Newbetuts

$f_*: \pi_1(\mathbb{C} \backslash \{-1, 0, 1\}; 2) \rightarrow \pi_1(\mathbb{C} \backslash \{0, 1\}; 4)$ is injective

Courses on Homotopy Theory

Are there spectral sequences for calculating homology or cohomology of homotopy (co)limits?

Homology of punctured projective space

Is the homology class of a compact complex submanifold non-trivial?

Proof of Borsuk-Ulam Theorem .

What's the loop space of a circle?

Proving that the join of a path-connected space with an arbitrary space is simply-connected

Serre Spectral Sequence and Fundamental Group Action on Homology

Orientation reversing diffeomorphism

A pair of spaces $(X,A)$, with $A$ non-contractible, such that the quotient $X \to X/A$ is a homotopy equivalence.

Is $\mathbb{R}^n$ properly homotopy equivalent to $\mathbb{R}^m$ if $n \neq m$?

Visualising $\mathbb CP^2$: a problem of attaching cells with a dimension gap >1

Representation theorems for groups

New posts in algebraic-topology

Functoriality of fundamental group

Is a CW complex, homeomorphic to a regular CW complex?

What is the surface obtained by identifying antipodal points of $\mathbb{S}^1 \times \mathbb{S}^1$?

Definition of $T$ operator in proof of Excision Theorem on Homology Theory

Statement about Homotopy in Brown's "Topology & Groupoids"

Is the interior of a contractible space contractible if it is path connected?

$f_*: \pi_1(\mathbb{C} \backslash \{-1, 0, 1\}; 2) \rightarrow \pi_1(\mathbb{C} \backslash \{0, 1\}; 4)$ is injective

Courses on Homotopy Theory

Are there spectral sequences for calculating homology or cohomology of homotopy (co)limits?

Homology of punctured projective space

Is the homology class of a compact complex submanifold non-trivial?

Proof of Borsuk-Ulam Theorem .

What's the loop space of a circle?

Proving that the join of a path-connected space with an arbitrary space is simply-connected

Serre Spectral Sequence and Fundamental Group Action on Homology

Orientation reversing diffeomorphism

A pair of spaces $(X,A)$, with $A$ non-contractible, such that the quotient $X \to X/A$ is a homotopy equivalence.

Is $\mathbb{R}^n$ properly homotopy equivalent to $\mathbb{R}^m$ if $n \neq m$?

Visualising $\mathbb CP^2$: a problem of attaching cells with a dimension gap >1

Representation theorems for groups