Search results for "rex"

showing 10 items of 701 documents

Differentiation, differentiated integration and disintegration in a ‘post-Brexit-era’

2019

In contrast to the ‘ever closer Union among the peoples of Europe’ invoked in the preamble of the Treaty of Rome, Frank Schimmelfennig and Thomas Winzen ponder whether the European Union (EU) is ‘growing ever looser’. Differentiation can take various forms which are often intertwined, such as functional, institutional, spatial/territorial as well as temporal differentiation. In 1998, Petersen studied Denmark’s integration policy in what he called a ‘dilemma’ between influence capability and stress sensitivity. With the Great Recession of 2007This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book 2008, the EU entered a new multi…

DilemmaWhite paperBrexitParliamentPolitical sciencePolitical economymedia_common.quotation_subjectEuropean integrationmedia_common.cataloged_instanceTreaty of RomeEuropean unionPreamblemedia_common
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On the number of constituents of products of characters

2022

It has been conjectured that if the number of distinct irreducible constituents of the product of two faithful irreducible characters of a finite p-group, for p ≥ 5, is bigger than (p + 1)/2, then it is at least p. We give a counterexample to this conjecture.

Discrete mathematicsAlgebra and Number TheoryConjectureApplied MathematicsProduct (mathematics)FOS: MathematicsGroup Theory (math.GR)Mathematics::Representation TheoryMathematics - Group TheoryCounterexampleMathematics
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A smallest irregular oriented graph containing a given diregular one

2004

AbstractA digraph is called irregular if its vertices have mutually distinct ordered pairs of semi-degrees. Let D be any diregular oriented graph (without loops or 2-dicycles). A smallest irregular oriented graph F, F=F(D), is constructed such that F includes D as an induced subdigraph, the smallest digraph being one with smallest possible order and with smallest possible size. If the digraph D is arcless then V(D) is an independent set of F(D) comprising almost all vertices of F(D) as |V(D)|→∞. The number of irregular oriented graphs is proved to be superexponential in their order. We could not show that almost all oriented graphs are/are not irregular.

Discrete mathematicsAlmost all verticesIrregularizationDigraphDirected graphSuperexponential cardinalityGraphTheoretical Computer ScienceCombinatoricsIndependent setOrdered pairDiscrete Mathematics and CombinatoricsDiregular digraphOriented graphMathematicsDiscrete Mathematics
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On Formations of Finite Groups with the Wielandt Property for Residuals

2001

Abstract Given two subgroups U, V of a finite group which are subnormal subgroups of their join 〈U, V〉 and a formation F , in general it is not true that 〈U, V〉 F  = 〈U F , V F 〉. A formation is said to have the Wielandt property if this equality holds universally. A formation with the Wielandt property must be a Fitting class. Wielandt proved that the most usual Fitting formations (e.g., nilpotent groups and π-groups) have the Wielandt property. At present, neither a general satisfactory result on the universal validity of the Wielandt property nor a counterexample is known. In this paper a criterion for a Fitting formation to have the Wielandt property is given. As an application, it is p…

Discrete mathematicsClass (set theory)Pure mathematicsFinite groupProperty (philosophy)Algebra and Number Theorylattice propertiesJoin (topology)subnormal subgroupsresidualsNilpotentLattice propertiesformationsUniversal validityMathematicsCounterexampleJournal of Algebra
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A reduction theorem for a conjecture on products of two π -decomposable groups

2013

[EN] For a set of primes pi, a group X is said to be pi-decomposable if X = X-pi x X-pi' is the direct product of a pi-subgroup X-pi and a pi'-subgroup X-pi', where pi' is the complementary of pi in the set of all prime numbers. The main result of this paper is a reduction theorem for the following conjecture: "Let pi be a set of odd primes. If the finite group G = AB is a product of two pi-decomposable subgroups A = A(pi) x A(pi') and B = B-pi x B-pi', then A(pi)B(pi) = B(pi)A(pi) and this is a Hall pi-subgroup of G." We establish that a minimal counterexample to this conjecture is an almost simple group. The conjecture is then achieved in a forthcoming paper. (C) 2013 Elsevier Inc. All ri…

