In this talk I discuss a technique for computing approximate single-source shortest paths using a hop set. A hop set is a set of weighted edges that, when added to the graph, allows to approximate all distances by using only a few edges. This approach was previously used by Cohen in the PRAM model [STOC '94]. I will show how to obtain almost tight approximate SSSP algorithms in both the distributed setting (CONGEST model) and the centralized deletions-only setting using a suitable hop set.
Joint work with Monika Henzinger and Danupon Nanongkai.