Is there any reference on the hardness of approximation for 2-partition problem? I tried to look for some references but could not find any. I knew it is proved to be NP-complete via a transformation from Knapsack or 3DM problem. But I couldn't find a way to apply PCP theorem to get the hardness of approximation for this problem. Thank you.
From the Wikipedia page on the Partition problem: "...there are fully polynomial-time approximation schemes for the subset-sum problem, and hence for the partition problem as well". The references given there are
Kellerer, Pferschy, Pisinger and Martello, Toth.