An application of Tomita’s theory of modular Hilbert algebras: duality for free bose fields
,”
J. Funct. Anal.
13
,
1
12
(
1973
).
19.
Evans, D. E. and Kawahigashi, Y., Quantum Symmetries and Operator Algebras, Oxford Science Publications (Clarendon, Oxford, 1998).
20.
Foit
,
J. J.
, “
Abstract twisted duality for free Fermi fields
,”
Publ. RIMS, Kyoto Univ.
19
,
729
741
(
1983
).
21.
Haag, R., Local Quantum Physics (Springer Verlag, Berlin, 1992).
22.
Halmos
,
P. R.
, “
Two subspaces
,”
Trans. Am. Math. Soc.
144
,
381
389
(
1969
).
23.
Hislop
,
P. D.
, “
A simple proof of duality for local algebras in free quantum field theory
,”
J. Math. Phys.
27
,
2542
2550
(
1986
).
24.
Jurke, M., “Ergebnisse zu massiven, freien Netzen über dem Minkowskiraum,” Ph.D. thesis, Universität Postdam, 1997.
25.
Kadison, R. V. and Ringrose, J. R., Fundamentals of the Theory of Operator Algebras II (Academic, Orlando, 1986).
26.
Kato, T., Perturbation Theory for Linear Operators (Springer Verlag, Berlin, 1995).
27.
Leyland, P., Roberts, J. E., and Testard, D., Duality for Quantum Free Fields, preprint (CNRS Marseille, 1978).
28.
Lledó
,
F.
, “
Conformal covariance of massless free nets
,”
Rev. Math. Phys.
13
,
1135
1161
(
2001
).
29.
Osterwalder
,
K.
, “
Duality for free bose fields
,”
Commun. Math. Phys.
29
,
1
14
(
1973
).
30.
Rieffel
,
M. A.
and
van Daele
,
A.
, “
A bounded operator approach to Tomita-Takesaki theory
,”
Pac. J. Math.
69
,
187
221
(
1977
).
31.
Summers
,
S. J.
, “
Normal product states for fermions and twisted duality for CCR- and CAR-type algebras with applications to Yukawa2 quantum field model
,”
Commun. Math. Phys.
86
,
111
141
(
1982
).
32.
Wassermann
,
A.
, “
Operator algebras and conformal field theory III
,”
Invent. Math.
133
,
467
538
(
1998
).
This content is only available via PDF.
You do not currently have access to this content.