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What could be the physical meaning of "exotic smoothness" in (and only in) 4-dimensional manifolds?

1010 views

As Carl Brans and others note, it seems too big a coincidence to ignore.

Why is exotic smoothness "good" (in the sense that it permits richer physics or something like that)?

Exotic Smoothness and Physics,arXiv

"there are an infinity of differentiable structures on topological R4, no two of which are equivalent, i.e., diffeomorphic, to each other... The fact that R4Θ’s arise only in the physically significant case of dimension four makes the result even more intriguing to physicists..."

Exotic Smoothness and Physics: Differential Topology and Spacetime Models, book

asked Jan 8, 2018 in Theoretical Physics by Giulio Prisco (190 points) [ no revision ]

interessant discussion linked from arxiv about the same question

commented Jan 8, 2018 by igael (360 points) [ no revision ]

Donaldson theory is able to predict nontrivial qualities of smooth structures.

commented Jan 8, 2018 by Ryan Thorngren (1,925 points) [ no revision ]

Thanks @igael for link to MathOverflow discussion. @RyanThorngren, could you give me an example that could be somehow related to physics?

commented Jan 9, 2018 by Giulio Prisco (190 points) [ no revision ]

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