New posts in algebraic-topology

Is every contractible space a cone?

For which topological spaces $X$ can one write $X \approx Y \times Y$? Is $Y$ unique?

Prerequisites for Algebraic Topology

Exercise 1.3.16 in Hatcher

Showing that an inclusion is null homotopic

Hatcher Ch.0 (P18) #5 Inclusion Map is Nullhomotopic

Show that $\Sigma(\mathbb{R} P^3)$ is not homotopy equivalent to $\Sigma(\mathbb{R} P^2 \vee S^3)$

Why are geodesically convex sets diffeomorphic to $\Bbb R^n$?

Motivation of Stone–Čech compactification

Intuition of non-free homology groups?

Fundamental Polygon of Real Projective Plane

What is $\pi_2(\mathbb{R}^2 - \mathbb{Q}^2)$?

What is a spectral sequence? [closed]

Homotopy group of pairs: equivalent descriptions

covering spaces and the fundamental groupoid

Thom isomorphism for generalized cohomology theories.

intuition on the fundamental group of $S^1$

Why is (co)homology useful and in which way?

How to prove a manifold is simply connected?... using geometry

Proving that the fundamental groups of two spaces with same homotopy type are isomorphic