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Ben123
  • Member for 3 years, 9 months
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5 votes
1 answer
122 views

Solution of inhomogenous system with fundamental matrix.

4 votes
2 answers
406 views

Interpretation of Ricci and Scalar curvature.

3 votes
2 answers
162 views

Sectional curvature independent of basis.

3 votes
1 answer
80 views

Comparison of terms in local formulation of Christoffel-symbols in relation to isometries.

3 votes
0 answers
53 views

Show that if $\operatorname{Hom}_{R}(-,D)$ is exact then the original sequence $0 \to L \to M \to N \to 0$ is *split* exact.

3 votes
2 answers
123 views

Dual space of $\mathbb{R}^{\mathbb{N}}$ as an infinite-dimensional vector space over $\mathbb{R}$.

3 votes
0 answers
161 views

Show that the ring of formal power series in a commutative ring $R$, $R[[x]]$ is noetherian.

3 votes
1 answer
190 views

Question about exc. $15.2.21.$b in Dummit and Foote.

3 votes
0 answers
74 views

Invertible objects in tensor categories.

3 votes
1 answer
66 views

Kernel of a (complex) character.

3 votes
1 answer
48 views

Induced irreducible character of degree $2$ of $S_4/V_4$ to $S_5$.

3 votes
2 answers
47 views

Dual functor in a rigid tensor category.

2 votes
2 answers
81 views

Let $P \in \text{Syl}_{5}(S_5)$. Show that the normalizer $N := N_{S_5}(P)$ is a monomial group.

2 votes
0 answers
31 views

Standard representation restricted to $S_5$ of $S_6$ acting on its set of sylow $5$-subgroups.

2 votes
2 answers
62 views

If $I = (xy,(x-y)z)$ is an ideal in $k[x,y,z]$ where $k$ is a field, then $\operatorname{rad} I = (xy,xz,yz)$.

2 votes
1 answer
61 views

Fields of characteristic $p$ where there exists an element $a$ that is not a p:th power.

2 votes
1 answer
82 views

Given two well-orders $\langle A,R \rangle$ and $\langle B,S \rangle$, one of the following holds.

2 votes
1 answer
75 views

Confusion about $k$-algebra homomorphisms from $k[W] \to k[V]$.

2 votes
0 answers
90 views

Commutative diagrams of exact rows.

2 votes
0 answers
53 views

Follow up question on diagram-chasing/short exact sequences.

2 votes
1 answer
98 views

Schanuel's Lemma

2 votes
0 answers
22 views

Exact sequence is such that it lifts for every homomorphism to another R-module, then it lifts to $\operatorname{Hom}_{\mathbb{Z}}(R,M)$

2 votes
1 answer
48 views

Partition of unity subordinate to an induced atlas on boundary of a manifold.

2 votes
1 answer
88 views

If $S$ is a unital commutative ring, and $R$ is a subring with unity $1_R = 1_S$, is it the case that $R[x]$ is an $S$-algebra?

2 votes
1 answer
85 views

Question regarding exterior derivative in local formulation.

2 votes
0 answers
90 views

Application of the spectral theorem to shape-operator.

1 vote
2 answers
84 views

Identity for coefficient functions of Riemann Curvature Tensor.

1 vote
1 answer
128 views

Orientation preserving diffeomorphism $\iff$ positive determinant

1 vote
1 answer
100 views

The projection to submanifold of the lie-bracket of extension of vector-fields coincide with lie-bracket of original vector-fields.

1 vote
0 answers
40 views

Proof that locally defining function implies submanifold of codimension $m-n$.