کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4654819 1632828 2008 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Block transitivity and degree matrices
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات ریاضیات گسسته و ترکیبات
پیش نمایش صفحه اول مقاله
Block transitivity and degree matrices
چکیده انگلیسی

We say that a square matrix M of order rr is a degree matrix of a given graph GG if there is a so-called equitable partition of its vertices into rr blocks with the following property: For any ii and jj it holds that a vertex from the iith block of the partition has exactly mi,jmi,j neighbors inside the jjth block.We ask whether for a given degree matrix M, there exists a graph GG such that M is a degree matrix of GG, and in addition, for any two edges e,fe,f spanning between the same pair of blocks there exists an automorphism of GG that sends ee to ff. In this work we affirmatively answer the question for all degree matrices and show a way to construct a graph that witnesses this fact.We further explore a case where the automorphism is required to exchange a given pair of edges and show some positive and negative results.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: European Journal of Combinatorics - Volume 29, Issue 5, July 2008, Pages 1160–1172
نویسندگان
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