Research Paper:
The Astrophysical Journal Letters: “Fast Radio Bursts from Extragalactic Light Sails” (PDF)
News Coverage:
Huffignton Post: “Harvard Scientists Say Aliens May Be Using Giant Radio Beams to Travel The Cosmos”
The Economist: “Strange signals from the sky may be signs of aliens”
WBUR, Radio Boston (audio): “Harvard Astronomer: Space Radio Bursts Could Be Signs of Alien Ships”
The Washington Post: “Harvard theorists: How sailing aliens could have caused fast radio bursts”
The Telegraph: “Mysterious flashes could be alien spacecraft at work, Harvard scientists say”
BBC Radio 4 (audio): “Are alien spacecraft causing mysterious flashes?”