Provide a $2$-tensor which is not decomposable on $\mathbb R^4$
128838
Showing a tensor is not a simple tensor
28819
A union of two subspaces not equal to the vector space.
27757
$\mathbb{R}\to\mathbb{R}$ Diffeomorphism with special property
109358
Prove the Curvature Tensor is a Tensor
111746
$(A/\mathfrak{a}) \otimes_A M \simeq M / \mathfrak{a}M$ by tensoring the canonical exact sequence.
6398
Can the product of an $4\times 3$ matrix and a $3\times 4$ matrix be invertible?
34712
Decomposable elements of $\Lambda^k(V)$
158343
how to prove an element is non-zero in a tensor-product
88474
$\mathbb{A}^{2}$ not isomorphic to affine space minus the origin
48524
Existence proof of the tensor product using the Adjoint functor theorem.
95412
Tensoring is not left exact
91222
Isomorphism between $\mathfrak o(4,\mathbb R)$ and $\mathfrak o (3,\mathbb R) \oplus\mathfrak o (3,\mathbb R) $
21992
Examples proving why the tensor product does not distribute over direct products.
41872
Show that $\mathbb{R}^2$ is not homeomorphic to $\mathbb{R}^2 \setminus\{(0,0)\}$
78592
Tensor product of Hadamard operators
67383
Prove that $G'$ is not planar.
93923
No surjective bounded linear map from $\ell^2(\mathbf{N})$ to $\ell^1(\mathbf{N})$