Abstract
The Casimir element of a fusion ring (R,B) gives rise to the so called Casimir matrix C of (R,B). This enables us to construct a generalized Cartan matrix D − C in the sense of Kac for a suitable diagonal matrix D. In this paper, we study some elementary properties of the Casimir matrix C and use them to realize certain fusion rings from the generalized Cartan matrix D−C of finite (resp. affine) type. It turns out that there exists a fusion ring with D−C being of finite (resp. affine) type if and only if D−C has only the form A 2 (resp. A (1)1 ). We also realize all fusion rings with D−C being a particular generalized Cartan matrix of indefinite type.
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References
Bakalov, B., Kirillov, A. A.: Lectures on Tensor Categories and Modular Functors. Amer. Math. Soc., Providence, RI, 2001
Francesco, P., Mathieu, P., Sénéchal D.: Conformal Field Theory, Springer–Verlag, New York, 1997
Gelaki, S., Nikshych, D.: Nilpotent fusion categories. Adv. Math., 217, 1053–1071 (2008)
Gepner, D., Kapustin, A.: On the classification of fusion rings. Physics Letters B, 349, 71–75 (1995)
Kac, V. G.: Infinite Dimensional Lie Algebras, Cambridge University Press, Cambridge, 1990
Larson, H. K.: Pseudo-unitary non-selfdual fusion categories of rank 4. J. Algebra, 415, 184–213 (2014)
Liu, Z. W., Morrison, S., Penneys, D.: 1-supertransitive subfactors with index at most 6 1 5. Comm. Math. Phys., 334, 889–922 (2015)
Lorenz, M.: Some applications of Frobenius algebras to Hopf algebras. Contemp. Math., 537, 269–289 (2011)
Moore, G., Seiberg, N.: Classical and quantum conformal field theory. Comm. Math. Phys., 123, 177–254 (1989)
Ostrik, V.: Fusion categories of rank 2. Math. Res. Lett., 10, 177–184 (2003)
Ostrik, V.: Pivotal fusion categories of rank 3. Moscow Math. J., 15, 373–396 (2015)
Ostrik, V.: On formal codegrees of fusion categories. Math. Res. Lett., 16, 895–901 (2009)
Siehler, J.: Near-group categories. Alg. Geom. Topol., 3, 719–775 (2003)
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We thank the referees for their careful reading of this article and for valuable comments.
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Supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 15KJB110013); the Natural Science Foundation of Jiangsu Province of China (Grant No. BK20150537) and NSFC (Grant No. 11471282)
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Wang, Z.H., Li, L.B. On realization of fusion rings from generalized Cartan matrices. Acta. Math. Sin.-English Ser. 33, 362–376 (2017). https://doi.org/10.1007/s10114-016-6088-9
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DOI: https://doi.org/10.1007/s10114-016-6088-9