Integrality Gap of the Hypergraphic Relaxation of Steiner Trees: A Short Proof of a 1.55 Upper Bound
- Deeparnab Chakrabarty ,
- Jochen Könemann ,
- David Pritchard
Operations Research Letters | , Vol 38(6): pp. 567-570
Recently, Byrka, Grandoni, Rothvoß and Sanità gave a 1.39 approximation for the Steiner tree problem, using a hypergraph-based linear programming relaxation. They also upper-bounded its integrality gap by 1.55. We describe a shorter proof of the same integrality gap bound, by applying some of their techniques to a randomized loss-contracting algorithm.