Is there a mistake in this paper or I am understanding it incorrectly? They defined an idempotent Armendariz ring.
Idempotent Armendariz ring: A ring $R$ is said to be idempotent Armendariz (id-Armendariz) if whenever polynomials $p(t)=\displaystyle\sum_{i=0}^{n}a_it^i$ and $q(t)=\displaystyle\sum_{j=0}^{m}b_jt^j$ in $R[t]$ satisfy $p(t)q(t)=0$, then $(a_ib_j)^2 =a_ib_j$ for each $i,j$. In theorem $2.12$ of this paper, they proved that $R$ is id-Armendariz if and only if $R[x]$ is id-Armendariz. I think this is not possible because the only idempotents of $R[x]$ are the idempotents of $R$. For example in some ring $R[x]$ the degree of $x$ will increase when we square the polynomial.