Minimal set of binomial generators for certain Veronese 3-fold projections (1905.02418v1)

Abstract: The goal of this paper is to explicitly describe a minimal binomial generating set of a class of lattice ideals, namely the ideal of certain Veronese $3$-fold projections. More precisely, for any integer $d\ge 4$ and any $d$-th root $e$ of 1 we denote by $X_d$ the toric variety defined as the image of the morphism $\varphi {T_d}:\mathbb{P}^3 \longrightarrow \mathbb{P}^{\mu (T_d)-1}$ where $T_d$ are all monomials of degree $d$ in $k[x,y,z,t]$ invariant under the action of the diagonal matrix $M(1,e,e^2,e^3).$ In this work, we describe a $\mathbb{Z}$-basis of the lattice $L{\eta }$ associated to $I(X_d)$ as well as a minimal binomial set of generators of the lattice ideal $I(X_d)=I_+(\eta)$.