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Sample records for twistor theory presentation

  1. Twistor-Space Recursive Formulation of Gauge-Theory Amplitudes

    CERN Document Server

    Bena, I; Kosower, D A

    2004-01-01

    Using twistor space intuition, Cachazo, Svrcek and Witten presented novel diagrammatic rules for gauge-theory amplitudes, expressed in terms of maximally helicity-violating (MHV) vertices. We define non-MHV vertices, and show how to use them to give a recursive construction of these amplitudes. We also use them to illustrate the equivalence of various twistor-space prescriptions, and to determine the associated combinatoric factors.

  2. From twistor string theory to recursion relations

    Science.gov (United States)

    Spradlin, Marcus; Volovich, Anastasia

    2009-10-01

    Witten’s twistor string theory gives rise to an enigmatic formula known as the “connected prescription” for tree-level Yang-Mills scattering amplitudes. We derive a link representation for the connected prescription by Fourier transforming it to mixed coordinates in terms of both twistor and dual twistor variables. We show that it can be related to other representations of amplitudes by applying the global residue theorem to deform the contour of integration. For six and seven particles we demonstrate explicitly that certain contour deformations rewrite the connected prescription as the Britto-Cachazo-Feng-Witten representation, thereby establishing a concrete link between Witten’s twistor string theory and the dual formulation for the S matrix of the N=4 SYM recently proposed by Arkani-Hamed Other choices of integration contour also give rise to “intermediate prescriptions.” We expect a similar though more intricate structure for more general amplitudes.

  3. Spacetime foam in twistor string theory

    CERN Document Server

    Hartnoll, S A; Hartnoll, Sean A.; Policastro, Giuseppe

    2004-01-01

    We show how a Kahler spacetime foam in four dimensional conformal (super)gravity may be mapped to twistor spaces carrying the D1 brane charge of the B model topological string theory. The spacetime foam is obtained by blowing up an arbitrary number of points in $\\C^2$ and can be interpreted as a sum over gravitational instantons. Some twistor spaces for blowups of $\\C^2$ are known explicitly. In these cases we write down a meromorphic volume form and suggest a relation to a holomorphic superform on a corresponding super Calabi-Yau manifold.

  4. AdS twistors for higher spin theory

    CERN Document Server

    Cederwall, M

    2004-01-01

    We construct spectra of supersymmetric higher spin theories in D=4, 5 and 7 from twistors describing massless (super-)particles on AdS spaces. A massless twistor transform is derived in a geometric way from classical kinematics. Relaxing the spin-shell constraints on twistor space gives an infinite tower of massless states of a ``higher spin particle'', generalising previous work of Bandos et al. This can generically be done in a number of ways, each defining the states of a distinct higher spin theory, and the method provides a systematic way of finding these. We reproduce known results in D=4, minimal supersymmetric 5- and 7-dimensional models, as well as supersymmetrisations of Vasiliev's Sp-models as special cases. In the latter models a dimensional enhancement takes place, meaning that the theory lives on a space of higher dimension than the original AdS space, and becomes a theory of doubletons. This talk was presented at the XIXth Max Born Symposium ``Fundamental Interactions and Twistor-Like Methods''...

  5. Non-relativistic twistor theory and Newton--Cartan geometry

    CERN Document Server

    Dunajski, Maciej

    2015-01-01

    We develop a non-relativistic twistor theory, in which Newton--Cartan structures of Newtonian gravity correspond to complex three-manifolds with a four-parameter family of rational curves with normal bundle ${\\mathcal O}\\oplus{\\mathcal O}(2)$. We show that the Newton--Cartan space-times are unstable under the general Kodaira deformation of the twistor complex structure. The Newton--Cartan connections can nevertheless be reconstructed from Merkulov's generalisation of the Kodaira map augmented by a choice of a holomorphic line bundle over the twistor space trivial on twistor lines. The Coriolis force may be incorporated by holomorphic vector bundles, which in general are non--trivial on twistor lines. The resulting geometries agree with non--relativistic limits of anti-self-dual gravitational instantons.

  6. Conformal Higher Spin Theory and Twistor Space Actions

    CERN Document Server

    Haehnel, Philipp

    2016-01-01

    We consider the twistor description of conformal higher spin theories and give twistor space actions for the self-dual sector of theories with spin greater than two that produce the correct flat space-time spectrum. We identify a ghost-free subsector, analogous to the embedding of Einstein gravity with cosmological constant in Weyl gravity, which generates the unique spin-s three-point anti-MHV amplitude consistent with Poincare invariance and helicity constraints. By including interactions between the infinite tower of higher-spin fields we give a geometric interpretation to the twistor equations of motion as the integrability condition for a holomorphic structure on an infinite jet bundle. Finally, we introduce anti-self-dual interaction terms to define a twistor action for the full conformal higher spin theory.

  7. Conformal higher-spin symmetries in twistor string theory

    Directory of Open Access Journals (Sweden)

    D.V. Uvarov

    2014-12-01

    Full Text Available It is shown that similarly to massless superparticle, classical global symmetry of the Berkovits twistor string action is infinite-dimensional. We identify its superalgebra, whose finite-dimensional subalgebra contains psl(4|4,R superalgebra. In quantum theory this infinite-dimensional symmetry breaks down to SL(4|4,R one.

  8. Confluence of general Schlesinger systems and Twistor theory

    OpenAIRE

    Kimura, Hironobu; Tseveennamjil, Damiran

    2016-01-01

    We give a description of confluence for the general Schlesinger systems (GSS) from the view point of twistor theory. GSS is a system of nonlinear di¤erential equations on the Grassmannian manifold $G_{2,N}(\\mathbf{C}$ which is obtained, for any partition $\\lambda$ of $N$, as the integrability condition of a connection $\

  9. On perturbative field theory and twistor string theory

    CERN Document Server

    Bedford, James

    2007-01-01

    It is well-known that perturbative calculations in field theory can lead to far simpler answers than the Feynman diagram approach might suggest. In some cases scattering amplitudes can be constructed for processes with any desired number of external legs yielding compact expressions which are inaccessible from the point of view of conventional perturbation theory. In this thesis we discuss some attempts to address the nature of this underlying simplicity and then use the results to calculate some previously unknown amplitudes of interest. Witten's twistor string theory is introduced and the CSW rules at tree-level and one-loop are described. We use these techniques to calculate the one-loop gluonic MHV amplitudes in N=1 super-Yang-Mills as a verification of their validity and then proceed to evaluate the general MHV amplitudes in pure Yang-Mills with a scalar running in the loop. This latter amplitude is a new result in QCD. In addition to this, we review some recent on-shell recursion relations for tree-leve...

  10. N=2 Conformal Supergravity from Twistor-String Theory

    CERN Document Server

    Ahn, C

    2004-01-01

    A chiral superfield strength in N=2 conformal supergravity at linearized level is obtained by acting two superspace derivatives on N=4 chiral superfield strength which can be described in terms of N=4 twistor superfields. By decomposing SU(4)_R representation of N=4 twistor superfields into the SU(2)_R representation with an invariant U(1)_R charge, the surviving N=2 twistor superfields contain the physical states of N=2 conformal supergravity. These N=2 twistor superfields are functions of homogeneous coordinates of weighted complex projective space WCP^{3|4} where the two weighted fermionic coordinates have weight -1 and 3.

  11. Composite Operators in the Twistor Formulation of $\\mathcal{N}=4$ SYM Theory

    CERN Document Server

    Koster, Laura; Staudacher, Matthias; Wilhelm, Matthias

    2016-01-01

    We incorporate gauge-invariant local composite operators into the twistor-space formulation of $\\mathcal{N}=4$ Super Yang-Mills theory. In this formulation, the interactions of the elementary fields are reorganized into infinitely many interaction vertices and we argue that the same applies to composite operators. To test our definition of the local composite operators in twistor space, we compute several corresponding form factors, thereby also initiating the study of form factors using the position twistor-space framework. Throughout this letter, we use the composite operator built from two identical complex scalars as a pedagogical example; we treat the general case in a follow-up paper.

  12. twistors and gauge fields

    Directory of Open Access Journals (Sweden)

    A. G. Sergeev

    1986-01-01

    Full Text Available We describe briefly the basic ideas and results of the twistor theory. The main points: twistor representation of Minkowsky space, Penrose correspondence and its geometrical properties, twistor interpretation of linear massless fields, Yang-Mills fields (including instantons and monopoles and Einstein-Hilbert equations.

  13. Studies In Field Theories: Mhv Vertices, Twistor Space, Recursion Relations And Chiral Rings

    CERN Document Server

    Svrcek, P

    2005-01-01

    In this thesis we study different aspects of four dimensional field theories. In the first chapter we give introduction and overview of the thesis. In the second chapter we review the connection between perturbative Yang-Mills and twistor string theory. Inspired by this, we propose a new way of constructing Yang-Mills scattering amplitudes from Feynman graphs in which the vertices are off-shell continuations of the tree level MHV amplitudes. The MHV diagrams lead to simple formulas for tree-level amplitudes. We then give a heuristic derivation of the diagrams from twistor string theory. In the third chapter, we explore the twistor structure of scattering amplitudes in theories for which a twistor string theory analogous to the one for N = 4 gauge theory has not yet been proposed. We study the differential equations of one-loop amplitudes of gluons in gauge theories with reduced supersymmetry and of tree level and one-loop amplitudes of gravitons in general relativity and supergravity. We find that the scat...

  14. Gauged twistor spinors and symmetry operators

    CERN Document Server

    Ertem, Ümit

    2016-01-01

    We consider gauged twistor spinors which are supersymmetry generators of supersymmetric and superconformal field theories in curved backgrounds. We show that the spinor bilinears of gauged twistor spinors satify the gauged conformal Killing-Yano equation. We prove that the symmetry operators of the gauged twistor spinor equation can be constructed from ordinary conformal Killing-Yano forms in constant curvature backgrounds. This provides a way to obtain gauged twistor spinors from ordinary twistor spinors.

  15. BPS Preons in Supergravity and Higher Spin Theories. An Overview From the Hill of Twistor Approach

    Science.gov (United States)

    Bandos, I. A.

    2005-04-01

    We review briefly the notion of BPS preons, first introduced in 11-dimensional context as hypothetical constituents of M-theory, in its generalization to arbitrary dimensions and emphasizing the relation with twistor approach. In particular, the use of a "twistor-like" definition of BPS preon (almost) allows us to remove supersymmetry arguments from the discussion of the relation of the preons with higher spin theories and also of the treatment of BPS preons as constituents. We turn to the supersymmetry in the second part of this contribution, where we complete the algebraic discussion with supersymmetric arguments based on the M-algebra (generalized Poincaré superalgebra), discuss the possible generalization of BPS preons related to the osp(1|n) (generalized AdS) superalgebra, review a twistor-like κ-symmetric superparticle in tensorial superspace, which provides a point-like dynamical model for BPS preon, and the rôle of BPS preons in the analysis of supergravity solutions. Finally we describe resent results on the concise superfield description of the higher spin field equations and on superfield supergravity in tensorial superspaces.

  16. BPS preons in supergravity and higher spin theories. An overview from the hill of twistor appraoch

    CERN Document Server

    Bandos, I A

    2005-01-01

    We review briefly the notion of BPS preons, first introduced in 11-dimensional context as hypothetical constituents of M-theory, in its generalization to arbitrary dimensions and emphasizing the relation with twistor approach. In particular, the use of a 'twistor-like' definition of BPS preon (almost) allows us to remove supersymmetry arguments from the discussion of the relation of the preons with higher spin theories and also of the treatment of BPS preons as constituents. We turn to the supersymmetry in the second part of this contribution, where we complete the algebraic discussion with supersymmetric arguments based on the M-algebra (generalized Poincare superalgebra), discuss the possible generalization of BPS preons related to the osp(1|n) (generalized AdS) superalgebra, review a twistor-like kappa-symmetric superparticle in tensorial superspace, which provides a point-like dynamical model for BPS preon, and the role of BPS preons in the analysis of supergravity solutions. Finally we describe resent re...

  17. A Twistor Approach to One-Loop Amplitudes in N=1 Supersymmetric Yang-Mills Theory

    CERN Document Server

    Bedford, J; Spence, B; Travaglini, G; Bedford, James; Brandhuber, Andreas; Spence, Bill; Travaglini, Gabriele

    2004-01-01

    We extend the twistor string theory inspired formalism introduced in hep-th/0407214 for calculating loop amplitudes in N=4 super Yang-Mills theory to the case of N=1 (and N=2) super Yang-Mills. Our approach yields a novel representation of the gauge theory amplitudes as dispersion integrals, which are surprisingly simple to evaluate. As an application we calculate one-loop maximally helicity violating (MHV) scattering amplitudes with an arbitrary number of external legs. The result we obtain agrees precisely with the expressions for the N=1 MHV amplitudes derived previously by Bern, Dixon, Dunbar and Kosower using the cut-constructibility approach.

  18. General split helicity gluon tree amplitudes in open twistor string theory

    Science.gov (United States)

    Dolan, Louise; Goddard, Peter

    2010-05-01

    We evaluate all split helicity gluon tree amplitudes in open twistor string theory. We show that these amplitudes satisfy the BCFW recurrence relations restricted to the split helicity case and, hence, that these amplitudes agree with those of gauge theory. To do this we make a particular choice of the sextic constraints in the link variables that determine the poles contributing to the contour integral expression for the amplitudes. Using the residue theorem to re-express this integral in terms of contributions from poles at rational values of the link variables, which we determine, we evaluate the amplitudes explicitly, regaining the gauge theory results of Britto et al. [25].

