https://www.youtube.com/watch?v=kvihUBO7rGo
Cosmological model with negative masses:
- https://januscosmologicalmodel.com/negativemass
Simulation:
- https://www.youtube.com/watch?v=vJgzH99t9w8
Based on Souriau symplectic geometry (where inverting energy is equivalent to inverting the arrow of time):
- http://www.jmsouriau.com/Grammaire_de_la_nature.htm