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DanielC
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5 votes
1 answer
1k views

Prove that the weak$^*$ topology on the space of tempered distributions is not 1st countable

5 votes
0 answers
161 views

Universal covering group of a semidirect product of Lie groups

4 votes
1 answer
175 views

Representations of Lie groups

4 votes
2 answers
74 views

Differentiability of tempered distributions over $\mathbb{R}^3$

3 votes
0 answers
139 views

Prove that the hydrogen continuum spectrum wavefunctions are distributions

2 votes
1 answer
499 views

Is the point spectrum always countable?

2 votes
1 answer
820 views

Fundamental group of topological product space

2 votes
1 answer
2k views

The simplest proof that $\mathbb{R}^n$ is simply connected

2 votes
1 answer
495 views

Does the spectrum of a bounded from below self-adjoint operator have a lower bound?

1 vote
0 answers
92 views

Skew-selfadjointness of commutator of self-adjoint unbounded operators

1 vote
1 answer
52 views

If a self-adjoint operator has a mixed spectrum, is it necessarily bounded from below?

1 vote
2 answers
50 views

How is a self-adjoint operator (hyper-)maximal?

1 vote
1 answer
662 views

Connected component of identity and normal subgroups

1 vote
1 answer
259 views

Is the continous spectrum of a self-adjoint operator always uncountable?

1 vote
1 answer
196 views

A basis in the space of all tempered distributions over $\mathbb{R}^n$

1 vote
0 answers
72 views

Splitting of Schwartz space of $\mathbb{R}^3$ upon Hilbert space isomorphism

1 vote
1 answer
87 views

Locus problem: 4 points on a segment with particular distances between them

0 votes
1 answer
58 views

Embedding $\mbox{Mat}_{n\times n}(\mathbb{R})$ into $\mathbb{R}^{n^2}$ and topologization

0 votes
1 answer
494 views

Is every matrix group a topological group?

0 votes
0 answers
1k views

Proof of implicit functions theorem in differential geometry

0 votes
1 answer
56 views

Elementary fact about compact (non-compact) topological/Lie groups

0 votes
1 answer
64 views

Orthogonality of a domain and image of an operator in a Hilbert space

0 votes
1 answer
632 views

Lie algebra of the connected component of a Lie group

0 votes
0 answers
44 views

Spectral theorem for completely continuous operators in a Hilbert space

0 votes
1 answer
90 views

Does a completely arbitrary unbounded operator in a separable Hilbert space have a spectrum?