The Experts below are selected from a list of 20112 Experts worldwide ranked by ideXlab platform

Tasho Kaletha - One of the best experts on this subject based on the ideXlab platform.

  • Epipelagic $$L$$ L -packets and rectifying characters
    Inventiones mathematicae, 2015
    Co-Authors: Tasho Kaletha
    Abstract:

    We provide an explicit construction of the local Langlands correspondence for general tamely-ramified reductive p-adic groups and a class of wildly ramified Langlands parameters. Furthermore, we verify that our construction satisfies many expected properties of such a correspondence. More precisely, we show that each $$L$$ L -packet we construct admits a parameterization in terms of the Langlands dual group, contains a unique Generic Element for a fixed Whittaker datum, satisfies the formal degree conjecture, is compatible with central and cocentral characters, provides a stable virtual character, and satisfies the expected endoscopic character identities. Moreover, we show that in the case of $$\mathrm{{GL}}_n$$ GL n , our construction coincides with the established local Langlands correspondence. Our techniques provide a general approach to the construction of the local Langlands correspondence for tamely-ramified groups and regular supercuspidal parameters.

  • Epipelagic L-packets and rectifying characters
    Inventiones mathematicae, 2015
    Co-Authors: Tasho Kaletha
    Abstract:

    We provide an explicit construction of the local Langlands correspondence for general tamely-ramified reductive p-adic groups and a class of wildly ramified Langlands parameters. Furthermore, we verify that our construction satisfies many expected properties of such a correspondence. More precisely, we show that each \(L\)-packet we construct admits a parameterization in terms of the Langlands dual group, contains a unique Generic Element for a fixed Whittaker datum, satisfies the formal degree conjecture, is compatible with central and cocentral characters, provides a stable virtual character, and satisfies the expected endoscopic character identities. Moreover, we show that in the case of \(\mathrm{{GL}}_n\), our construction coincides with the established local Langlands correspondence. Our techniques provide a general approach to the construction of the local Langlands correspondence for tamely-ramified groups and regular supercuspidal parameters.

  • Epipelagic L-packets and rectifying characters
    arXiv: Representation Theory, 2012
    Co-Authors: Tasho Kaletha
    Abstract:

    We provide an explicit construction of the local Langlands correspondence for general tamely-ramified reductive p-adic groups and a class of wildly ramified Langlands parameters. Furthermore, we verify that our construction satisfies the expected properties of such a correspondence. More precisely, we show that each L-packet we construct admits a parameterization in terms of the Langlands dual group, contains a unique Generic Element for a fixed Whittaker datum, satisfies the formal degree conjecture, is compatible with twists by central and cocentral characters, provides a stable virtual character, and satisfies the expected endoscopic character identities. Moreover, we show that in the case of GL_n, our construction coincides with the one given by Bushnell and Henniart. Our results suggest a general approach to the construction of the local Langlands correspondence for tamely-ramified groups and regular supercuspidal parameters.

  • Simple wild L-packets
    arXiv: Representation Theory, 2011
    Co-Authors: Tasho Kaletha
    Abstract:

    In a recent paper, Gross and Reeder study arithmetic properties of discrete Langlands parameters for semi-simple p-adic groups and conjecture that a special class of these -- the simple wild parameters -- should correspond to L-packets consisting of simple supercuspidal representations. We provide a construction of this correspondence and show that the simple wild L-packets satisfy many expected properties. In particular, they admit a description in terms of the Langlands dual group and contain a unique Generic Element for a fixed Whittaker datum. Moreover, we prove their stability on an open subset of the regular semi-simple Elements, and show that they satisfy a natural compatibility with respect to unramified base-change.