  19. Tractors and twistors from conformal Cartan geometry: a gauge theoretic approach II. Twistors

    Science.gov (United States)

    Attard, J.; François, J.

    2017-04-01

    Tractor and Twistor bundles provide natural conformally covariant calculi on 4D-Riemannian manifolds. They have different origins but are closely related, and usually constructed bottom–up through prolongation of defining differential equations. We propose alternative top–down gauge theoretic constructions, starting from the conformal Cartan bundle P and its vectorial E and spinorial {E associated bundles. Our key ingredient is the dressing field method of gauge symmetry reduction, which allows tractors and twistors and their associated connections to exhibit as gauge fields of a non-standard kind as far as Weyl rescaling transformation is concerned. By non-standard we mean that they implement the gauge principle of physics, but are of a different geometric nature than the well-known differential geometric objects usually underlying gauge theories. We provide the corresponding BRST treatment. In a companion paper we dealt with tractors, in the present one we address the case of twistors.

  20. Demystifying the twistor construction of composite operators in N=4 super-Yang-Mills theory

    CERN Document Server

    Chicherin, Dmitry

    2016-01-01

    We explain some details of the construction of composite operators in N=4 SYM that we have elaborated earlier in the context of Lorentz harmonic chiral (LHC) superspace. We give a step-by-step elementary derivation and show that the result coincides with the recent hypothesis put forward in arXiv:1603.04471 within the twistor approach. We provide the appropriate LHC-to-twistors dictionary.

  1. Twistors and antipodes in de Sitter space

    Science.gov (United States)

    Neiman, Yasha

    2014-03-01

    We develop the basics of twistor theory in de Sitter space, up to the Penrose transform for free massless fields. We treat de Sitter space as fundamental, as one does for Minkowski space in conventional introductions to twistor theory. This involves viewing twistors as spinors of the de Sitter group SO(4,1). When attached to a spacetime point, such a twistor can be reinterpreted as a local SO(3,1) Dirac spinor. Our approach highlights the antipodal map in de Sitter space, which gives rise to doublings in the standard relations between twistors and spacetime. In particular, one can generate a field with both handedness signs from a single twistor function. Such fields naturally live on antipodally identified de Sitter space dS4/Z2, which has been put forward as the ideal laboratory for quantum gravity with a positive cosmological constant.

  2. Twistor geometry

    NARCIS (Netherlands)

    van den Broek, P.M.

    1984-01-01

    The aim of this paper is to give a detailed exposition of the relation between the geometry of twistor space and the geometry of Minkowski space. The paper has a didactical purpose; no use has been made of differential geometry and cohomology.

  3. BOOK REVIEW: Solitons, Instantons, and Twistors Solitons, Instantons, and Twistors

    Science.gov (United States)

    Witt, Donald M.

    2011-04-01

    Solitons and instantons play important roles both in pure and applied mathematics as well as in theoretical physics where they are related to the topological structure of the vacuum. Twistors are a useful tool for solving nonlinear differential equations and are useful for the study of the antiself-dual Yang-Mills equations and the Einstein equations. Many books and more advanced monographs have been written on these topics. However, this new book by Maciej Dunajski is a complete first introduction to all of the topics in the title. Moreover, it covers them in a very unique way, through integrable systems. The approach taken in this book is that of mathematical physics à la field theory. The book starts by giving an introduction to integrable systems of ordinary and partial differential equations and proceeds from there. Gauge theories are not covered until chapter 6 which means the reader learning the material for the first time can build up confidence with simpler models of solitons and instantons before encountering them in gauge theories. The book also has an extremely clear introduction to twistor theory useful to both mathematicians and physicists. In particular, the twistor theory presentation may be of interest to string theorists wanting understand twistors. There are many useful connections to research into general relativity. Chapter 9 on gravitational instantons is great treatment useful to anyone doing research in classical or quantum gravity. There is also a nice discussion of Kaluza-Klein monopoles. The three appendices A-C cover the necessary background material of basic differential geometry, complex manifolds, and partial differential equations needed to fully understand the subject. The reader who has some level of expertise in any of the topics covered can jump right into that material without necessarily reading all of the earlier chapters because of the extremely clear writing style of the author. This makes the book an excellent reference on

  4. Twistor methods for AdS$_5$

    CERN Document Server

    Adamo, Tim; Williams, Jack

    2016-01-01

    We consider the application of twistor theory to five-dimensional anti-de Sitter space. The twistor space of AdS$_5$ is the same as the ambitwistor space of the four-dimensional conformal boundary; the geometry of this correspondence is reviewed for both the bulk and boundary. A Penrose transform allows us to describe free bulk fields, with or without mass, in terms of data on twistor space. Explicit representatives for the bulk-to-boundary propagators of scalars and spinors are constructed, along with twistor action functionals for the free theories. Evaluating these twistor actions on bulk-to-boundary propagators is shown to produce the correct two-point functions.

  5. Scattering amplitudes and Wilson loops in twistor space

    Energy Technology Data Exchange (ETDEWEB)

    Adamo, Tim; Mason, Lionel [Mathematical Institute, 24-29 St. Giles' , Oxford OX1 3LB (United Kingdom); Bullimore, Mathew [Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Skinner, David, E-mail: adamo@maths.ox.ac.uk [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2 L 2Y5 (Canada)

    2011-11-11

    This paper reviews the recent progress in twistor approaches to Wilson loops, amplitudes and their duality for N=4 super-Yang-Mills. Wilson loops and amplitudes are derived from first principles using the twistor action for maximally supersymmetric Yang-Mills theory. We start by deriving the MHV rules for gauge theory amplitudes from the twistor action in an axial gauge in twistor space, and show that this gives rise to the original momentum space version given by Cachazo, Svrcek and Witten. We then go on to obtain from these the construction of the momentum twistor space loop integrand using (planar) MHV rules and show how it arises as the expectation value of a holomorphic Wilson loop in twistor space. We explain the connection between the holomorphic Wilson loop and certain light-cone limits of correlation functions. We give a brief review of other ideas in connection with amplitudes in twistor space: twistor-strings, recursion in twistor space, the Grassmannian residue formula for leading singularities and amplitudes as polytopes. This paper is an invited review for a special issue of Journal of Physics A: Mathematical and Theoretical devoted to 'Scattering amplitudes in gauge theories'. (review)

  6. Instantons, Twistors, and Emergent Gravity

    CERN Document Server

    Heckman, Jonathan J

    2011-01-01

    Motivated by potential applications to holography on space-times of positive curvature, and by the successful twistor description of scattering amplitudes, we propose a new dual matrix formulation of N = 4 gauge theory on S(4) coupled to 4D gravity. The matrix model is defined by taking the low energy limit of a holomorphic Chern-Simons theory on CP(3|4), in the presence of a large instanton flux. The theory comes with a choice of S(4) radius L and a parameter N controlling the overall size of the matrices. The flat space variant of the 4D effective theory arises by taking the large N scaling limit of the matrix model, with l_pl^2 ~ L^2 / N held fixed. Its massless spectrum contains both spin one and spin two excitations, which we identify with gluons and gravitons. As shown in the companion paper, the matrix model correlation functions of both these excitations correctly reproduce the corresponding MHV scattering amplitudes. We present evidence that the scaling limit defines a gravitational theory with a fin...

  7. All Tree-Level MHV Form Factors in $\\mathcal{N}=4$ SYM from Twistor Space

    CERN Document Server

    Koster, Laura; Staudacher, Matthias; Wilhelm, Matthias

    2016-01-01

    We incorporate all gauge-invariant local composite operators into the twistor-space formulation of N=4 SYM theory, detailing and expanding on ideas we presented recently in arXiv:1603.04471. The vertices for these operators contain infinitely many terms and we show how they can be constructed by taking suitable derivatives of a light-like Wilson loop in twistor space and shrinking it down to a point. In particular, these vertices directly yield the tree-level MHV super form factors of all composite operators in N=4 SYM theory.

  8. Pure Connection Formulation, Twistors and the Chase for a Twistor Action for General Relativity

    CERN Document Server

    Herfray, Yannick

    2016-01-01

    This paper establishes the relation between traditional results from (euclidean) twistor theory and chiral formulations of General Relativity, especially the pure connection formulation. Starting from a $SU(2)$-connection only we show how to construct natural complex data on twistor space, mainly an almost Hermitian structure and a connection on some complex line bundle. Only when this almost Hermitian structure is integrable is the connection related to an anti-self-dual-Einstein metric and makes contact with the usual results. This leads to a new proof of the non-linear-graviton theorem. Finally we discuss what new strategies this "connection approach" to twistors suggests for constructing a twistor action for gravity. In appendix we also review all known chiral Lagrangians for GR.

  9. Loops in Twistor Space

    CERN Document Server

    Bena, I; Kosower, D A; Roiban, R; Bena, Iosif; Bern, Zvi; Kosower, David A.; Roiban, Radu

    2004-01-01

    We elucidate the one-loop twistor-space structure corresponding to momentum-space MHV diagrams. We also discuss the infrared divergences, and argue that only a limited set of MHV diagrams contain them. We show how to introduce a twistor-space regulator corresponding to dimensional regularization for the infrared-divergent diagrams. We also evaluate explicitly the `holomorphic anomaly' pointed out by Cachazo, Svrcek, and Witten, and use the result to define modified differential operators which can be used to probe the twistor-space structure of one-loop amplitudes.

  10. Quasi-Hopf twistors for elliptic quantum groups

    CERN Document Server

    Jimbo, M; Odake, S; Shiraishi, J

    1997-01-01

    The Yang-Baxter equation admits two classes of elliptic solutions, the vertex type and the face type. On the basis of these solutions, two types of elliptic quantum groups have been introduced (Foda et al., Felder). Fronsdal made a penetrating observation that both of them are quasi-Hopf algebras, obtained by twisting the standard quantum affine algebra U_q(g). In this paper we present an explicit formula for the twistors in the form of an infinite product of the universal R matrix of U_q(g). We also prove the shifted cocycle condition for the twistors, thereby completing Fronsdal's findings. This construction entails that, for generic values of the deformation parameters, representation theory for U_q(g) carries over to the elliptic algebras, including such objects as evaluation modules, highest weight modules and vertex operators. In particular, we confirm the conjectures of Foda et al. concerning the elliptic algebra A_{q,p}(^sl_2).

  11. All conjugate-maximal-helicity-violating amplitudes from topological open string theory in twistor space.

    Science.gov (United States)

    Roiban, Radu; Volovich, Anastasia

    2004-09-24

    It has recently been proposed that the D-instanton expansion of the open topological B model on P(3|4) is equivalent to the perturbative expansion of the maximally supersymmetric Yang-Mills theory in four dimensions. In this letter we show how to construct the gauge theory results for all n-point conjugate-maximal-helicity-violating amplitudes by computing the integral over the moduli space of curves of degree n-3 in P(3|4), providing strong support to the string theory construction.

  12. Scattering Equations, Twistor-string Formulas and Double-soft Limits in Four Dimensions

    CERN Document Server

    He, Song; Wu, Jun-Bao

    2016-01-01

    We study scattering equations and formulas for tree amplitudes of various theories in four dimensions, in terms of spinor helicity variables and on-shell superspace for supersymmetric theories. As originally obtained in Witten's twistor string theory and other twistor-string models, the equations can take either polynomial or rational forms, and we clarify the simple relation between them. We present new, four-dimensional formulas for all tree amplitudes in the non-linear sigma model, a special Galileon theory and the maximally supersymmetric completion of the Dirac-Born-Infeld theory. Furthermore, we apply the formulas to study various double-soft theorems in these theories, including the emissions of a pair of soft photons, fermions and scalars for super-amplitudes in super-DBI theory.

  13. Causality and Borromean linking in twistor space

    Energy Technology Data Exchange (ETDEWEB)

    Low, Robert J, E-mail: mtx014@coventry.ac.uk [Department of Mathematics, Statistics and Engineering Science, Coventry University, Coventry CV1 5FB (United Kingdom)

    2011-10-01

    We consider the notion of the Borromean triple from classical linking theory, and develop an analogue of it in the case of linking of skies in twistor space. I would like to dedicate this paper to Roger Penrose, on the occasion of his 80th birthday.

  14. Twistor Transform in d Dimensions and a Unifying Role for Twistors

    CERN Document Server

    Bars, Itzhak; Bars, Itzhak; Picon, Moises

    2006-01-01

    Twistors in four dimensions d=4 have provided a convenient description of massless particles with any spin, and this led to remarkable computational techniques in Yang-Mills field theory. Recently it was shown that the same d=4 twistor provides also a unified description of an assortment of other particle dynamical systems, including special examples of massless or massive particles, relativistic or non-relativistic, interacting or non-interacting, in flat space or curved spaces. In this paper, using 2T-physics as the primary theory, we derive the general twistor transform in d-dimensions that applies to all cases, and show that these more general twistor transforms provide d dimensional holographic images of an underlying phase space in flat spacetime in d+2 dimensions. Certain parameters, such as mass, parameters of spacetime metric, and some coupling constants appear as moduli in the holographic image while projecting from d+2 dimensions to (d-1)+1 dimensions or to twistors. We also extend the concept of t...

