In which sense is u a solution for (1) on $ Omega=B_1(0) $?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
1
down vote

favorite
1












Consider $$ beginequation
begincases
-Deltaomega=f on Omega \
omega=0 on partialOmega
endcases (1)endequation $$
Definition 1 : $$ Let uin W^1,2_0(Omega) such that \
int_Omega(nabla u*nablaphi-fphi)dx=0 for all phiin W^1,2_0(Omega) , $$
$$ then u is called a weak solution for (1) on Omega .$$
$$ \ $$
Definition 2 :$$ Let uin C_0(overline Omega) such that \
int_Omega(- u*Deltaphi-fphi)dx=0 for all phiin C^infty_0(Omega) ,$$
$$ then u is called a distributional solution for (1) on Omega .$$
$$ \ $$
I'm not really sure , but I think u is a distributional solution for (1) . Using a few times partial Integration and keeping in mind that the integral on the boundary disappears and that u is continuously differentiable I get the following :
$$ -int_B_1(0)uDeltaphi dx=-int_partial B_1(0)unablaphinu dsigma_x+int_B_1(0)nabla u nabla phi dx\
=int_partial B_1(0)nabla u phinu dsigma_x-int_B_1(0)Delta uphi dx=-int_B_1(0)Delta uphi dx=int_B_1(0)fphi dx . $$
I forgot something to mention $$ u(x_1,x_2)= x_1x_2(1-sqrtx_1^2+x_2^2) , where (x_1,x_2)in overlineB_1(0)subset mathbbR^2$$










share|cite|improve this question























  • I did a quick calculation, and it appears that $uin W^1,2_0$ for the $u$ that you provided. This may mean it is a weak solution. Someone may need to confirm, though.
    – MasterYoda
    Sep 10 at 20:46










  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . Well then it follows that $$ u in B_1(0)0 $$ is a distributional solution for (1) .
    – Matillo
    Sep 11 at 6:17











  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . In fact I computed that u is in $$ W^3,p(B_1(0)) cap W^4,1(B_1(0)) $$ .
    – Matillo
    Sep 11 at 6:36










  • Can someone explain me how I can show that u is a distributional solution for (1) on $$ B_1(0)diagdown (0,0) $$ ? I know that $$ uin C^infty(B_1(0)diagdown(0,0)) $$ .
    – Matillo
    Sep 11 at 14:11














up vote
1
down vote

favorite
1












Consider $$ beginequation
begincases
-Deltaomega=f on Omega \
omega=0 on partialOmega
endcases (1)endequation $$
Definition 1 : $$ Let uin W^1,2_0(Omega) such that \
int_Omega(nabla u*nablaphi-fphi)dx=0 for all phiin W^1,2_0(Omega) , $$
$$ then u is called a weak solution for (1) on Omega .$$
$$ \ $$
Definition 2 :$$ Let uin C_0(overline Omega) such that \
int_Omega(- u*Deltaphi-fphi)dx=0 for all phiin C^infty_0(Omega) ,$$
$$ then u is called a distributional solution for (1) on Omega .$$
$$ \ $$
I'm not really sure , but I think u is a distributional solution for (1) . Using a few times partial Integration and keeping in mind that the integral on the boundary disappears and that u is continuously differentiable I get the following :
$$ -int_B_1(0)uDeltaphi dx=-int_partial B_1(0)unablaphinu dsigma_x+int_B_1(0)nabla u nabla phi dx\
=int_partial B_1(0)nabla u phinu dsigma_x-int_B_1(0)Delta uphi dx=-int_B_1(0)Delta uphi dx=int_B_1(0)fphi dx . $$
I forgot something to mention $$ u(x_1,x_2)= x_1x_2(1-sqrtx_1^2+x_2^2) , where (x_1,x_2)in overlineB_1(0)subset mathbbR^2$$










share|cite|improve this question























  • I did a quick calculation, and it appears that $uin W^1,2_0$ for the $u$ that you provided. This may mean it is a weak solution. Someone may need to confirm, though.
    – MasterYoda
    Sep 10 at 20:46










