Newbetuts

In a Hilbert space $X$, $T \in B(X)$, $|\lambda|=\lVert T \rVert$. Prove that $Im(\lambda I - T)+Ker(\lambda I-T)$ is dense in $X$

$L^p$-space is a Hilbert space if and only if $p=2$

Minimizing the energy in a ruler

No trace on $B(H)$ if $H$ is infinite dimensional

Is there a non-multiplication operator on $L^2([0,1])$?

Equicontinuity and uniform boundedness for "distributions"

Use Lax-Milgram theorem to prove the existence of weak solution for an elliptic equation

$\int_{\mathbb{R}}f(x)e^{-ixz}d\mu_x$ analytic for $f\in L_1$

Isometry on a dense sub-space of a Banach space?

The constant in the Sobolev trace theorem inequality

Does the implicit function theorem imply Peano existence theorem

infinite-dimensional Banach spaces has linear subspaces of finite-codimension that are not closed

Orthonormal Basis for Hilbert Spaces

Characterization of compactness in weak* topology

Parallelogram / Polarization Inequality

Showing that Sobolev norms on manifolds are equivalent

The the image of the unit ball in X is weak-* dense in the unit ball of X**

New posts in functional-analysis

average of maximal function is less than its infimum?

Proof Nehari manifold of semilineal subcritical $-\Delta u = f(u)$ in $\Omega$ is not empty.

identity operator isn't bounded

In a Hilbert space $X$, $T \in B(X)$, $|\lambda|=\lVert T \rVert$. Prove that $Im(\lambda I - T)+Ker(\lambda I-T)$ is dense in $X$

$L^p$-space is a Hilbert space if and only if $p=2$

Minimizing the energy in a ruler

No trace on $B(H)$ if $H$ is infinite dimensional

Is there a non-multiplication operator on $L^2([0,1])$?

Equicontinuity and uniform boundedness for "distributions"

Use Lax-Milgram theorem to prove the existence of weak solution for an elliptic equation

$\int_{\mathbb{R}}f(x)e^{-ixz}d\mu_x$ analytic for $f\in L_1$

Isometry on a dense sub-space of a Banach space?

The constant in the Sobolev trace theorem inequality

Does the implicit function theorem imply Peano existence theorem

infinite-dimensional Banach spaces has linear subspaces of finite-codimension that are not closed

Orthonormal Basis for Hilbert Spaces

Characterization of compactness in weak* topology

Parallelogram / Polarization Inequality

Showing that Sobolev norms on manifolds are equivalent

The the image of the unit ball in X is weak-* dense in the unit ball of X**