  15. Studies In Non-anticommutative Gauge Theories, Geometric Dualities, And Twistor Strings

    CERN Document Server

    Robles Llana, D

    2005-01-01

    In this Dissertation we consider three different topics. The first one is the study of instantons in U(2) super Yang-Mills theories defined on non-anticommutative superspace. We extend the ordinary instanton calculus to this class of theories by solving the appropriate equations of motion iteratively in the deformation parameter C. In the case without matter, we solve the equations exactly. We find that the SU(2) part of the instanton is the same as in ordinary SU (2) N = 1 super Yang-Mills, but acquires in addition a non-trivial U(1) part which depends on the fermionic collective coordinates and the deformation parameter C. In the case with matter we solve the equations of motion to leading order in the coupling constant. We find that also the profile of the matter fields is deformed through linear and quadratic corrections in C. The instanton effective action for pure gluodynamics is unaffected by C, but gets a contribution of order C2 in addition to the usual 't Hooft term when the matter is included....

  16. Twistors and Black Holes

    NARCIS (Netherlands)

    Neitzke, A.; Pioline, B.; Vandoren, S.

    2007-01-01

    Motivated by black hole physics in N = 2,D = 4 supergravity, we study the geometry of quaternionic-K¨ahler manifolds Mobtained by the c-map construction from projective special Kähler manifolds Ms. Improving on earlier treatments, we compute the Käahler potentials on the twistor space Z and Swann sp

  17. Scattering amplitudes and BCFW recursion in twistor space

    Science.gov (United States)

    Mason, Lionel; Skinner, David

    2010-01-01

    Twistor ideas have led to a number of recent advances in our understanding of scattering amplitudes. Much of this work has been indirect, determining the twistor space support of scattering amplitudes by examining the amplitudes in momentum space. In this paper, we construct the actual twistor scattering amplitudes themselves. We show that the recursion relations of Britto, Cachazo, Feng and Witten have a natural twistor formulation that, together with the three-point seed amplitudes, allows us to recursively construct general tree amplitudes in twistor space. We obtain explicit formulae for n-particle MHV and NMHV super-amplitudes, their CPT conjugates (whose representations are distinct in our chiral framework), and the eight particle N2MHV super-amplitude. We also give simple closed form formulae for the mathcal{N} = 8 supergravity recursion and the MHV and overline {text{MHV}} amplitudes. This gives a formulation of scattering amplitudes in maximally supersymmetric theories in which superconformal symmetry and its breaking is manifest. For N k MHV, the amplitudes are given by 2 n - 4 integrals in the form of Hilbert transforms of a product of n - k - 2 purely geometric, superconformally invariant twistor delta functions, dressed by certain sign operators. These sign operators subtly violate conformal invariance, even for tree-level amplitudes in mathcal{N} = 4 super Yang-Mills, and we trace their origin to a topological property of split signature space-time. We develop the twistor transform to relate our work to the ambidextrous twistor diagram approach of Hodges and of Arkani-Hamed, Cachazo, Cheung and Kaplan.

  18. Twistors and Black Holes

    CERN Document Server

    Neitzke, A; Vandoren, S; Neitzke, Andrew; Pioline, Boris; Vandoren, Stefan

    2007-01-01

    Motivated by black hole physics in N=2, D=4 supergravity, we study the geometry of quaternionic-Kahler manifolds M obtained by the c-map construction from projective special Kahler manifolds M_s. Improving on earlier treatments, we compute the Kahler potentials on the twistor space Z and Swann space S in the complex coordinates adapted to the Heisenberg symmetries. The results bear a simple relation to the Hesse potential \\Sigma of the special Kahler manifold M_s, and hence to the Bekenstein-Hawking entropy for BPS black holes. We explicitly construct the ``covariant c-map'' and the ``twistor map'', which relate real coordinates on M x CP^1 (resp. M x R^4/Z_2) to complex coordinates on Z (resp. S). As applications, we solve for the general BPS geodesic motion on M, and provide explicit integral formulae for the quaternionic Penrose transform relating elements of H^1(Z,O(-k)) to massless fields on M annihilated by first or second order differential operators. Finally, we compute the exact radial wave function ...

  19. On Form Factors and Correlation Functions in Twistor Space

    CERN Document Server

    Koster, Laura; Staudacher, Matthias; Wilhelm, Matthias

    2016-01-01

    In this paper, we continue our study of form factors and correlation functions of gauge-invariant local composite operators in the twistor-space formulation of N=4 super Yang-Mills theory. Using the vertices for these operators obtained in our recent papers arXiv:1603.04471 and arXiv:1604.00012, we show how to calculate the twistor-space diagrams for general N^kMHV form factors via the inverse soft limit, in analogy to the amplitude case. For general operators without $\\dot\\alpha$ indices, we then reexpress the NMHV form factors from the position-twistor calculation in terms of momentum twistors, deriving and expanding on a relation between the two twistor formalisms previously observed in the case of amplitudes. Furthermore, we discuss the calculation of generalized form factors and correlation functions as well as the extension to loop level, in particular providing an argument promised in arXiv:1410.6310.

  20. First-Order Twistor Lifts

    Directory of Open Access Journals (Sweden)

    Simões BrunoAscenso

    2010-01-01

    Full Text Available The use of twistor methods in the study of Jacobi fields has proved quite fruitful, leading to a series of results. L. Lemaire and J. C. Wood proved several properties of Jacobi fields along harmonic maps from the two-sphere to the complex projective plane and to the three- and four-dimensional spheres, by carefully relating the infinitesimal deformations of the harmonic maps to those of the holomorphic data describing them. In order to advance this programme, we prove a series of relations between infinitesimal properties of the map and those of its twistor lift. Namely, we prove that isotropy and harmonicity to first order of the map correspond to holomorphicity to first order of its lift into the twistor space, relatively to the standard almost complex structures and . This is done by obtaining first-order analogues of classical twistorial constructions.

  1. On blow-up "twistors" for the Navier--Stokes equations in $R^3$: a view from reaction-diffusion theory

    OpenAIRE

    Galaktionov, V. A.

    2009-01-01

    Various formal blow-up scenarious for the Navier--Stokes equaitons in 3D are discussed. A particular interest is payed to "twistor mechanisms" based on angular logarithmic blow-up travelling waves, and to a formation of "blow-up tornado" about the singular stationary Slezkin--Landau solutions (1934--44) of a submerged jet. A survey on various related aspects of singularity analysis for nonlinear parabolic PDEs is enclosed.

  2. Gauged twistor formulation of a massive spinning particle in four dimensions

    CERN Document Server

    Deguchi, Shinichi

    2015-01-01

    We present a gauged twistor model of a free massive spinning particle in four-dimensional Minkowski space. This model is governed by an action, referred to here as the gauged generalized Shirafuji (GGS) action, that consists of twistor variables, auxiliary variables, and $U(1)$ and $SU(2)$ gauge fields on the one-dimensional parameter space of a particle's world-line. The GGS action remains invariant under reparametrization and the local $U(1)$ and $SU(2)$ transformations of the relevant variables, although the $SU(2)$ symmetry is nonlinearly realized. We consider the canonical Hamiltonian formalism based on the GGS action in the unitary gauge by following Dirac's recipe for constrained Hamiltonian systems. It is shown that just sufficient constraints for the twistor variables are consistently derived by virtue of the gauge symmetries of the GGS action. In the subsequent quantization procedure, these constraints turn into simultaneous differential equations for a twistor function. We perform the Penrose trans...

  3. Approximate twistors and positive mass

    Science.gov (United States)

    Bäckdahl, Thomas; Valiente Kroon, Juan A.

    2011-04-01

    In this paper, the problem of comparing initial data to a reference solution for the vacuum Einstein field equations is considered. This is not done in a coordinate sense, but through quantification of the deviation from a specific symmetry. In a recent paper (Bäckdahl and Valiente Kroon 2010 Phys. Rev. Lett. 104 231102), this problem was studied with the Kerr solution as a reference solution. This analysis was based on valence 2 Killing spinors. In order to better understand this construction, we analyse the analogous construction for valence 1 spinors solving the twistor equation. This yields an invariant that measures how much the initial data deviates from Minkowski data. Furthermore, we prove that this invariant vanishes if and only if the mass vanishes. Hence, we get a proof of the positivity of mass.

  4. Approximate twistors and positive mass

    Energy Technology Data Exchange (ETDEWEB)

    Baeckdahl, Thomas; Valiente Kroon, Juan A, E-mail: t.backdahl@qmul.ac.uk, E-mail: j.a.valiente-kroon@qmul.ac.uk [School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

    2011-04-07

    In this paper, the problem of comparing initial data to a reference solution for the vacuum Einstein field equations is considered. This is not done in a coordinate sense, but through quantification of the deviation from a specific symmetry. In a recent paper (Baeckdahl and Valiente Kroon 2010 Phys. Rev. Lett. 104 231102), this problem was studied with the Kerr solution as a reference solution. This analysis was based on valence 2 Killing spinors. In order to better understand this construction, we analyse the analogous construction for valence 1 spinors solving the twistor equation. This yields an invariant that measures how much the initial data deviates from Minkowski data. Furthermore, we prove that this invariant vanishes if and only if the mass vanishes. Hence, we get a proof of the positivity of mass.

  5. Twistor variables for Anti-de Sitter (super)particles

    CERN Document Server

    Arvanitakis, Alex S; Townsend, Paul K

    2016-01-01

    Starting from the classical action for a spin-zero particle in a (D + 1)-dimensional anti-Sitter spacetime, we recover the Breitenlohner-Freedman bound by quantization. We then find a twistor form of the action for D = 3, 4, 6 for which the SO(2, D) isometry group is a linearly realized symmetry. The supertwistor generalization yields superparticle actions that are manifestly invariant under the isometry supergroup of the near-horizon geometries of the M2, D3 and M5 brane solutions of string/M-theory; in each case quantization yields a supermultiplet with 128 + 128 states.

  6. The twistor geometry of three-qubit entanglement

    CERN Document Server

    Lévai, Peter

    2004-01-01

    A geometrical description of three qubit entanglement is given. A part of the transformations corresponding to stochastic local operations and classical communication on the qubits is regarded as a gauge degree of freedom. Entangled states can be represented by the points of the Klein quadric ${\\cal Q}$ a space known from twistor theory. It is shown that three-qubit invariants are vanishing on special subspaces of ${\\cal Q}$. An invariant vanishing for the $GHZ$ class is proposed. A geometric interpretation of the canonical decomposition and the inequality for distributed entanglement is also given.

  7. Noncommutative Space-time from Quantized Twistors

    CERN Document Server

    Lukierski, Jerzy

    2013-01-01

    We consider the relativistic phase space coordinates (x_{\\mu},p_{\\mu}) as composite, described by functions of the primary pair of twistor coordinates. It appears that if twistor coordinates are canonicaly quantized the composite space-time coordinates are becoming noncommutative. We obtain deformed Heisenberg algebra which in order to be closed should be enlarged by the Pauli-Lubanski four-vector components. We further comment on star-product quantization of derived algebraic structures which permit to introduce spin-extended deformed Heisenberg algebra.

  8. Conformal higher spin scattering amplitudes from twistor space

    CERN Document Server

    Adamo, Tim; McLoughlin, Tristan

    2016-01-01

    We use the formulation of conformal higher spin (CHS) theories in twistor space to study their tree-level scattering amplitudes, finding expressions for all three-point anti-MHV amplitudes and all MHV amplitudes involving positive helicity conformal gravity particles and two negative helicity higher spins. This provides the on-shell analogue for the covariant coupling of CHS fields to a conformal gravity background. We discuss the restriction of the theory to a ghost-free unitary subsector, analogous to restricting conformal gravity to general relativity with a cosmological constant. We study the flat-space limit and show that the restricted amplitudes vanish, supporting the conjecture that in the unitary sector the S-matrix of CHS theories is trivial. However, by appropriately rescaling the amplitudes we find non-vanishing results which we compare with chiral flat-space higher spin theories.

  9. D3-instantons, Mock Theta Series and Twistors

    CERN Document Server

    Alexandrov, Sergei; Pioline, Boris

    2013-01-01

    The D-instanton corrected hypermultiplet moduli space of type II string theory compactified on a Calabi-Yau threefold is known in the type IIA picture to be determined in terms of the generalized Donaldson-Thomas invariants, through a twistorial construction. At the same time, in the mirror type IIB picture, and in the limit where only D3-D1-D(-1)-instanton corrections are retained, it should carry an isometric action of the S-duality group SL(2,Z). We prove that this is the case in the one-instanton approximation, by constructing a holomorphic action of SL(2,Z) on the linearized twistor space. Using the modular invariance of the D4-D2-D0 black hole partition function, we show that the standard Darboux coordinates in twistor space have modular anomalies controlled by period integrals of a Siegel-Narain theta series, which can be canceled by a contact transformation generated by a holomorphic mock theta series.

  10. D3-instantons, mock theta series and twistors

    Science.gov (United States)

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2013-04-01

    The D-instanton corrected hypermultiplet moduli space of type II string theory compactified on a Calabi-Yau threefold is known in the type IIA picture to be determined in terms of the generalized Donaldson-Thomas invariants, through a twistorial construction. At the same time, in the mirror type IIB picture, and in the limit where only D3-D1-D(-1)-instanton corrections are retained, it should carry an isometric action of the S-duality group SL(2, {Z} ). We prove that this is the case in the one-instanton approximation, by constructing a holomorphic action of SL(2, {Z} ) on the linearized twistor space. Using the modular invariance of the D4-D2-D0 black hole partition function, we show that the standard Darboux coordinates in twistor space have modular anomalies controlled by period integrals of a Siegel-Narain theta series, which can be canceled by a contact transformation generated by a holomorphic mock theta series.

