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Questions tagged [poincare-duality]

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Relative, local coefficient Poincaré duality

Let $X$ be a connected, oriented and aspherical (meaning $\pi_i(X) = 0$ for $i\geq 2$) manifold of dimension $n$, and $S$ a local coefficient system (i.e., a $\pi_1(X)$-module). If $X$ is closed, we ...
Qwert Otto's user avatar
3 votes
0 answers
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Reference request: inverse image in singular homology as in Chow groups

I come from algebraic geometry and I have trouble finding a reference to check the construction of the inverse image in singular homology, analogous to that of the Chow groups. Let me be more precise: ...
Tintin's user avatar
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Is the cap-product map injective for singular varieties?

Let $X$ be a singular, projective (complex) variety of dimension $n$ with at worst isolated singularities. We know that taking cup-product with the cohomology class of $X$ induces a morphism from the ...
user45397's user avatar
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1 vote
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Duality in Spc with ∧ and [-,-]

I am thinking about two duality theorems for H-spaces and their actions. By H-space is meant a commutative monoid in the derived (homotopy) category of based connected CW-complexes. We can consider ...
user avatar
1 vote
1 answer
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Simplicial cochain representing the pullback of a class Poincaré dual of a submanifold

Let $K$ be a simplicial complex of dimension $n$, $M$ be a topological manifold, and $f \colon |K| \to M$ be a continuous map. Let $X$ be an embedded manifold in $M$ of codimension $n$, such that $f(|...
Alex's user avatar
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5 votes
1 answer
545 views

Betti numbers of non-orientable $3$-manifolds

Let $M^3$ be a compact $3$-manifold with boundary $\partial M$. If $M$ is orientable, then it is known (see Lemma 3.5 here) that $2\dim(\ker(H_1(\partial M,\mathbb{Q})\rightarrow H_1(M,\mathbb{Q})))=\...
Alessio Di Prisa's user avatar
3 votes
1 answer
320 views

Pontryagin dual of cokernel, $(\operatorname{coker} F)^* \cong \hat{H}^0(\operatorname{Gal}(L/K),E(L)), $

Let $L/K$ be a quadratic Galois extension of number fields. Let $E$ be an elliptic curve. Consider the natural map $$ F: H^1(\operatorname{Gal}(L/K), E(L)) \to \bigoplus_{v \in M_K} H^1(\operatorname{...
Duality's user avatar
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1 vote
1 answer
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Confusion about relative Poincaré duality in the context of $\ell$-adic cohomology

I have recently learned about relative Poincaré duality in the book Weil conjectures, perverse sheaves and $\ell$-adic Fourier transform by Kiehl and Weissauer (2001). The reference is section II.7. ...
Suzet's user avatar
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2 votes
1 answer
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Composition of Gysin and restriction maps on $\ell$-adic cohomology

I already posted this question on mathstackexchange there, but I figured that it may have more replies here. I follow the notations of Milne's lectures notes on etale cohomology, most specifically ...
Suzet's user avatar
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Gysin isomorphism in de Rham cohomology using currents

I'd like to find a reference for the following fact. First, some background: we can define de Rham cohomology of a smooth manifold $X$ of dimension $d$ using the de Rham complex $$ \Omega^0_X\to \...
xir's user avatar
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Does Poincaré duality link topological study and representation study of a given Lie group?

The Poincaré duality for an oriented n-manifold M takes the form : $$H^\star(M) \simeq H_c^{n-\star}(M)^\vee.$$ Instead of M take now a real Lie group G. We can basically study it by looking at its ...
TopGenAx's user avatar
2 votes
0 answers
122 views

Triple insersection number of a surface in three-manifolds

I heard something about the triple intersection number $\text{mod}(2)$ (but maybe also $\text{mod}(n)$) of a surface in an orientable three-manifold but I couldn't find a precise definition. My guess ...
Andrea Antinucci's user avatar
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Proving an equality of differential forms by assuming some perhaps topological condition

Let say I want to show two differential forms $\omega_1$ and $\omega_2$ on a smooth manifold $M$ are equal. Of course it suffices to show $\omega_1=\omega_2$ locally, i.e. the equality holds over ...
Ho Man-Ho's user avatar
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3 votes
2 answers
655 views

Does the cohomology Bockstein homomorphism map to the homology Bockstein homomorphism under Poincarè duality?

Given a manifold $X$ and short exact sequence of abelian groups $$ 1\rightarrow A_1\overset{\iota}{\rightarrow} A_2\overset{\pi}{\rightarrow} A_3\rightarrow 1 $$ we get the Bockstein map in cohomology ...
Andrea Antinucci's user avatar
2 votes
0 answers
89 views

Is it possible to deduce Poincaré duality from duality of polytopes?

I'm having trouble understanding Poincaré duality, as it seems unmotivated. Here for instance: https://math.stackexchange.com/a/14469/454016 Poincaré duality is explained through a duality of ...
Alexander Praehauser's user avatar