The projective limit functor is not right-exact: if $G_\bullet\rightarrowtail H_\bullet\twoheadrightarrow K_\bullet$ is a projective system of extensions, then there is a long exact sequence $$ 0\to\varprojlim G_\bullet\to\varprojlim H_\bullet\to\varprojlim K_\bullet\to\varprojlim\ ^1 G_\bullet\to\varprojlim\ ^1 H_\bullet\to\varprojlim\ ^1 K_\bullet\to\cdots. $$ Is there an example of a projective system of extensions $G_\bullet\rightarrowtail H_\bullet\twoheadrightarrow K_\bullet$ such that the map $\varprojlim H_\bullet\to\varprojlim K_\bullet$ is surjective and such that the term $\varprojlim\ ^1 G_\bullet$ is non-zero?
2026-03-26 19:01:54.1774551714
Does $\varprojlim\ ^1$ vanish whenever it doesn't have to account for non-right exactness of $\varprojlim$?
119 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in LIMITS
- How to prove $\lim_{n \rightarrow\infty} e^{-n}\sum_{k=0}^{n}\frac{n^k}{k!} = \frac{1}{2}$?
- limit points at infinity
- Calculating the radius of convergence for $\sum _{n=1}^{\infty}\frac{\left(\sqrt{ n^2+n}-\sqrt{n^2+1}\right)^n}{n^2}z^n$
- Maximal interval of existence of the IVP
- Divergence of power series at the edge
- Compute $\lim_{x\to 1^+} \lim_{n\to\infty}\frac{\ln(n!)}{n^x} $
- why can we expand an expandable function for infinite?
- Infinite surds on a number
- Show that f(x) = 2a + 3b is continuous where a and b are constants
- If $a_{1}>2$and $a_{n+1}=a_{n}^{2}-2$ then Find $\sum_{n=1}^{\infty}$ $\frac{1}{a_{1}a_{2}......a_{n}}$
Related Questions in HOMOLOGICAL-ALGEBRA
- How does $\operatorname{Ind}^G_H$ behave with respect to $\bigoplus$?
- Describe explicitly a minimal free resolution
- $A$ - dga over field, then $H^i(A) = 0, i > 1$ implies $HH_i(A) = 0, i < -1$
- Tensor product $M\otimes_B Hom_B(M,B)$ equals $End_B(M)$, $M$ finitely generated over $B$ and projective
- Group cohomology of $\mathrm{GL}(V)$
- two maps are not homotopic equivalent
- Existence of adjugant with making given natural transformation be the counit
- Noetherian property is redundant?
- What is the monomorphism that forms the homology group?
- Rational points on conics over fields of dimension 1
Related Questions in DERIVED-FUNCTORS
- Derived functors in the category of sheaves
- Question about $\mbox{Ext}$ groups in abelian categories
- Determining right derived functor of the left exact functor $M \to M[p]$.
- Defining contravariant left/right-exact functor with opposite category?
- Transfer modules and Weyl algebra
- Derived functors and induced functors
- Tor functor on a torsion ring
- Properties of derived functors
- Cohomology of $Hom$'s between Complexes
- When does the inverse image functor commute with internal hom?
Related Questions in EXACT-SEQUENCE
- Does every sequence of digits occur in one of the primes
- Linear transformation and Exact sequences
- Snake lemma and regular epi mono factorization
- Replacing terms of an exact sequence by quotients
- Module over integral domain, "Rank-nullity theorem", Exact Sequence
- Inclusion and quotient mappings in exact sequences
- Parsing the Bockstein morphism
- Short exact sequence on modules
- G-groups homomorphism regarding the subgroup fixed by G
- A problem about split exact sequences.
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?
Yes. For example, take any $G_\bullet$ for which $\varprojlim\ ^1 G_\bullet$ is non-zero, and consider the projective system $G_\bullet\rightarrowtail G_\bullet\twoheadrightarrow 0$, where the first map is the identity.