On strongly closed subgraphs with diameter two and the Q-polynomial property
نویسنده
چکیده
1Introduction Let $\Gamma=(X, R)$ be a distance-regular graph (DRG) of diameter $\Gamma_{j}(u)=\{x\in X|\partial(u, x)=j\}$ and $\Gamma(u)=\Gamma_{1}(u)$. For two vertices $u$ and $v\in X$ with $\partial(u, v)=j$ let $C(u., v)$ $=$ $\Gamma_{j-1}(u)\cap\Gamma(v)$ , $A(u, v)$ $=$ $\Gamma_{j}(u)\cap\Gamma(v)$ , and $B(u, v)$ $=$ $\Gamma_{j+1}(u)\cap\Gamma(v)$ .
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ورودعنوان ژورنال:
- Eur. J. Comb.
دوره 28 شماره
صفحات -
تاریخ انتشار 2007