857 research outputs found
Generators of the quantum finite W-algebras in type A
No full textWe prove a conjecture proposed in [A. De Sole, V. G. Kac and D. Valeri, Finite W-algebras for N, Adv. Math. 327 (2018) 173-224.] describing the Lax type operator L(z) for the quantum finite W-algebras of N in terms of a PBW generating system for the W-algebra. In doing so, we extend this result to an arbitrary good grading and an arbitrary isotropic subspace of [1 2]
A, W. Lind, Hawaii, the Last of the Magic Isles
No full textValeri Valerio. A, W. Lind, Hawaii, the Last of the Magic Isles. In: L'Homme, 1972, tome 12 n°1. pp. 147-150
W -algebras via Lax type operators
No full textW-algebras are certain algebraic structures associated to a finite-dimensional Lie algebra Open image in new window and a nilpotent element f via Hamiltonian reduction. In this note we give a review of a recent approach to the study of (classical affine and quantum finite) W-algebras based on the notion of Lax type operators.
For a finite-dimensional representation of Open image in new window a Lax type operator for W-algebras is constructed using the theory of generalized quasideterminants. This operator carries several pieces of information about the structure and properties of the W-algebras and shows the deep connection of the theory of W-algebras with Yangians and integrable Hamiltonian hierarchies of Lax type equations
Classical W-algebras within the theory of Poisson vertex algebras
No full textWe review the Poisson vertex algebra theory approach to classical W-algebras. First, we provide a description of the Drinfeld-Sokolov Hamiltonian reduction for the construction of classical W-algebras within the framework of Poisson vertex algebras and we establish, under certain sufficient conditions, the applicability of the Lenard-Magri scheme of integrability and the existence of the corresponding integrable hierarchy of bi-Hamiltonian equations. Then we provide a Poisson vertex algebra analogue of the Gelfand-Dickey construction of classical W-algebras and we show the relations with the Drinfeld-Sokolov Hamiltonian reduction. It will be also shown that classical W-algebras are the Poisson vertex algebras which are of interest from the conformal field theory point of view
W-algebras in type A and the Arakawa-Moreau conjecture
No full textW-algebras are an important class of vertex algebras associated with a reductive Lie algebra g, a nilpotent element f ∈ g and a scalar k ∈ C, which are closely related with various area of mathematics such as integrable systems, two-dimensional conformal field theories, modular representation theory, four dimensional gauge theory, and geometric Langlands program. Moreover, there has been a renewed interest in W-algebras since they appear as invariants of Argyres-Douglas theory via the 4D/2D correspondence recently discovered in physics. However, despite of the importance of W-algebras the problem of finding all the generators for every affine W-algebra remains unsolved. The only results known so far are from Kac-Wakimoto for minimal nilpotent elements, and from Arakawa-Molev for rectangular nilpotent elements, with the restriction of g = glN. In this thesis we obtained an explicit list of generators of W-algebras of type A associated with quasi-rectangular nilpotent elements. This is a nice generalization of the aforementioned results, since both are quasi-rectangular. Furthermore, as an application we were able to confirm a conjecture of Anne Moreau and Tomoyuki Arakawa in some cases on the isomorphism of simple quotients of W-algebras. This is a promising result since it confirms also some expectations by physicists that arose in the recent study of the 4D/2D correspondence
MasterPVA and WAlg: Mathematica packages for Poisson vertex algebras and classical affine -algebras
No full textWe give an introduction to the Mathematica packages MasterPVA and MasterPVAmulti used to compute λ-brackets in Poisson vertex algebras, which play an important role in the theory of infinite-dimensional Hamiltonian systems. As an application, we give an introduction to the Mathematica package WAlg aimed to compute the λ-brackets among the generators of classical affine W-algebras. The use of these packages is shown by providing some explicit examples
Interfacial reactivity and morphology at the Au/NiO(001) interface
No full textThe interest on metal-oxide interfaces is stimulated stimulated by the applications in many fields, such as catalysis, magnetic ecording, hard coatings. In the first stages of growth, gold nanoparticles dispersed on different oxides exhibit unusual electronic properties, depending on cluster size and gold-substrate interaction [1,2]. In particular a partial charge transfer
can occur, especially when the substrate is defective since gold tends to nucleate on oxygen vacancies. Thus the properties of goldoxide systems are critically dependent on interface reactions, in turn influenced by substrate preparation. A deeper understanding of the reactivity at the gold-oxide interface is essential to determine and control properties and behaviour of supported gold clusters. In this work we present a study of Au nucleation on top of 10 ML NiO film on Ag(001). By means of XPS, XPD and STM/AFM we studied electronic properties and morphology of the first stages of growth. It was previously reported that deposition of 15 A Au on NiO/Ag(001) causes oxide reduction [3]. We provide detailed and quantitative description
of the chemical interactions at this interface. From these results we aim to determine a relation between NiO reduction and morphological modifications (cluster formation and step decoration) in order to understand the driving force of the reduction process. Similar metal-oxide interfaces have been
also studied [4,5] to identify a general trend
in nucleation and reaction processes. In particular Fe, Pt on NiO and Fe, Pt, Au on MgO have been comparatively investigated.
