Tomás's user avatar
Tomás's user avatar
Tomás's user avatar
Tomás
  • Member for 11 years, 7 months
  • Last seen more than a month ago
  • Brazil
37 votes
Accepted

$\ell_p$ is Hilbert if and only if $p=2$

27 votes

Different ways to prove $\sum_{k=1}^\infty \frac{1}{k^2}=\frac{\pi^2}{6}$ (the Basel problem)

20 votes
Accepted

What will be the support of the convolution of two test functions.

17 votes

Do diffeomorphisms act transitively on a manifold?

16 votes
Accepted

Why does a positive definite matrix defines a convex cone?

14 votes
Accepted

What are the higher derivatives of a multivariate function?

12 votes

Do weak convergence and convergence of norms imply convergence in $L^2$?

10 votes
Accepted

Sobolov Space $W^{2,2}\cap W^{1,2}_0$ norm equivalence

10 votes

Is the closure of a convex set again a convex set?

10 votes
Accepted

Counterexample for the solvability of $-\Delta u = f$ for $f\in C^{0}$

10 votes

Weak convergence and strong convergence

9 votes
Accepted

Approximate Holder continuous functions by smooth functions

9 votes

Book searching in Elliptic Equation

9 votes
Accepted

Eigenvalues of symmetric elliptic operators

9 votes
Accepted

About composition of Holder functions.

8 votes

The equation $\,\,\Delta u+\cos u=0\,\,$ possesses a weak solution in $\,W^{1,2}_0(D)$

8 votes

Why is compactness so important?

8 votes
Accepted

Is the Dirac delta a function?

7 votes
Accepted

Are Hoelder spaces continuously embedded into Lp spaces?

7 votes
Accepted

A question about curves in $\mathbb{R}^2$

7 votes

Geodesic distance from point to manifold

7 votes

If $f$ is measurable and $fg$ is in $L^1$ for all $g \in L^q$, must $f \in L^p$?

7 votes
Accepted

Differences between $C_c^\infty[0,T]$ and $C_c^\infty(0,T)$

7 votes

How to show that $p-$Laplacian operator is monotone?

7 votes
Accepted

Is $C^\infty_0$ dense in $C^\infty$ w.r.t. $\|\cdot\|_{L^p}$ and $\|\cdot\|_{W^{1,p}}$?

7 votes
Accepted

Smallest constant of Lipschitz retraction from bounded to continuous functions

7 votes
Accepted

What is the dense subset in $H_0^1(\Omega)\cap H^2(\Omega)$

6 votes
Accepted

The Courant Min-Max theorem of elliptic pdes.

6 votes
Accepted

Riesz representation theorem, uniqueness of the measure.

6 votes
Accepted

Sobolev embedding into $L^\infty$

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