Let $k, d \in \mathbb{Z}_{\geq 1}$ be positive integers.
I want to prove the following.There exists a large enough $r \in \mathbb{Z}_{\geq 1}$ (depending on $k$ and $d$) and a Zariski open set $U \subseteq \mathbb{R}^{r+1}$ such that the following holds. For any real univariate polynomial $\sigma$ of degree $r$ whose coefficients lie in $U$, and distinct non-constant multivariate polynomials $p_1, \ldots ,p_k \in \mathbb{R}[x_1, \ldots, x_d]$, the multivariate polynomials $\sigma(p_1), \ldots, \sigma(p_k)$ are linearly independent.
Any ideas on how to prove this? Thank you so much in advance.