Spectrum of an abelian category via premonoform objects
Reza Sazeedeh
TL;DR
The paper introduces the pspectrum $\PSpec\mathcal{A}$ of an abelian category and its noetherian subspace $\nPSpec\mathcal{A}$ to classify subcategories via closed/extension-closed subsets, establishing a bridge between torsion classes and spectral data. It develops prem monoform/premoform objects, connects them to extreme/prime ideals in noncommutative and commutative rings, and demonstrates how these objects yield structural classifications of Serre, localizing, and torsion subcategories. A new Serre-based topology on $\PSpec\mathcal{A}$ (via Serre psupports) provides bijections between Serre subcategories of noetherian objects and Serre closed/extension-closed subsets of $\nPSpec\mathcal{A}$, and, in the locally noetherian setting, a correspondence between localizing subcategories and Serre-closed, Serre-extension-closed subsets. In the commutative noetherian case, $\nPSpec A$ is homeomorphic to $\Spec A$, and closed subsets of $\nPSpec A$ correspond to open subsets of $\ASpec A$, yielding a network of lattice isomorphisms among Ziegler, atom, Serre, null, coherent, thick, and localization lattices. These results unify several known spectra (Spec, Zg, ASpec) with new spectral data from premonoform objects, and provide practical tools for understanding subcategory lattices via topological invariants.
Abstract
Let $\cA$ be an abelian category. In this paper, we study ${\rm (n)PSpec}\cA$, a topological space formed by equivalence classes derived from an equivalence relation on (noetherian) premonoform objects. We classify torsion classes of $\cA$ via closed subclasses of $\nPSpec\cA$. We introduce a new topology on $\PSpec\cA$ and we classify Serre subcategories of $\noeth A$ and localizing subcategories of $\cA$ using this topology. If $A$ is a commutative noetherian ring, we show that $\nPSpec A$ is homeomorphic to $\Spec A$. Moreover, there is a one-to-one correspondence between the closed subsets of $\nPSpec A$ and the open subsets of $\ASpec A$, the atom spectrum of $A$. Finally, we explore the relationships between the new subctegories of $\Mod A$ and subsets of $\nPSpec A$ introduced in this paper, and the known subcategories of $\Mod A$ and subsets of other spectra of $A$.
