Abstract
We introduce four new cocycle conjugacy invariants for E 0-semigroups on II 1 factors: a coupling index, a dimension for the gauge group, a super product system and a C*-semiflow. Using noncommutative Itô integrals we show that the dimension of the gauge group can be computed from the structure of the additive cocycles. We do this for the Clifford flows and even Clifford flows on the hyperfinite II 1 factor, and for the free flows on the free group factor \({L(F_\infty)}\) . In all cases the index is 0, which implies they have trivial gauge groups. We compute the super product systems for these families and, using this, we show they have trivial coupling index. Finally, using the C*-semiflow and the boundary representation of Powers and Alevras, we show that the families of Clifford flows and even Clifford flows contain infinitely many mutually non-cocycle-conjugate E 0-semigroups.
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References
Alevras A.: One parameter semigroups of endomorphisms of factors of type II1. J. Op. Th. 51, 161–179 (2004)
Arveson W.: Pure E0-semigroups and absorbing states. Commun. Math. Phys. 187, 19–43 (1997)
Arveson W.: Interactions in noncommutative dynamics. Commun. Math. Phys. 211, 63–83 (2000)
Arveson, W.: Noncommutative dynamics and E-semigroups. Springer Monogr. in Math., New York: Springer-Verlag, 2003
Rajarama Bhat, B.V.: Cocycles of CCR flows. Mem. Amer. Math. Soc. 149 no.709, Providence, RI: Amer. Math.soc, 2001
Rajarama Bhat, B.V., Mukherjee, M.: Inclusion systems and amalgamated product of product systems. http://arxiv.org/abs/0907.0095v2 [math.OA], 2010
Rajarama Bhat B.V., Barreto S.D., Liebscher V., Skeide M.: Type I product systems of Hilbert modules. J. Funct. Anal. 212(1), 121–181 (2004)
Rajarama Bhat B.V., Skeide M.: Tensor product systems of Hilbert modules and dilations of completely positive semigroups. Infinite Dimensional Analysis, Quantum Probability and Related Topics 3(4), 519–575 (2000)
Bikram P., Mukherjee K., Srinivasan R., Sunder V.S.: Hilbert von Neumann modules. (special issue of) Commun. Stoch. Anal. (in honour of Professor K. R. Parthasarathy) 6(1), 49–64 (2012)
Bures D., Yin H.S.: Outer conjugacy of shifts on the hyperfinite II1 factor. Pac. J. Math. 142(2), 245–257 (1990)
Floricel R.: A conjugacy criterion for pure E0-semigroups. J. Math. Anal. Appl. 373(1), 175–178 (2011)
Fowler N.J.: Free E0-semigroups. Canad. J. Math. 47(4), 744–785 (1995)
Hellmich, J., Köstler, C., Kümmerer, B.: Non-commutative continuous Bernoulli shifts. http://arxiv.org/abs/0411565v1 [math.OA] 2004
Izumi M., Srinivasan R.: Generalized CCR flows. Commun. Math. Phys. 281, 529–571 (2008)
Izumi M., Srinivasan R.: Toeplitz CAR flows and type I factorizations. Kyoto J. Math. 50(1), 1–32 (2010)
Kawahigashi Y.: One-parameter automorphism groups of the hyperfinite type II1 factor. J. Op. Th. 25, 37–59 (1991)
Köstler, C.: Survey on a quantum stochastic extension of Stone’s theorem. In: Advances in quantum dynamics, Contemporary Math., Vol. 335, Providence, RI: Amer. Math. Soc., 2003, pp. 209–222
Lance, C.: Hilbert C*-modules: a toolkit for operator algebraists. LMS Lecture Note Series, Cambridge: Cambridge University Press, 1995
Liebscher, V.: Random sets and invariants for (type II) continuous tensor product systems of Hilbert spaces. Mem. Amer. Math. Soc. 199, no. 930 Providence, RI: Amer. Math. Soc, (2009)
Shalit O., Solel B.: Subproduct systems. Doc. Math. 14, 801–868 (2009)
Parthasarathy K.R.: An Introduction to Quantum Stochastic Calculus. Basel, Boston, Berlin: Birkauser 1992
Powers R.T.: An index theory for semigroups of *-endomorphisms of \({B(\mathcal{H})}\) and type II1 factors. Canad. J. Math. 40, 86–114 (1988)
Powers R.T., Robinson D.W.: An index for continuous semigroups of *-endomorphisms of \({B(\mathcal{H})}\) . J. Funct. Anal. 84(1), 85–96 (1989)
Powers R.T., Price G.L.: Continuous spatial semigroups of *-endomorphisms of \({B(\mathcal{H})}\) . Tran. Amer. Math. Soc. 321, 347–361 (1990)
Skeide, M.: Hilbert modules and applications in quantum probability. Habilitationsschrift, Cottbus, 2001
Takesaki, Masamichi: Theory of operator algebras. II Encyclopaedia of Mathematical Sciences, 125, Berlin, New York: Springer In: 2003
Tsirelson, B.: Non-isomorphic product systems. In: 2003 Advances in Quantum Dynamics (South Hadley, MA, 2002), Contemp. Math., 335, Providence, RI: Amer. Math. Soc., 2003, pp. 273–328
Voiculescu, D., Dykema, K., Nica, A.: Free random variables. CRM Monogr. Ser., Vol. 1, Providence, RI: Amer. Math. Soc., 1992
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Communicated by Y. Kawahigashi
We humbly dedicate this paper to the memory of Bill Arveson.
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Margetts, O.T., Srinivasan, R. Invariants for E0-Semigroups on II1 Factors. Commun. Math. Phys. 323, 1155–1184 (2013). https://doi.org/10.1007/s00220-013-1790-2
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DOI: https://doi.org/10.1007/s00220-013-1790-2