Strongly Closed Subgraphs in a Regular Thick Near Polygon
نویسندگان
چکیده
منابع مشابه
A Distance-Regular Graph with Strongly Closed Subgraphs
Let be a distance-regular graph of diameter d, valency k and r := max{i | (ci , bi ) = (c1, b1)}. Let q be an integer with r + 1 ≤ q ≤ d − 1. In this paper we prove the following results: Theorem 1 Suppose for any pair of vertices at distance q there exists a strongly closed subgraph of diameter q containing them. Then for any integer i with 1 ≤ i ≤ q and for any pair of vertices at distance i ...
متن کاملA distance-regular graph with bipartite geodetically closed subgraphs
Let Γ be a distance-regular graph of diameter d , and t be an integer with 2 ≤ t ≤ d − 1 such that at−1 = 0. For any pair (u, v) of vertices, let Π (u, v) be the subgraph induced by the vertices lying on shortest paths between u and v. We prove that if Π (u, v) is a bipartite geodetically closed subgraph for some pair (u, v) of vertices at distance t , then Π (x, y) is a bipartite geodetically ...
متن کاملWeak-Geodetically Closed Subgraphs in Distance-Regular Graphs
We show that if the intersection number c2 > 1 then any weak-geodetically closed subgraph of X is distance-regular. Γ is said to be i-bounded, whenever for all x, y ∈ X at distance δ(x, y) ≤ i, x, y are contained in a common weakgeodetically closed subgraph of Γ of diameter δ(x, y). By a parallelogram of length i, we mean a 4-tuple xyzw of vertices in X such that δ(x, y) = δ(z, w) = 1, δ(x,w) =...
متن کاملClassification of some strongly regular subgraphs of the McLaughlin graph
By means of an exhaustive computer search we have proved that the strongly regular graphs with parameters (v, k, λ, μ) = (105, 32, 4, 12), (120, 42, 8, 18) and (176, 70, 18, 34) are unique upto isomorphism. Each of these graphs occurs as an induced subgraph in the strongly regular McLaughlin graph. We have used an orderly backtracking algorithm with look-ahead and look-back strategies, applying...
متن کاملSome Induced Subgraphs of Strongly Regular Graphs with no Triangles
Let G be a strongly regular graph with no triangles (SRNT graph) with the parameters (n, k, 0, μ) , if v is a vertex of G, a subgraph which induced by the set of vertices at distance one denoted by G1(v) and subgraph which induced by the set of vertices at distance two denoted by G2(v). In this paper we introduce and study the subgraph which induced by the set U and denoted by G2(U) where, U ca...
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: European Journal of Combinatorics
سال: 1999
ISSN: 0195-6698
DOI: 10.1006/eujc.1999.0335