Let $K$ be a field and $G$ an algebraic group defined over $K$. If $M\supseteq L$ are two finite Galois extensions of $K$, then the groups $\text{Gal}(M/K)$ and $\text{Gal}(L/K)$ act, respectively, on the $M$-points $G_M$ and the $L$-points $G_L$ of $G$, and one may then define $$\rho_L^M:H^1(\text{Gal}(M/K), G_M) \to H^1(\text{Gal}(L/K), G_L)$$ Well, it is the last definition that I don't get. How is $\rho_L^M$ defined? If I have a representative $\phi$ of a class in the first cohomology set, this is a function $\phi:\text{Gal}(M/K)\to G_M$, how do I get a function from $\text{Gal}(L/K)$ to $G_L$? From my point of view, it should be the other way, since $G_L$ is a subset of $G_M$ and elements in $\text{Gal}(M/K)$ map to $\text{Gal}(L/K)$ via restriction.
2026-03-30 00:02:40.1774828960
Problem defining morphism in Galois cohomology of algebraic group
60 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in GALOIS-THEORY
- Fixed points of automorphisms of $\mathbb{Q}(\zeta)$
- A weird automorphism
- $S_3$ action on the splitting field of $\mathbb{Q}[x]/(x^3 - x - 1)$
- Question about existence of Galois extension
- Prove that K/L is a Galois extension
- discriminant and irreducibility of $x^p - (p+1)x - 1$
- galois group of irreducible monic cubic polynomial
- Proof of normal basis theorem for finite fields
- Regular inverse Galois problem for Q(t)
- When a certain subfield of $\mathbb{C}(x,y^2)$ is Galois
Related Questions in ALGEBRAIC-GROUPS
- How do you prove that category of representations of $G_m$ is equivalent to the category of finite dimensional graded vector spaces?
- How to realize the character group as a Lie/algebraic/topological group?
- Action of Unipotent algebraic group
- From a compact topological group to a commutative Hopf algebra
- When do we have $C(G) \otimes C(G) =C(G\times G)?$
- What is the internal Hom object in the category $\mathcal{C} = \mathbf{Rep}_k(G)$?
- Is the product of simply connected algebraic groups simply connected?
- Connected subgroup of $(K^\times)^n$ of Zariski dimension 1
- Action of $ \mathbb{G}_m $ on $ \mathbb{A}^n $ by multiplication.
- Book recommendation for Hopf algebras
Related Questions in GALOIS-COHOMOLOGY
- Square classes of a real closed field
- Surjectivity of the inv map in Global class field theory
- $H^1(G, \mathbb{Z}/p \mathbb{Z})$ and linearly independent elements in open subgroups.
- First cohomology group of the $n$-torsion of an elliptic curve
- Surjectivity of map of étale sheaves
- Hilbert 90 and K-forms
- How can a point on an elliptic curve be considered a galois cohomology class?
- Tate Cohomology of Squares
- Galois extension of exponent $mp^r$ in characteristic $p$
- What should one know before learning galois cohomology
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?
Indeed, it should go the other way, and is the inflation map : $Gal(L/K)$ is the quotient of $G=Gal(M/K)$ by $H=Gal(M/L)$ so for any $G$-group $A$ (here $A=G_M$) you have the inflation map $H^1(G/H,A^H)\to H^1(G,A)$ (and here $A^H = M_L$).