  11. Twisted geometries, twistors and conformal transformations

    CERN Document Server

    Långvik, Miklos

    2016-01-01

    The twisted geometries of spin network states are described by simple twistors, isomorphic to null twistors with a time-like direction singled out. The isomorphism depends on the Immirzi parameter, and reduces to the identity when the parameter goes to infinity. Using this twistorial representation we study the action of the conformal group SU(2,2) on the classical phase space of loop quantum gravity, described by twisted geometry. The generators of translations and conformal boosts do not preserve the geometric structure, whereas the dilatation generator does. It corresponds to a 1-parameter family of embeddings of T*SL(2,C) in twistor space, and its action preserves the intrinsic geometry while changing the extrinsic one - that is the boosts among polyhedra. We discuss the implication of this action from a dynamical point of view, and compare it with a discretisation of the dilatation generator of the continuum phase space, given by the Lie derivative of the group character. At leading order in the continuu...

  12. Twistor-Inspired Construction of Electroweak Vector Boson Currents

    CERN Document Server

    Bern, Z; Kosower, D A; Mastrolia, Pierpaolo; Bern, Zvi; Forde, Darren; Kosower, David A.; Mastrolia, Pierpaolo

    2004-01-01

    We present an extension of the twistor-motivated MHV vertices and accompanying rules presented by Cachazo, Svrvcek and Witten to the construction of vector-boson currents coupling to an arbitrary source. In particular, we give rules for constructing off-shell vector-boson currents with one fermion pair and n gluons of arbitrary helicity. These currents may be employed directly in the computation of electroweak amplitudes. The rules yield expressions in agreement with previously-obtained results for Z,W,\\gamma^* --> qbar q + n gluons (analytically up to n=3, beyond via the Berends--Giele recursion relations). We also confirm that the contribution to a seven-point amplitude containing the non-abelian triple vector-boson coupling obtained using the next-to-MHV currents matches the previous result in the literature.

  13. Operator algebra of free conformal currents via twistors

    Energy Technology Data Exchange (ETDEWEB)

    Gelfond, O.A. [Institute of System Research of Russian Academy of Sciences, Nakhimovsky prospect 36-1, 117218 Moscow (Russian Federation); Vasiliev, M.A., E-mail: vasiliev@lpi.ru [I.E. Tamm Department of Theoretical Physics, Lebedev Physical Institute, Leninsky prospect 53, 119991 Moscow (Russian Federation)

    2013-11-21

    Operator algebra of (not necessarily free) higher-spin conformal conserved currents in generalized matrix spaces, that include 3d Minkowski space–time as a particular case, is shown to be determined by an associative algebra M of functions on the twistor space. For free conserved currents, M is the universal enveloping algebra of the higher-spin algebra. Proposed construction greatly simplifies computation and analysis of correlators of conserved currents. Generating function for n-point functions of 3d (super)currents of all spins, built from N free constituent massless scalars and spinors, is obtained in a concise form of certain determinant. Our results agree with and extend earlier bulk computations in the HS AdS{sub 4}/CFT{sub 3} framework. Generating function for n-point functions of 4d conformal currents is also presented.

  14. Single twistor description of massless, massive, AdS, and other interacting particles

    CERN Document Server

    Bars, Itzhak; Bars, Itzhak; Picon, Moises

    2006-01-01

    The Penrose transform between twistors and the phase space of massless particles is generalized from the massless case to an assortment of other particle dynamical systems, including special examples of massless or massive particles, relativistic or non-relativistic, interacting or non-interacting, in flat space or curved spaces. Our unified construction involves always the \\it{same} twistor Z^A with only four complex degrees of freedom and subject to the \\it{same} helicity constraint. Only the twistor to phase space transform differs from one case to another. Hence a unification of diverse particle dynamical systems is displayed by the fact that they all share the same twistor description. Our single twistor approach seems to be rather different and strikingly economical construction of twistors compared to other past approaches that introduced multiple twistors to represent some similar but far more limited set of particle phase space systems.

  15. Quaternionic (super) twistors extensions and general superspaces

    Science.gov (United States)

    Cirilo-Lombardo, Diego Julio; Pervushin, Victor N.

    2017-09-01

    In a attempt to treat a supergravity as a tensor representation, the four-dimensional N-extended quaternionic superspaces are constructed from the (diffeomorphyc) graded extension of the ordinary Penrose-twistor formulation, performed in a previous work of the authors [D. J. Cirilo-Lombardo and V. N. Pervushin, Int. J. Geom. Methods Mod. Phys., doi: http://dx.doi.org/10.1142/S0219887816501139.], with N = p + k. These quaternionic superspaces have 4 + k(N - k) even-quaternionic coordinates and 4N odd-quaternionic coordinates, where each coordinate is a quaternion composed by four ℂ-fields (bosons and fermions respectively). The fields content as the dimensionality (even and odd sectors) of these superspaces are given and exemplified by selected physical cases. In this case, the number of fields of the supergravity is determined by the number of components of the tensor representation of the four-dimensional N-extended quaternionic superspaces. The role of tensorial central charges for any N even USp(N) = Sp(N, ℍℂ) ∩ U(N, ℍℂ) is elucidated from this theoretical context.

  16. New constructions of twistor lifts for harmonic maps

    DEFF Research Database (Denmark)

    Svensson, Martin; C. Wood, John

    2014-01-01

    We show that given a harmonic map \\varphi from a Riemann surface into a classical simply connected compact inner symmetric space, there is a J_2-holomorphic twistor lift of \\varphi (or its negative) if and only if it is nilconformal. In the case of harmonic maps of finite uniton number, we give...... algebraic formulae in terms of holomorphic data which describes their extended solutions. In particular, this gives explicit formulae for the twistor lifts of all harmonic maps of finite uniton number from a surface to the above symmetric spaces....

  17. Complex Variable Methods for 3D Applied Mathematics: 3D Twistors and the biharmonic equation

    CERN Document Server

    Shaw, William T

    2010-01-01

    In applied mathematics generally and fluid dynamics in particular, the role of complex variable methods is normally confined to two-dimensional motion and the association of points with complex numbers via the assignment w = x+i y. In this framework 2D potential flow can be treated through the use of holomorphic functions and biharmonic flow through a simple, but superficially non-holomorphic extension. This paper explains how to elevate the use of complex methods to three dimensions, using Penrose's theory of twistors as adapted to intrinsically 3D and non-relativistic problems by Hitchin. We first summarize the equations of 3D steady viscous fluid flow in their basic geometric form. We then explain the theory of twistors for 3D, resulting in complex holomorphic representations of solutions to harmonic and biharmonic problems. It is shown how this intrinsically holomorphic 3D approach reduces naturally to the well-known 2D situations when there is translational or rotational symmetry, and an example is given...

  18. Spinors and Twistors in Loop Gravity and Spin Foams

    CERN Document Server

    Dupuis, Maite; Tambornino, Johannes

    2012-01-01

    Spinorial tools have recently come back to fashion in loop gravity and spin foams. They provide an elegant tool relating the standard holonomy-flux algebra to the twisted geometry picture of the classical phase space on a fixed graph, and to twistors. In these lectures we provide a brief and technical introduction to the formalism and some of its applications.

  19. Weyl-Euler-Lagrange equations on twistor space for tangent structure

    Science.gov (United States)

    Kasap, Zeki

    2016-06-01

    Twistor spaces are certain complex three-manifolds, which are associated with special conformal Riemannian geometries on four-manifolds. Also, classical mechanic is one of the major subfields for mechanics of dynamical system. A dynamical system has a state determined by a collection of real numbers, or more generally by a set of points in an appropriate state space for classical mechanic. Euler-Lagrange equations are an efficient use of classical mechanics to solve problems using mathematical modeling. On the other hand, Weyl submitted a metric with a conformal transformation for unified theory of classical mechanic. This paper aims to introduce Euler-Lagrage partial differential equations (mathematical modeling, the equations of motion according to the time) for the movement of objects on twistor space and also to offer a general solution of differential equation system using the Maple software. Additionally, the implicit solution of the equation will be obtained as a result of a special selection of graphics to be drawn.

  20. Differential and Twistor Geometry of the Quantum Hopf Fibration

    CERN Document Server

    Brain, Simon

    2011-01-01

    We study a quantum version of the SU(2) Hopf fibration $S^7 \\to S^4$ and its associated twistor geometry. Our quantum sphere $S^7_q$ arises as the unit sphere inside a q-deformed quaternion space $\\mathbb{H}^2_q$. The resulting four-sphere $S^4_q$ is a quantum analogue of the quaternionic projective space $\\mathbb{HP}^1$. The quantum fibration is endowed with compatible non-universal differential calculi. By investigating the quantum symmetries of the fibration, we obtain the geometry of the corresponding twistor space $\\mathbb{CP}^3_q$ and use it to study a system of anti-self-duality equations on $S^4_q$, for which we find an `instanton' solution coming from the natural projection defining the tautological bundle over $S^4_q$.

  1. About Twistor Spinors with Zero in Lorentzian Geometry

    Directory of Open Access Journals (Sweden)

    Felipe Leitner

    2009-07-01

    Full Text Available We describe the local conformal geometry of a Lorentzian spin manifold (M,g admitting a twistor spinor φ with zero. Moreover, we describe the shape of the zero set of φ. If φ has isolated zeros then the metric g is locally conformally equivalent to a static monopole. In the other case the zero set consists of null geodesic(s and g is locally conformally equivalent to a Brinkmann metric. Our arguments utilise tractor calculus in an essential way. The Dirac current of φ, which is a conformal Killing vector field, plays an important role for our discussion as well.

  2. Integrable systems twistors, loop groups, and Riemann surfaces

    CERN Document Server

    Hitchin, NJ; Ward, RS

    2013-01-01

    This textbook is designed to give graduate students an understanding of integrable systems via the study of Riemann surfaces, loop groups, and twistors. The book has its origins in a series of lecture courses given by the authors, all of whom are internationally known mathematicians and renowned expositors. It is written in an accessible and informal style, and fills a gap in the existing literature. The introduction by Nigel Hitchin addresses the meaning of integrability: how do werecognize an integrable system? His own contribution then develops connections with algebraic geometry, and inclu

  3. College Impact Theories Past and Present

    Science.gov (United States)

    Ozaki, C. Casey

    2016-01-01

    This chapter critically examines the fit and applicability of foundational college impact theories to the community college context and students. Implications for the literature and campuses are explored.

  4. Lectures on Higher Structures in M-Theory

    CERN Document Server

    Saemann, Christian

    2016-01-01

    These are notes for four lectures on higher structures in M-theory as presented at workshops at the Erwin Schroedinger Institute and Tohoku University. The first lecture gives an overview of systems of multiple M5-branes and introduces the relevant mathematical structures underlying a local description of higher gauge theory. In the second lecture, we develop the corresponding global picture. A construction of non-abelian superconformal gauge theories in six dimensions using twistor spaces is discussed in the third lecture. The last lecture deals with the problem of higher quantization and its relation to loop space. An appendix summarizes the relation between 3-Lie algebras and Lie 2-algebras.

  5. Theory of porous media - past and present

    Energy Technology Data Exchange (ETDEWEB)

    Boer, R. de [Essen Univ. (Germany). Inst. fuer Mechanik

    1998-10-01

    Porous solids filled with liquid or gas play an important role in engineering, e.g., in material science, petroleum industry, chemical engineering, and soil mechanics as well as in biomechanics. Although porous media are of considerable practical significance the description of their mechanical and thermodynamical behavior has been unsatisfactory for a long time. The theory to describe the complex thermodynamical behavior of such saturated porous solids has come to certain well-founded conclusions only recently. It is the goal of this paper to show the historical development of the porous media theory, which already started in the eighteenth century, formed in some areas by polemic disputes and tragic events in the lifes of the scientists involved. Furthermore, the current state of the research into this subject is discussed, whereby the state of the development of the material independent basic equations and the constitutive theory is illustrated. For a certain class of models general theorems, such as minimum and maximum problems, are derived and the uniqueness of solutions of boundary value problems is proved. (orig.)

  6. A twistor sphere of generalized Kahler potentials on hyperkahler manifolds

    CERN Document Server

    Dyckmanns, Malte

    2011-01-01

    We consider the generalized Kahler structures (g,J_+,J_-) that arise on a hyperkahler manifold (M,g,I,J,K) when we choose J_+ and J_- from the twistor space of M. We find a relation between semichiral and arctic superfields which can be used to determine the generalized Kahler potential for hyperkahler manifolds whose description in projective superspace is fully understood. We use this relation to determine an S^2-family of generalized Kahler potentials for Euclidean space and for the Eguchi-Hanson geometry. Cotangent bundles of Hermitian symmetric spaces constitute a class of hyperkahler manifolds where our method can be applied immediately since the necessary results from projective superspace are already available. As a non-trivial higher-dimensional example, we determine the generalized potential for T*CP^n, which generalizes the Eguchi-Hanson result.

  7. The connected prescription for form factors in twistor space

    CERN Document Server

    Brandhuber, Andreas; Panerai, Rodolfo; Spence, Bill; Travaglini, Gabriele

    2016-01-01

    We propose a connected prescription formula in twistor space for all tree-level form factors of the stress tensor multiplet operator in $\\mathcal{N}=4$ super Yang-Mills, which is a generalisation of the expression of Roiban, Spradlin and Volovich for superamplitudes. By introducing link variables, we show that our formula is identical to the recently proposed four-dimensional scattering equations for form factors. Similarly to the case of amplitudes, the link representation of form factors is shown to be directly related to BCFW recursion relations, and is considerably more tractable than the scattering equations. We also discuss how our results are related to a recent Grassmannian formulation of form factors, and comment on a possible derivation of our formula from ambitwistor strings.

