Search results for " Representation."

showing 10 items of 791 documents

Brauer characters and coprime action

2016

Abstract It is an open problem to show that under a coprime action, the number of invariant Brauer characters of a finite group is the number of the Brauer characters of the fixed point subgroup. We prove that this is true if the non-abelian simple groups satisfy a stronger condition.

Discrete mathematicsModular representation theoryPure mathematicsFinite groupAlgebra and Number TheoryBrauer's theorem on induced charactersCoprime integers010102 general mathematics02 engineering and technologyFixed point021001 nanoscience & nanotechnology01 natural sciencesSimple group0101 mathematicsInvariant (mathematics)Mathematics::Representation Theory0210 nano-technologyBrauer groupMathematicsJournal of Algebra
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Finite Groups with Only One NonLinear Irreducible Representation

2012

Let 𝕂 be an algebraically closed field. We classify the finite groups having exactly one irreducible 𝕂-representation of degree bigger than one. The case where the characteristic of 𝕂 is zero, was done by G. Seitz in 1968.

Discrete mathematicsNonlinear systemAlgebra and Number TheoryDegree (graph theory)Irreducible representationZero (complex analysis)Algebraically closed fieldMathematicsCommunications in Algebra
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The structure of the state representation of shift invariant controllable and observable group codes

2000

AbstractIn this paper an investigation on the structure of the canonical trellis section of shift invariant, l-controllable and m-observable group codes is carried out. Necessary and sufficient conditions for a set of group homomorphisms in order that they represent the trellis section of this class of codes are established.

Discrete mathematicsNumerical AnalysisAlgebra and Number TheoryObservableCanonical representationsBehavioral analysisGroup codeGroup codesDiscrete Mathematics and CombinatoricsHomomorphismCanonical formGeometry and TopologyInvariant (mathematics)Behavioral approachState representationComputer Science::Information TheoryMathematics
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Transportation cost inequalities on path and loop groups

2005

AbstractLet G be a connected Lie group with the Lie algebra G. The action of Cameron–Martin space H(G) on the path space Pe(G) introduced by L. Gross (Illinois J. Math. 36 (1992) 447) is free. Using this fact, we define the H-distance on Pe(G), which enables us to establish a transportation cost inequality on Pe(G). This method will be generalized to the path space over the loop group Le(G), so that we obtain a transportation cost inequality for heat measures on Le(G).

Discrete mathematicsPath (topology)Adjoint representationLie groupGirsanov theoremSpace (mathematics)Action (physics)Heat measuresLoop groupsLoop (topology)Loop groupLie algebraWasserstein distanceAnalysisMathematicsH-distanceJournal of Functional Analysis
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Loop-free Gray code algorithm for the e-restricted growth functions

2011

The subject of Gray codes algorithms for the set partitions of {1,2,...,n} had been covered in several works. The first Gray code for that set was introduced by Knuth (1975) [5], later, Ruskey presented a modified version of [email protected]?s algorithm with distance two, Ehrlich (1973) [3] introduced a loop-free algorithm for the set of partitions of {1,2,...,n}, Ruskey and Savage (1994) [9] generalized [email protected]?s results and give two Gray codes for the set of partitions of {1,2,...,n}, and recently, Mansour et al. (2008) [7] gave another Gray code and loop-free generating algorithm for that set by adopting plane tree techniques. In this paper, we introduce the set of e-restricte…

Discrete mathematicsPrefix codeGeneralizationOrder (ring theory)Computer Science ApplicationsTheoretical Computer ScienceCombinatoricsSet (abstract data type)Gray codeTree (descriptive set theory)Signal ProcessingFunction representationRepresentation (mathematics)AlgorithmInformation SystemsMathematicsInformation Processing Letters
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Indecomposable modules over the Virasoro Lie algebra and a conjecture of V. Kac

1991

We consider a class of indecomposable modules over the Virasoro Lie algebra that we call bounded admissible modules. We get results concerning the center and the dimensions of the weight spaces. We prove that these modules always contain a submodule with one-dimensional weight spaces. From this follows the proof of a conjecture of V. Kac concerning the classification of simple admissible modules.

Discrete mathematicsPure mathematics17B10Statistical and Nonlinear PhysicsUniversal enveloping algebraLie superalgebraAffine Lie algebra17B68Lie conformal algebraGraded Lie algebraAlgebra representationVirasoro algebraMathematics::Representation TheoryIndecomposable moduleMathematical PhysicsMathematicsCommunications in Mathematical Physics
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Non-integrality of the PI-exponent of special Lie algebras

2013

If L is a special Lie algebra over a field of characteristic zero, its sequence of codimensions is exponentially bounded. The PI-exponent measures the exponential rate of growth of such sequence and here we give a first example of a special Lie algebra whose (upper and lower) PI-exponent is non-integer.

Discrete mathematicsPure mathematicsAdjoint representation of a Lie algebraApplied MathematicsSimple Lie groupLie algebraLie algebraReal formKilling formAffine Lie algebraMathematicsLie conformal algebraGraded Lie algebra
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On the Codimension Growth of Finite-Dimensional Lie Algebras

1999

Abstract We study the exponential growth of the codimensions cn(L) of a finite-dimensional Lie algebra L over a field of characteristic zero. We show that if the solvable radical of L is nilpotent then lim n → ∞ c n ( L ) exists and is an integer.

Discrete mathematicsPure mathematicsAdjoint representation of a Lie algebraNilpotentAlgebra and Number TheorySimple Lie groupUniversal enveloping algebraKilling formAffine Lie algebraMathematicsLie conformal algebraGraded Lie algebraJournal of Algebra
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LEFT INVARIANT COMPLEX STRUCTURES ON NILPOTENT SIMPLY CONNECTED INDECOMPOSABLE 6-DIMENSIONAL REAL LIE GROUPS

2007

Integrable complex structures on indecomposable 6-dimensional nilpotent real Lie algebras have been computed in a previous paper, along with normal forms for representatives of the various equivalence classes under the action of the automorphism group. Here we go to the connected simply connected Lie group G0 associated to such a Lie algebra 𝔤. For each normal form J of integrable complex structures on 𝔤, we consider the left invariant complex manifold G = (G0, J) associated to G0 and J. We explicitly compute a global holomorphic chart for G and we write down the multiplication in that chart.

Discrete mathematicsPure mathematicsAdjoint representation of a Lie algebraRepresentation of a Lie groupGeneral MathematicsSimple Lie groupLie algebraAdjoint representationReal formMathematicsLie conformal algebraGraded Lie algebraInternational Journal of Algebra and Computation
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A computational criterion for the Kac conjecture

2006

Abstract We give a criterion for the Kac conjecture asserting that the free term of the polynomial counting the absolutely indecomposable representations of a quiver over a finite field of given dimension coincides with the corresponding root multiplicity of the associated Kac–Moody algebra. Our criterion suits very well for computer tests.

Discrete mathematicsPure mathematicsAlgebra and Number TheoryConjectureQuiverMultiplicity (mathematics)16G20High Energy Physics::TheoryFinite fieldMathematics::Quantum AlgebraFOS: MathematicsRepresentation Theory (math.RT)Mathematics::Representation TheoryIndecomposable moduleMathematics - Representation TheoryMathematicsJournal of Algebra
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