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math.CO2008
Graph Powers and Graph Homomorphisms
Hossein Hajiabolhassan, Ali Taherkhani
In this paper we investigate some basic properties of fractional powers. In this regard, we show that for any rational number , $G^{2r+1\over 2s+1}\l…
math.CO2008
A Note on Chromatic Sum
Meysam Alishahi, Ali Taherkhani
The chromatic sum of a graph is the smallest sum of colors among of proper coloring with the natural number. In this paper, we introduce a necessary condition for the ex…