Abstract
It is well-known that the halved graphs of a bipartite distance-regular graph are distance-regular. Examples are given to show that the converse does not hold. Thus, a natural question is to find out when the converse is true. In this paper we give a quasi-spectral characterization of a connected bipartite weighted 2-punctually distance-regular graph whose halved graphs are distance-regular. In the case the spectral diameter is even we show that the graph characterized above is distance-regular.
Original language | English |
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Pages (from-to) | 91-103 |
Number of pages | 13 |
Journal | Linear Algebra and Its Applications |
Volume | 446 |
DOIs | |
State | Published - 1 Apr 2014 |
Keywords
- Distance matrices
- Distance-regular graph
- Predistance polynomials
- Spectral diameter
- Spectral excess theorem