Results 31 to 40 of about 6,291 (145)
On groups with conjugacy classes of distinct sizes
Journal of Algebra, 2004 We say that a finite group \(G\) is an ah-group if any two distinct conjugacy classes of \(G\) have different sizes. (The ah-group name comes from the phrase anti-homogeneous.) An ah-group is easily seen to be rational, meaning that all its characters are rational valued. This fact alone greatly restricts the structure of an ah-group.
Arad, Zvi +2 more
openaire +2 more sources
On the number of connected components of divisibility graph for certain simple groups [PDF]
Transactions on Combinatorics, 2016 The divisibility graph D(G) D(G) for a finite group G G is a graph with vertex set cs(G)∖{1} cs(G)∖{1} where cs(G) cs(G) is the set of conjugacy class sizes of G G. Two vertices a a and b b are adjacent whenever a a divides b b or b b divides a a.
Adeleh Abdolghafourian +1 more
doaj
Groups having complete bipartite divisor graphs for their conjugacy class sizes [PDF]
, 2013 Given a finite group G, the bipartite divisor graph for its conjugacy class sizes is the bipartite graph with bipartition consisting of the set of conjugacy class sizes of G-Z (where Z denotes the centre of G) and the set of prime numbers that divide ...
Hafezieh, Roghayeh, Spiga, Pablo
core
Fixed point spaces, primitive character degrees and conjugacy class sizes [PDF]
Proceedings of the American Mathematical Society, 2006 Let \(F\) be a field, let \(G\) be a finite group, and let \(V\) be a finite-dimensional completely reducible \(FG\)-module such that \(C_V(G)=0\). Moreover, let \(p\) be the smallest prime divisor of \(|G|\). Using the classification of finite simple groups, the authors show that \[ \dim C_V(g)\leq\tfrac 1p\dim V\quad\text{for some }g\in G,\qquad\text{
Isaacs, I. M. +3 more
openaire +1 more source
An observation‐driven state‐space model for claims size modelling
Canadian Journal of Statistics, EarlyView.Abstract State‐space models are popular in econometrics. Recently, these models have gained some popularity in the actuarial literature. The best known state‐space models are of the Kalman‐filter type. These are called parameter‐driven because the observations do not impact the state‐space dynamics.
Jae Youn Ahn +2 more
wiley +1 more source
On divisibility graph for simple Zassenhaus groups [PDF]
, 2014 The divisibility graph $D(G)$ for a finite group $G$ is a graph with vertex set $cs~(G)\setminus\{1\}$ where $cs~(G)$ is the set of conjugacy class sizes of $G$. Two vertices $a$ and $b$ are adjacent whenever $a$ divides $b$ or $b$ divides $a$.
A. Abdolghafourian +2 more
core
Partial identification with categorical data and nonignorable missing outcomes
Canadian Journal of Statistics, EarlyView.Abstract Nonignorable missing outcomes are common in real‐world datasets and often require strong parametric assumptions to achieve identification. These assumptions can be implausible or untestable, and so we may wish to forgo them in favour of partially identified models that narrow the set of a priori possible values to an identification region.
Daniel Daly‐Grafstein, Paul Gustafson
wiley +1 more source
Bayesian Inference for Joint Estimation Models Using Copulas to Handle Endogenous Regressors
Oxford Bulletin of Economics and Statistics, EarlyView.ABSTRACT This study proposes a Bayesian approach for finite‐sample inference of the Gaussian copula endogeneity correction. Extant studies use frequentist inference, build on a priori computed estimates of marginal distributions of explanatory variables, and use bootstrapping to obtain standard errors. The proposed Bayesian approach facilitates precise
Rouven E. Haschka
wiley +1 more source
Strictly transversal slices to conjugacy classes in algebraic groups [PDF]
, 2017 We show that for every conjugacy class O in a connected semisimple algebraic group G over a field of characteristic good for G one can find a special transversal slice S to the set of conjugacy classes in G such that O intersects S and dim O = codim S ...
Sevostyanov, A.
core
Unipotent elements forcing irreducibility in linear algebraic groups
, 2017 Let $G$ be a simple algebraic group over an algebraically closed field $K$ of characteristic $p > 0$. We consider connected reductive subgroups $X$ of $G$ that contain a given distinguished unipotent element $u$ of $G$. A result of Testerman and Zalesski
Korhonen, Mikko
core +1 more source