Stability of Brans-Dicke thin shell wormholes
  Recently, a class of spherically symmetric thin-shell wormholes in Brans-Dicke gravity have been introduced. Such wormholes can be supported by matter satisfying the weak energy condition (WEC). In this paper, we first obtain all the exact solutions satisfying the WEC. Then we show these solutions can be stable for certain parameters. A general requirement for stability is that $\beta^2>1$, which may imply that the speed of sound exceeds the speed of light. 
Xiaojun Yue, Sijie Gao
gr-qc hep-th