New posts in group-actions

Two subgroups $H_1, H_2$ of a group $G$ are conjugate iff $G/H_1$ and $G/H_2$ are isomorphic

Does an equivalence of $G$-sets and $H$-sets imply an isomorphism of $G$ and $H$?

Difference of fixed points by subgroup action

Transitive action of a discrete group on a compact space

Are symmetries necessary in group action?

Why is conjugacy as an equivalence relation special in groups?

Why is $|H \cdot gP|=1$?

Does conjugation imply equivariantly conjugation?

$\mathbb{Z}_pH$-module

A question about equivariance to 3D transformations using semi-direct and direct products.

Elementary Combinatorial Proofs using group action

Let $H$ be a subgroup of $G$, and suppose that $G$ acts by multiplication over the set $X:=G/H$ of the left-hand side classes of $H$ over $G$.

What is the definition of the vector field which is generated by rotations of the circle

Grothendieck's Galois theory: fundamental theorem

Why a map is equivariant if and only if it is equivariant in the infinitesimal version?

Prove that $SL(2,\mathbb{R})$ acts transitively on the upper half plane

Euler characteristic expression in terms the number of fixed points of an $\mathbb{S}^1$ action

Clarification of notion of proper group action.

What about linearity makes it so useful?

Orbits of vectors under the action of $\mathrm{GL}_n(\mathbb Q)$