The existence of orthonormal basis in the dense subspace
32420
A complete orthonormal system contained in a dense sub-space.
65963
Dense sets in Hilbert space of square summable sequences?
59192
Basis of cotangent space
92202
Linear separability for a sum of kernel functions
131998
let ${v_1}, {v_2} $ be orthonormal basis for subspace $W$. Prove that if $z$ is a vector in $W$, then
5506
Perturbation property of Orthonormal basis for Hilbert space
78648
Find an orthonormal basis for the subspace of $\mathbb R^4$
48111
Invariant Subspace of Two Linear Involutions
61484
Continuously invertible operators
14550
Every Hilbert space has an orthonomal basis - using Zorn's Lemma
59598
The vectors are orthonormal
100749
How to find bases for a subspace defined by an equation
17517
Efficient implementation of tensorial Rayleigh product
30017
Orthogonality and linear independence
118025
Kernel of composition of linear transformations
137769
How to find a basis for a subspace?
145885
Linear transformation preserving orthogonality