Partially metric association schemes with a multiplicity three
نویسندگان
چکیده
منابع مشابه
There are finitely many Q-polynomial association schemes with given first multiplicity at least three
In this paper, we will prove a result which is formally dual to the long-standing conjecture of Bannai and Ito which claims that there are only finitely many distanceregular graphs of valency k for each k > 2. That is, we prove that, for any fixed m1 > 2, there are only finitely many cometric association schemes (X,R) with the property that the first idempotent in a Q-polynomial ordering has ra...
متن کاملMultiplicity of Jet Schemes of Monomial Schemes
This article studies jet schemes of monomial schemes. They are known to be equidimensional but usually are not reduced [13]. We thus investigate their structure further, giving a formula for the multiplicity along every component of the jet schemes of a general reduced monomial hypersurface (that is, the case of a simple normal crossing divisor).
متن کاملMultiplicity mod 2 as a Metric Invariant
We study the multiplicity modulo 2 of real analytic hypersurfaces. We prove that, under some assumptions on the singularity, the multiplicity modulo 2 is preserved by subanalytic bi-Lipschitz homeomorphisms of R. In the first part of the paper, we find a subset of the tangent cone which determines the multiplicity mod 2 and prove that this subset of S is preserved by the antipodal map. The stud...
متن کاملThree-weight Codes and Association Schemes
Three-weight projective codes C are considered for which the restrietion to C of the Hamming association scheme Hn(q) is an association scheme with three classes. Sufficient conditions are established and restrictions on the three weights of C are obtained. It is shown in the binary case that the three-weight subcodes of the shortened second-order Reed-Muller codes provide a large class of exam...
متن کاملThree-class association schemes from cyclotomy
We give three constructions of three-class association schemes as fusion schemes of the cyclotomic scheme, two of which are primitive.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series B
سال: 2018
ISSN: 0095-8956
DOI: 10.1016/j.jctb.2017.09.011