l'univers est un orbifold. L'extension temporelle de l'univers devient finie, à la fois vers le passé et vers le futur. L'instant zéro disparait.

https://www.jp-petit.org/papers/cosmo/janus24.pdf
https://www.jp-petit.org/books/asb.pdf
https://www.jp-petit.org/papers/bourbakof_fr.pdf
https://www.jp-petit.org/papers/CRAS/geometry_1978b.pdf
https://www.jp-petit.org/papers/CRAS/geometry_1978d.pdf
https://www.jp-petit.org/papers/pls_jan_79.pdf
http://www.savoir-sans-frontieres.com/JPP/telechargeables/Francais/LE%20TOPOLOGICON.pdf
https://www.jp-petit.org/papers/CRAS/geometry_1981.pdf
https://www.jp-petit.org/science/f300/f3100/f3101.htm
https://www.jp-petit.org/papers/CRAS/cosmology_1977a.pdf
https://www.jp-petit.org/papers/CRAS/cosmology_1977b.pdf
https://www.jp-petit.org/papers/cosmo/janus24.pdf
https://www.youtube.com/watch?v=7WGGLhdki9Q

tout janus
https://www.jp-petit.org/janus/janus-contenus.pdf