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Algebraic Topology

Fundamental groups, homology: counting holes with algebra.

Дарсҳо

Advanced The fundamental group Loops up to deformation; the circle's winding number; van Kampen. polar form of -1 Advanced Homology and the Euler characteristic Counting holes in every dimension with chain complexes. 6 - 12 + 8

Attach a group to a space so that continuous maps become homomorphisms. Then the question "are these two spaces the same shape?" becomes an algebra computation, which is how we know a doughnut is not a sphere.

Дарси иловагӣ

Homotopy

Algebraic topology Homotopy Covering space Seifert–Van Kampen theorem Homotopy group Simply connected space Deformation retract

Homology

Homology (mathematics)Simplicial complex Singular homology Chain complex Exact sequence Betti number Euler characteristic CW complex Mayer–Vietoris sequence Cohomology Poincaré duality

Consequences

Brouwer fixed-point theorem Borsuk–Ulam theorem Hairy ball theorem Jordan curve theorem Poincaré conjecture Classification of manifolds

Баъзе аз ин дарсҳо аз матнҳои кушода гирифта шудаанд: Wikipedia. Ҳар саҳифаи дарс номи манбаи онро ва иҷозатномаро дорад.

Символы, используемые здесь

Барои муайянкунии пурраи маъно, тасвир ва маънои ҳар як ҳарф дар он, ба ҳар як аломат пахш кунед.

Саволҳои маъмул

What does the fundamental group measure?

Loops in a space up to deformation. In a plane every loop shrinks to a point (trivial group); around a hole a loop can wind n times (the integers).

Шумо мушкилоти худро доред?
Дар саҳифаи ҳалкунанда онро навишта ё кашед: ҳар қадам, тасвир, ҷавоб то он даме, ки шумо пурсед, пинҳон аст. & Ҷудо кардан →

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