Newbetuts

If ${\bf v},{\bf w}\in\mathbb R^n$, $\lVert{\bf v}+{\bf w}\rVert=\lVert{\bf v}\rVert+\lVert{\bf w}\rVert$, what can you say about $\bf v$ and $\bf w$?

Simple explanation of uniform norm / sup-norm?

Given $T \in L(X,Y)$, show the equivalence between: existence of $S$ such that $S(T(x))=x$, and $T$ being injective with $T(X)$ complemented in $Y$

Every compact operator on a Banach space with the approximation property is a norm-limit of finite rank operators

Find the closure of $C^{1}[-1, 1]$ in the space ${(\scr{B}} [-1, 1],||•||_\infty)$

$T$ is surjective if and only if the adjoint $T^*$ is an isomorphism (onto its image)

Examples of metric spaces which are not normed linear spaces?

Why is the operator norm $||T||_{op} = \text{sup}\{\frac{||Tv||}{||v||} = \text{sup}\{||Tv|| : ||v|| \leq 1\}$

The Principle of Condensation of Singularities

how to construct an absolutely convergent series which is not convergent in the space $(C[a, b], ||•||_1) $?

Is the metric space $(\mathbb{R}^\omega, d_f) $ separable?

Every map $G$ from $Y^* \to X^$ can be expresed as $T^$ where $T: X \to Y$ [duplicate]

Is the norm on a Hilbert space always finite?

Monotonicity of $\ell_p$ norm

Is the unit sphere in a preHilbert space a total set?

Are these sequences total sequences?

Rank, nuclear norm and Frobenius norm of a matrix.

New posts in normed-spaces

Prove of inequality under a Hilbert space.

Is there a semi-norm that respects matrix similitary?

From norm to scalar product

If ${\bf v},{\bf w}\in\mathbb R^n$, $\lVert{\bf v}+{\bf w}\rVert=\lVert{\bf v}\rVert+\lVert{\bf w}\rVert$, what can you say about $\bf v$ and $\bf w$?

Simple explanation of uniform norm / sup-norm?

Given $T \in L(X,Y)$, show the equivalence between: existence of $S$ such that $S(T(x))=x$, and $T$ being injective with $T(X)$ complemented in $Y$

Every compact operator on a Banach space with the approximation property is a norm-limit of finite rank operators

Find the closure of $C^{1}[-1, 1]$ in the space ${(\scr{B}} [-1, 1],||•||_\infty)$

$T$ is surjective if and only if the adjoint $T^*$ is an isomorphism (onto its image)

Examples of metric spaces which are not normed linear spaces?

Why is the operator norm $||T||_{op} = \text{sup}\{\frac{||Tv||}{||v||} = \text{sup}\{||Tv|| : ||v|| \leq 1\}$

The Principle of Condensation of Singularities

how to construct an absolutely convergent series which is not convergent in the space $(C[a, b], ||•||_1) $?

Is the metric space $(\mathbb{R}^\omega, d_f) $ separable?

Every map $G$ from $Y^* \to X^$ can be expresed as $T^$ where $T: X \to Y$ [duplicate]

Is the norm on a Hilbert space always finite?

Monotonicity of $\ell_p$ norm

Is the unit sphere in a preHilbert space a total set?

Are these sequences total sequences?

Rank, nuclear norm and Frobenius norm of a matrix.