User Goa'uld

7 votes

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The bigger picture the Five Lemma fits into

answered May 19, 2016 at 3:32

7 votes

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Attempted proof of an open mapping theorem for Lie groups

answered Apr 13, 2017 at 18:09

6 votes

cohomology of pullback

answered May 30, 2017 at 23:48

6 votes

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Degree 1 maps from $S^1 \times S^2$

answered Jun 8, 2017 at 20:39

5 votes

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Cohomological dimension of direct product

answered Jun 15, 2017 at 18:09

5 votes

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Adapting a proof of the Universal Coefficient Theorem for Homology, but for Cohomology

answered Jun 26, 2017 at 22:25

5 votes

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How to understand the two definitions of path algebra?

answered May 26, 2017 at 19:31

5 votes

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Natural action of $\mathbb{Z}G$ on $\mathbb{Z}$?

answered May 20, 2016 at 16:36

5 votes

Is wedge sum for finite CW complexes cancellative in the homotopy category?

answered May 26, 2016 at 16:32

4 votes

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Intuition behind cohomology operations

answered Apr 7, 2017 at 17:54

3 votes

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Proving that $\xi$ is a trivial vector bundle iff $\xi \oplus \varepsilon^1$ is trivial

answered May 4, 2017 at 17:26

3 votes

Infinite Sphere is connected but not compact

answered Jun 22, 2017 at 20:04

3 votes

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Compact subsets of $S^\infty$ and other inductive limits

answered Jun 27, 2017 at 22:02

3 votes

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Non-trivial group action with trivial action of maximal torus?

answered Jun 27, 2017 at 16:56

3 votes

Is it true that cohomological dimension of a group $G$ over a ring $R$ is zero, then group ring $RG$ is semisimple?

answered Jun 13, 2017 at 15:26

3 votes

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What are the homology groups of an abelian group?

answered May 19, 2016 at 21:21

3 votes

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If $(X, A)$ is a Good Pair then $i_*:H_n(X, A)\to H_n(X, V)$ is an Isomorphism

answered Jun 13, 2016 at 15:31

2 votes

Automatic additivity of multiplicative maps

answered May 21, 2016 at 12:54

2 votes

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A Natural Question When Reading Van Kampen Theorem

answered May 21, 2016 at 15:35

2 votes

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Vector addition over orthogonal group

answered Jun 9, 2016 at 21:32

2 votes

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Multiplication of unitary matrices to make symmetric off-diagonal elements zero

answered May 28, 2016 at 17:35

1 vote

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Non-trivial explicit example of a partition of unity

answered May 22, 2016 at 17:01

1 vote

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Is $\mathbb{Z}[G^n]$ isomorphic to $\bigoplus_n\mathbb{Z}[G]$?

answered Jun 12, 2016 at 14:33

1 vote

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Group of order $210$

answered May 26, 2016 at 13:14

1 vote

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First homology group of $\pi$ with $G$ when $(|\pi|,|G|)=1$

answered May 21, 2016 at 0:59

1 vote

Definition of isomorphism classes of vector bundles with reduced structure group

answered Feb 14, 2017 at 18:59

1 vote

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Representation of $Q_8$ over $\mathbb{R}$

answered May 22, 2016 at 15:26

1 vote

Mapping cone of $BF:B\mathcal C\to B\mathcal D$ is a classifying space?

answered May 4, 2017 at 14:34

1 vote

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Representation of Sylow which does not extend

answered May 15, 2016 at 13:57

1 vote

Sylow $p$-subgroup of a finite group

answered Jun 10, 2016 at 17:01

Stack Exchange Network

39 Answers

The bigger picture the Five Lemma fits into

Attempted proof of an open mapping theorem for Lie groups

cohomology of pullback

Degree 1 maps from $S^1 \times S^2$

Cohomological dimension of direct product

Adapting a proof of the Universal Coefficient Theorem for Homology, but for Cohomology

How to understand the two definitions of path algebra?

Natural action of $\mathbb{Z}G$ on $\mathbb{Z}$?

Is wedge sum for finite CW complexes cancellative in the homotopy category?

Intuition behind cohomology operations

Proving that $\xi$ is a trivial vector bundle iff $\xi \oplus \varepsilon^1$ is trivial

Infinite Sphere is connected but not compact

Compact subsets of $S^\infty$ and other inductive limits

Non-trivial group action with trivial action of maximal torus?

Is it true that cohomological dimension of a group $G$ over a ring $R$ is zero, then group ring $RG$ is semisimple?

What are the homology groups of an abelian group?

If $(X, A)$ is a Good Pair then $i_*:H_n(X, A)\to H_n(X, V)$ is an Isomorphism

Automatic additivity of multiplicative maps

A Natural Question When Reading Van Kampen Theorem

Vector addition over orthogonal group

Multiplication of unitary matrices to make symmetric off-diagonal elements zero

Non-trivial explicit example of a partition of unity

Is $\mathbb{Z}[G^n]$ isomorphic to $\bigoplus_n\mathbb{Z}[G]$?

Group of order $210$

First homology group of $\pi$ with $G$ when $(|\pi|,|G|)=1$

Definition of isomorphism classes of vector bundles with reduced structure group

Representation of $Q_8$ over $\mathbb{R}$

Mapping cone of $BF:B\mathcal C\to B\mathcal D$ is a classifying space?

Representation of Sylow which does not extend

Sylow $p$-subgroup of a finite group