V-numbers of powers of cover ideals of unimodular hypergraphs

Let $H$ be a unimodular hypergraph with cover ideal $J(H)$. We prove that the local $v$-numbers of $J(H{)}^t$ are linear in $t$ for all $t\ge 1$. We further show that the global $v$-number of $J(H{)}^t$ is linear in $t$ for all $t\ge n-1$. Finally, we prove that the global $v$-number of the powers of the cover ideal of any tree is linear in $t$ for all $t\ge 1$.