摘要
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 A2 （resp. A1^（1）））. We also realize all fusion rings with D - C being a particular generalized Cartan matrix of indefinite type.
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 A2 （resp. A1^（1）））. We also realize all fusion rings with D - C being a particular generalized Cartan matrix of indefinite type.
基金
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)
NSFC(Grant No.11471282)
