2,791 research outputs found
Abelian 3-form gauge theory: superfield approach
We discuss a D-dimensional Abelian 3-form gauge theory within the framework
of Bonora-Tonin's superfield formalism and derive the off-shell nilpotent and
absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST
symmetry transformations for this theory. To pay our homage to Victor I.
Ogievetsky (1928-1996), who was one of the inventors of Abelian 2-form
(antisymmetric tensor) gauge field, we go a step further and discuss the above
D-dimensional Abelian 3-form gauge theory within the framework of BRST
formalism and establish that the existence of the (anti-)BRST invariant
Curci-Ferrari (CF) type of restrictions is the hallmark of any arbitrary p-form
gauge theory (discussed within the framework of BRST formalism).Comment: LaTeX file, 8 pages, Talk delivered at BLTP, JINR, Dubna, Moscow
Region, Russi
Toda lattice realization of integrable hierarchies
We present a new realization of scalar integrable hierarchies in terms of the
Toda lattice hierarchy. In other words, we show on a large number of examples
that an integrable hierarchy, defined by a pseudodifferential Lax operator, can
be embedded in the Toda lattice hierarchy. Such a realization in terms the Toda
lattice hierarchy seems to be as general as the Drinfeld--Sokolov realization.Comment: 11 pages, Latex (minor changes, to appear in Lett.Math.Phys.
Nilpotent (anti-)BRST symmetry transformations for dynamical non-Abelian 2-form gauge theory: superfield formalism
We derive the off-shell nilpotent and absolutely anticommuting
Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for the
dynamical non-Abelian 2-form gauge theory within the framework of geometrical
superfield formalism. We obtain the (anti-) BRST invariant coupled Lagrangian
densities that respect the above nilpotent symmetry transformations. We
discuss, furthermore, this (anti-) BRST invariance in the language of the
superfield formalism. One of the novel features of our investigation is the
observation that, in addition to the horizontality condition, we have to invoke
some other physically relevant restrictions to deduce the exact (anti-) BRST
symmetry transformations for all the fields of the topologically massive
non-Abelian gauge theory.Comment: LaTeX file, 8 pages, typos fixed in some equations, journal-versio
Supersymmetrization of horizontality condition: nilpotent symmetries for a free spinning relativistic particle
We derive the off-shell nilpotent and absolutely anticommuting
Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for a
supersymmetric system of a free spinning relativistic particle within the
framework of superfield approach to BRST formalism. A novel feature of our
present investigation is the consistent and clear supersymmetric modification
of the celebrated horizontality condition for the precise determination of the
proper (anti-)BRST symmetry transformations for all the bosonic and fermionic
dynamical variables of our theory which is considered on a (1, 2)-dimensional
supermanifold parameterized by an even (bosonic) variable (\tau) and a pair of
odd (fermionic) variables \theta and \bar\theta (with \theta^2 = \bar\theta^2 =
0,\; \theta \bar\theta + \bar\theta \theta = 0) of the Grassmann algebra. One
of the most important features of our present investigation is the derivation
of (anti-)BRST invariant Curci-Ferrari type restriction which turns out to be
responsible for the absolute anticommutativity of the (anti-)BRST symmetry
transformations and existence of the coupled (but equivalent) Lagrangians for
the present theory of a supersymmetric system.Comment: LaTeX file, 24 pages, version to appear in EPJ
Bi-photon propagation control with optimized wavefront by means of Adaptive Optics
We present an efficient method to control the spatial modes of entangled
photons produced through SPDC process. Bi-photon beam propagation is controlled
by a deformable mirror, that shapes a 404nm CW diode laser pump interacting
with a nonlinear BBO type-I crystal. Thanks to adaptive optical system, the
propagation of 808nm SPDC light produced is optimized over a distance of 2m.
