Explicit valuation of elliptic nets for elliptic curves with complex multiplication

Abstract

Division polynomials associated to an elliptic curve $E/K$ are polynomials $ϕ_n, ψ_n^2$ that arise from the sequence of points $\{nP\}_{n \in \N}$ on this curve. If one wishes to study $\Z$--linear combination of points on $E(K)$, we can use net polynomials $Φ_{\bm{v}}, Ψ_{\bm{v}}^2$ which are higher--dimensional \textcolor{red}{analogues} of division polynomials. It turns out they are also elliptic nets, an $n$--dimensional array with values in $K$ satisfying the same nonlinear recurrence relation that division polynomials do as well. Now further assume the elliptic curve $E/K$ has complex multiplication by an order of a quadratic imaginary field $F \subseteq K$, we will prove a formula for the common valuation of $Φ_{\bm{v}}$ and $Ψ_{\bm{v}}^2$ associated to multiples of points by elements of an order in $F$. As an application, we will use the formula to show that elliptic divisibility sequences associated to multiples of points indexed by elements of an order also satisfy a recurrence relation when indexed by elements of an order, subject to certain conditions on the indices.