List questions from hilbert-spaces

Published on 26 Mar 2026 - 4:52

85

Views

Is a orthogonal projection in a Hilbert space automatically selfadjoint?

Published on 26 Mar 2026 - 4:51

102

Views

Does $x_n \rightharpoonup 0$, where $\|x_n \| \leq 1$ imply $Ax_n\rightarrow 0$, when $A$ is a compact, self-adjoint projection?

Published on 26 Mar 2026 - 11:17

16

Views

Dense subspace for arbitrary powers of a positive operator

Published on 10 Mar 2026 - 0:30

45

Views

Eigenvalues of a resriction of a compact operator

Published on 11 Apr 2026 - 4:17

45

Views

sequential compactness of saddle-point lagrangians

Published on 11 Apr 2026 - 13:08

34

Views

Orthogonal complement between two sets?

Published on 11 Apr 2026 - 21:12

91

Views

Domain of adjoint of annihilation operator

Published on 11 Apr 2026 - 4:15

89

Views

If $T$ is self-adjoint, then $T^2 + tI$ is bijective for any $t>0$

Published on 26 Mar 2026 - 6:30

97

Views

Compact operator in squence spaces $T(u) = \left(\sum_{k=1}^\infty \frac{u_k}{n+k}\right)_{n\in\mathbb{N}}$

Published on 14 Apr 2026 - 7:06

49

Views

Brezis' exercise 6.22.4: prove that $Q(T)$ is bijective

Published on 15 Apr 2026 - 7:29

33

Views

Does bases of operators on two Hilbert spaces span the operators on the tensor product of the two spaces?

Published on 12 Apr 2026 - 17:27

238

Views

The vector space of square-integrable complex functions and the triangle inequality squared

Published on 16 Apr 2026 - 3:38

84

Views

A self-adjoint operator related to prime numbers?

Published on 26 Mar 2026 - 4:52

78

Views

Inequality for inner product in Hilbert space $L^2([0, 2 \pi])$

Published on 16 Apr 2026 - 16:51

List Question

Version of Weyl's criterion for absolutely continuous spectrum

Is a orthogonal projection in a Hilbert space automatically selfadjoint?

Does $x_n \rightharpoonup 0$, where $\|x_n \| \leq 1$ imply $Ax_n\rightarrow 0$, when $A$ is a compact, self-adjoint projection?

Dense subspace for arbitrary powers of a positive operator

Eigenvalues of a resriction of a compact operator

sequential compactness of saddle-point lagrangians

Orthogonal complement between two sets?

Domain of adjoint of annihilation operator

If $T$ is self-adjoint, then $T^2 + tI$ is bijective for any $t>0$

Compact operator in squence spaces $T(u) = \left(\sum_{k=1}^\infty \frac{u_k}{n+k}\right)_{n\in\mathbb{N}}$

Brezis' exercise 6.22.4: prove that $Q(T)$ is bijective

Does bases of operators on two Hilbert spaces span the operators on the tensor product of the two spaces?

The vector space of square-integrable complex functions and the triangle inequality squared

A self-adjoint operator related to prime numbers?

Inequality for inner product in Hilbert space $L^2([0, 2 \pi])$

Trending Questions

Popular # Hahtags

Popular Questions