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Konstantin
  • Member for 7 years, 3 months
  • Last seen more than a month ago
  • Russia
18 votes
1 answer
8k views

What is a resolvent of an operator?

10 votes
4 answers
1k views

Why dense subsets are convenient to prove theorems

8 votes
1 answer
2k views

Relationship between Cauchy's Integral formula and Poisson kernel

7 votes
3 answers
546 views

Compactness of the open and closed unit intervals

7 votes
1 answer
398 views

Relationship between the Wronskian and the Gramian

6 votes
3 answers
11k views

Fourier transform of a complex exponential

6 votes
1 answer
2k views

Elementary factors in the Weierstrass Factorization Theorem

6 votes
3 answers
2k views

Completeness of Measure spaces

4 votes
1 answer
2k views

Meaning of the continuous spectrum and the residual spectrum

4 votes
1 answer
430 views

Graphical explanation of Riesz's lemma

4 votes
1 answer
322 views

Interchanging derivative and integrals

4 votes
3 answers
4k views

Absolute convergence implies convergence in complete spaces

4 votes
2 answers
2k views

The correct mathematical term for nth integral

4 votes
1 answer
440 views

Questions about the proof of the Sturm oscillation theorem

4 votes
2 answers
223 views

Kreyszig 2.10.4 Implication of operator convergence

4 votes
2 answers
2k views

Sinc function vs Dirichlet kernel

3 votes
1 answer
769 views

Can every metric on a vector space be obtained from a norm?

3 votes
2 answers
3k views

Hamel basis of an infinite dimensional space

2 votes
2 answers
134 views

Rational complex exponent and proof that a matrix is unitary

2 votes
1 answer
2k views

Uniform convergence and interchange of limits

2 votes
1 answer
501 views

Equivalence of the Hardy spaces on the unit disk and the unit circle

2 votes
0 answers
109 views

Complex functions with zero derivative at some point

2 votes
1 answer
283 views

What is a category of locales?

2 votes
1 answer
608 views

What is a singular inner function

2 votes
2 answers
152 views

Finite number of negative elements in a sequence converging to infinity

2 votes
3 answers
465 views

Kreyszig 1.6.7: If $(X,d)$ is complete, show that $(X,\tilde{d})$, where $\tilde{d}=d/(1+d)$, is complete.

2 votes
2 answers
44 views

Norm of the operator that zeroes out parts of a sequence

2 votes
1 answer
187 views

Unconditional basis and the Banach-Steinhaus theorem

2 votes
1 answer
196 views

Injectivity and the lower bound of an operator

1 vote
2 answers
423 views

How to show that functions are equicontinuous