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F. Conrad's user avatar
F. Conrad's user avatar
F. Conrad's user avatar
F. Conrad
  • Member for 7 years, 3 months
  • Last seen this week
  • Aachen, Germany
10 votes
Accepted

Show that $|f(x)|$ is continuous at $a$

10 votes
Accepted

Functions in Sobolev Spaces that are NOT continuous

8 votes
Accepted

Is strict positivity preserved by weak convergence?

7 votes
Accepted

Definition for pseudoholomorphic curves

6 votes

Show that Laplace's equation $\Delta u=0$ is rotation invariant

5 votes
Accepted

Smoothness and the eigenvalues of the Hessian

5 votes
Accepted

Motivation for differential Manifolds

5 votes

Is there a way to solve $\vec{y}=\vec{y}\times\vec{a}+\vec{b}$ for arbitrary vectors?

4 votes

Confused about Georgiev's definition of $C^{\infty}_c$

4 votes
Accepted

How is Hölder's inequality and Parseval's identity applied here?

4 votes

Representation of harmonic function as a series

4 votes
Accepted

Proof: If $f$ is continuous and $||f||_1$ and $||f||_{\infty}$ are finite, then $||f||_2$ is finite

4 votes
Accepted

Inequality involving magnetic derivative

4 votes
Accepted

How to prove $|x_i - x_j| \geq |y_i - y_j| - 2 ||x - y||_\infty $

4 votes
Accepted

Integration by parts in $\mathbb{R}^n$

4 votes
Accepted

Determine $f'(x)$ when f satisfies $f(a + b) = f(a) + f(b) + ab$ and the limit...

4 votes

Prove $f(x)$ is continuous for $\mathbb{R}$

4 votes
Accepted

f has at least one zero in C

3 votes

Characterising holomorphic functions

3 votes

What's the Laplace operator in a complex plane $z=x+iy$?

3 votes
Accepted

Show $x = \frac{1}{2}(z+\frac{1}{z})$ if $z = x+iy$

3 votes

If $f$ is analytic then $|f|$ is not constant unless $f$ is constant

3 votes

Meaning of the space $W_0^{1,p}$

3 votes
Accepted

Functional distance in a manifold

3 votes

The functional $\int_{\Omega} |\nabla u|^p dx$ is invariant under dialation and translation in $\mathbb{R}^N$. How?

3 votes

Whether $\cos z$ is onto?

3 votes

Norm of the gradient of a function between Riemannian manifolds.

3 votes
Accepted

Why is $d_{\infty} \leq d_2 \leq d_1 \leq 2 d_{\infty}$

3 votes

Doubly periodic solutions to $\frac{|\partial w|^2}{(1+|w|^2)^2} = C^2$?

3 votes
Accepted

Representation of function in $W^{1,2}([-1,1])$ by function in $W^{1,2}_0([-1,1])$

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