The above question comes from the Serre spectral sequence in cohomology. One would like to write something like $H^p(B,H^q(F,R))\cong Hom(H_p(B;\mathbb{Z});Hom(H_q(F;\mathbb{Z});R))\cong Hom(H_p(B;\mathbb{Z})\otimes H_q(F;\mathbb{Z});R)\cong Hom(H_p(B;\mathbb{Z});R)\otimes Hom(H_q(F;\mathbb{Z});R)\cong H^p(B,R)\otimes H^q(F,R)$ but we are invoking the UCT a few times and would get some Ext-terms and we are interchanging $Hom$ with $\otimes$. This works well if $R$ is a field and everything is finitely generated. But what if for example $R=\mathbb{Z}$ and everything is finitely generated? Is it still possible? If necessary one can assume, that cohomology only appears in degrees far appart.
2026-04-02 18:42:59.1775155379
Under what circumstances is $H^p(B,H^q(F,R))\cong H^p(B,R)\otimes H^q(F,R)$?
70 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in ALGEBRAIC-TOPOLOGY
- How to compute homology group of $S^1 \times S^n$
- the degree of a map from $S^2$ to $S^2$
- Show $f$ and $g$ are both homeomorphism mapping of $T^2$ but $f$ is not homotopy equivalent with $g.$
- Chain homotopy on linear chains: confusion from Hatcher's book
- Compute Thom and Euler class
- Are these cycles boundaries?
- a problem related with path lifting property
- Bott and Tu exercise 6.5 - Reducing the structure group of a vector bundle to $O(n)$
- Cohomology groups of a torus minus a finite number of disjoint open disks
- CW-structure on $S^n$ and orientations
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?
Let us assume that all the homology groups of $B$ are finitely generated and that $B$ is simply connected. There is a universal coefficient theorem for cohomology which involves $\mathrm{Tor}$. It follows that $$ H^p(B,H^q(F,R))\cong H^p(B,\mathbb{Z})\otimes H^q(F,R)\oplus \mathrm{Tor}\,(H^{p+1}(B,\mathbb{Z}),H^q(F,R)) $$
So if $H^{p+1}(B,\mathbb{Z})$ or $H^q(F,R)$ does not contain torsion you get a nice formula. I'm not sure how this interacts with the cup products in the SSS.