V. V. Bavula - One of the best experts on this subject based on the ideXlab platform.

  • Structure of maximal commutative subalgebras of the first Weyl Algebra
    Annali Dell'universita' Di Ferrara, 2005
    Co-Authors: V. V. Bavula
    Abstract:

    A short proof is given to Dixmier's sixth problem from [9] for the first Weyl algebra which askswhether a polynomial of a Generic Element of the first Weyl algebra is a Generic Element. Anaffirmative answer to this question was given by A. Joseph [14]. In the paper we give an answer to a similar question but for an arbitrary Element of the first Weyl algebra. This result is used then to clarify structure of maximal commutative subalgebras in the first Weyl algebraA 1: for a given maximal commutative subalgebra C of the Weyl algebra A1 (almost) all non-scalar Elements of it have the sametype, more precisely, have one of the following types: (i) strongly nilpotent, (ii) weakly nilpotent, (iii) Generic, (iv) Generic except for a subset, K *a+K of Elements of strongly semi-simple type where a∈C is an Element of strongly semi-simple type and K*=K/{0}, (v) Generic except for a subset, K*a+K of Elements of weakly semi-simple type where a∈C is an Element of weakly semi-simple type.

  • Structure of maximal commutative subalgebras of the first Weyl Algebra
    Annali dell’Università di Ferrara, 2005
    Co-Authors: V. V. Bavula
    Abstract:

    A short proof is given to Dixmier's sixth problem from [9] for the first Weyl algebra which asks whether a polynomial of a Generic Element of the first Weyl algebra is a Generic Element . An affirmative answer to this question was given by A. Joseph [14]. In the paper we give an answer to a similar question but for an arbitrary Element of the first Weyl algebra. This result is used then to clarify structure of maximal commutative subalgebras in the first Weyl algebra A _1: for a given maximal commutative subalgebra C of the Weyl algebra A_1 (almost) all non-scalar Elements of it have the same type, more precisely, have one of the following types: (i) strongly nilpotent, (ii) weakly nilpotent, (iii) Generic, (iv) Generic except for a subset, K ^*a+K of Elements of strongly semi-simple type where a∈C is an Element of strongly semi-simple type and K^*=K/{0}, (v) Generic except for a subset, K^*a+K of Elements of weakly semi-simple type where a∈C is an Element of weakly semi-simple type. Si fornisce una dimostrazione breve al sesto problema di Dixmier enunciato in [9] per la prima algebra di Weyl che chiede se un polinomio di un Elemento Generico della prima algebra di Weyl è un Elemento Generico . Una risposta affermativa a questo problema à stata data da A. Joseph in [14]. In questo articolo formiamo una risposta ad un quesito simile ma per un Elemento arbitrario della prima algebra di Weyl. Questo risultato è usato quindi per chiarire la struttura delle sottoalgebre commutative massimali della prima algebra di Weyl A _1: per una data sottoalgebra commutativa massimale C dell'algebra di Weyl A_1 (quasi) tutti i suoi Elementi non scalari hanno lo stesso tipo; più precisamente, hanno uno dei seguenti tipi: (i) fortemente nilpotente, (ii) debolmente nilpotente, (iii) Generico, (iv) Generico eccetto che per un sottoinsieme K ^*a+K di Elementi di tipo fortemente semisemplice, dove a∈C è un Elemento di tipo debolmente semisemplice.

Hannes Thiel - One of the best experts on this subject based on the ideXlab platform.

Michael I. Friswell - One of the best experts on this subject based on the ideXlab platform.

  • Damage detection using Generic Elements: Part II. Damage detection
    Computers & Structures, 2003
    Co-Authors: Branislav Titurus, Michael I. Friswell, Ladislav Starek
    Abstract:

    This paper proposes the use of Generic Elements in damage detection, based on the use of an updated baseline finite Element model, modal sensitivities and changes in the measured modal quantities arising from structural damage. A companion paper presented the fundamental theory of model updating and Generic Element or substructure parameterisation. The experimental structure was chosen so that a considerable difference existed between the baseline finite Element model and the undamaged (healthy) structure. However the structure was successfully updated so that the model can be used effectively for damage detection and location. The main aim of this paper is to propose a method for the estimation of damage location and apply it to an experimental case study. The novel aspects of this approach are the type of parameterisation employed for the model updating and damage detection studies and the use of measured mode shapes to handle geometrical symmetry of the structure.

