Results 61 to 70 of about 12,511,421 (301)

Note on the space group selection rule for closed strings on orbifolds

open access: yesJournal of High Energy Physics, 2019
It is well-known that the space group selection rule constrains the interactions of closed strings on orbifolds. For some examples, this rule has been described by an effective Abelian symmetry that combines with a permutation symmetry to a non-Abelian ...
Saúl Ramos-Sánchez   +1 more
doaj   +1 more source

Compact K\"ahler manifolds admitting large solvable groups of automorphisms

open access: yes, 2015
Let G be a group of automorphisms of a compact K\"ahler manifold X of dimension n and N(G) the subset of null-entropy elements. Suppose G admits no non-abelian free subgroup.
Dinh, Tien-Cuong, Hu, Fei, Zhang, De-Qi
core   +1 more source

Commuting Pairs in Quasigroups

open access: yesJournal of Combinatorial Designs, EarlyView.
ABSTRACT A quasigroup is a pair (Q,∗) $(Q,\ast )$, where Q $Q$ is a nonempty set and ∗ $\ast $ is a binary operation on Q $Q$ such that for every (a,b)∈Q2 $(a,b)\in {Q}^{2}$, there exists a unique (x,y)∈Q2 $(x,y)\in {Q}^{2}$ such that a∗x=b=y∗a $a\ast x=b=y\ast a$. Let (Q,∗) $(Q,\ast )$ be a quasigroup. A pair (x,y)∈Q2 $(x,y)\in {Q}^{2}$ is a commuting
Jack Allsop, Ian M. Wanless
wiley   +1 more source

Bases in finite groups of small order

open access: yesKarpatsʹkì Matematičnì Publìkacìï, 2021
A subset $B$ of a group $G$ is called a basis of $G$ if each element $g\in G$ can be written as $g=ab$ for some elements $a,b\in B$. The smallest cardinality $|B|$ of a basis $B\subseteq G$ is called the basis size of $G$ and is denoted by $r[G]$.
T.O. Banakh, V.M. Gavrylkiv
doaj   +1 more source

c-Regular cyclically ordered groups [PDF]

open access: yes, 2013
We define and we characterize regular and c-regular cyclically ordered abelian groups. We prove that every dense c-regular cyclically ordered abelian group is elementarily equivalent to some cyclically ordered group of unimodular complex numbers, that ...
Leloup, Gérard, Lucas, Francois
core  

On Endomorphism Universality of Sparse Graph Classes

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT We show that every commutative idempotent monoid (a.k.a. lattice) is the endomorphism monoid of a subcubic graph. This solves a problem of Babai and Pultr and the degree bound is best‐possible. On the other hand, we show that no class excluding a minor can have all commutative idempotent monoids among its endomorphism monoids. As a by‐product,
Kolja Knauer, Gil Puig i Surroca
wiley   +1 more source

On the number of diamonds in the subgroup lattice of a finite abelian group

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016
The main goal of the current paper is to determine the total number of diamonds in the subgroup lattice of a finite abelian group. This counting problem is reduced to finite p-groups. Explicit formulas are obtained in some particular cases.
Fodor Dan Gregorian   +1 more
doaj   +1 more source

Normalizers and centralizers of subgroups in non-Abelian groups of small order [PDF]

open access: yesКомпьютерные исследования и моделирование, 2012
By applying the computer program, which is created by authors, we obtain the exact representation of normalizers and centralizers of all nontrivial subgroups in non-Abelian groups G under the condition |G|20.
Ilya Anatolievih Shilin   +1 more
doaj   +1 more source

On Bipartite Biregular Large Graphs Derived From Difference Sets

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT A bipartite graph G = ( V , E ) $G=(V,E)$ with V = V 1 ∪ V 2 $V={V}_{1}\cup {V}_{2}$ is biregular if all the vertices of each stable set, V 1 ${V}_{1}$ and V 2 ${V}_{2}$, have the same degree, r $r$ and s $s$, respectively. This paper studies difference sets derived from both Abelian and non‐Abelian groups.
Gabriela Araujo‐Pardo   +3 more
wiley   +1 more source

Generalised fluxes, Yang-Baxter deformations and the O(d,d) structure of non-abelian T -duality

open access: yesJournal of High Energy Physics, 2018
Based on the construction of Poisson-Lie T -dual σ-models from a common parent action we study a candidate for the non-abelian respectively Poisson-Lie T -duality group.
Dieter Lüst, David Osten
doaj   +1 more source

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