Results 51 to 60 of about 576,514 (220)

The Two Extremal Rays of Some Hyper–Kähler Fourfolds

open access: yesMathematische Nachrichten, EarlyView.
ABSTRACT We consider projective Hyper–Kähler manifolds of dimension 4 that are deformation equivalent to Hilbert squares of K3 surfaces. In case such a manifold admits a divisorial contraction, the exceptional divisor is a conic bundle over a K3 surface. A classification of lattice embeddings implies that there are five types of such conic bundles.
Federica Galluzzi, Bert van Geemen
wiley   +1 more source

On the formal power series algebras generated by a vector space and a linear functional [PDF]

open access: yesJournal of Hyperstructures, 2017
Let R be a vector space ( on C) and ϕ be an element of R∗ (the dual space of R), the product r · s = ϕ(r)s converts R into an associative algebra that we denote it by Rϕ.
A. R. Khoddami
doaj   +1 more source

Perfect zero-divisor graphs

open access: yesDiscrete Mathematics, 2017
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Avinash Patil   +2 more
openaire   +2 more sources

THE ZERO-DIVISOR GRAPHS OF RINGS AND SEMIRINGS [PDF]

open access: yesInternational Journal of Algebra and Computation, 2012
In this paper we study zero-divisor graphs of rings and semirings. We show that all zero-divisor graphs of (possibly noncommutative) semirings are connected and have diameter less than or equal to 3. We characterize all acyclic zero-divisor graphs of semirings and prove that in the case zero-divisor graphs are cyclic, their girths are less than or ...
David Dolzan, Polona Oblak
openaire   +1 more source

A Linear Generalization of the Nearly Gorenstein Property, With Applications to Veronese Subalgebras

open access: yesMathematische Nachrichten, EarlyView.
ABSTRACT We study the nearly Gorenstein property for Veronese subalgebras of (semi‐)standard graded algebras. We introduce a condition (♮)$(\natural)$ for Cohen–Macaulay semi‐standard graded rings, motivated by the study of Ehrhart rings. We show that if a semi‐standard graded algebra R$ R$ satisfies (♮)$(\natural)$, then its Veronese subalgebras R(k)$
Sora Miyashita
wiley   +1 more source

The Zero Divisor Graph of the Ring Z_(2^2 p)

open access: yesARO-The Scientific Journal of Koya University, 2016
In this paper, we consider the crossing number and the chromatic number of the zero divisor graph Γ(Z_(2^2 p)) to show that this type of zero divisor graphs is bipartite graph, and the smallest cycle in Γ(Z_(2^2 p)) is of length four this implies that ...
Nazar H. Shuker, Payman A. Rashed
doaj   +1 more source

Reduced zero-divisor graphs of posets [PDF]

open access: yesTransactions on Combinatorics, 2018
This paper investigates properties of the reduced zero-divisor graph of a poset. We show that a vertex is an annihilator prime ideal if and only if it is adjacent to all other annihilator prime ideals and there are always two annihilator prime ideals ...
Deiborlang Nongsiang, Promode Saikia
doaj   +1 more source

Suppression of Oscillation and Ghosting in RF‐Spoiled Gradient‐Echo‐Based Dynamic Imaging

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose This study aims to address the suppression of oscillation and ghosting appearing in RF‐spoiled gradient‐echo‐based dynamic imaging, which is caused by the pseudo‐steady state (PSS) of magnetization. Theory and Methods We extended the concept of the previous RF phase‐cycle‐adapted averaging method to RF‐spoiled gradient‐echo‐based cine (
Jae‐Youn Keum, Jang‐Yeon Park
wiley   +1 more source

Planar Zero-Divisor Graphs [PDF]

open access: yes, 2006
Associated to every nonzero commutative ring with identity is a graph whose vertices are the nonzero zero-divisors, and such that two distinct vertices x and y are adjacent if and only if xy = 0.
Chapman, Jeremy M.
core  

Cut-structures in zero-divisor graphs of commutative rings [PDF]

open access: yes, 2016
Zero-divisor graphs, and more recently, compressed zero-divisor graphs are well represented in the commutative ring literature. In this work, we consider various cut structures, sets of edges or vertices whose removal disconnects the graph, in both ...
Axtell, Mike   +2 more
core   +1 more source

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