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Jan
25
comment Compute the asymptotic expansion of the integral by Watson's Lemma
I don't think so. Because $\psi_{even}(z^{1/4})$ may not be analytic, so Watson's Lemma still can't be applied.
Jan
24
asked Compute the asymptotic expansion of the integral by Watson's Lemma
Dec
26
comment Functions over a finite domain that cannot be represented by Fourier series
Yeah, are there any continuous example, or maybe differentiable example?
Dec
26
revised Functions over a finite domain that cannot be represented by Fourier series
added 125 characters in body
Dec
25
asked Functions over a finite domain that cannot be represented by Fourier series
Dec
12
comment An exponential map of a matrix computation
Nice computation! But I can only accept one solution :(
Dec
12
accepted An exponential map of a matrix computation
Dec
12
comment An exponential map of a matrix computation
I see. So $A$ also commutes with $e^{At},$ which gives $Aexp(At)Mexp(A^{T}t)-Aexp(At)Mexp(A^{T}t)=0.$ Am I correct?
Dec
12
comment An exponential map of a matrix computation
Upon differentiaing I obtain $exp(At)AMexp(A^{T}t)+exp(At)Mexp(A^{T}t)A^{T}$ which seems not vanishing. I perceive your aim is to show the derivative is zero and thus let $t=0$ to obtain the answer.
Dec
12
asked An exponential map of a matrix computation
Dec
12
accepted Density of smooth compactly supported functions in Sobolev space over unbounded domain.
Dec
11
awarded  Popular Question
Dec
5
comment Density of smooth compactly supported functions in Sobolev space over unbounded domain.
Thanks for pointing that out. It should be $C^{\infty}_{c}(\mathbb{R}^n)$ instead of $C^{\infty}_{c}(U).$ I have just corrected it.
Dec
5
revised Density of smooth compactly supported functions in Sobolev space over unbounded domain.
added 11 characters in body
Dec
2
revised Density of smooth compactly supported functions in Sobolev space over unbounded domain.
edited body
Dec
2
revised Density of smooth compactly supported functions in Sobolev space over unbounded domain.
added 27 characters in body
Dec
2
asked Density of smooth compactly supported functions in Sobolev space over unbounded domain.
Nov
21
accepted Laplace equation in polar coordinates
Nov
21
comment Laplace equation in polar coordinates
Thanks! I made a mistake when solvin for $R$. The solution is $\left(\frac{4}{3r}-\frac{r}{3}\right)\sin (\theta)$
Nov
20
asked Laplace equation in polar coordinates