Searching for interstellar quantum communications
https://arxiv.org/abs/2104.06446
Three microlensing planets with no caustic-crossing features
https://arxiv.org/abs/2104.06544
Significant interstellar object production by close stellar flybys
https://arxiv.org/abs/2104.06845
Positive Energy Warp Drive from Hidden Geometric Structures
https://arxiv.org/abs/2104.06488