0
$\begingroup$

What mean a $0$ in the set of functions infinitely differentiable $C_0^\infty$

  • 0
    If i understood you question, its means the set of $C^{\infty}$ functions with compact support.2012-10-24

1 Answers 1

3

It means "compactly supported", i.e. elements of that space identically vanish outside a compact subset.

Sometimes it means that the elements $u$ decay to zero "at infinity", in the sense that for any $\epsilon >0$ there exists a compact subset $K$ such that $|u|<\epsilon$ on $\complement K$.