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Aug 14, 2023 at 2:57 comment added Davidi Cone @GiorgioMetafune how to guarantee that $(1+K u^{\frac{4}{n-2}}) \geq 0$ in $B\left(x_0, r\right)$? since $K$ may be always negative.
Aug 13, 2023 at 19:07 answer added Giorgio Metafune timeline score: 3
Aug 12, 2023 at 3:31 comment added Davidi Cone Sorry, I just don't know how to quote your name, may be @ Giorgio Metafune like this? And I guess this may not need the sign condition of $K$ by write $K=K^{+}+K^{-}$.
Aug 11, 2023 at 11:48 comment added Giorgio Metafune Please quote my name so I receive a notification, I saw your reply by chance. Sorry, I just realized that K is not a positive constant!
Aug 11, 2023 at 8:12 comment added Davidi Cone I'm wondering if we do not need the sign condition of $K(x)$?
Aug 10, 2023 at 21:50 comment added Giorgio Metafune I just use that a superharmonic function with a global miniminum is constant in a open connected set. No boundedness assumption on the set is needed. So, if your u is zero somewhere, since it is nonegative, it has a minimum and it is zero everywhere.
Aug 10, 2023 at 14:32 comment added Davidi Cone Can you give some details about the proof, thanks.
Aug 10, 2023 at 6:54 comment added Giorgio Metafune Yes, the usual proof for subharmonic/superharmonic functions works in any open connected set and gives $u=0$ if u vanishes somewhere. Or else you can use the strong minimun principle in any ball.
Aug 10, 2023 at 5:30 history edited Davidi Cone CC BY-SA 4.0
added 4 characters in body
Aug 10, 2023 at 4:32 history edited Davidi Cone CC BY-SA 4.0
added 15 characters in body
Aug 10, 2023 at 4:31 comment added Davidi Cone sorry, here $u$ not equal to 0.
Aug 10, 2023 at 2:57 comment added Michael Renardy Isn't u=0 a nonnegative solution?
Aug 10, 2023 at 1:58 history edited LSpice CC BY-SA 4.0
Proofreading; deleted "thanks"
Aug 9, 2023 at 23:12 history asked Davidi Cone CC BY-SA 4.0