arXiv subjects

Jason Gaddis

Publications and source records attributed to Jason Gaddis.

At least 19 recordsLinked to original sources

arXiv2026

Normal extensions of twisted graded Calabi--Yau algebras

We discuss three families of twisted graded Calabi--Yau algebras of dimension three that arise through the process of normal extensions. In addition to the twisted Calabi--Yau condition, we prove that these algebras are noetherian piecewise domains under a non-degeneracy condition. We show that these algebras can also be constructed as certain iterated skew polynomial rings. Finally, we discuss how these algebras shed light on possible types of twisted graded Calabi--Yau algebras of dimension four.

math.RA↗

arXiv2026

Twisted generalized Weyl Poisson algebras of type $(A_1)^n$

We introduce a generalization of generalized Weyl Poisson algebras. This is a Poisson analogue of the twisted generalized Weyl algebras defined by Mazorchuk and Turowska. We prove existence of these algebras in two ways, using Ore extensions and by using skew Laurent Poisson algebras. It is shown that this structure is preserved under tensor products, Poisson twists, and by taking invariant rings. Finally, we prove a simplicity criterion for these Poisson algebras.

math.RA↗

arXiv2025

A family of algebras with trivial ozone group

We study a family of Calabi--Yau algebras that include the quadratic Artin--Schelter regular algebras associated to a nodal cubic. It is shown that these algebras have trivial ozone group, that is, the identity is the only automorphism that fixes the center pointwise. The graded members of this family of algebras are shown to be rigid in the sense that the invaraint ring under a nontrivial group of graded automorphisms is not Artin--Schelter regular.

math.RA↗

arXiv2025

Quiver down-up algebras of type A

We present a generalization of down-up algebras, originally defined by Benkart and Roby. These quiver down-up algebras arise as quotients of the double of the extended Dynkin quiver of type A. Under a certain non-degeneracy condition, we show that quiver down-up algebras are noetherian piecewise domains, and that they are twisted Calabi--Yau. Finally, we consider the isomorphism problem for graded quiver down-up algebras.

math.RA↗

arXiv2025

Dimension two twisted graded Calabi--Yau algebras on two-vertex quivers

We classify, up to isomorphism, twisted graded Calabi--Yau algebras of dimension two on two-vertex quivers. By work of Reyes and Rogalski, such algebras may be presented as quotients of translation quivers by mesh relations. We also consider the isomorphism problem for certain families of twisted graded Calabi--Yau algebras on larger quivers.

math.RA↗

arXiv2025

Log-ozone groups and centers of polynomial Poisson algebras

In previous work, the authors introduced the ozone group of an associative algebra as the subgroup of automorphisms which fix the center pointwise. The authors studied PI skew polynomial algebras, using the ozone group to understand their centers and to characterize them among graded algebras. In this work, we introduce and study the log-ozone group of a Poisson algebra over a field of positive characteristic. The log-ozone group is then used to characterize polynomial Poisson algebras with skew symmetric structure. We prove that unimodular Poisson algebras with skew symmetric structure have Gorenstein centers. A related result is proved for graded polynomial Poisson algebras of dimension three.

math.RA↗

arXiv2025

Higher rank Bell--Rogalski algebras

We generalize a construction of Bell and Rogalski to realize new examples of $\mathbb{Z}^n$-graded simple rings. This construction also generalizes TGWAs of type $(A_1)^n$. In addition to considering basic properties of these algebras, we provide a classification of weight modules in the setting of torsion-free orbits, study their (twisted) tensor products, and provide a simplicity criterion.

math.RA↗

arXiv2025

Hopf actions on Poisson algebras

We study finite-dimensional Hopf actions on Poisson algebras and explore the phenomenon of quantum rigidity in this context. Our main focus is on filtered (and especially quadratic) Poisson algebras, including the Weyl Poisson algebra in $2n$ variables and certain Poisson algebras in two variables. In particular, we show that any finite-dimensional Hopf algebra acting inner faithfully on these Poisson algebras must necessarily factor through a group algebra-mirroring well-known rigidity theorems for Weyl algebras in the associative setting. The proofs hinge on lifting the Hopf actions to associated Rees algebras, where we construct suitable noncommutative "quantizations" that allow us to leverage classification results for Hopf actions on quantum (or filtered) algebras. We also discuss how group actions on Poisson algebras extend to universal enveloping algebras, and we give partial classifications of Taft algebra actions on certain low-dimensional Poisson algebras.

math.QA↗

arXiv2024

Taft algebra actions on preprojective algebras

We classify actions of generalized Taft algebras on preprojective algebras of extended Dynkin quivers of type $A$. This may be viewed as an extension of the problem of classifying actions on the polynomial ring in two variables. In cases where the grouplike element acts via rotation on the underlying quiver, we compute invariants of the Taft action and, in certain cases, show that the invariant ring is isomorphic to the center of the preprojective algebra.

