Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options answers only not deleted user 113756

Questions about partial differential equations of elliptic type. Often used in combination with the top-level tag ap.analysis-of-pdes.

5 votes

Reinforced Maximum Principle

As soon as $n=2$, and $A$ is a symmetric matrix, the answer is surely yes: $u$ has no critical points in $U$. Indeed, we can have a look at what is possibly (to my knowledge) the most recent paper on …
Daniele Tampieri's user avatar
5 votes
Accepted

Proof of Littman-Stampacchia-Weinberger theorem on the fundamental solution for elliptic PDEs

Perhaps the best self contained reference on this result is the book [2] by Stampacchia himself. It is a set of typewritten course notes in French, taken from a graduate course on elliptic equations h …
Daniele Tampieri's user avatar
19 votes
Accepted

Fundamental solution of an elliptic PDE in divergence form with non-symmetric matrix

This question requires an articulated answer, since the topic dealt is complex and ramified. A fundamental solution for a not necessarily divergence form $2$nd order elliptic system with $C^{2,h}$ coe …
Daniele Tampieri's user avatar
3 votes
Accepted

Reference request: Parabolic Equations

Premise This is a long, possibly tedious, comment. In my opinion, the problem with new books on such topics is that in most cases their contents are either expositions of the classical theory or speci …
Daniele Tampieri's user avatar
5 votes
Accepted

How to prove the second Korn inequality?

You can find a full proof (to my knowledge the simpler one currently known) in the paper [1] and in the book [2], chapter I, §2.1 pp. 14-21. The original proof of Arthur Korn is so long and involved t …
Daniele Tampieri's user avatar
2 votes

About the Hausdorff dimension of removable singularities of PDE

I am not familiar with the current studies on the Hausdorff dimension of the singular set of solutions to PDE, but I know that in [1] a necessary and sufficient condition for the holding of Hartogs ph …
Daniele Tampieri's user avatar
3 votes
Accepted

Reference request on Pucci extremal operators

The original references are the works of Pucci [2] and [3] which, however, are written in Italian. A perhaps more accessible introduction to these kind of operators is found in the monograph [1], §2.2 …
Daniele Tampieri's user avatar
2 votes

Contours for harmonic functions in bounded domains

I am not sure if I have correctly understood your question, but it seems to me that you are searching for a method of finding harmonic functions based on tomography/integral geometry: roughly speaking …
Daniele Tampieri's user avatar
1 vote

Euler-Lagrange equation for a functional

It means that the functional derivative of $J(u)$ is zero (i.e. $J(u)$ has $u$ as a stationary point) if the function $u$ solves the given divergence form PDE, i.e. $$\DeclareMathOperator{\divg}{\math …
Daniele Tampieri's user avatar
7 votes

Representing a nonlinear elliptic PDE as an energy minimization problem

As already said by Kosh, you are trying to solve an inverse problem in the calculus of variation: in its classical formulation, given a system of PDE, the problem consists in finding a functional whos …
Daniele Tampieri's user avatar