Discrete mathematicsFinite groupConjectureAlgebra and Number TheoryGroup (mathematics)Prime numberProducts of subgroupsFinite groupsHall subgroupsCombinatoricsLocally finite groupSimple grouppi-structureMATEMATICA APLICADAMinimal counterexampleDirect productpi-decomposable groupsMathematicsJournal of Algebra
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A note on Taskinen's counterexamples on the problem of topologies of Grothendieck

1989

By the work of Taskinen (see [4, 5]), we know that there is a Fréchet space E such that Lb(E, l2) is not a (DF)-space. Moreover there is a Fréchet–Montel space F such that is not (DF). In this second example, the duality theorem of Buchwalter (cf. [2, §45.3]) can be applied to obtain that and hence is a (gDF)-space (cf. [1, Ch. 12 or 3, Ch. 8]). The (gDF)-spaces were introduced by several authors to extend the (DF)-spaces of Grothendieck and to provide an adequate frame to consider strict topologies.

Discrete mathematicsFréchet spaceGeneral MathematicsFrame (networking)ComputingMethodologies_DOCUMENTANDTEXTPROCESSINGSpace (mathematics)Network topologyMathematicsCounterexampleProceedings of the Edinburgh Mathematical Society
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The existence of an a.c.i.p.m. for an expanding map of the interval; the study of a counterexample

1989

Discrete mathematicsGeneral Earth and Planetary SciencesInterval (graph theory)General Environmental ScienceMathematicsCounterexampleBanach Center Publications
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Compound conditionals, Fr\'echet-Hoeffding bounds, and Frank t-norms

2021

Abstract In this paper we consider compound conditionals, Frechet-Hoeffding bounds and the probabilistic interpretation of Frank t-norms. By studying the solvability of suitable linear systems, we show under logical independence the sharpness of the Frechet-Hoeffding bounds for the prevision of conjunctions and disjunctions of n conditional events. In addition, we illustrate some details in the case of three conditional events. We study the set of all coherent prevision assessments on a family containing n conditional events and their conjunction, by verifying that it is convex. We discuss the case where the prevision of conjunctions is assessed by Lukasiewicz t-norms and we give explicit s…

Discrete mathematicsSettore MAT/06 - Probabilita' E Statistica MatematicaLogical independenceFrank t-normsApplied MathematicsLinear systemProbabilistic logicRegular polygon02 engineering and technologyConjunction and disjunctionConditional previsionTheoretical Computer ScienceConvexityFréchet-Hoeffding boundArtificial Intelligence020204 information systems0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingPairwise comparisonCoherenceSoftwareMathematics - ProbabilityCounterexampleMathematicsCorresponding conditional
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On the continuity of discrete maximal operators in Sobolev spaces

2014

We investigate the continuity of discrete maximal operators in Sobolev space W 1;p (R n ). A counterexample is given as well as it is shown that the continuity follows under certain sucient assumptions. Especially, our research verifies that for the continuity in Sobolev spaces the role of the partition of the unity used in the construction of the maximal operator is very delicate.

Discrete mathematicsSobolev spaceGeneral Mathematicsta111Maximal operatorPartition (number theory)Modulus of continuityCounterexampleSobolev inequalitySobolev spaces for planar domainsMathematicsAnnales Academiae Scientiarum Fennicae Mathematica
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Partial Finitely Generated Bi-Ideals

2016

Partial words have been studied by Blanchet-Sadri et al., but bi-ideals or reccurrent words have been studied for centuries by many researchers. This paper gives a solution for some problems for partial reccurrent words. This paper gives an algorithm for a given finitely generated bi-ideal, how to construct a new basis of ultimately finitely generated bi-ideal, which generates the same given bi-ideal. The paper states that it is always possible to find a basis for a given finitely generated bi-ideal. The main results of this paper are presented in third section. At first, we show that if two irreduciable bi-ideals are different, they will differ in infinitely many places. This led to the st…

Discrete mathematicsStatement (computer science)Mathematics::Commutative Algebra020207 software engineering0102 computer and information sciences02 engineering and technologyBasis (universal algebra)01 natural sciencesElectronic mailSection (category theory)Stallings theorem about ends of groups010201 computation theory & mathematics0202 electrical engineering electronic engineering information engineeringFinitely-generated abelian groupFinite setCounterexampleMathematics2016 18th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing (SYNASC)
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