Projection of a closed subspace
15508
Projection map being a closed map
32420
A complete orthonormal system contained in a dense sub-space.
118996
Prove that $T$ is an orthogonal projection
115368
Diagonal Subspace of Cartesian Product
156922
Proving convergence iff projection converges in product topology
143869
Showing that the norm of the canonical projection $X\to X/M$ is $1$
19946
Let $W$ be a given subspace of $V$ find the orthogonal complement $W^{\perp}$
67106
Projection on the hyperplane $H: \sum x_i=0$
16692
a representation condition of Hilbert space
56083
Find the eigenvalues of a projection operator
141762
The direct sum of two closed subspace is closed? (Hilbert space)
125623
Subspaces of separable normed spaces
12212
Showing a certain subspace of Hilbert space is dense
44747
Finding the effective Hamiltonian in a certain subspace
17159
Proof of Closest Point Theorem in Hilbert Space
138025
How to show the solution of $\dot{x} = Ax $ is an invariant subspace?
69893
An inner product space and its proper closed subspace with trivial orthogonal complement