{ "id": "1007.3546", "version": "v2", "published": "2010-07-21T01:08:47.000Z", "updated": "2010-07-24T00:18:12.000Z", "title": "Lower bounds for designs in symmetric spaces", "authors": [ "Noa Eidelstein", "Alex Samorodnitsky" ], "comment": "Abstract and introduction slightly expanded", "categories": [ "math.CO" ], "abstract": "A design is a finite set of points in a space on which every \"simple\" functions averages to its global mean. Illustrative examples of simple functions are low-degree polynomials on the Euclidean sphere or on the Hamming cube. We prove lower bounds on designs in spaces with a large group of symmetries. These spaces include globally symmetric Riemannian spaces (of any rank) and commutative association schemes with 1-transitive group of symmetries. Our bounds are, in general, implicit, relying on estimates on the spectral behavior of certain symmetry-invariant linear operators. They reduce to the first linear programming bound for designs in globally symmetric Riemannian spaces of rank 1 or in distance regular graphs. The proofs are different though, coming from viewpoint of abstract harmonic analysis in symmetric spaces. As a dividend we obtain the following geometric fact: a design is large because a union of \"spherical caps\" around its points \"covers\" the whole space.", "revisions": [ { "version": "v2", "updated": "2010-07-24T00:18:12.000Z" } ], "analyses": { "keywords": [ "lower bounds", "symmetric spaces", "globally symmetric riemannian spaces", "distance regular graphs", "abstract harmonic analysis" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1007.3546E" } } }