Department of Mathematics, Rutgers University, New Brunswick, New Jersey 08903.
Proc Natl Acad Sci U S A. 1981 Feb;78(2):699-701. doi: 10.1073/pnas.78.2.699.
The two Rogers-Ramanujan identities, which equate certain infinite products with infinite sums, are among the most intriguing of the classical formal power series identitites. It has been found by Lepowsky and Milne that the product side of each of them differs by a certain factor from the principally specialized character of a certain standard module for the Euclidean Kac-Moody Lie algebra A(1) ((1)). On the other hand, the present authors have introduced an infinite-dimensional Heisenberg subalgebra [unk] of A(1) ((1)) which leads to a construction of A(1) ((1)) in terms of differential operators given by the homogeneous components of an "exponential generating function." In the present announcement, we use [unk] to formulate a natural "abstract Rogers-Ramanujan identity" for an arbitrary standard A(1) ((1))-module which turns out to coincide with the classical identities in the cases of the two corresponding standard modules. The abstract identity equates two expressions, one a product and the other a sum, for the principally specialized character of the space Omega of highest weight vectors or "vacuum states" for [unk] in the module. The construction of A(1) ((1)) leads to a concrete realization of Omega as the span of certain spaces of symmetric polynomials occurring as the homogeneous components of exponential generating functions. The summands in the Rogers-Ramanujan identities turn out to "count" the dimensions of these spaces. For general standard A(1) ((1))-modules, we conjecture that the abstract identities agree with generalizations of the Rogers-Ramanujan identities due to Gordon, Andrews, and Bressoud.
罗格斯-拉马努金恒等式将某些无穷乘积与无穷级数等同起来,是古典形式幂级数恒等式中最引人注目的等式之一。莱波夫斯基和米尔恩发现,每个等式的乘积一侧与某个标准模块的主要特殊特征相差一定的因子,该标准模块为欧几里得 Kac-Moody 李代数 A(1) ((1))。另一方面,本文作者引入了 A(1) ((1)) 的无限维海森堡子代数 [unk],这导致了 A(1) ((1)) 的构造,由“指数生成函数”的齐次分量给出的微分算子。在本公告中,我们使用 [unk] 为任意标准 A(1) ((1))-模块制定一个自然的“抽象罗格斯-拉马努金恒等式”,该恒等式在对应两个标准模块的情况下与经典恒等式一致。抽象恒等式将空间 Ω的主要特殊特征的两个表达式相匹配,一个是乘积,另一个是和,Ω是模块中 [unk] 的最高权向量或“真空态”的空间。A(1) ((1)) 的构造导致 Ω作为某些对称多项式空间的张成的具体实现,这些空间作为指数生成函数的齐次分量出现。罗格斯-拉马努金恒等式中的和项“计数”这些空间的维度。对于一般标准 A(1) ((1))-模块,我们猜测抽象恒等式与戈登、安德鲁斯和布雷苏德的罗格斯-拉马努金恒等式的推广一致。