  8. The connected prescription for form factors in twistor space

    Science.gov (United States)

    Brandhuber, A.; Hughes, E.; Panerai, R.; Spence, B.; Travaglini, G.

    2016-11-01

    We propose a connected prescription formula in twistor space for all tree-level form factors of the stress tensor multiplet operator in {N} = 4 super Yang-Mills, which is a generalisation of the expression of Roiban, Spradlin and Volovich for superamplitudes. By introducing link variables, we show that our formula is identical to the recently proposed four-dimensional scattering equations for form factors. Similarly to the case of amplitudes, the link representation of form factors is shown to be directly related to BCFW recursion relations, and is considerably more tractable than the scattering equations. We also discuss how our results are related to a recent Grassmannian formulation of form factors, and comment on a possible derivation of our formula from ambitwistor strings.

  9. Quaternionic (super)twistors extensions and general superspaces

    CERN Document Server

    Cirilo-Lombardo, Diego Julio

    2016-01-01

    In a attempt to treat a supergravity as a tensor representation, the 4-dimensional N-extended quaternionic superspaces are constructed from the (diffeomorphyc)graded extension of the ordinary Penrose-twistor formulation, performed in a previous work of the authors[14], with N = p + k: These quaternionic superspaces have 4 + k (N - k) even-quaternionic coordinates and 4N odd- quaternionic coordinates where each coordinate is a quaternion composed by four C-felds (bosons and fermions respectively). The fields content as the dimensionality (even and odd sectors) of these superspaces are given and exemplified by selected physical cases. In this case the number of felds of the supergravity is determined by the number of components of the tensor representation of the 4-dimensional N-extended quaternionic superspaces. The role of tensorial central charges for any N even USp (N) = Sp (N;HC) \\ U (N;HC) is elucidated from this theoretical context.

  10. Rotating Black Hole, Twistor-String and Spinning Particle

    CERN Document Server

    Burinskii, A

    2005-01-01

    We discuss basic features of the model of spinning particle based on the Kerr solution. It contains a very nontrivial {\\it real} stringy structure consisting of the Kerr circular string and an axial stringy system. We consider also the complex and twistorial structures of the Kerr geometry and show that there is a {\\it complex} twistor-string built of the complex N=2 chiral string with a twistorial $(x,\\theta)$ structure. By imbedding into the real Minkowski $\\bf M^4$, the N=2 supersymmetry is partially broken and string acquires the open ends. Orientifolding this string, we identify the chiral and antichiral structures. Target space of this string is equivalent to the Witten's `diagonal' of the $\\bf CP^3\\times CP^{*3}.$

  11. The Prototype Theory and the Simple Present Tense Teaching

    Institute of Scientific and Technical Information of China (English)

    袁昌玲; 杨唐峰

    2016-01-01

    The prototype theory has been widely applied to the language teaching. In this paper, the author analyzes the relations between different uses of the simple present tense from the perspective of the prototype theory, hoping to help students understand this tense better and promote the application of this theory to English tense teaching.

  12. Summary of papers presented in the Theory and Modelling session

    OpenAIRE

    Lin-Liu Y.R.; Westerhof E.

    2012-01-01

    A total of 14 contributions were presented in the Theory and Modelling sessions at EC-17. One Theory and Modelling paper was included in the ITER ECRH and ECE sessions each. Three papers were in the area of nonlinear physics discussing parametric processes accompanying ECRH. Eight papers were based on the quasi-linear theory of wave heating and current drive. Three of these addressed the application of ECCD for NTM stabilization. Two papers considered scattering of EC waves by edge density fl...

  13. A non-normal Fefferman-type construction of split-signature conformal structures admitting twistor spinors

    CERN Document Server

    Hammerl, Matthias

    2011-01-01

    We treat a non-normal Fefferman-type construction based on an inclusion $\\SL(n+1)\\embed\\Spin(n+1,n+1)$. The construction associates a split signature $(n,n)$-conformal spin structure to a projective structure of dimension $n$. For $n\\geq 3$ the induced conformal Cartan connection is shown to be normal if and only if it is flat. The main technical work of this article consists in showing that in the non-flat case the normalised conformal Cartan connection still allows a parallel (pure) spin-tractor and thus a corresponding (pure) twistor spinor on the conformal space. The Fefferman-type construction presented here is an alternative approach to study a construction of Dunajski-Tod

  14. Summary of papers presented in the Theory and Modelling session

    Directory of Open Access Journals (Sweden)

    Lin-Liu Y.R.

    2012-09-01

    Full Text Available A total of 14 contributions were presented in the Theory and Modelling sessions at EC-17. One Theory and Modelling paper was included in the ITER ECRH and ECE sessions each. Three papers were in the area of nonlinear physics discussing parametric processes accompanying ECRH. Eight papers were based on the quasi-linear theory of wave heating and current drive. Three of these addressed the application of ECCD for NTM stabilization. Two papers considered scattering of EC waves by edge density fluctuations and related phenomena. In this summary, we briefly describe the highlights of these contributions. Finally, the three papers concerning modelling of various aspects of ECE are reported in the ECE session.

  15. Towards an Integral Critical Theory of the Present Age

    Directory of Open Access Journals (Sweden)

    Martin Beck Matuštík

    2007-12-01

    Full Text Available A new model of a critical theory that is integral is introduced. It adds a seventhstage to a six-stage model of critical theory. Building on the model’s predecessors, fromKant, Hegel, and Marx to Habermas and Wilber, this proposal is a three-pronged modelof material, socio-political, and spiritual critique of the present age. Each dimension isnon-reducible to the other. The current model echoes the attempts to bridge social andexistential perspectives by early Marcuse and Sartre, and the author’s prior work that didthis for Habermas and Kierkegaard. This model of an integral critical theory introduces aself-transformational axis, the integer or witness-self, complementing transversally thevertical stages and horizontal states of consciousness.

  16. Towards an Integral Critical Theory of the Present Age

    Directory of Open Access Journals (Sweden)

    Martin Beck Matuštík

    2007-12-01

    Full Text Available A new model of a critical theory that is integral is introduced. It adds a seventh stage to a six-stage model of critical theory. Building on the model’s predecessors, from Kant, Hegel, and Marx to Habermas and Wilber, this proposal is a three-pronged model of material, socio-political, and spiritual critique of the present age. Each dimension is non-reducible to the other. The current model echoes the attempts to bridge social and existential perspectives by early Marcuse and Sartre, and the author’s prior work that did this for Habermas and Kierkegaard. This model of an integral critical theory introduces a self-transformational axis, the integer or witness-self, complementing transversally the vertical stages and horizontal states of consciousness.

  17. Twistor quantization of the space of half-differentiable vector functions on the circle revisited

    Institute of Scientific and Technical Information of China (English)

    SERGEEV; Armen

    2009-01-01

    We discuss the twistor quantization problem for the classical system(Vd,Ad),represented by the phase space Vd,identified with the Sobolev space H 1/2 0 (S1,Rd)of half-differentiable vector functions on the circle,and the algebra of observables Ad,identified with the semi-direct product of the Heisenberg algebra of Vd and the algebra Vect(S1)of tangent vector fields on the circle.

  18. International Entrepreneurship Theory: Past, Present and Way Forward

    Directory of Open Access Journals (Sweden)

    Ikemefuna Allen

    2016-12-01

    Full Text Available Objective: This paper recounts the historical development of International Entrepreneurship as a study field, and demonstrates how concepts brought forth contribute to a broader understanding of fundamental international business and entrepreneurship theories. Research Design & Methods: The analytical work makes reference to the existing literature on International Entrepreneurship. Based on the categorisation of themes and sub-themes, the historical development of international entrepreneurship theory is recounted, creating a foundation for the assessment of its relationships and linkages with international business and entrepreneurship theories. Findings: The findings indicate that International Entrepreneurship is still in a developmental stage. However, the field is rich with novel ideas and concepts that can give an impetus to researchers as they strive to explore themes such as international entrepreneurial orientation and entrepreneurial internationalization. Implications & Recommendations: The lack of theoretical foundation presents challenges to researchers. Research must be directed at answering the fundamental questions that distinguish International Entrepreneurship from the two related, but more established fields; international business and entrepreneurship. Contribution & Value Added: The paper provides a point of reference for scholars that want to attain a comprehensive insight into the state of international entrepreneurial research, and distinctions from, and relevance to the fields of international business and entrepreneurship.

  19. The Theory of Magnetic Reconnection: Past, Present, and Future

    Science.gov (United States)

    Cassak, P. A.

    2008-05-01

    Magnetic reconnection underlies the energy release observed in eruptive events in the solar corona (such as solar flares and coronal mass ejections) and in the Earth's magnetosphere. The theory of magnetic reconnection was originally developed to understand observations by Ron Giovanelli, who discovered that solar flares occur where the coronal magnetic field changes directions. Pioneers in space plasma theory such as James Dungey, Peter Sweet, Eugene Parker, and Harry Petschek first elucidated the underlying physical effects that lead to this massive energy release. Since then, much effort has been made to understand what process or processes cause magnetic reconnection to be fast enough to be consistent with observations, such as anomalous resistivity, secondary instabilities, and the Hall effect. However, a thorough understanding of this important process remains a topic of intense study. In celebration of the 50th anniversary of Parker's paper predicting the high-speed solar wind, this talk will review the history of the theory of magnetic reconnection. The present status of the field will be discussed, and remaining unanswered questions will be summarized.

  20. International Entrepreneurship Theory: Past, Present and Way Forward

    OpenAIRE

    Ikemefuna Allen

    2016-01-01

    Objective: This paper recounts the historical development of International Entrepreneurship as a study field, and demonstrates how concepts brought forth contribute to a broader understanding of fundamental international business and entrepreneurship theories. Research Design & Methods: The analytical work makes reference to the existing literature on International Entrepreneurship. Based on the categorisation of themes and sub-themes, the historical development of international entrepren...

  1. D3-instantons, Mock Theta Series and Twistors

    OpenAIRE

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2012-01-01

    The D-instanton corrected hypermultiplet moduli space of type II string theory compactified on a Calabi-Yau threefold is known in the type IIA picture to be determined in terms of the generalized Donaldson-Thomas invariants, through a twistorial construction. At the same time, in the mirror type IIB picture, and in the limit where only D3-D1-D(-1)-instanton corrections are retained, it should carry an isometric action of the S-duality group SL(2,Z). We prove that this is the case in the one-i...

  2. Studies on instantons, twistor strings, and half-BPS geometries

    Science.gov (United States)

    Ricci, Riccardo

    2006-12-01

    In this Dissertation we discuss three different topics. We begin by studying supersymmetric instantons for Yang-Mills theories on non-anticommutative superspace. Performing an iterative expansion in the non-commutativity parameter C, we solve the equation of motions for U(2) Super Yang-Mills with and without matter. For pure Yang-Mills, we solve the equations exactly. In addition to the usual 't Hooft SU(2) instanton, the deformation turns on a non-trivial U(1) conncetion which depends on the fermionic collective coordinates and the deformation parameter C. In the Higgs phase on the other hand, we solve the equations of motion to leading order in the coupling constant. Even though the instanton effective action receives a contribution of order C 2, the gluino condensate and the non-perturbative Affleck-Dine-Seiberg superpotential remain as in N = 1 super Yang-Mills. The second topic is related to twister strings. Perturbative super Yang-Mills can be reinterpreted as a D-instanton expansion of the topological B-model on the supermanifold CP3|4 . We extend this contruction to N = 1 and N = 2 quiver gauge theories by contructing fermionic orbifolds of CP3|4 . Topological string suggest some efficient rules for computing Yang-Mills perturbative amplitudes. We consider possible extensions of these rules to gravity amplitudes. We conclude by analyzing some mathematical aspects of super Calabi-Yau manifolds. The final topic is devoted to the study of half-BPS type IIB supergravity solutions. The moduli space of these solutions can be associated to a one-dimensional, zero temperature fermion gas in a harmonic potential. We studied a natural generalization of the fermion-supergravity map, considering the fermions at non-zero temperature. We found that the ADM energy of the supergravity solution reproduces the thermal fermion energy. One important effect of the temperature is that the background develops a null singularity. This singularity is naked, that is not "covered" by

  3. Theory of Constraints for Services: Past, Present, and Future

    Science.gov (United States)

    Ricketts, John A.

    Theory of constraints (TOC) is a thinking process and a set of management applications based on principles that run counter to conventional wisdom. TOC is best known in the manufacturing and distribution sectors where it originated. Awareness is growing in some service sectors, such as Health Care. And it's been adopted in some high-tech industries, such as Computer Software. Until recently, however, TOC was barely known in the Professional, Scientific, and Technical Services (PSTS) sector. Professional services include law, accounting, and consulting. Scientific services include research and development. And Technical services include development, operation, and support of various technologies. The main reason TOC took longer to reach PSTS is it's much harder to apply TOC principles when services are highly customized. Nevertheless, with the management applications described in this chapter, TOC has been successfully adapted for PSTS. Those applications cover management of resources, projects, processes, and finances.

  4. A twistor formulation of the heterotic D=10 superstring with manifest (8,0) worldsheet supersymmetry

    CERN Document Server

    Delduc, F; Howe, Paul S; Sokatchev, Emery S

    1993-01-01

    We propose a new formulation of the heterotic $D=10$ Green-Schwarz superstring whose worldsheet is a superspace with two even and eight odd coordinates. The action is manifestly invariant under both target-space supersymmetry and a worldsheet reparametrisation supergroup. It contains only a finite set of auxiliary fields. The key ingredient are the commuting spinor (twistor) variables, which naturally arise as worldsheet superpartners of the target space Grassmann coordinates. These spinors parametrise the sphere $S^8$ regarded as a coset space of the $D=10$ Lorentz group. The sphere is associated with the lightlike vector of one of the string Virasoro constraints. The origin of the on-shell $D=10$ fermionic kappa symmetry of the standard Green-Schwarz formulation is explained. An essential and unusual feature is the appearance of the string tension only on shell as an integration constant.

