18,929 research outputs found

    (Anti-)chiral Superfield Approach to Nilpotent Symmetries: Self-Dual Chiral Bosonic Theory

    Get PDF
    We exploit the beauty and strength of the symmetry invariant restrictions on the (anti-)chiral superfields to derive the Becchi-Rouet-Stora-Tyutin (BRST), anti-BRST and (anti-)co-BRST symmetry transformations in the case of a two (1+1)-dimensional (2D) self-dual chiral bosonic field theory within the framework of augmented (anti-)chiral superfield formalism. Our 2D ordinary theory is generalized onto a (2, 2)-dimensional supermanifold which is parameterized by the superspace variable Z^M = (x^\mu, \theta, \bar\theta) where x^\mu (with \mu = 0, 1) are the ordinary 2D bosonic coordinates and (\theta,\, \bar\theta) are a pair of Grassmannian variables with their standard relationships: \theta^2 = {\bar\theta}^2 =0, \theta\,\bar\theta + \bar\theta\theta = 0. We impose the (anti-)BRST and (anti-)co-BRST invariant restrictions on the (anti-)chiral superfields (defined on the (anti-)chiral (2, 1)-dimensional super-submanifolds of the above general (2, 2)-dimensional supermanifold) to derive the above nilpotent symmetries. We do not exploit the mathematical strength of the (dual-)horizontality conditions anywhere in our present investigation. We also discuss the properties of nilpotency, absolute anticommutativity and (anti-)BRST and (anti-)co-BRST symmetry invariance of the Lagrangian density within the framework of our augmented (anti-)chiral superfield formalism. Our observation of the absolute anticommutativity property is a completely novel result in view of the fact that we have considered only the (anti-)chiral superfields in our present endeavor.Comment: LaTeX file, 20 pages, journal reference is give

    Conflicts and projections

    Get PDF
    This paper studies abstraction methods suitable to verify very large models of discrete-event systems to be nonconflicting. It compares the observer property to methods known from process algebra, namely to conflict equivalence and observation equivalence. The observer property is shown to be the property that corresponds to conflict equivalence in the case where natural projection is used for abstraction. In this case, the observer property turns out to be the least restrictive condition that can be imposed on natural projection to enable compositional reasoning about conflicts. The observer property is also shown to be closely related to observation equivalence. Several examples and propositions are presented to relate different aspects of these methods of abstraction

    Abelian 2-form gauge theory: superfield formalism

    Full text link
    We derive the off-shell nilpotent Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for {\it all} the fields of a free Abelian 2-form gauge theory by exploiting the geometrical superfield approach to BRST formalism. The above four (3 + 1)-dimensional (4D) theory is considered on a (4, 2)-dimensional supermanifold parameterized by the four even spacetime variables x^\mu (with \mu = 0, 1, 2, 3) and a pair of odd Grassmannian variables \theta and \bar\theta (with \theta^2 = \bar\theta^2 = 0, \theta \bar\theta + \bar\theta \theta = 0). One of the salient features of our present investigation is that the above nilpotent (anti-)BRST symmetry transformations turn out to be absolutely anticommuting due to the presence of a Curci-Ferrari (CF) type of restriction. The latter condition emerges due to the application of our present superfield formalism. The actual CF condition, as is well-known, is the hallmark of a 4D non-Abelian 1-form gauge theory. We demonstrate that our present 4D Abelian 2-form gauge theory imbibes some of the key signatures of the 4D non-Abelian 1-form gauge theory. We briefly comment on the generalization of our supperfield approach to the case of Abelian 3-form gauge theory in four (3 + 1)-dimensions of spacetime.Comment: LaTeX file, 23 pages, journal versio

    An Alternative To The Horizontality Condition In Superfield Approach To BRST Symmetries