math.RA↗

arXiv2024

Actions of Taft Algebras on Noetherian Down-Up Algebras

We consider actions of Taft algebras on noetherian graded down-up algebras. We classify all such actions and determine properties of the corresponding invariant rings $A^T$. We identify precisely when $A^T$ is commutative, when it is Artin-Schelter regular, and give sufficient conditions for it to be Artin-Schelter Gorenstein. Our results show that many results and conjectures in the literature concerning actions of semisimple Hopf algebras on Artin-Schelter regular algebras can fail when the semisimple hypothesis is omitted.

math.RA↗

arXiv2024

Twists of twisted generalized Weyl algebras

We study graded twisted tensor products and graded twists of twisted generalized Weyl algebras (TGWAs). We show that the class of TGWAs is closed under these operations assuming mild hypotheses. We generalize a result on cocycle equivalence amongst multiparameter quantized Weyl algebras to the setting of TGWAs. As another application we prove that certain TGWAs of type $A_2$ are noetherian.

math.RA↗

arXiv2023

Ozone groups of Artin--Schelter regular algebras satisfying a polynomial identity

We study the ozone group of noetherian Artin--Schelter regular algebras satisfying a polynomial identity (or PI for short). The ozone group was shown in previous work by the authors to be an important invariant in the study of PI skew polynomial rings and their centers. In this paper, we show that skew polynomial rings are in fact characterized as those algebras with maximal rank ozone groups. We also classify those with trivial ozone groups, which must necessarily be Calabi--Yau. This class includes most three-dimensional PI Sklyanin algebras. Further examples and applications are given, including applications to the Zariski Cancellation Problem.

math.RA↗

arXiv2023

Ozone groups and centers of skew polynomial rings

We introduce the ozone group of a noncommutative algebra $A$, defined as the group of automorphisms of $A$ which fix every element of its center. In order to initiate the study of ozone groups, we study PI skew polynomial rings, which have long proved to be a fertile testing ground in noncommutative algebra. Using the ozone group and other invariants defined herein, we give explicit conditions for the center of a PI skew polynomial to be Gorenstein (resp. regular) in low dimension.

math.RA↗

arXiv2023

Weight modules over Bell--Rogalski algebras

We study a class of $\mathbb{Z}$-graded algebras introduced by Bell and Rogalski. Their construction generalizes in large part that of rank one generalized Weyl algebras (GWAs). We establish certain ring-theoretic properties of these algebras and study their connection to GWAs. We classify the simple weight modules in the infinite orbit case and provide a partial classification in the case of orbits of finite order.

math.RA↗

arXiv2023

Four-vertex quivers supporting twisted graded Calabi-Yau algebras

We study quivers supporting twisted graded Calabi-Yau algebras, building on work of Rogalski and the first author. Specifically, we classify quivers on four vertices in which the Nakayama automorphism acts on the degree zero part by either a four-cycle, a three-cycle, or two two-cycles. In order to realize algebras associated to some of these quivers, we show that graded twists of a twisted graded Calabi-Yau algebra is another algebra of the same type.

math.RA↗

arXiv2023

The Weyl algebra and its friends: a survey

We survey several generalizations of the Weyl algebra including generalized Weyl algebras, twisted generalized Weyl algebras, quantized Weyl algebras, and Bell-Rogalski algebras. Attention is paid to ring-theoretic properties, representation theory, and invariant theory.

math.RA↗

arXiv2022

Centers and automorphisms of PI Quantum Matrix Algebras

We study PI quantum matrix algebras and their automorphisms using the noncommutative discriminant. In the multi-parameter case at $n=2$ and $n=3$, we show that all automorphisms are graded when the center is a polynomial ring. In the single-parameter case, we determine a presentation of the center and show that the automorphism group is not graded, though are able to describe certain families of automorphisms in this case, as well as those of certain subalgebras.

math.RA↗

arXiv2022

Auslander's Theorem for dihedral actions on preprojective algebras of type A

Given an algebra $R$ and $G$ a finite group of automorphisms of $R$, there is a natural map $η_{R,G}:R\#G \to \mathrm{End}_{R^G} R$, called the Auslander map. A theorem of Auslander shows that $η_{R,G}$ is an isomorphism when $R=\mathbb{C}[V]$ and $G$ is a finite group acting linearly and without reflections on the finite-dimensional vector space $V$. The work of Mori and Bao-He-Zhang has encouraged study of this theorem in the context of Artin-Schelter regular algebras. We initiate a study of Auslander's result in the setting of non-connected graded Calabi-Yau algebras. When $R$ is a preprojective algebra of type $A$ and $G$ is a finite subgroup of $D_n$ acting on $R$ by automorphism, our main result shows that $η_{R,G}$ is an isomorphism if and only if $G$ does not contain all of the reflections through a vertex.

math.RA↗