447
edits
Line 1,639: | Line 1,639: | ||
</div> | </div> | ||
Penrose also has an article explaining the mathematical meaning of his tribar via the standard machinery of cohomology [https://www.iri.upc.edu/people/ros/StructuralTopology/ST17/st17-05-a2-ocr.pdf here]. A later review of his is located [https://personal.math.ubc.ca/~liam/Courses/2022/Math527/tribar.pdf here] and another by Tony Philips with more calculations [https://www.ams.org/publicoutreach/feature-column/fc-2014-10 here] | Penrose also has an article explaining the mathematical meaning of his tribar via the standard machinery of cohomology [https://www.iri.upc.edu/people/ros/StructuralTopology/ST17/st17-05-a2-ocr.pdf here]. A later review of his is located [https://personal.math.ubc.ca/~liam/Courses/2022/Math527/tribar.pdf here] and another by Tony Philips with more calculations [https://www.ams.org/publicoutreach/feature-column/fc-2014-10 here] | ||
[[File:Penrosetribar.png|thumb|The tribar shown in pieces, embedded into three open sets. The numbered and circled subregions contain duplicate overlapping points and the rules for translating into the other open sets.]] | |||
=== Spinors and Cohomology === | === Spinors and Cohomology === |