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the_firehawk
  • Member for 7 years
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12 votes
3 answers
5k views

Is every self-adjoint operator bounded?

9 votes
1 answer
2k views

Euler-Poisson-Darboux equation - PDE Evans

7 votes
1 answer
2k views

Proof of polar coordinates theorem in Evans' PDE Book

7 votes
2 answers
125 views

quick question about the limit of a two-variable function as $x,y\to\infty$

7 votes
1 answer
173 views

closed form for $\int_{1/4}^{3/4} x^n(1-x)^n \, dx$

6 votes
2 answers
195 views

Prove that if the series is convergent then the law of large numbers hold.

6 votes
3 answers
12k views

deriving the formula of the torsion of a curve

6 votes
1 answer
1k views

is there a way to prove the Mean-value formulas using complex analysis?

6 votes
4 answers
13k views

why is the PDF of the sum of two continuous random variables the convolution of the PDF's?

6 votes
1 answer
165 views

In the formula $\frac{(x+y)^n}{x}=\sum_{k=0}^n\binom{n}{k}(x-ak)^{k-1}(y+ak)^{n-k}$, what is $a$? What is this formula named?

5 votes
2 answers
425 views

Is there a fixed point theorem I could use to solve this problem?

5 votes
2 answers
532 views

What is the operator norm of $Tf(x) = x^2f(x)$?

5 votes
1 answer
103 views

Which of the following conditions should be weaker?

5 votes
1 answer
501 views

Show that $e^{X^2/2} \in L^1$ iff $e^{XY} \in L^1$ iff $e^{|XY|} \in L^1$

4 votes
0 answers
92 views

show that $fp(\frac{1}{x^2})$ defines a distribution?

4 votes
1 answer
56 views

why are these two sets equal?

4 votes
2 answers
3k views

Book recommendation on Sobolev spaces

4 votes
1 answer
57 views

How to compute the partial derivatives of this function?

3 votes
1 answer
112 views

trying to approximately compute $0.93^{2.98}$ without using a calculator

3 votes
4 answers
2k views

($X^{T}AX=0,\;\;\forall X$) iff $A$ is a skew symmetric matrix

3 votes
0 answers
56 views

Proof that $fg \geq 1 \implies \int_E f\ d\mu\int_E g\ d\mu \geq \mu^2(E)$

3 votes
2 answers
102 views

Compute $\mathbb{E}\big[\exp(XY+X)\big]$ where $X, Y$ are independent uniformly distributed over $[0,1]$ r.v's.

3 votes
2 answers
77 views

Calculate $\lim_{n \to \infty} \int_{\mathbb{R_{+}}} \exp((\cos^n x) -x) d\lambda(x)$

3 votes
2 answers
579 views

let $\Lambda(\lambda) = \int_{\mathbb{R}} e^{-x^2} \cos {\lambda x} \,dx$

3 votes
1 answer
58 views

construction of a sequence in a complex Hilbert space which fulfills some specific properties

3 votes
2 answers
245 views

is the Laplacian just the gradient dotted with itself?

3 votes
1 answer
99 views

Find the support of $T(\phi) = \sum_{j = 1}^{+\infty} \frac{1}{j}(\phi(\frac{1}{j}) - \phi(0))$

3 votes
1 answer
73 views

Prove that $\mathbb{P}(T_y < \infty) = \frac{a}{y}$

3 votes
0 answers
23 views

why can $\mathbb{E}_{x}[M^{\lambda}_{\inf{\{m, T_0, T_a\}}}]$ be decomposed this way?

3 votes
1 answer
87 views

can $\sum_{k=2}^{n} \frac{1}{k!} \sum_{i=0}^{n-k} \frac{(-1)^i}{i!}$ be simplified?

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