KAZHDAN-LUSZTIG CONJECTURE FOR GENERALIZED KAC-MOODY ALGEBRAS .2. PROOF OF THE CONJECTURE

摘要

Generalized Kac-Moody algebras were introduced by Borcherds in the study of Conway and Norton's moonshine conjectures for the Monster sporadic simple group. In this paper, we prove the Kazhdan-Lusztig conjecture for generalized Kac-Moody algebras under a certain mild condition, by using a generalization (to the case of generalized Kac-Moody algebras) of Jantzen's character sum formula. Our (main) formula generalizes the celebrated result for the case of Kac-Moody algebras, and describes the characters of irreducible highest weight modules over generalized Kac-Moody algebras in terms of the ''extended'' Kazhdan-Lusztig polynomials. [References: 15]