  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . Well then it follows that $$ u in B_1(0)0 $$ is a distributional solution for (1) .
    – Matillo
    Sep 11 at 6:17











  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . In fact I computed that u is in $$ W^3,p(B_1(0)) cap W^4,1(B_1(0)) $$ .
    – Matillo
    Sep 11 at 6:36










  • Can someone explain me how I can show that u is a distributional solution for (1) on $$ B_1(0)diagdown (0,0) $$ ? I know that $$ uin C^infty(B_1(0)diagdown(0,0)) $$ .
    – Matillo
    Sep 11 at 14:11












up vote
1
down vote

favorite
1









up vote
1
down vote

favorite
1






1





Consider $$ beginequation
begincases
-Deltaomega=f on Omega \
omega=0 on partialOmega
endcases (1)endequation $$
Definition 1 : $$ Let uin W^1,2_0(Omega) such that \
int_Omega(nabla u*nablaphi-fphi)dx=0 for all phiin W^1,2_0(Omega) , $$
$$ then u is called a weak solution for (1) on Omega .$$
$$ \ $$
Definition 2 :$$ Let uin C_0(overline Omega) such that \
int_Omega(- u*Deltaphi-fphi)dx=0 for all phiin C^infty_0(Omega) ,$$
$$ then u is called a distributional solution for (1) on Omega .$$
$$ \ $$
I'm not really sure , but I think u is a distributional solution for (1) . Using a few times partial Integration and keeping in mind that the integral on the boundary disappears and that u is continuously differentiable I get the following :
$$ -int_B_1(0)uDeltaphi dx=-int_partial B_1(0)unablaphinu dsigma_x+int_B_1(0)nabla u nabla phi dx\
=int_partial B_1(0)nabla u phinu dsigma_x-int_B_1(0)Delta uphi dx=-int_B_1(0)Delta uphi dx=int_B_1(0)fphi dx . $$
I forgot something to mention $$ u(x_1,x_2)= x_1x_2(1-sqrtx_1^2+x_2^2) , where (x_1,x_2)in overlineB_1(0)subset mathbbR^2$$










share|cite|improve this question















Consider $$ beginequation
begincases
-Deltaomega=f on Omega \
omega=0 on partialOmega
endcases (1)endequation $$
Definition 1 : $$ Let uin W^1,2_0(Omega) such that \
int_Omega(nabla u*nablaphi-fphi)dx=0 for all phiin W^1,2_0(Omega) , $$
$$ then u is called a weak solution for (1) on Omega .$$
$$ \ $$
Definition 2 :$$ Let uin C_0(overline Omega) such that \
int_Omega(- u*Deltaphi-fphi)dx=0 for all phiin C^infty_0(Omega) ,$$
$$ then u is called a distributional solution for (1) on Omega .$$
$$ \ $$
I'm not really sure , but I think u is a distributional solution for (1) . Using a few times partial Integration and keeping in mind that the integral on the boundary disappears and that u is continuously differentiable I get the following :
$$ -int_B_1(0)uDeltaphi dx=-int_partial B_1(0)unablaphinu dsigma_x+int_B_1(0)nabla u nabla phi dx\
=int_partial B_1(0)nabla u phinu dsigma_x-int_B_1(0)Delta uphi dx=-int_B_1(0)Delta uphi dx=int_B_1(0)fphi dx . $$
I forgot something to mention $$ u(x_1,x_2)= x_1x_2(1-sqrtx_1^2+x_2^2) , where (x_1,x_2)in overlineB_1(0)subset mathbbR^2$$







pde






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Sep 10 at 18:44

























asked Sep 10 at 18:14









Matillo

114




114











  • I did a quick calculation, and it appears that $uin W^1,2_0$ for the $u$ that you provided. This may mean it is a weak solution. Someone may need to confirm, though.
    – MasterYoda
    Sep 10 at 20:46