  5. A twistor-like D=10 superparticle action with manifest N=8 world-line supersymmetry

    CERN Document Server

    Galperin, A

    1992-01-01

    We propose a new formulation of the $D=10$ Brink-Schwarz superparticle which is manifestly invariant under both the target-space super-Poincar\\'e group and the world-line local $N=8$ superconformal group. This twistor-like construction naturally involves the sphere $S^8$ as a coset space of the $D=10$ Lorentz group. The action contains only a finite set of auxiliary fields, but they appear in unusual trilinear combinations. The origin of the on-shell $D=10$ fermionic $\\kappa$ symmetry of the standard Brink-Schwarz formulation is explained. The coupling to a $D=10$ super-Maxwell background requires a new mechanism, in which the electric charge appears only on shell as an integration constant.

  6. Presentations of the 11. European fusion theory conference

    Energy Technology Data Exchange (ETDEWEB)

    Militello, F.; Ottaviani, M.; Porcelli, F.; Hastie, J.; Llewellyn Smith, C.; Cheng, C.Z.; Bourdelle, C.; Diamond, P.; Ryutov, D.D.; Saarelma, S.; Van Eester, D.; Castaldo, C.; Sanchez, R.; Cappello, S.; Brun, S.; Connor, J.W.; Waelbroeck, F.; Militello, F.; Heikkinen, J.A.; Newton, S.L.; Angelino, P.; Lamalle, Ph.; Lerche, E.A

    2005-07-01

    This document gathers the slides of some of the presentations made at the conference. It concerns the following papers: 1) saturation of the neoclassical tearing mode islands, 2) Einstein's legacy, 3) neoclassical momentum transport and radial electric field in tokamak transport barriers, 4) magnetic geometry, plasma profiles and stability, and 5) edge stability in tokamak plasmas.

  7. Intelligent Multi-Media Presentation Using Rhetorical Structure Theory

    Science.gov (United States)

    2015-01-01

    to see a restaurant menu structured into courses: Entrée; Main; Dessert; and Beverages. The placement of each dish within the menu establishes its...be presented before its nucleus. This provides a convenient way of ensuring that multimedia display channels are appropriately initialised within

  8. Theory of spin transport in antiferromagnets (Conference Presentation)

    Science.gov (United States)

    Manchon, Aurélien; Saidaoui, Hamed; Akosa, Collins

    2016-10-01

    Antiferromagnets (AF) have long remained an intriguing and exotic state of matter, their application being restricted to enabling interfacial exchange bias in spin-valves. Their role in the expanding field of applied spintronics has been mostly passive and the in-depth investigation of their basic properties considered as fundamental condensed matter physics. A conceptual breakthrough was achieved ten years ago with the proposal that spin transfer torque could be used to electrically control the direction of the order parameter of AF spin valves, henceforth making these materials potential candidates for low energy spin devices. In spite of substantial theoretical efforts and experimental attempts to observe such a torque, the difficulty to independently detect the direction of the AF order parameter has remained a major obstacle. In this talk, I will first introduce the original concept of spin transfer torque in AF spin-valves, demonstrating that it is strongly limited by the spin decoherence and dramatically vanishes in the presence of disorder, leaving little hope to observe this effect experimentally. Then, I will present the newly proposed concept of spin-orbit torque that utilizes bulk or interfacial the spin-orbit coupling in non-centrosymmetric magnets to directly generate a torque on the AF order parameter. This torque, being local, is much more robust against impurities, as will be demonstrated for the specific case of interfacial Rashba spin-orbit coupling. Finally, I will discuss about spin motive force and torques in antiferromagnetic textures, intriguing effects that remained to be experimentally observed.

  9. PRESENTATION. Experimental and behavioral economics. Theory, tools and topics

    Directory of Open Access Journals (Sweden)

    Brañas-Garza, Pablo

    2012-03-01

    Full Text Available This note presents the special issue on Experimental and Behavioral Economics. The volume includes some recent contributions from these correlated disciplines –empirical the former and theoretical the latter– and their potential contribution to the intersection of Economics with Psychology and Sociology. The project “El papel de la comparación social en las decisiones económicas bajo incertidumbre” (Junta de Andalucía, P07- SEJ-03155” provided us with inspiration and financial support to publish this volume.

    Este trabajo presenta el número especial de Revista Internacional de Sociología dedicado a la Economía Experimental y del Comportamiento. El volumen se compone de una serie de trabajos tanto teóricos como empíricos ubicados en la intersección de la Economía con la Psicología y la Sociología. El proyecto “El papel de la comparación social en las decisiones económicas bajo incertidumbre” (Junta de Andalucía, P07- SEJ-03155” nos proporcionó inspiración y financiación para publicar este volumen.

  10. All tree amplitudes of supersymmetric Einstein-Yang-Mills theory

    CERN Document Server

    Adamo, Tim; Roehrig, Kai A; Skinner, David

    2015-01-01

    We present a new formula for all tree amplitudes in four dimensional supergravity coupled to super Yang-Mills. Like the Cachazo-He-Yuan formula, our expression is supported on solutions of the scattering equations, but with momenta written in terms of spinor helicity variables. Supersymmetry and parity are both manifest. In the pure gravity and pure Yang-Mills sectors, it reduces to the known twistor-string formulae. We show that the formula behaves correctly under factorization. We sketch how these amplitudes may be obtained from a four-dimensional (ambi)twistor string.

  11. On pluri-half-anticanonical system of LeBrun twistor spaces

    CERN Document Server

    Honda, Nobuhiro

    2009-01-01

    In this note, we investigate pluri-half-anticanonical systems on the so called LeBrun twistor spaces. We determine its dimension, the base locus, structure of the associated rational map, and also structure of general members, in precise form. In particular, we show that if n>2 and m>1, the base locus of the system |mK^{-1/2}| on nCP^2 consists of two non-singular rational curves, along which any member has singularity, and that if we blow-up these curves, then the strict transform of a general members of |mK^{-1/2}| becomes an irreducible non-singular surface. We also show that if n>3 and m>n-2, then the last surface is a minimal surface of general type with vanishing irregularity. We also show that the rational map associated to the system |mK^{-1/2}| is birational if and only if m> n-2.

  12. Language, word and discourse: the Lacanian path into the tradition and present of political theory

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Rossi

    2010-12-01

    Full Text Available The goal of this paper is to flesh out the relationship between language, word and discourse in the tradition and present of Political Theory, resorting to some Lacanian categories. The first part of this text will focus on Lacan’s distinction between the notions of language, word and discourse. The second part is meant to track those notions in some key aspects of the tradition and present of Political Theory and Political Philosophy.

  13. On twistor transformations and invariant differential operator of simple Lie group G2(2)

    Science.gov (United States)

    Wang, Wei

    2013-01-01

    The twistor transformations associated to the simple Lie group G2 are described explicitly. We consider the double fibration G_2/P_2 xleftarrow {η } {G_2/B} xrArr {tau }G_2/P_1, where P1 and P2 are two parabolic subgroups of G2 and B is a Borel subgroup, and its local version: H^*_2 xleftarrow {η } F xrArr {tau } H_1, where H_1 is the Heisenberg group of dimension 5 embedded in the coset space G2/P1, F = {CP}^1 × H_1 and H^*_2 contains the nilpotent Lie group H_2 of step three. The Baker-Campbell-Hausdorff formula is used to parametrize the coset spaces, coordinates charts, their transition functions and the fibers of the projection η as complex curves. We write down the relative De-Rham sequence on F along the fibers and push it down to H_1 to get a family of matrix-valued differential operators {D}_k. Then we establish a kind of Penrose correspondence for G2: the kernel of {D}_k is isomorphic to the first cohomology of the sheaf {O} (-k ) over H^*_2. We also give the Penrose-type integral transformation u = Pf for fin {O} (-k ), which gives solutions to equations {D}_ku=0. When restricted to the real Heisenberg group, the differential operators are invariant under the action of G2(2). Exchanging P1 and P2, we derive corresponding results on H_2.

  14. All Next-to-Maximally-Helicity-Violating One-Loop Gluon Amplitudes in N=4 Super-Yang-Mills Theory

    CERN Document Server

    Bern, Z; Kosower, D A; Bern, Zvi; Dixon, Lance J.; Kosower, David A.

    2004-01-01

    We compute the next-to-MHV one-loop n-gluon amplitudes in N=4 super-Yang-Mills theory. These amplitudes contain three negative-helicity gluons and an arbitrary number of positive-helicity gluons, and are the first infinite series of amplitudes beyond the simplest, MHV, amplitudes. We also discuss some aspects of their twistor-space structure.

  15. All Non-Maximally-Helicity-Violating One-Loop Seven-Gluon Amplitudes in N=4 Super-Yang-Mills Theory

    CERN Document Server

    Bern, Z; Dixon, L J; Kosower, D A; Bern, Zvi; Duca, Vittorio Del; Dixon, Lance J.; Kosower, David A.

    2004-01-01

    We compute the non-MHV one-loop seven-gluon amplitudes in N=4 super-Yang-Mills theory, which contain three negative-helicity gluons and four positive-helicity gluons. There are four independent color-ordered amplitudes, (- - - + + + +), (- - + - + + +), (- - + + -+ +) and (- + - + - + +). The MHV amplitudes containing two negative-helicity and five positive-helicity gluons were computed previously, so all independent one-loop seven-gluon helicity amplitudes are now known for this theory. We present partial information about an infinite sequence of next-to-MHV one-loop helicity amplitudes, with three negative-helicity and n-3 positive-helicity gluons, and the color ordering (- - - + + ... + +); we give a new coefficient of one class of integral functions entering this amplitude. We discuss the twistor-space properties of the box-integral-function coefficients in the amplitudes, which are quite simple and suggestive.

  16. The Extended Relativity Theory in Born-Clifford Phase Spaces with a Lower and Upper Length Scales and Clifford Group Geometric Unification

    CERN Document Server

    Castro, C

    2004-01-01

    We construct the Extended Relativity Theory in Born-Clifford-Phase spaces with an upper and lower length scales (infrared/ultraviolet cutoff). The invariance symmetry leads naturally to the real Clifford algebra Cl (2, 6, R ) and complexified Clifford Cl_C ( 4 ) algebra related to Twistors. We proceed with an extensive review of Smith's 8D model based on the Clifford algebra Cl ( 1 ,7) that reproduces at low energies the physics of the Standard Model and Gravity; including the derivation of all the coupling constants, particle masses, mixing angles, ....with high precision. Further results by Smith are discussed pertaining the interplay among Clifford, Jordan, Division and Exceptional Lie algebras within the hierarchy of dimensions D = 26, 27, 28 related to bosonic string, M, F theory. Two Geometric actions are presented like the Clifford-Space extension of Maxwell's Electrodynamics, Brandt's action related the 8D spacetime tangent-bundle involving coordinates and velocities (Finsler geometries) followed by a...

  17. The Non-Maximally-Helicity-Violating One-Loop Seven-Gluon Amplitudes in N=4 Super-Yang-Mills Theory

    Energy Technology Data Exchange (ETDEWEB)

    Bern, Z.

    2004-10-22

    We compute the non-MHV one-loop seven-gluon amplitudes in N = 4 super-Yang-Mills theory, which contain three negative-helicity gluons and four positive-helicity gluons. There are four independent color-ordered amplitudes, (---++++), (--+-+++), (--++-++) and (-+-+-++). The MHV amplitudes containing two negative-helicity and five positive-helicity gluons were computed previously, so all independent one-loop seven-gluon helicity amplitudes are now known for this theory. We present partial information about an infinite sequence of next-to-MHV one-loop helicity amplitudes, with three negative-helicity and n - 3 positive-helicity gluons, and the color ordering (---+{center_dot}{center_dot}{center_dot}++); we give a new coefficient of one class of integral functions entering this amplitude. We discuss the twistor-space properties of the box-integral-function coefficients in the amplitudes, which are quite simple and suggestive.

  18. Tactics for male reproductive success in plants: contrasting insights of sex allocation theory and pollen presentation theory.

    Science.gov (United States)

    Thomson, James D

    2006-08-01

    The basic tenet of sex allocation theory is that an organism's reproductive success, through either male or female function, can be represented as a sex-specific, monotonic, increasing function of the organism's investment of resources in that function. The shapes of these curves determine what patterns of resource allocation can be evolutionarily stable. Although SA theory has stimulated creative thinking about plant sexual tactics, quantifying the shapes of male and female gain curves has proven so difficult that other approaches must be considered. I contrast sex allocation theory to a different, emerging viewpoint, pollen presentation theory (PPT), which attempts to address variation in reproductive success by measuring and modeling the quantitative fates of pollen grains. Models suggest that RS through male function depends heavily on the packaging and gradual dispensing of pollen to pollinators, even with the amount of investment held constant. Many plants do deploy pollen gradually, through morphological and "behavioral" mechanisms that range from obvious to subtle. They may thereby influence many aspects of the evolution of sexual modes in plants, including transitions between dioecy and cosexuality. After reviewing the main implications of the models, I discuss recent work aimed at testing some key assumptions and predictions by functional and comparative studies in the genus Penstemon. Species of Penstemon conform to PPT predictions that bee-adapted flowers will restrict per-visit pollen availability more than hummingbird-adapted flowers.

