E-ideals in exponential polynomial ring
P. D'Aquino, A. Fornasiero, G. Terzo
TL;DR
The paper develops a systematic theory of exponential ideals (E-ideals) in exponential polynomial rings, introducing and contrasting three notions of maximality: primeness, maximality, and E-maximality. It shows these concepts are independent in the exponential setting and that classical correspondences (e.g., between points and maximal ideals) fail over algebraically closed fields, motivating the introduction of exponential radical ideals. By constructing and analyzing partial E-domains, free completions, and extension methods, it provides foundational results on factorization, Nullstellensatz-type phenomena, Noetherianity, and the structure of maximal E-ideals. The work also characterizes E-radical ideals via kernels, varieties, and Horn-clause logic, and highlights surprising departures from classical algebra in the exponential context, including non-Noetherianity and failure of standard Nullstellensatz results.
Abstract
We investigate exponential ideals within the context of exponential polynomial rings over exponential fields. We establish two distinct notions of maximality for exponential ideals and explore their relationship to primeness. These three concepts--prime, maximal, and E-maximal--are shown to be independent, in contrast to the classical scenario. Furthermore, we demonstrate that, over an algebraically closed field K, the correspondence between points of $K^n$ and maximal exponential ideals of the ring of exponential polynomials breaks down. Finally, we introduce and characterize exponential radical ideals. We investigate exponential ideals in the exponential polynomial ring over an exponential field. We study two notions of maximality for exponential ideals, and relate them to primeness. These three notions are independent, unlike in the classical case. We also show that over an algebraically closed field K the correspondence between points of K^n and maximal ideals of the ring of exponential polynomials does not hold.
