Article
Mathematics, Applied
Ruipeng Zhu
Summary: We prove a version of Auslander's theorem for finite group actions or coactions on noetherian polynomial identity Artin-Schelter regular algebras.
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY
(2023)
Article
Mathematics
E. Kirkman, R. Won, J. J. Zhang
Summary: We study semisimple Hopf algebra actions on Artin-Schelter regular algebras and prove upper bounds on the degrees of minimal generators of the invariant subring, as well as the degrees of syzygies of modules over the invariant subring. These results resemble those obtained by Noether, Fogarty, Fleischmann, Derksen, Sidman, Chardin, and Symonds for group actions on commutative polynomial rings.
ADVANCES IN MATHEMATICS
(2022)
Article
Mathematics, Applied
Jun Li
Summary: This paper investigates Artin-Schelter regular algebras of dimension 5 with three generators in degree 1, under the assumption that GKdim >= 4. It determines the degree types of the relations for the number of the generating relations less than five. The study proves that the only possible degree type for three generating relations is (2, 2, 3), and the only possible degree type for four generating relations is (2, 2, 3, 4).
JOURNAL OF ALGEBRA AND ITS APPLICATIONS
(2022)
Article
Mathematics
Ruipeng Zhu
Summary: This article provides a formula for computing the discriminant of skew Calabi-Yau algebra over a central Calabi-Yau algebra, and applies this method to study the Jacobian and discriminant for reflection Hopf algebras.
JOURNAL OF ALGEBRA
(2022)
Article
Mathematics
E. Kirkman, R. Won, J. J. Zhang
Summary: This paper introduces and studies weighted sums of homological and internal degrees of cochain complexes of graded A-modules, providing weighted versions of Castelnuovo-Mumford regularity, Tor-regularity, Artin-Schelter regularity, and concavity. In some cases, an infinite invariant can be replaced with a weighted invariant that is finite, and several homological invariants of complexes can be expressed as weighted homological regularities. The paper proves several weighted homological identities that unify different classical homological identities and generate interesting new ones.
TRANSACTIONS OF THE AMERICAN MATHEMATICAL SOCIETY
(2023)
Article
Mathematics
Luigi Ferraro, Ellen Kirkman, W. Frank Moore, Robert Won
Summary: The study determines the smallest dimension inner-faithful representation of a nontrivial semisimple Hopf algebra acting on a quadratic AS regular algebra of dimension 2 or 3, along with each invariant subring A(H). When A(H) is also AS regular, it provides a generalization of the Chevalley-Shephard-Todd Theorem, defining H as a reflection Hopf algebra for A.
ALGEBRAS AND REPRESENTATION THEORY
(2022)
Article
Mathematics
Xin Tang, Helbert J. Venegas Ramirez, James J. Zhang
Summary: This study focuses on a noncommutative version of the Zariski cancellation problem for certain classes of connected graded Artin-Schelter regular algebras with global dimension three.
PACIFIC JOURNAL OF MATHEMATICS
(2021)
Article
Mathematics
Hui-Xiang Chen, Ding-Guo Wang, James J. Zhang
Summary: This paper classifies all inner-faithful U-actions on noetherian Koszul Artin-Schelter regular algebras of global dimension up to three.
ALGEBRAS AND REPRESENTATION THEORY
(2023)
Article
Mathematics, Applied
Alex Chirvasitu, Ryo Kanda, S. Paul Smith
Summary: The paper introduces the algebras Q(n,k)(E, t) as generalizations of the 4-dimensional Sklyanin algebras introduced by Feigin and Odesskii. These algebras are quadratic algebras parametrized by coprime integers n > k= 1, a complex elliptic curve E, and a point t ? E. The main result of the paper is that Q(n,k)(E, t) has the same Hilbert series as the polynomial ring on n variables when t is not a torsion point. It is also shown that Q(n,k)(E, t) is a Koszul algebra of global dimension n when t is not a torsion point, and, for all but countably many t, Q(n,k)(E, t) is Artin-Schelter regular. The proofs utilize the fact that the space of quadratic relations defining Q(n,k)(E, t) is the image of an operator R-t (t) that belongs to a family of operators R-t (z): C-n ? C-n? C-n ? C-n, z ? C, which satisfy the quantum Yang-Baxter equation with spectral parameter.
SELECTA MATHEMATICA-NEW SERIES
(2023)
Article
Mathematics
Ehud Meir
Summary: This article explores the encoding and properties of algebraic or coalgebraic structures in vector spaces over an algebraically closed field, as well as the characteristics of the corresponding invariant rings. It describes a commutative ring with additional structure, generated by a combinatorial method, and demonstrates its usefulness in calculating invariant rings in specific cases.
INTERNATIONAL MATHEMATICS RESEARCH NOTICES
(2022)
Article
Mathematics
Y. Shen, Y. Guo
Summary: In this paper, we introduce an invariant called sigma-divergence for a degree-one sigma-derivation and explicitly describe the Nakayama automorphism of graded Ore extensions using this invariant. Additionally, we construct a twisted superpotential for the extension and compute the Nakayama automorphisms of graded Ore extensions of dimension 2 for noetherian Artin-Schelter regular algebras.
JOURNAL OF ALGEBRA
(2021)
Article
Mathematics
Keith Conrad, Ambar N. Sengupta
Summary: This article presents results on the behavior of rotation generators on polynomials over a commutative ring and explores harmonic polynomials in a purely algebraic setting.
JOURNAL OF ALGEBRA
(2022)
Article
Mathematics
Daniel Lannstrom
Summary: The paper presents a new characterization of graded von Neumann regular rings involving nearly epsilon-strongly graded rings, and generalizes Hazrat's result on the graded von Neumann regularity of Leavitt path algebras over fields. It is shown that Leavitt path algebras and corner skew Laurent polynomial rings over von Neumann regular rings are both semiprimitive and semiprime, thereby extending a result by Abrams and Aranda Pino on the semiprimitivity of Leavitt path algebras over fields.
JOURNAL OF ALGEBRA
(2021)
Article
Mathematics
Emanuele Dotto, Achim Krause, Thomas Nikolaus, Irakli Patchkoria
Summary: In this paper, an abelian group W(R;M) of Witt vectors with coefficients in an R-bimodule M is defined for a not-necessarily commutative ring R. These groups generalize the usual big Witt vectors of commutative rings and share similar formal properties and structure. One important result is the Morita invariance of W(R) := W(R; R) in R. Moreover, a non-commutative analogue of the classical characteristic polynomial, called characteristic element chi(f), is introduced for an R-linear endomorphism f of a finitely generated projective R-module, and its properties are established. The mapping f bar right arrow chi(f) induces an isomorphism between a suitable completion of cyclic K-theory K-0(cyc)(R) and W(R).
COMPOSITIO MATHEMATICA
(2022)
Article
Mathematics
M. S. Moslehian, G. A. Munoz-Fernandez, A. M. Peralta, J. B. Seoane-Sepulveda
Summary: This article provides a modern exposition on the subtle differences between complex and real Banach spaces, and the corresponding linear operators between them. It deeply discusses aspects of the complexification of real Banach spaces and presents several examples to demonstrate the drastic differences in behavior between real and complex Banach spaces.
REVISTA DE LA REAL ACADEMIA DE CIENCIAS EXACTAS FISICAS Y NATURALES SERIE A-MATEMATICAS
(2022)