Skip to main content
3 of 4
edited body
Iosif Pinelis
  • 127.7k
  • 8
  • 107
  • 229

Property of $p$-norm in the $N$-simplex

Let $\mathbb{S}^{n}$ be the canonical simplex of $\mathbb{R}^{n}$ and let $u = (1/n,\dotsc,1/n)$. Is it true that

$$\lVert x - u \rVert_p \leq \lVert y - u \rVert_p$$

implies that

$$\lVert x\rVert_p \leq \lVert y\rVert_p$$

for all $x,y \in \mathbb{S}^{n}$? It seems intuitive to me that this proposition is indeed true because the $p$-norm is minimized by $u$ in the $n$-simplex. However, I can't find a formal proof for that. Any ideas?