The whole system optimization is carried out by a feedback between deformable
mirror action and entangled photon coincidence counts. We also demonstrated the
improvement of the two-photon coupling into single mode fibers
The integrable hierarchy constructed from a pair of KdV-type hierarchies and its associated algebra
For any two arbitrary positive integers `' and `', using the --th
KdV hierarchy and the --th KdV hierarchy as building blocks, we are able
to construct another integrable hierarchy (referred to as the --th KdV
hierarchy). The --algebra associated to the \shs\, of the --th KdV
hierarchy (called algebra) is isomorphic via a Miura map to the direct
sum of --algebra, --algebra and an additional current
algebra. In turn, from the latter, we can always construct a representation of
--algebra.Comment: 26p, latex, BONN--TH-94-17, SISSA-ISAS-118/94/EP, AS-ITP-94-43,
revised version with addition
Corago in LOD. The debut of an Opera repository into the Linked Data arena
The paper examines the adoption of the Semantic Web (SW) technologies and Linked Data (LD) principles to manage a knowledge base about opera. The Corago repository collects historical data and documentation about opera works, performances and librettos from the 16th to the 20th century. We experimented the use of semantic technologies to manage the repository’s knowledge catalogued following the Functional Requirements for Bibliographic Records (FRBR) relational model. Cultural Heritage Knowledge Bases (CHKB) as Corago could leverage SW and LD to overcome proprietary models and to introduce new information to better satisfy user’s requirements. Two well-established reference ontologies as CIDOC Conceptual Reference Model (CIDOC CRM) and FRBR Object Oriented (FRBRoo) are adopted to transpose contents form the legacy conceptual model to RDF. Through the process, we observed that formal semantics allow, not only to adequately represent the opera domain, but also enable to define the way information is being presented to users. This led to the definition of “reception pathways” which become themselves part of the knowledge about opera within the KB. This novel semantic approach is introduced with the Corago Semantic Model (Corago SM), a domain ontology dedicated to functional representation of opera’s historical data. Advancements have been tested with an experimental system and assessed through a questionnaire submitted to a panel of users
Notoph Gauge Theory: Superfield Formalism
We derive absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) and
anti-BRST symmetry transformations for the 4D free Abelian 2-form gauge theory
by exploiting the superfield approach to BRST formalism. The antisymmetric
tensor gauge field of the above theory was christened as the "notoph" (i.e. the
opposite of "photon") gauge field by Ogievetsky and Palubarinov way back in
1966-67. We briefly outline the problems involved in obtaining the absolute
anticommutativity of the (anti-) BRST transformations and their resolution
within the framework of geometrical superfield approach to BRST formalism. One
of the highlights of our results is the emergence of a Curci-Ferrari type of
restriction in the context of 4D Abelian 2-form (notoph) gauge theory which
renders the nilpotent (anti-) BRST symmetries of the theory to be absolutely
anticommutative in nature.Comment: LaTeX file, 12 pages, Talk delivered at SQS'09 (BLTP, JINR, Dubna
RePIM in LOD: semantic technologies to manage, preserve, and disseminate knowledge about Italian secular music and lyric poetry from the 16th-17th centuries
Il progetto RePIM in LOD si è posto l’obiettivo di pubblicare il "Repertorio della Poesia Italiana
in Musica, 1500-1700" (RePIM) come dataset Linked Open Data (LOD). Per l'ampiezza e il
dettaglio dei suoi contenuti, il RePIM è un archivio di riferimento per la ricerca sulla musica
profana italiana dei secoli XVI-XVII. Negli ultimi anni, gli studiosi hanno potuto accedervi
attraverso un'applicazione web realizzata nei primi anni Duemila. A causa dell'obsolescenza della
sua piattaforma informatica, l'archivio RePIM era destinato a essere messo offline. Per preservare
questa preziosa fonte, il progetto ha migrato i suoi contenuti in una base di conoscenza adottando tecnologie semantiche e progettando un'applicazione aggiornata per l'utente finale. L'articolo
illustra le problematiche poste dalla gestione delle informazioni sulla tradizione madrigalistica e
della conservazione digitale delle informazioni bibliografiche e filologiche nel campo della musica
profana italiana e della poesia lirica dei secoli XVI-XVII.The RePIM in LOD project aimed to publish the "Repertorio della Poesia Italiana in Musica,
1500-1700" (RePIM) as Linked Open Data (LOD) dataset. For the extent and detail of its
contents, RePIM is a reference archive for research on Italian secular music from the 16th-17th
centuries. In recent years, scholars have been able to access it through a public web-based
application. Due to the obsolescence of its information technology platform, the RePIM
repository was set to be taken offline. To preserve this precious source, the project migrated its
contents into a knowledge base adopting semantic technologies and designing an up-to-date enduser
application. The article illustrates the challenges of managing information about madrigal
tradition and the digital knowledge preservation of bibliographic and philological information
in the field of Italian secular music and lyric poetry of the 16th-17th centuries
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