12.07.2015 Views

Ivancevic_Applied-Diff-Geom

Ivancevic_Applied-Diff-Geom

Ivancevic_Applied-Diff-Geom

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

118 <strong>Applied</strong> <strong>Diff</strong>erential <strong>Geom</strong>etry: A Modern Introductiona 2−category is a commutative triangle:Af∨ α❘ FB✒g❅❅❅❅❅❅❅❘G ◦ FG(F (A))G(F (f))∨G(F (g))F (f)✲❘F (A) F (α) F (B)∨ ✒ F (g) G✠ ❘G(F (α))G(F (B))✒a 3−category is a commutative triangle:fF (f)Aαψ ❘> βFB ❅✒g ❅❅❅F ◦ G❅ ❅❅❅❅ ❅❘G(F (f))G(F (ψ))G(F (α))G(F (A))G(F (g))F (ψ)✲ F (A) F (α) > F (g)G✠ ❘> G(F (β))G(F (B)) ✒❘F (β) F (B)✒etc., up to n−categories.Many deep–sounding results in mathematical sciences are get by theprocess of categorification 14 of the high school mathematics [Crane andFrenkel (1994); Baez and Dolan (1998)].An n−category is a generic mathematical structure consisting of a collectionof objects, a collection of arrows between objects, a collection of2−arrows between arrows [Bénabou (1967)], a collection of 3−arrows be-14 Categorification means replacing sets with categories, functions with functors, andequations between functions by natural equivalences between functors. Iterating thisprocess requires a theory of n−categories.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!