Results 61 to 70 of about 12,511,421 (301)
Note on the space group selection rule for closed strings on orbifolds
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
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
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
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]
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
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
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]
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
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
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