Results 41 to 50 of about 222 (151)
ADDITIVE GROUPS OF ASSOCIATIVE RINGS
An abelian group is said to be semisimple if it is an additive group of at least one semisimple associative ring. It is proved that the description problem for semisimple groups is reduced to the case of reduced groups. As a consequence, it is shown that
E. I. Kompantseva
doaj
Abelian threefolds with imaginary multiplication
Abstract Let A$A$ be an abelian threefold defined over a number field K$K$ with potential multiplication by an imaginary quadratic field M$M$. Under mild assumptions on K$K$, if A$A$ has signature (2,1) and the multiplication by M$M$ is defined over KM$KM$, we attach to A$A$ an elliptic curve defined over K$K$ with potential complex multiplication by M$
Francesc Fité, Pip Goodman
wiley +1 more source
Prismatic F‐crystals and Wach modules
Abstract We show that the category of analytic/completed prismatic F-crystals$F\text{-crystals}$ on the absolute prismatic site of a small (unramified at p$p$) base ring is naturally equivalent to the category of relative Wach modules from the theory of (φ,Γ)-modules$(\varphi, \Gamma)\text{-modules}$.
Abhinandan
wiley +1 more source
TORSION-FREE WEAKLY TRANSITIVE ABELIAN GROUPS
ABSTRACT We introduce the notion of weak transitivity for torsion-free abelian groups. A torsion-free abelian group G is called weakly transitive if for any pair of elements x, y ∈ G and endomorphisms ϕ, ψ ∈ End(G) such that xϕ = y, yψ = x, there exists an automorphism of G mapping x onto y.
Goldsmith, Brendan, Strungmann, Lutz
openaire +4 more sources
The singularity category and duality for complete intersection groups
Abstract If G$G$ is a finite group, the structure of the modular representation theory depends on the cochains C∗(BG;k)$C^*(BG; k)$, viewed as a commutative ring spectrum. We consider here its singularity category (in the sense of the author and Stevenson [Adv. Math.
J. P. C. Greenlees
wiley +1 more source
E-transitive torsion-free abelian groups
The author extends the well-known notion of a strongly homogeneous group G, an abelian group with Aut G acting transitively on the pure rank-one subgroups of G, to E-transitive groups. In this case the endomorphism ring \(E=End G\) acts transitive on the pure rank-one subgroups.
openaire +2 more sources
Separable torsion-free abelian E∗-groups
The first half of this paper characterizes the torsion-free separable abelian groups \(G\) whose endomorphism semigroup \(E(G)^*\) admits a unique addition; that is, the endomorphism ring \(E(G)\) is isomorphic to any ring \(S\) for which \(E(G)^*\) is isomorphic to \(S^*\).
Lubimcev, O. +2 more
openaire +1 more source
Cohomogeneity‐one solitons in Laplacian flow: Local, smoothly‐closing and steady solitons
Abstract We initiate a systematic study of cohomogeneity‐one solitons in Bryant's Laplacian flow of closed G2$\text{G}_2$‐structures on a 7‐manifold, motivated by the problem of understanding finite‐time singularities of that flow. Here, we focus on solitons with symmetry groups Sp(2)${\rm Sp}(2)$ and SU(3)${\rm SU}(3)$; in both cases, we prove the ...
Mark Haskins, Johannes Nordström
wiley +1 more source
Uniquely Transitive Torsion-Free Abelian Groups
We will answer a question raised by Emmanuel Dror Farjoun concerning the existence of torsion-free abelian groups G such that for any ordered pair of pure elements there is a unique automorphism mapping the first element onto the second one. We will show the existence of such a group of cardinality lambda for any successor cardinal lambda=mu^+ with mu ...
Göbel, Rüdiger, Shelah, Saharon
openaire +2 more sources
Rickard's derived Morita theory: Review and outlook
Abstract We survey the main results in Jeremy Rickard's seminal papers ‘Morita theory for derived categories’ and ‘Derived equivalences and derived functors’. These papers catalysed the later development of the Morita theory of (enhanced) compactly generated triangulated categories by Keller in the algebraic setting and by Schwede and Shipley in the ...
Gustavo Jasso +2 more
wiley +1 more source

