I have read the first answer for this question Centralizer of a finite normal subgroup has finite index and I did not understood, why if $|Aut(H)| < \infty$, then $kernel = C_G(H)$ must have finite index?
2026-03-25 23:10:11.1774480211
Index of centralizer if $H\lhd G$ and $|H| < \infty$
129 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail AtRelated Questions in GROUP-THEORY
- What is the intersection of the vertices of a face of a simplicial complex?
- Group with order $pq$ has subgroups of order $p$ and $q$
- How to construct a group whose "size" grows between polynomially and exponentially.
- Conjugacy class formula
- $G$ abelian when $Z(G)$ is a proper subset of $G$?
- A group of order 189 is not simple
- Minimal dimension needed for linearization of group action
- For a $G$ a finite subgroup of $\mathbb{GL}_2(\mathbb{R})$ of rank $3$, show that $f^2 = \textrm{Id}$ for all $f \in G$
- subgroups that contain a normal subgroup is also normal
- Could anyone give an **example** that a problem that can be solved by creating a new group?
Related Questions in NORMAL-SUBGROUPS
- subgroups that contain a normal subgroup is also normal
- Prime Ideals in Subrings
- Comparing centers of group and a subgroup
- Example for subgroups $H$ and $K$ where $HK = K H$ and neither $H$ nor $K$ is normal?
- How to show that every group in the normal series of $G$ is normal in $G$
- Lie groups with SU(12) as a subgroup
- determine if a subgroup of a free group is normal
- Is being a contranormally closed subgroup a transitive property?
- $G_{1}, G_{2} \triangleleft G$, $G_{1}G_{2} = G$, $G_{1} \cap G_{2} = \{ e \}$ implies $G_{1} \times G_{2} \cong G$?
- For prime $p$, normal subgroups of $SL(2, \mathbb Z/p\mathbb Z)$ remains normal in $GL(2, \mathbb Z/p\mathbb Z)$?
Related Questions in AUTOMORPHISM-GROUP
- Fixed points of automorphisms of $\mathbb{Q}(\zeta)$
- A weird automorphism
- Confusing step in proof of property of cyclic group automorphisms
- ord$(a) = p, f(a) = a, \forall f : G \to G$ automorphism $\implies |G|$ is not square-free
- Arbitrary automorphism function on Aut(Quaternion Group)?
- writing a computer program in magma that finds a linear code and a specific automorphism group to the code.
- Let $G$ be a group. Show that, for every $a\in G$, the map $\phi_a:G\to G$, defined by $\phi_a(g) := aga^{−1}$ ($g\in G$), is a group automorphism.
- homomorphism from $F^\times \times F^\times$ to Aut$(F)$
- Extension of isomorphism of fields
- Graph with distinct automorphisms but no fixed-point free automorphism
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?