  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . Well then it follows that $$ u in B_1(0)0 $$ is a distributional solution for (1) .
    – Matillo
    Sep 11 at 6:17











  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . In fact I computed that u is in $$ W^3,p(B_1(0)) cap W^4,1(B_1(0)) $$ .
    – Matillo
    Sep 11 at 6:36










  • Can someone explain me how I can show that u is a distributional solution for (1) on $$ B_1(0)diagdown (0,0) $$ ? I know that $$ uin C^infty(B_1(0)diagdown(0,0)) $$ .
    – Matillo
    Sep 11 at 14:11
















  • I did a quick calculation, and it appears that $uin W^1,2_0$ for the $u$ that you provided. This may mean it is a weak solution. Someone may need to confirm, though.
    – MasterYoda
    Sep 10 at 20:46










  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . Well then it follows that $$ u in B_1(0)0 $$ is a distributional solution for (1) .
    – Matillo
    Sep 11 at 6:17











  • I don't really understand what I've to do if $$ u in W^1,2_0 $$ . In fact I computed that u is in $$ W^3,p(B_1(0)) cap W^4,1(B_1(0)) $$ .
    – Matillo
    Sep 11 at 6:36










  • Can someone explain me how I can show that u is a distributional solution for (1) on $$ B_1(0)diagdown (0,0) $$ ? I know that $$ uin C^infty(B_1(0)diagdown(0,0)) $$ .
    – Matillo
    Sep 11 at 14:11















I did a quick calculation, and it appears that $uin W^1,2_0$ for the $u$ that you provided. This may mean it is a weak solution. Someone may need to confirm, though.
– MasterYoda
Sep 10 at 20:46




I did a quick calculation, and it appears that $uin W^1,2_0$ for the $u$ that you provided. This may mean it is a weak solution. Someone may need to confirm, though.
– MasterYoda
Sep 10 at 20:46












I don't really understand what I've to do if $$ u in W^1,2_0 $$ . Well then it follows that $$ u in B_1(0)0 $$ is a distributional solution for (1) .
– Matillo
Sep 11 at 6:17





I don't really understand what I've to do if $$ u in W^1,2_0 $$ . Well then it follows that $$ u in B_1(0)0 $$ is a distributional solution for (1) .
– Matillo
Sep 11 at 6:17













I don't really understand what I've to do if $$ u in W^1,2_0 $$ . In fact I computed that u is in $$ W^3,p(B_1(0)) cap W^4,1(B_1(0)) $$ .
– Matillo
Sep 11 at 6:36




I don't really understand what I've to do if $$ u in W^1,2_0 $$ . In fact I computed that u is in $$ W^3,p(B_1(0)) cap W^4,1(B_1(0)) $$ .
– Matillo
Sep 11 at 6:36












Can someone explain me how I can show that u is a distributional solution for (1) on $$ B_1(0)diagdown (0,0) $$ ? I know that $$ uin C^infty(B_1(0)diagdown(0,0)) $$ .
– Matillo
Sep 11 at 14:11




Can someone explain me how I can show that u is a distributional solution for (1) on $$ B_1(0)diagdown (0,0) $$ ? I know that $$ uin C^infty(B_1(0)diagdown(0,0)) $$ .
– Matillo
Sep 11 at 14:11















active

oldest

votes











Your Answer




StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
);
);
, "mathjax-editing");

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "69"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: false,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);













 

draft saved


draft discarded


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2912190%2fin-which-sense-is-u-a-solution-for-1-on-omega-b-10%23new-answer', 'question_page');

);

Post as a guest



































active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes















 

draft saved


draft discarded















































 


draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2912190%2fin-which-sense-is-u-a-solution-for-1-on-omega-b-10%23new-answer', 'question_page');

);

Post as a guest













































































這個網誌中的熱門文章

tkz-euclide: tkzDrawCircle[R] not working

How to combine Bézier curves to a surface?

1st Magritte Awards