  19. Early Hebrew education and its significance for present-day educational theory and practice

    Directory of Open Access Journals (Sweden)

    S. Schoeman

    1997-01-01

    Full Text Available Early Hebrew education and its significance for present-day educational theory and practice The history of education in antiquity is not without relevance to present-day educational theory and practice. The focus in this article is on the early Hebrews and their education. A study of early Hebrew education may in itself not provide solutions to current educational problems, but it may be useful in offering new perspectives, encouragement and suggestions for a juture South African educational dispensation.

  20. Assessment of theory of mind in children with communication disorders: Role of presentation mode

    NARCIS (Netherlands)

    Buijsen, M. van; Hendriks, A.W.C.J.; Ketelaars, M.P.; Verhoeven, L.T.W.

    2011-01-01

    Children with communication disorders have problems with both language and social interaction. The theory-of-mind hypothesis provides an explanation for these problems, and different tests have been developed to test this hypothesis. However, different modes of presentation are used in these tasks,

  1. Assessment of Theory of Mind in Children with Communication Disorders: Role of Presentation Mode

    Science.gov (United States)

    van Buijsen, Marit; Hendriks, Angelique; Ketelaars, Mieke; Verhoeven, Ludo

    2011-01-01

    Children with communication disorders have problems with both language and social interaction. The theory-of-mind hypothesis provides an explanation for these problems, and different tests have been developed to test this hypothesis. However, different modes of presentation are used in these tasks, which make the results difficult to compare. In…

  2. Group theory in quantum mechanics an introduction to its present usage

    CERN Document Server

    Heine, Volker

    1960-01-01

    Group Theory in Quantum Mechanics: An Introduction to its Present Usage introduces the reader to the three main uses of group theory in quantum mechanics: to label energy levels and the corresponding eigenstates; to discuss qualitatively the splitting of energy levels as one starts from an approximate Hamiltonian and adds correction terms; and to aid in the evaluation of matrix elements of all kinds, and in particular to provide general selection rules for the non-zero ones. The theme is to show how all this is achieved by considering the symmetry properties of the Hamiltonian and the way in w

  3. The Present Situation in Quantum Theory and its Merging with General Relativity

    Science.gov (United States)

    Khrennikov, Andrei

    2017-08-01

    We discuss the problems of quantum theory (QT) complicating its merging with general relativity (GR). QT is treated as a general theory of micro-phenomena—a bunch of models. Quantum mechanics (QM) and quantum field theory (QFT) are the most widely known (but, e.g., Bohmian mechanics is also a part of QT). The basic problems of QM and QFT are considered in interrelation. For QM, we stress its nonrelativistic character and the presence of spooky action at a distance. For QFT, we highlight the old problem of infinities. And this is the main point of the paper: it is meaningless to try to unify QFT so heavily suffering of infinities with GR. We also highlight difficulties of the QFT-treatment of entanglement. We compare the QFT and QM based measurement theories by presenting both theoretical and experimental viewpoints. Then we discuss two basic mathematical constraints of both QM and QFT, namely, the use of real (and, hence, complex) numbers and the Hilbert state space. We briefly present non-archimedean and non-hilbertian approaches to QT and their consequences. Finally, we claim that, in spite of the Bell theorem, it is still possible to treat quantum phenomena on the basis of a classical-like causal theory. We present a random field model generating the QM and QFT formalisms. This emergence viewpoint can serve as the basis for unification of novel QT (may be totally different from presently powerful QM and QFT) and GR. (It may happen that the latter would also be revolutionary modified.)

  4. Invited and contributed papers presented by the theory group at the joint Varenna-Lausanne international workshop `theory of fusion plasmas`

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    In this report eight invited and contributed papers of the theory group are included which were presented at joint Varenna-Lausanne international workshop on `theory of fusion plasmas`. (author) figs., tabs., refs.

  5. Theory of Neutrino-Atom Collisions: The History, Present Status, and BSM Physics

    Directory of Open Access Journals (Sweden)

    Konstantin A. Kouzakov

    2014-01-01

    Full Text Available An overview of the current theoretical studies on neutrino-atom scattering processes is presented. The ionization channel of these processes, which is studied in experiments searching for neutrino magnetic moments, is brought into focus. Recent developments in the theory of atomic ionization by impact of reactor antineutrinos are discussed. It is shown that the stepping approximation is well applicable for the data analysis practically down to the ionization threshold.

  6. Theory of Neutrino-Atom Collisions: The History, Present Status, and BSM Physics

    OpenAIRE

    Kouzakov, Konstantin A.; Studenikin, Alexander I.

    2014-01-01

    An overview of the current theoretical studies on neutrino-atom scattering processes is presented. The ionization channel of these processes, which is studied in experiments searching for neutrino magnetic moments, is brought into focus. Recent developments in the theory of atomic ionization by impact of reactor antineutrinos are discussed. It is shown that the stepping approximation is well applicable for the data analysis practically down to the ionization threshold.

  7. Presentation

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Freire Vieira

    2013-12-01

    Full Text Available This dossier focuses on one of the essential debate topics today about the territorial dimension of the new development strategies concerned with the worsening of the global socioecological crisis, that is: the challenges related to the activation and integration in networks of localized agri-food systems. For its composition, some contributions presented and debated during the VI International Conference on Localized Agri-food System - The LAFS facing the opportunities and challenges of the new global context have been gathered. The event took place in the city of Florianópolis, from May 21th to 25th of 2013. The event was promoted by the Federal University of Santa Catarina (UFSC and by the Center for the International Cooperation on Agricultural Research for Development (CIRAD. Besides UFSC and CIRAD, EPAGRI, State University of Santa Catarina (UDESC, as well as research institutes and universities from other states (UFMG, IEA/SP, UFS, UFRGS and Mexican and Argentinian partners from the RED SIAL Latino Americana also participated in the organization of lectures, discussion tables and workshops.

  8. Presentation

    Directory of Open Access Journals (Sweden)

    Eduardo Vicente

    2013-06-01

    Full Text Available In the present edition of Significação – Scientific Journal for Audiovisual Culture and in the others to follow something new is brought: the presence of thematic dossiers which are to be organized by invited scholars. The appointed subject for the very first one of them was Radio and the invited scholar, Eduardo Vicente, professor at the Graduate Course in Audiovisual and at the Postgraduate Program in Audiovisual Media and Processes of the School of Communication and Arts of the University of São Paulo (ECA-USP. Entitled Radio Beyond Borders the dossier gathers six articles and the intention of reuniting works on the perspectives of usage of such media as much as on the new possibilities of aesthetical experimenting being build up for it, especially considering the new digital technologies and technological convergences. It also intends to present works with original theoretical approach and original reflections able to reset the way we look at what is today already a centennial media. Having broadened the meaning of “beyond borders”, four foreign authors were invited to join the dossier. This is the first time they are being published in this country and so, in all cases, the articles where either written or translated into Portuguese.The dossier begins with “Radio is dead…Long live to the sound”, which is the transcription of a thought provoking lecture given by Armand Balsebre (Autonomous University of Barcelona – one of the most influential authors in the world on the Radio study field. It addresses the challenges such media is to face so that it can become “a new sound media, in the context of a new soundscape or sound-sphere, for the new listeners”. Andrew Dubber (Birmingham City University regarding the challenges posed by a Digital Era argues for a theoretical approach in radio studies which can consider a Media Ecology. The author understands the form and discourse of radio as a negotiation of affordances and

  9. Present State of the Coacervate-Incoacervate Theory - Origin and Evolution of Cell Structure

    Science.gov (United States)

    Novak, Vladimir J. A.

    1984-12-01

    In agreement with the views of Oparin, Fox, Dose etc., the theory assumes that coacervation of protein-like polyaminoacids began with their accumulation along the coasts of the Archaic water basins. Unlike the above authors, however, the present author views the original coacervates as a suitable “culture medium” from which the first polynucleotides orginated and their partial replication started. Their base sequence was not fortuitous, but determined by the proteinoids on the basis of their mutual affinity. The polyfunctional enzymic activity of the proteinoids catalyzed their replication as well as other activities. Around the replicating DNA molecules secondary coacervates (coacervates in coacervates) accumulated which developed gradually to the first prokaryotic cells. Their most probable evolution to the first eukaryotic organisms is discussed on the basis of the modified Studitsky's synbacteriogenesis theory.

  10. Social class conflict presented in “the kite runner” novel based on marxism theory

    Directory of Open Access Journals (Sweden)

    Yohanes Eko Rubiyanto

    2017-04-01

    The writer conducts the research related to class conflict which is presented in Khaled Hosseini’s “The Kite Runner” novel. This qualitative research is written to analyze the conflicts that happen in Afghan society which is mainly caused by difference of social class. The research is conducted by using library research. The method used in this research is descriptive qualitative method as the data are described in the form of sentences. The steps of collecting the data in this research are reading both the novel and the supporting theories related, analyzing, organizing and displaying the data to allow conclusions to be drawn. The results show that the society in the twentieth is fundamentally separated by two large groups namely Pashtun and Hazara. They are inhabit Afghanistan as told in The Kite Runner. The Pashtuns act as the dominant upper class and the Hazaras fill the society of the lower class which fits the theory of Marxism.

  11. Presentation

    Directory of Open Access Journals (Sweden)

    Helmut Renders

    2008-10-01

    Full Text Available We present to our esteemed readers the second edition of our journal for 2008. We have chosen the theme “The life and work of Prof. Dr. Jürgen Moltmann” as its special emphasis. It is our way to pay homage to J. Moltmann in the year the Universidade Metodista de São Paulo awards him an honorary Doctor Honoris Causa degree. Sincethe seventies, Moltmann and Latin America have been in dialog. In his emblematic work “A Theology of Liberation”, Gustavo Gutiérrez, the Catholic, discussed with Moltmann, the Reformed, the relationship between eschatology and history (GUTIÉRREZ, Gustavo.Teologia da Libertação. 5ª edição. Petrópolis, RJ: Vozes, 1985, p. 27, 137-139. A dialog held in the premises of IMS, which nowadays is called UMESP, has produced the little book “Passion for life” (MOLTMANN, Jürgen. Paixão pela vida. São Paulo, SP: ASTE - Associaçãode Seminários Teológicos Evangélicos, 1978.In the following years, the wide theological work of J. Moltmann went all the way from debates to congresses and has conquered the classrooms. Most probably, J. Moltmann is nowadays the most widely read European author in Brazilian theological seminaries. Thisrecognition can only be held in unison and the wide response to our request for articles confirms the huge repercussion that Moltmann’s work has been having up to today in Brazil. The ecumenical theologian J. Moltmann is ecumenically read. We believe that thisway we may be better equipped to answer to anyone who asks us for the reason there is hope in us. We have organized the articles on J. Moltmann’s theology according to the original publication date of the books dealt with in each essay. We also communicate that some articles which were originally requested for this edition of the journal will be published in the journal Estudos de Regilião in May 2009.As it is usual with the journal Caminhando, we have, besides this thematic emphasis, yet other contributions in the areas of

  12. Presentation

    Directory of Open Access Journals (Sweden)

    Nicanor Lopes

    2010-11-01

    Full Text Available The Journal Caminhando debuts with a new editorial format: eachmagazine will have a Dossier.In 2010 Christianity celebrated the centenary of Edinburgh. TheWorld Missionary Conference in Edinburgh in 1910 is regarded by manyas missiological watershed in the missionary and ecumenical movement.So the Faculty of Theology of the Methodist Church (FATEO decidedto organize a Wesleyan Week discussing the issue of mission. For anevent of this magnitude FATEO invited the Rev. Dr. Wesley Ariarajah,Methodist pastor and teacher of Sri Lanka with extensive experience inpastoral ministry in local churches and professor of History of Religionsand the New Testament at the Theological College of Lanka, maintainedby the Protestant Churches in Sri Lanka. In 1981 he was invited to jointhe World Council of Churches, where he presided for over ten years theCouncil of Interreligious Dialogue. From 1992 he served as Deputy GeneralSecretary of the WCC.The following texts are not the speeches of the Rev. Dr. WesleyAriarajah, for they will be published separately. Nevertheless, the journaldialogs with the celebrations of the centenary of Edinburgh, parting formthe intriguing theme: "Mission in the 21st century in Brazil". After all, howis it that mission takes place among us in personal, church, and communityactivities?Within the Dossier, as common to the journal, the textos are organizedas follows: Bible, Theology / History and Pastoral Care. Other items thatdo not fit within the Dossier, but, do articulate mission, can be found inthe section Declarations and Documents and Book Reviews.The authors of the Dossier have important considerations in buildinga contemporary missiological concept considering Brazilian reality.Anderson de Oliveira, in the Bible-Section, presents a significantexegeses of Matthew 26.6-13. What does it mean when Jesus is quotedwith the words: "For the poor always ye have with you, but me ye havenot always." Is this declaration challenging the gospels

  13. [The theory of mechanical activity of lungs--a creation history, the present and development prospects].

    Science.gov (United States)

    Tetenev, F F; Tetenev, K F

    2014-01-01

    In article the history of creation of the doctrine about respiratory movements of lungs, history of classical mechanics of breathing is stated. Supervision of the paradoxical facts which became a basis for hypothesis creation, then the theory of mechanical activity of lungs are presented. The facts proving mechanical activity of lungs on an inspiration and an expiration are given. Options of interaction of intra pulmonary and extra pulmonary sources of mechanical energy are considered. Theoretical justification for development of the new direction of studying of physiology of mechanical movements of the internal which does not have own skeleton is stated.

