Gravitational waves from binary supermassive black holes missing in pulsar observations

Ryan M Shannon, Vikram Ravi, Lindley Lentati, Paul Daniel Lasky, George B Hobbs, Matthew Kerr, Richard Norman Manchester, William A Coles, Yuri Levin, Matthew Bailes, N D Ramesh Bhat, Sarah Burke-Spolaor, Shi Dai, Michael Keith, Stefan Oslowski, Daniel Reardon, Willem van Straten, Lawrence Toomey, J B Wang, Linqing WenJ Stuart B Wyithe, Xing Jiang Zhu