Bazin

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Name Bazin
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6h
comment Is a Cauchy principal value invariant under a “change of variables”?
You are right, I have changed my answer and added some explanations on Calderon-Zygmund operators.
6h
revised Is a Cauchy principal value invariant under a “change of variables”?
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7h
revised Is a Cauchy principal value invariant under a “change of variables”?
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18h
comment Is a Cauchy principal value invariant under a “change of variables”?
With the bi-Lipschitz continuity hypothesis, for every $\delta>0$, you get $\epsilon,\sigma >0$ such that $$ \\{\vert G(v)-G(w)\vert\le \sigma\\}\subset\\{\vert v-w\vert\le \delta\\}\subset\\{\vert G(v)-G(w)\vert\le \epsilon\\} $$ implying that last step.
1d
answered Is a Cauchy principal value invariant under a “change of variables”?
May
13
answered about smoothing pseudodifferential operators
May
8
answered Is there an equivalent of Heisenberg’s uncertainty principle in the decision sciences ?
May
8
accepted Infinite Real Symmetric Toeplitz Matrix Reference
Apr
27
accepted Is there existence and uniqueness theory of this system of ODE?
Apr
25
answered Is there existence and uniqueness theory of this system of ODE?
Apr
24
answered Replacing large-dimensional ODE systems with one PDE
Apr
22
answered Can a nowhere continuous function be integrable ?
Apr
18
comment Applications of pseudodifferential operators to PDE
Bazin (mathoverflow.net/users/21907), Motivation for and history of pseudo-differential operators, mathoverflow.net/questions/97604 (version: 2012-05-23)
Apr
16
answered Nonharmonic solutions of Laplace’s equation
Apr
15
answered Does the derivative of log have a Dirac delta term?
Apr
14
answered Increasing regularity for $L^2$ function
Apr
13
answered Polynomial growth of Fourier transforms
Apr
13
answered Oscillatory Integral
Apr
10
answered Global Implicit Function Theorem
Apr
9
awarded  Nice Answer
Mar
25
answered Smoothness of $f(\sqrt x)$
Mar
22
accepted The Periodic Schrödinger Group
Mar
22
answered The Periodic Schrödinger Group
Mar
20
accepted Every function in W^{1,1}(0,1) is continuous on (0,1)
Mar
13
accepted Embedding of weighted Sobolev spaces
Mar
13
comment Embedding of weighted Sobolev spaces
Yes of course, because of the $(1+\vert x\vert^2)^s$, locally in $x$ comparable to 1.
Mar
13
answered Embedding of weighted Sobolev spaces
Mar
12
answered problem related to airy function
Mar
10
comment Eigenfunctions of elliptic operator form an orthonormal basis for L_2?
I meant compact manifold without boundary.
Mar
9
answered Eigenfunctions of elliptic operator form an orthonormal basis for L_2?
Mar
9
comment analysis of the regularity using Hormander condition
@Kamil I agree with you on this shrinking business. However, my claim is that the method suggested by my answer is providing an explicit integral solution for your problem. With that explicit solution, you should be able to decide the smoothness properties.
Mar
9
answered Every function in W^{1,1}(0,1) is continuous on (0,1)
Mar
7
accepted Analogue of the integral Fourier operator with angle in some cone
Mar
6
awarded  Yearling
Feb
28
accepted About the boundedness of a multiplication operator.
Feb
26
answered Solving Stokes Equations using 3D Fourier transforms
Feb
25
answered About the boundedness of a multiplication operator.
Feb
24
answered Nth root of a matrix as an analytic function?
Feb
24
answered Class of functions that the Fourier inversion holds
Feb
23
answered Pullback measures
Feb
22
revised First Order PDE Solution Method Issues
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Feb
22
comment First Order PDE Solution Method Issues
@ sponsoredwalk I added a couple of comments on the quasilinear case.
Feb
21
answered First Order PDE Solution Method Issues
Feb
20
accepted An interpolation inequality.
Feb
19
comment An interpolation inequality.
The only problem is when $\epsilon$ is small, and you do have a singularity at $\epsilon=0$. Now for $x>1,0<\epsilon<1/4$, $$ \frac{x-1}{2}\ln(1-\epsilon)\le\frac{x(-\epsilon/2)}{2} $$ so you can take $a=1/4$. The bounded values of $x$ are unimportant.
Feb
19
revised An interpolation inequality.
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Feb
18
answered An interpolation inequality.
Feb
16
comment analysis of the regularity using Hormander condition
I have made an explicit computation and you can find as well an explicit solution with my formula above by plugging the values of $v$ in terms of your $u$. The regularity business, say for the function $v$ follows from the explicit integral expression: you get easily that the $L^2$ norm of $\mathcal K v$ controls the $H^1$ norm in the $x$ variable of $v$. The expression of $w$ shows that you control 2/3 of derivatives for the $z$ variable: if you want an isotropic control then you cannot do better than $2/3$. To see that is not completely obvious: just compute exactly the integral in the phase
Feb
16
answered Analogue of the integral Fourier operator with angle in some cone
Feb
10
accepted Exponential stability in nonlinear differential equations