Approximation Complexity of Max-Cut on Power Law Graphs
  In this paper we study the MAX-CUT problem on power law graphs (PLGs) with power law exponent $\beta$. We prove some new approximability results on that problem. In particular we show that there exist polynomial time approximation schemes (PTAS) for MAX-CUT on PLGs for the power law exponent $\beta$ in the interval $(0,2)$. For $\beta>2$ we show that for some $\epsilon>0$, MAX-CUT is NP-hard to approximate within approximation ratio $1+\epsilon$, ruling out the existence of a PTAS in this case. Moreover we give an approximation algorithm with improved constant approximation ratio for the case of $\beta>2$. 
Mikael Gast, Mathias Hauptmann and Marek Karpinski
cs.DS cs.CC cs.DM math.CO math.OC