  • Physical Realization of Generic-Element Parameters in Model Updating
    Journal of Vibration and Acoustics, 2002
    Co-Authors: Hamid Ahmadian, John E. Mottershead, Michael I. Friswell
    Abstract:

    The selection of parameters is most important to successful updating of finite Element models. When the parameters are chosen on the basis of engineering understanding the model predictions are brought into agreement with experimental observations, and the behavior of the structure, even when differently configured, can be determined with confidence. Physical phenomena may be misrepresented in the original model, or may be absent altogether. In any case the updated model should represent an improved physical understanding of the structure and not simply consist of unrepresentative numbers which happen to cause the results of the model to agree with particular test data. The present paper introduces a systematic approach for the selection and physical realization of updated terms. In the realization process, the discrete equilibrium equation formed by mass, and stiffness matrices is converted to a continuous form at each node. By comparing the resulting differential equation with governing equations known to represent physical phenomena, the updated terms and their physical effects can be recognized. The approach is demonstrated by an experimental example.

  • Parameterisation and identification of a rubber seal
    1997
    Co-Authors: Hamid Ahmadian, John E. Mottershead, Michael I. Friswell
    Abstract:

    The parameterisation and identification of the rubber seal which joins the window glass to a car body structure is considered. A Generic Element approach is adopted in the first instance, and it is shown how this leads toa model based on two physical parameters for a distributed elastic support. Direct identification of the two parameters is carried out and the resulting model is shown to provide excellent predictions even when the glass is replaced by a steel plate.

Christian Retoré - One of the best experts on this subject based on the ideXlab platform.

  • “Chaque vin a sa lie." versus “Toute nuit a un jour." --- does the difference in the human processing of " chaque" and " tout" match the difference between the proof rules for conjunction and quantification?
    2015
    Co-Authors: Alda Mari, Christian Retoré
    Abstract:

    This paper claims that the difference between the way French native speakers use the two universal quantifiers "tout" and "chaque" corresponds rather well to the proof theoretical difference between 1) proving P(a i) for each Element a i in the domain and conjoining them and 2) proving P(x) for a Generic Element x. Experiments have been designed (but not yet realized) in order to support this claim.

  • Variable types for meaning assembly: a logical syntax for Generic noun phrases introduced by most
    Recherches linguistiques de Vincennes, 2012
    Co-Authors: Christian Retoré
    Abstract:

    We propose a way to compute the meanings associated with sentences with Generic noun phrases corresponding to the generalized quantifier “most”. We call these Generics “specimens” and they resemble stereotypes or prototypes in lexical semantics. The meanings are viewed as logical formulae that can thereafter be interpreted in your favourite models. To do so, we depart from the Fregean view with a single untyped universe and we adopt a type theory with some hints from Hilbert e-calculus and from medieval philosophy. Our type theoretic analysis bears some resemblance with ongoing work in lexical semantics by Asher, Luo and us. Our model applies to classical examples involving a class, or a Generic Element of this class, which is not uttered but provided by the context. Thus, in the minimalism-contextualism debate, our type theoretical view is that terms encode the purely semantic meaning while types are pragmatically determined.

  • Specimens: "most of" Generic NPs in a contextually flexible type theory
    2011
    Co-Authors: Christian Retoré
    Abstract:

    This paper proposes to compute the meanings associated to sentences with Generic NPs correspond- ing to the most of generalized quantifier. We call these Generics specimens and they resemble stereotypes or pro- totypes in lexical semantics. The meanings are viewed as logical formulae that can be thereafter interpreted in your favorite models. We rather depart from the dominant Fregean single untyped universe and go for type theory with hints from Hilbert epsilon calculus and from medieval philosophy. Our type theoretic analysis bears some resemblance with on going work in lexical semantics. Our model also applies to classical examples involving a class (or a Generic Element of this class) which is pro- vided by the context. An outcome of this study is that, in the minimalism-contextualism debate, if one adopts a type theoretical view, terms encode the purely semantic meaning component while their typing is pragmatically determined.