[1] A. Sanchez, S. Abbet, U. Heiz, W.-D. Schneider, H. Hkkinen, R.N. Barnett, U. Landman, J. Phys. Chem. A 103(1999) 9573
[2] Z. Yang, R. Wu, D.W. Goodman, Phys. Rev. B 61 (2000) 14066
[3] R. de Masi, D. Reinicke, F. Mller, P. Steiner, S. Hfner, Surf. Sci. 515 (2002) 523
[4] S. Benedetti, P. Luches, M. Liberati, S. Valeri, Surf. Sci. 572 (2004) L348
[5] P. Luches, S. Benedetti, M. Liberati, F. Boscherini, I.I. Pronin, S. Valeri, Surf. Sci., in pres
CANTIERE INTERNAZIONALE TEATRO GIOVANI 2009- X EDIZIONE
No full textBREVE NOTA ALLA DECIMA EDIZIONE DEL CANTIERE
[www.cantiereinternazionaleteatrogiovani.it] [www.centrodistuditeatrali.it]
A partire dalla nona edizione del Cantiere Internazionale Teatro Giovani (2008), il Centro di Studi Teatrali del Dipartimento SITLeC si è assunto la responsabilità di produrre e dare continuità alla manifestazione, con la collaborazione dell’International Theater Center of New England, della Scuola Superiore di Lingue Moderne per Interpreti e Traduttori di Forlì, del Centro Diego Fabbri, del Comune di Forlì - Assessorato Cultura e Università, e del Comune di Cesenatico - Casa Moretti. Tale collaborazione ha creato uno stretto vincolo tra eventi spettacolari e spazi di riflessione scientifica e interdisciplinare, dando al Cantiere un’impronta sempre più universitaria, contrassegnata da un costante dialogo tra la cittadinanza e il mondo accademico.
Questa svolta ha comportato un’altra importante evoluzione: la consueta programmazione del Centro di Studi Teatrali si è trasformata in una vera e propria Babele Teatrale “in costruzione”, preparando il terreno per celebrare la decima edizione del Cantiere. Le conferenze, i laboratori e gli spettacoli realizzati nel corso dell’anno hanno dato vita a un Cantiere permanente, caratterizzato da un lavoro costante e sistematico, che ci ha portato a riflettere sul ruolo dell’esperienza teatrale, sull’impatto che il suo ritmo lento esercita in ambito universitario, sulla sua capacità di trasformare in conoscenza le informazioni e le nozioni proposte in aula.
Incontro, dialogo e confronto sono stati elementi centrali per l’ideazione e la realizzazione di tutte le attività in programma. In quest’ottica, è emblematico lo scambio di esperienze con il “Departamento de Artes Escénicas” della Universidad de Caldas (Colombia), ospite del Polo forlivese nel mese di marzo. La presenza di studenti e docenti di un’altra realtà universitaria, che ha adottato l’esperienza del teatro in lingua, è stata fonte di innumerevoli stimoli e ha riaffermato la valenza didattica del teatro in lingua straniera. Un’attività che può concretizzarsi in una formidabile esperienza intellettuale ed emotiva, specie quando fa affiorare temi e idee per i quali i giovani sentono una naturale passione.
Altra presenza emblematica, che ci riempie di gioia, è la partecipazione di Franca Rame, grazie alla quale diamo inizio ad un progetto triennale sulla “drammaturgia al femminile” a confronto. Un progetto che offre nuovi impulsi, sia per noi che per le generazioni a venire, e che si concretizzerà con la realizzazione di un laboratorio/spettacolo interamente dedicato ai monologhi di Franca Rame: Parti femminili. Siamo convinti che la diffusione e la promozione delle drammaturgie contemporanee, soprattutto tra i giovani, sia un obbiettivo prioritario su cui investire le nostre future energie perché, come afferma Peter Brook, il teatro è un’arte tutta al presente, il luogo pubblico dove si può esprimere la viva concentrazione della conoscenza e del sapere umano.
direzione artistica
Walter Valeri
direzione scientifica
Isabel Fernández, Marie-Line Zucchiatti
organizzazione generale
Maria Giovanna Biscu
realizzato da
Polo Scientifico-Didattico di Forlì - Università di Bologna
Centro di Studi Teatrali - Dipartimento SITLeC
Scuola Superiore di Lingue Moderne per Interpreti e Traduttori
International Theater Center of New England
Centro Diego Fabbri
Comune di Forlì - Assessorato Cultura e Università
Comune di Cesenatico - Casa Moretti
in collaborazione con
Elsinor - Teatro Testori
Harvard University
Columbia University
State University of New York
Universidad de Caldas - “Departamento de Artes Escénicas”
International University Theater Association
Facoltà di Scienze Politiche “Roberto Ruffilli”, Università di Bologna - sede di Forlì
Associazione studentesca SSenzaLiMITi (Forlì)
Scuola Media Statale “V. Felice Orsini” - plesso Maroncelli
Centro Diurno AUSL - Forlì
BioArt Theatr..
Structure of classical (finite and affine) W-algebras
No full textFirst, we derive an explicit formula for the Poisson bracket of the classical finite W- Algebra Wfin(g, f), the algebra of polynomial functions on the Slodowy slice associated to a simple Lie algebra g and its nilpotent element f . On the other hand, we produce an explicit set of generators and we derive an explicit formula for the Poisson vertex algebra structure of the classical affine W- Algebra W(g, f). As an immediate consequence, we obtain a Poisson algebra isomorphism between Wfin(g, f) and the Zhu algebra of W(g, f).We also study the generalized Miura map for classicalW- Algebras
Finite W-algebras for gl_N
No full textWe study the quantum finite W-algebras W(gl_N,f), associated to the Lie
algebra gl_N, and its arbitrary nilpotent element f. We construct for such an
algebra an r_1 x r_1 matrix L(z) of Yangian type, where r_1 is the number of
maximal parts of the partition corresponding to f. The matrix L(z) is the
quantum finite analogue of the operator of Adler type which we introduced in
the classical affine setup. As in the latter case, the matrix L(z) is obtained
as a generalized quasideterminant. It should encode the whole structure of
W(gl_N,f), including explicit formulas for generators and the commutation
relations among them. We describe in all detail the examples of principal,
rectangular and minimal nilpotent elements
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