This one estimated a beam emitter "on the scale of a large rocky planet": https://arxiv.org/abs/1701.01109 https://arxiv.org/abs/1701.01109 (my highly sophist

This one estimated a beam emitter "on the scale of a large rocky planet": https://arxiv.org/abs/1701.01109 https://arxiv.org/abs/1701.01109 (my highly sophisticated approach to finding academic papers about outlandish alien technology is to search on Loeb).