New posts in algebraic-topology

Klein-bottle and Möbius-strip together with a homeomorphism

Antipodal map on $ S^n $ homotopic to identity map if $n$ is odd

A contractible space is path connected.

Show that the Euler characteristic of a chain complex is equal to the Euler characteristic of its homology

$S^n \backslash S^m $ homotopy equivalent to $ S^{n-m-1} $

Cohomology easier to compute (algebraic examples)

Homotopy groups of a wedge sum

Give an explicit embedding from $\mathbb{R}P_2$ to $\mathbb{R}^4$

Embeddability of the cone of Klein bottle to $\mathbb R^4$

How did Chern pictured the first Chern number?

Getting the most general form of Mayer-Vietoris from the axioms of homology

Abelian Covering Space of Surface of genus $g$

Problem 1.1.5 from Hatcher's

Zeroth homotopy group: what exactly is it?

Question about identifying pairs of edges of disjoint $2$ simplices

How far from research frontier is Hatcher's book

$\mathbb{Z}$ vs. $\hat{\mathbb{Z}}$ coefficents in Singular Cohomology

Codimension 1 homology represented by Embedded Submanifold

Homology group of Real projective plane

Minimum number of sets required for a good open cover