Showing papers in "Journal of Algebra in 2019"

TL;DR: In this paper, the heart of a cotorsion pairs on an exact category and a triangulated category is studied by means of the notion of extriangulated categories, and it is shown that the heart is abelian.

TL;DR: In this paper, the authors give a strong finite generation of the coset Com (V k ( g, B ), A k ) for generic values of k. They also give a new proof of the rationality of the simple N = 2 superconformal algebra with c = 3 k k + 2 for all positive integers k.

TL;DR: In this article, Grothendieck's conjecture on Resolution of Singularities for quasi-excellent schemes X of dimension three and of arbitrary characteristic was shown to hold for algebraic or arithmetical varieties of dimension 3.

TL;DR: In this article, it was shown that every increasing positive monoid of an ordered field is an FF-monoid, provided that P ∖ { 0 } does not have 0 as a limit point.

TL;DR: A negative answer to the question of whether a monoid algebra over a field F is atomic provided that both M and R are atomic dates back to the 1980s and was shown in this paper.

TL;DR: In this article, the authors classified all skew braces of Heisenberg type for a prime number p > 3 and determined the automorphism group of each one of these skew braces, as well as their socle and annihilator.

TL;DR: In this paper, the relation between key polynomials and minimal pairs of definition of a valuation is established, and it is shown that a valuation ν is equal to its truncation on some polynomial ring K [x ] if and only if it is valuation-transcendental.

TL;DR: In this paper, the authors study the universal Hopf algebra L of Majid and Lyubashenko in the case that the underlying ribbon category is the category of representations of a finite dimensional ribbon quasi-Hopf algebra A. The point of this exercise is to provide the groundwork for the applications to ribbon categories arising in logarithmic conformal field theories and to test a conjectural non-semisimple Verlinde formula.

TL;DR: An algebraic theory of non-involutive set-theoretic solutions to the Yang-Baxter equation by means of a non-commutative version of braces is established in this article.

TL;DR: In this paper, it was shown that if T = End T T is the endomorphism algebra of T, then T / I is equivalent to a d-cluster tilting subcategory of mod ǫ in the sense of Iyama.

TL;DR: In this article, it was shown that every submodule of a finitely generated FI-module over a noetherian polynomial FI-algebra has a finite Grobner basis, which translates into stabilization of syzygies in any fixed homological degree.

TL;DR: In this paper, the authors consider S-weakly cotorsion and S-strongly flat R-modules and show that all Rmodules have S-flat covers if and only if all flat modules are S-statically flat.

TL;DR: In this paper, a class of objects P of a triangulated category C _ that satisfies a certain (countable) negativity condition (there are no C _ -extensions of positive degrees between elements of P ; we actually need a somewhat stronger condition of this sort) to obtain a weight structure both "halves" of which are closed either with respect to C _-coproducts of less than α objects (where α is a fixed regular cardinal) or with respectto all coproductors (provided that C _ is closed with regard to coproduct

TL;DR: In this article, it was shown that for two quandles X and Y the inner automorphism groups act 2-transitively and k [ X ] is isomorphic to k [ Y ], then the quandle rings are of the same partition type.

TL;DR: In this article, the authors extend the known results by allowing more general coefficient rings and by weakening the hypotheses on the groupoids, but they only need to impose conditions on one of the two groupoids.

TL;DR: In this paper, the authors introduce the concept of a representation of a Lie Der pair and study the corresponding cohomologies, showing that a Lie der pair is rigid if the second cohomology group is trivial, and a deformation of order n is extensible if its obstruction class is trivial.

TL;DR: In this paper, it was shown that there is no transfer homomorphism from the multiplicative monoid of Int (D ) to a block monoid, and that there exists no transfer from Int(D) to a polynomial ring of polynomials.

TL;DR: For a prime number p, a new restriction on pro-p groups G which are realizable as the maximal p-Galois group G F (p) for a field F containing a root of unity of order p was given in this paper.

TL;DR: In this article, the derived intersection of two smooth subvarieties of a smooth variety is formalized and a derived base change theorem for non-transversal intersections is obtained.

TL;DR: In this article, the irreducible modules for the Z 2 -orbifold vertex operator subalgebra of the parafermion vertex operator algebra associated to the highest weight modules of the affine Kac-Moody algebra A 1 ( 1 ) of level k are classified and constructed.

TL;DR: In this paper, a classification of the l-blocks of finite special linear and unitary groups SL n ( ϵ q ) in the non-defining characteristic l ≥ 3 is given.

TL;DR: The notion of compatible O -operators on bimodules over associative algebras was introduced in this paper, and the notion of O N -structures was introduced as a hierarchy of O-operators.

TL;DR: In this article, it was shown that if the multiplicative group of a two-sided skew brace is abelian, then the additive group of this skew brace can be solvable of class at most 2k.

TL;DR: It is shown that the minimal base size of a finite primitive permutation group of degree $n$ is at most $2 (\log |G|/\log n) + 24$.

TL;DR: In this paper, the notion of relative Frobenius actions on local cohomology modules over a local ring of prime characteristic has been introduced, and it has been shown that a ring has F-nilpotent singularities if and only if the tight closure of every parameter ideal is equal to its Frobius closure.

TL;DR: In this paper, the authors introduced twisted and folded AR-quivers of type A 2 n + 1, D n+ 1, E 6 and D 4 associated to (triply) twisted Coxeter elements.

TL;DR: In this article, the growth and matrix-valued Hilbert series of N -graded twisted Calabi-Yau algebras of weighted quivers are studied. But they do not make any assumptions on the degrees of generators or relations of the algesbras.

TL;DR: In this paper, the triangulated structure of the bounded derived category of a gentle algebra is described by describing the triangles induced by the morphisms between indecomposable objects in a basis of their Hom-space.

TL;DR: In this article, it was shown that the elasticity ρ ( a ) of a non-unit a ∈ H is the supremum of m/n over all m, n for which there are factorizations of the form a = u 1 ⋅ …⋅ u m = v 1/n, where all u i and v j are irreducible.

TL;DR: A criterion for elements of free Zinbiel algebras to be Lie or Jordan is established in this article, which is used in studying speciality problems of Tortkara algesbras.