Timeline for Density of smooth functions in Sobolev space, respecting nonnegative traces
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
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| Mar 10, 2015 at 15:31 | comment | added | Nate Eldredge | @DenisSerre: That will certainly work. You can also do it by hand, by approximating $\phi(s) = s^+$ pointwise by $C^\infty$ functions with controlled derivatives. | |
| Mar 10, 2015 at 15:29 | comment | added | Denis Serre | Actually, a Theorem due to Stampacchia says that if $\phi$ is a Lipschit functin, then $u\mapsto\phi\circ u$ is a Lipschitz function from $W^{1,p}$ into itself. Apply this to $\phi(s)=s^+$. | |
| Mar 10, 2015 at 15:11 | vote | accept | Martin | ||
| Mar 10, 2015 at 14:55 | history | answered | Nate Eldredge | CC BY-SA 3.0 |