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user33869
  • Member for 11 years, 8 months
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39 votes
4 answers
14k views

What is spectrum for Laplacian in $\mathbb{R}^n$?

9 votes
2 answers
5k views

How to best approximate higher-degree polynomial in space of lower-degree polynomials?

8 votes
3 answers
345 views

What kind of matrix $A$ satisfies $Ax\geq 0\Rightarrow x\geq 0$?

4 votes
1 answer
1k views

Uniform convergence of polynomial with degree less than N+1

4 votes
1 answer
426 views

Is there an asymmetric positive definite second-order linear differential operator?

3 votes
1 answer
926 views

How is the inner product in $H^{-1/2}$ defined?

3 votes
0 answers
714 views

Relationship between DFT and FFT/DTFT

3 votes
2 answers
1k views

Why is $H^1[a,b]\subset C^0[a,b]$?

3 votes
1 answer
2k views

Is restriction of compact operator always compact?

2 votes
2 answers
146 views

Is the space of continuous function with given order of decrease closed?

2 votes
1 answer
310 views

Probability distribution of Poisson process

2 votes
1 answer
506 views

Are there $L^2$ functions whose Laplacian is in $L^2$ yet its gradient is not in $\mathbf{L}^2$?

1 vote
1 answer
201 views

Is the sum of two Sobolev spaces defined on two different sets the Sobolev space defined on the union of these two sets?

1 vote
1 answer
85 views

What kind of functions lie in $L^2(\Omega )-H^{1/2}(\Omega )$?

1 vote
1 answer
141 views

Is that a counterexample to sampling theorem?

1 vote
1 answer
182 views

Can Cauchy theorem be applied to $\log{(z)}e^{ixz}$?

0 votes
1 answer
345 views

restriction of multivariate polynomial on hyperplane

0 votes
1 answer
86 views

How to convert trignometric polynomial to standard form?