A quantum-inspired classical algorithm for recommendation systems
By Tang, Ewin
Interesting that the quantum algorithm inspired an equally performant classical one.
See also Tang's paper published in PRL: arXiv:1811.00414 (cs)
Oracle Separation of BQP and PH
A paper showing that there are problems quantum computers solve that aren't even solvable by a generalization of NP in classical computers.
Muometric positioning system (μPS) with cosmic muons as a new underwater and underground positioning technique (2020)
Using the time of flight of relativistic cosmic ray muons to estimate relative position.
There is also a 2024 paper on a more practical, wireless system and another on time synchronization from 2022.
Here is the author, Hiroyuki K.M. Tanaka's inspirehep page.
Emergence of collective oscillations in massive human crowds
Observational study of crowds with interesting modeling and analysis.