    Full text link
    We provide an alternative to the gauge covariant horizontality condition which is responsible for the derivation of the nilpotent (anti-)BRST symmetry transformations for the gauge and (anti-)ghost fields of a (3 + 1)-dimensional (4D) interacting 1-form non-Abelian gauge theory in the framework of the usual superfield approach to Becchi-Rouet-Stora-Tyutin (BRST) formalism. The above covariant horizontality condition is replaced by a gauge invariant restriction on the (4, 2)-dimensional supermanifold, parameterized by a set of four spacetime coordinates x^\mu (\mu = 0, 1, 2, 3) and a pair of Grassmannian variables \theta and \bar\theta. The latter condition enables us to derive the nilpotent (anti-)BRST symmetry transformations for all the fields of an interacting 4D 1-form non-Abelian gauge theory where there is an explicit coupling between the gauge field and the Dirac fields. The key differences and striking similarities between the above two conditions are pointed out clearly.Comment: LaTeX file, 20 pages, journal versio

    Geometrical Aspects Of BRST Cohomology In Augmented Superfield Formalism

    Full text link
    In the framework of augmented superfield approach, we provide the geometrical origin and interpretation for the nilpotent (anti-)BRST charges, (anti-)co-BRST charges and a non-nilpotent bosonic charge. Together, these local and conserved charges turn out to be responsible for a clear and cogent definition of the Hodge decomposition theorem in the quantum Hilbert space of states. The above charges owe their origin to the de Rham cohomological operators of differential geometry which are found to be at the heart of some of the key concepts associated with the interacting gauge theories. For our present review, we choose the two (1+1)(1 + 1)-dimensional (2D) quantum electrodynamics (QED) as a prototype field theoretical model to derive all the nilpotent symmetries for all the fields present in this interacting gauge theory in the framework of augmented superfield formulation and show that this theory is a {\it unique} example of an interacting gauge theory which provides a tractable field theoretical model for the Hodge theory.Comment: LaTeX file, 25 pages, Ref. [49] updated, correct page numbers of the Journal are give

    The Wear Project

    Get PDF
    When we meet a character in a performance, the implicit understanding is that they have existed until the point where we join their journey and will continue existing after we leave them. Their clothing tells a story to the audience before any words are spoken and before any action takes place. As a Costume Designer and Lecturer, my awareness of costuming as an anthropological practice has led me to explore these principles using myself as the subject of scrutiny. For one year I am logging every clothing combination I go through along with memories, prices, locations and dates etc. in order to explore the clothing decisions I make and the stories, embedded in my clothes, that I am surrounded by every day. What does my wardrobe mean to me inwardly and reveal outwardly to others? How does this 'me-search' extend my artistic practice? The Wear Project will be a visual archive, a teaching tool, and a foundation for further academic research/writing through the questions it raises about design, visual storytelling, memory, dress and audience: a personal interrogation generating a critical framework for understanding the dramaturgical significance of costume. I welcome any interest, suggestions, questions, provocations, conversations or counter- projects that could lead my research, costume design or performance related teaching in general into unexplored areas. The Wear Project is available for anybody to view or use on flickr at http://bit.ly/1kAYv74

    Pedagogies applied to develop student self-awareness and written self-evaluations: a costume case study

    Get PDF
    In 2013–14 a change in assessment criteria percentage weightings on the BA Stage Management and Technical Theatre course at East 15 Acting School was implemented – a course taught mainly through authentic learning processes. This change, coupled with the increase in emphasis on reflective processes in higher education in general, highlighted that students not only on this course but also more widely need to be able to articulate their learning more rigorously than before through more comprehensively written self-evaluations. Through a discussion of critical thinking and reflection and instinctively applying Art and Design pedagogies to teaching on what is traditionally considered to be a vocational course, this article charts an experimental case study following students on the Costume Pathway, hoping to improve their ability in this area. The aim was to develop the self-awareness and analytical and reflective thinking involved in evaluating personal working practices to a high standard in order to improve the written communication thereof. Therefore, this article is also a reflection on how a thorough understanding from educators of what self-evaluation demands of students can enrich student learning experiences and develop transferable skills to produce industry-ready and life-ready graduates
    • 

    corecore