The diameter of bipartite distance-regular graphs

نویسندگان

چکیده

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Bipartite regular graphs with fixed diameter

For given nonnegative integers k and D , we consider the problem of determining n,(k, D ) , the smallest number n for which there exists a k-regular bipartite graph on n vertices with diameter D . We solve the problem for all pairs ( k , D ) with D + 2 (mod 4) and D + 3 (mod 4), for all pairs ( k , D ) with k even or k prime and D + 3 (mod 4), for all pairs with D I 9 or k I 4, and for a few ot...

متن کامل

A characterization of bipartite distance-regular graphs

Article history: Received 9 April 2013 Accepted 15 December 2013 Available online 13 January 2014 Submitted by R. Brualdi

متن کامل

Taut Distance-Regular Graphs of Odd Diameter

Let denote a bipartite distance-regular graph with diameter D ≥ 4, valency k ≥ 3, and distinct eigenvalues θ0 > θ1 > · · · > θD . Let M denote the Bose-Mesner algebra of . For 0 ≤ i ≤ D, let Ei denote the primitive idempotent of M associated with θi . We refer to E0 and ED as the trivial idempotents of M . Let E, F denote primitive idempotents of M . We say the pair E, F is taut whenever (i) E,...

متن کامل

Codes in Bipartite Distance^regular Graphs

For each bipartition_of a bipartite distance-regular graph F, there naturally corresponds another distance-regular graph F called a halved graph. It is shown that the existence of a perfect e-code in a halved graph F is equivalent to the existence of a uniformly packed 2e-code in F with certain specific parameters. Using this equivalence, we show the non-existence of perfect codes for two class...

متن کامل

On bipartite Q-polynomial distance-regular graphs

Let Γ denote a bipartite Q-polynomial distance-regular graph with vertex set X, diameter d ≥ 3 and valency k ≥ 3. Let RX denote the vector space over R consisting of column vectors with entries in R and rows indexed by X. For z ∈ X, let ẑ denote the vector in RX with a 1 in the z-coordinate, and 0 in all other coordinates. Fix x, y ∈ X such that ∂(x, y) = 2, where ∂ denotes path-length distance...

متن کامل

ذخیره 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: 1982

ISSN: 0095-8956

DOI: 10.1016/0095-8956(82)90034-x