{ "id": "math/0410491", "version": "v1", "published": "2004-10-22T14:34:26.000Z", "updated": "2004-10-22T14:34:26.000Z", "title": "Tensor algebras and displacement structure. IV. Invariant kernels", "authors": [ "T. Banks", "T. Constantinescu", "Nermine El-Sissi" ], "comment": "19 pages, 5 figures", "categories": [ "math.FA", "math.CO" ], "abstract": "In this paper we investigate the class of invariant positive definite kernels on the free semigroup on N generators. We provide a combinatorial description of the positivity of the kernel in terms of Dyck paths and then we find a displacement equation that encodes the invariance property of the kernel.", "revisions": [ { "version": "v1", "updated": "2004-10-22T14:34:26.000Z" } ], "analyses": { "subjects": [ "15A69", "47A57" ], "keywords": [ "displacement structure", "invariant kernels", "tensor algebras", "invariant positive definite kernels", "free semigroup" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math.....10491B" } } }