Search results for "RINGS"
showing 10 items of 434 documents
Specht property for some varieties of Jordan algebras of almost polynomial growth
2019
Abstract Let F be a field of characteristic zero. In [25] it was proved that U J 2 , the Jordan algebra of 2 × 2 upper triangular matrices, can be endowed up to isomorphism with either the trivial grading or three distinct non-trivial Z 2 -gradings or by a Z 2 × Z 2 -grading. In this paper we prove that the variety of Jordan algebras generated by U J 2 endowed with any G-grading has the Specht property, i.e., every T G -ideal containing the graded identities of U J 2 is finitely based. Moreover, we prove an analogue result about the ordinary identities of A 1 , a suitable infinitely generated metabelian Jordan algebra defined in [27] .
Graded polynomial identities and exponential growth
2009
Let $A$ be a finite dimensional algebra over a field of characteristic zero graded by a finite abelian group $G$. Here we study a growth function related to the graded polynomial identities satisfied by $A$ by computing the exponential rate of growth of the sequence of graded codimensions of $A$. We prove that the $G$-exponent of $A$ exists and is an integer related in an explicit way to the dimension of a suitable semisimple subalgebra of $A$.
An uncountable family of almost nilpotent varieties of polynomial growth
2017
A non-nilpotent variety of algebras is almost nilpotent if any proper subvariety is nilpotent. Let the base field be of characteristic zero. It has been shown that for associative or Lie algebras only one such variety exists. Here we present infinite families of such varieties. More precisely we shall prove the existence of 1) a countable family of almost nilpotent varieties of at most linear growth and 2) an uncountable family of almost nilpotent varieties of at most quadratic growth.
Fibered aspects of Yoneda's regular span
2018
In this paper we start by pointing out that Yoneda's notion of a regular span $S \colon \mathcal{X} \to \mathcal{A} \times \mathcal{B}$ can be interpreted as a special kind of morphism, that we call fiberwise opfibration, in the 2-category $\mathsf{Fib}(\mathcal{A})$. We study the relationship between these notions and those of internal opfibration and two-sided fibration. This fibrational point of view makes it possible to interpret Yoneda's Classification Theorem given in his 1960 paper as the result of a canonical factorization, and to extend it to a non-symmetric situation, where the fibration given by the product projection $Pr_0 \colon \mathcal{A} \times \mathcal{B} \to \mathcal{A}$ i…
The graded Lie algebra structure of Lie superalgebra deformation theory
1989
We show how Lie superalgebra deformation theory can be treated by graded Lie algebras formalism. Rigidity and integrability theorems are obtained.
Cercospora beticola toxins. Part XVII. The role of the beticolin/Mg2+ complexes in their biological activity Study of plasma membrane H+-ATPase, vacu…
1996
Beticolin-1 and beticolin-2, yellow toxins produced by the phytopathogenic fungus Cercospora beticola, inhibit the plasma membrane H(+)-ATPase. Firstly, since beticolins are able to form complexes with Mg2+, the role of the beticolin/Mg2+ complexes in the inhibition of the plasma membrane proton pump has been investigated. Calculations indicate that beticolins could exist under several forms, in the H(+)-ATPase assay mixture, both free or complexed with Mg2+. However, the percentage inhibition of the H(+)-ATPase activity is correlated to the concentration of one single form of beticolin, the dimeric neutral complex Mg2H2B2, which appears to be the active form involved in the H(+)-ATPase inh…
New, Rare and Constant Habitats for Endangered Aquatic Plant Communities: The Importance of Microhabitats for Global biodiversity
2019
Natural water reservoirs are very valuable floristic sites, with springs particularly important for the preservation of floral biodiversity. This paper presents, as a case study, a community of water plants that is new to limnocrene karst springs in Europe: Potametum alpini (Potametea), found in Poland. The paper provides the floristic composition and ecological requirements of this plant association, which is rare and endangered in Europe. According to our knowledge, the habitat data presented here are unique as they are published for the first time for this plant community, and thus it is currently not possible to compare them with data from other authors. Our study confirms the importanc…
On Associative Rings with Locally Nilpotent Adjoint Semigroup
2003
Abstract The set of all elements of an associative ring R, not necessarily with a unit element, forms a semigroup R ad under the circle operation r ∘ s = r + s + rs for all r, s in R. This semigroup is locally nilpotent if every finitely generated subsemigroup of R ad is nilpotent (in sense of A. I. Mal'cev or B. H. Neumann and T. Taylor). The ring R is locally Lie-nilpotent if every finitely generated subring of R is Lie-nilpotent. It is proved that R ad is a locally nilpotent semigroup if and only if R is a locally Lie-nilpotent ring.
Rekomendācijas aizsargājamās jūras teritorijas "Rīgas līča rietumu piekraste" monitoringa metožu uzlabošanai
2021
Akmeņu sēkļi ir svarīgi jūras vides bioloģiskās daudzveidības un kvalitātes nodrošināšanai – tie ir mājvieta gan daudzām sēdošām un peldošām bentisko jūras dzīvnieku un aļģu sugām, gan nozīmīga nārsta vieta zivju sugām. Dažādu abiotisko faktoru ietekmē akmeņu sēkļos nereti veidojas mikrobiotopi vai atšķirīgi biotopu kompleksi, kas savas mozaīkveida struktūras, kā arī mainīgā dziļuma dēļ apgrūtina šo aizsargājamo jūras biotopu monitoringu. Šo apgrūtinājumu dēļ nepieciešams uzlabot monitoringa metožu efektivitāti un rekomendēt tādas monitoringa metodes, kas pietiekami atspoguļotu teritorijas bioloģisko daudzveidību. Galvenās rekomendācijas monitoringa uzlabošanai, būtu veikt monitoringu staci…
Graded metrics adapted to splittings
1997
Homogeneous graded metrics over split ℤ2-graded manifolds whose Levi-Civita connection is adapted to a given splitting, in the sense recently introduced by Koszul, are completely described. A subclass of such is singled out by the vanishing of certain components of the graded curvature tensor, a condition that plays a role similar to the closedness of a graded symplectic form in graded symplectic geometry: It amounts to determining a graded metric by the data {g, ω, Δ′}, whereg is a metric tensor onM, ω 0 is a fibered nondegenerate skewsymmetric bilinear form on the Batchelor bundleE → M, and Δ′ is a connection onE satisfying Δ′ω = 0. Odd metrics are also studied under the same criterion an…