  14. Cannabis careers revisited: applying Howard S. Becker's theory to present-day cannabis use.

    Science.gov (United States)

    Järvinen, Margaretha; Ravn, Signe

    2014-01-01

    A considerable part of today's sociological research on recreational drug use is (explicitly or implicitly) inspired by Howard Becker's classical model of deviant careers. The aim of the present paper is to directly apply Becker's theory to empirical data on present-day cannabis use and to suggest a revision of the theory. As part of this, we propose a stretch of the sociological approach represented by Becker and followers in order to include, not only recreational drug use, but also use for which young people have sought treatment. The paper is based on 30 qualitative interviews with young people in treatment for cannabis problems in Copenhagen, Denmark. We suggest a revision of Becker's career model in relation to four aspects: initiation of cannabis use, differentiation between socially integrated and individualised, disintegrated use, social control from non-users, and the users' moral stance on cannabis. A central point of the paper is that social interaction may both motivate cannabis use, as Becker proposed, and serve as a protective factor against extensive, problematic use.

  15. Global Fits of the Electroweak Standard Theory: Past, Present and Future

    Science.gov (United States)

    Baak, M.; Haller, J.; Mönig, K.

    2016-10-01

    The last decades have seen tremendous progress in the experimental techniques for measuring key observables of the Standard Theory (ST) as well as in theoretical calculations that has led to highly precise predictions of these observables. Global electroweak fits of the ST compare the precision measurements of electroweak observables from lepton and hadron colliders at CERN and elsewhere with accurate theoretical predictions of the ST calculated at multi-loop level. For a long time, global fits have been used to assess the validity of the ST and to constrain indirectly (by exploiting contributions from quantum loops) the remaining free ST parameters, like the masses of the top quark and Higgs boson before their direct discovery. With the discovery of the Higgs boson at the Large Hadron Collider (LHC), the electroweak sector of the ST is now complete and all fundamental ST parameters are known. Hence the global fits are a powerful tool to probe the internal consistency of the ST, to predict ST parameters with high precision, and to constrain theories describing physics beyond the ST. In this chapter we review the global fits of the electroweak sector of the ST from an experimentalist's perspective. We briefly recall the most important achievements from the past (mainly driven by the precise measurements of Z pole observables), discuss the present situation after the accurate measurements of the top quark and Higgs boson masses, and present prospects of the fits as expected from new measurements at the LHC and future lepton colliders.

  16. DOES MULTIMEDIA THEORY APPLY TO ALL STUDENTS? THE IMPACT OF MULTIMEDIA PRESENTATIONS ON SCIENCE LEARNING

    Directory of Open Access Journals (Sweden)

    Peter G. Schrader

    2016-01-01

    Full Text Available User You are logged in as... mocak My Profile Log Out Log Out as User Journal Content Search Search Scope Browse By Issue By Author By Title Indexing/Abstracting -Doaj -Google Scholar -J Gate/Informatics -Ulrich's Under review by: -Ebsco -Journal Seek -info BASE INDEX -ERIC -Ulakbim/tr index Article Tools Abstract Print this article Indexing metadata How to cite item Finding References Review policy Email this article Email the author Related Items Show all The fourth issue of Journal of Learning and Teaching in Digital Age(JOLTIDA has been published. Editorial Board Open Journal Systems Journal Help Notifications View (564 new Manage Information For Readers For Authors For Librarians Creative Commons License Font Size Make font size smaller Make font size default Make font size larger Home About User Home Search Current Archives Announcements Home > Vol 1, No 1 (2016 > Schrader  DOES MULTIMEDIA THEORY APPLY TO ALL STUDENTS? THE IMPACT OF MULTIMEDIA PRESENTATIONS ON SCIENCE LEARNING Peter G. Schrader University of Nevada Las Vegas, USA pg.schrader@unlv.edu Eric E. Rapp ericrapp@icloud.com ABSTRACT In K-12 school settings in the United States, there is a preponderance of information delivered via multimedia to students everyday (e.g., visual aids found in science textbooks, electronic tablets, streamed video content, web pages, animations, and PowerPoint presentations. The cognitive theory of multimedia learning (CTML outlines numerous principles associated with learning from and with multimedia (Mayer, Hegarty, Mayer, & Cambell, 2005. However, the bulk of the research like the CTML has been conducted using college age students (Jones, 2010; McTigue, 2009. There is ample evidence that college age students and younger students exhibit numerous and important differences when learning from multimedia content (Hannus & Hyona, 1999; McTique, 2009; Moreno, 2007; Van Parreren, 1983. As a result, the objective of the current study is to examine the

  17. Integrable amplitude deformations for N =4 super Yang-Mills and ABJM theory

    Science.gov (United States)

    Bargheer, Till; Huang, Yu-Tin; Loebbert, Florian; Yamazaki, Masahito

    2015-01-01

    We study Yangian-invariant deformations of scattering amplitudes in 4d N =4 super Yang-Mills theory and 3d N =6 Aharony-Bergman-Jafferis-Maldacena (ABJM) theory. In particular, we obtain the deformed Graßmannian integral for 4d N =4 supersymmetric Yang-Mills theory, both in momentum and momentum-twistor space. For 3d ABJM theory, we initiate the study of deformed scattering amplitudes. We investigate general deformations of on-shell diagrams, and find the deformed Graßmannian integral for this theory. We furthermore introduce the algebraic R-matrix construction of deformed Yangian invariants for ABJM theory.

  18. N=4 super-Yang-Mills in LHC superspace. Part I: Classical and quantum theory

    CERN Document Server

    Chicherin, Dmitry

    2017-02-10

    We present a formulation of the maximally supersymmetric N=4 gauge theory in Lorentz harmonic chiral (LHC) superspace. It is closely related to the twistor formulation of the theory but employs the simpler notion of Lorentz harmonic variables. They parametrize a two-sphere and allow us to handle efficiently infinite towers of higher-spin auxiliary fields defined on ordinary space-time. In this approach the chiral half of N=4 supersymmetry is manifest. The other half is realized non-linearly and the algebra closes on shell. We give a straightforward derivation of the Feynman rules in coordinate space. We show that the LHC formulation of the N=4 super-Yang-Mills theory is remarkably similar to the harmonic superspace formulation of the N=2 gauge and hypermultiplet matter theories. In the twin paper \\cite{twin} we apply the LHC formalism to the study of the non-chiral multipoint correlation functions of the N=4 stress-tensor supermultiplet.

  19. N = 4 super-Yang-Mills in LHC superspace part I: classical and quantum theory

    Science.gov (United States)

    Chicherin, Dmitry; Sokatchev, Emery

    2017-02-01

    We present a formulation of the maximally supersymmetric N = 4 gauge theory in Lorentz harmonic chiral (LHC) superspace. It is closely related to the twistor formulation of the theory but employs the simpler notion of Lorentz harmonic variables. They parametrize a two-sphere and allow us to handle efficiently infinite towers of higher-spin auxiliary fields defined on ordinary space-time. In this approach the chiral half of N =4 supersymmetry is manifest. The other half is realized non-linearly and the algebra closes on shell. We give a straightforward derivation of the Feynman rules in coordinate space. We show that the LHC formulation of the N = 4 super-Yang-Mills theory is remarkably similar to the harmonic superspace formulation of the N = 2 gauge and hypermultiplet matter theories. In the twin paper arXiv:1601.06804 we apply the LHC formalism to the study of the non-chiral multipoint correlation functions of the N = 4 stress-tensor supermultiplet.

  20. N=4 super-Yang-Mills in LHC superspace. Part I: Classical and quantum theory

    CERN Document Server

    Chicherin, Dmitry

    2016-01-01

    We present a formulation of the maximally supersymmetric N=4 gauge theory in Lorentz harmonic chiral (LHC) superspace. It is closely related to the twistor formulation of the theory but employs the simpler notion of Lorentz harmonic variables. They parametrize a two-sphere and allow us to handle efficiently infinite towers of higher-spin auxiliary fields defined on ordinary space-time. In this approach the chiral half of N=4 supersymmetry is manifest. The other half is realized non-linearly and the algebra closes on shell. We give a straightforward derivation of the Feynman rules in coordinate space. We show that the LHC formulation of the N=4 super-Yang-Mills theory is remarkably similar to the harmonic superspace formulation of the N=2 gauge and hypermultiplet matter theories. In the twin paper \\cite{twin} we apply the LHC formalism to the study of the non-chiral multipoint correlation functions of the N=4 stress-tensor supermultiplet.

  1. Generalized Supersymmetries and Composite Structure in M-Theory

    CERN Document Server

    Lukierski, J

    2002-01-01

    We describe generalized D=11 Poincar\\'{e} and conformal supersymmetries. The corresponding generalization of twistor and supertwistor framework is outlined with $OSp(1|64)$ superspinors describing BPS preons. The $\\frac{k}{32}$ BPS states as composed out of $n=32 - k$ preons are introduced, and basic ideas concerning BPS preon dynamics is presented. The lecture is based on results obtained by J.A. de Azcarraga, I. Bandos, J.M. Izquierdo and the author$^1$.

  2. Generalized Supersymmetries and Composite Structure in M-Theory

    Science.gov (United States)

    Iajkierski, Jerzy

    2002-11-01

    We describe generalized D = 11 Poincaré and conformal supersymmetries. The corresponding generalization of twistor and supertwistor framework is outlined with OSp(l|64) superspinors describing BPS preons. The (k)/(32) BPS states as composed out of n = 32 - k preons are introduced, and basic ideas concerning BPS preon dynamics is presented. The lecture is based on results obtained by J.A. de Azcarraga, I. Bandos, J.M. Izquierdo and the author.

  3. Revisiting Gustave Le Bon’s crowd theory in light of present-day critique

    DEFF Research Database (Denmark)

    Laursen, Rasmus Beedholm; Møller, Verner

    2017-01-01

    In establishing a valid crowd theory, it seems to have become comme il faut to criticize French mass psychologist Gustave Le Bon’s mass theory. In this respect, football fan studies are no exception. A repeated criticism of Le Bon echoes in publications from scholars who analyse football fan...

  4. Automation of Presentation Record Production Based on Rich-Media Technology Using SNT Petri Nets Theory.

    Science.gov (United States)

    Martiník, Ivo

    2015-01-01

    Rich-media describes a broad range of digital interactive media that is increasingly used in the Internet and also in the support of education. Last year, a special pilot audiovisual lecture room was built as a part of the MERLINGO (MEdia-rich Repository of LearnING Objects) project solution. It contains all the elements of the modern lecture room determined for the implementation of presentation recordings based on the rich-media technologies and their publication online or on-demand featuring the access of all its elements in the automated mode including automatic editing. Property-preserving Petri net process algebras (PPPA) were designed for the specification and verification of the Petri net processes. PPPA does not need to verify the composition of the Petri net processes because all their algebraic operators preserve the specified set of the properties. These original PPPA are significantly generalized for the newly introduced class of the SNT Petri process and agent nets in this paper. The PLACE-SUBST and ASYNC-PROC algebraic operators are defined for this class of Petri nets and their chosen properties are proved. The SNT Petri process and agent nets theory were significantly applied at the design, verification, and implementation of the programming system ensuring the pilot audiovisual lecture room functionality.

  5. Automation of Presentation Record Production Based on Rich-Media Technology Using SNT Petri Nets Theory

    Directory of Open Access Journals (Sweden)

    Ivo Martiník

    2015-01-01

    Full Text Available Rich-media describes a broad range of digital interactive media that is increasingly used in the Internet and also in the support of education. Last year, a special pilot audiovisual lecture room was built as a part of the MERLINGO (MEdia-rich Repository of LearnING Objects project solution. It contains all the elements of the modern lecture room determined for the implementation of presentation recordings based on the rich-media technologies and their publication online or on-demand featuring the access of all its elements in the automated mode including automatic editing. Property-preserving Petri net process algebras (PPPA were designed for the specification and verification of the Petri net processes. PPPA does not need to verify the composition of the Petri net processes because all their algebraic operators preserve the specified set of the properties. These original PPPA are significantly generalized for the newly introduced class of the SNT Petri process and agent nets in this paper. The PLACE-SUBST and ASYNC-PROC algebraic operators are defined for this class of Petri nets and their chosen properties are proved. The SNT Petri process and agent nets theory were significantly applied at the design, verification, and implementation of the programming system ensuring the pilot audiovisual lecture room functionality.

  6. Automation of Presentation Record Production Based on Rich-Media Technology Using SNT Petri Nets Theory

    Science.gov (United States)

    Martiník, Ivo

    2015-01-01

    Rich-media describes a broad range of digital interactive media that is increasingly used in the Internet and also in the support of education. Last year, a special pilot audiovisual lecture room was built as a part of the MERLINGO (MEdia-rich Repository of LearnING Objects) project solution. It contains all the elements of the modern lecture room determined for the implementation of presentation recordings based on the rich-media technologies and their publication online or on-demand featuring the access of all its elements in the automated mode including automatic editing. Property-preserving Petri net process algebras (PPPA) were designed for the specification and verification of the Petri net processes. PPPA does not need to verify the composition of the Petri net processes because all their algebraic operators preserve the specified set of the properties. These original PPPA are significantly generalized for the newly introduced class of the SNT Petri process and agent nets in this paper. The PLACE-SUBST and ASYNC-PROC algebraic operators are defined for this class of Petri nets and their chosen properties are proved. The SNT Petri process and agent nets theory were significantly applied at the design, verification, and implementation of the programming system ensuring the pilot audiovisual lecture room functionality. PMID:26258164

  7. Clinical reasoning assessment through medical expertise theories: past, present and future directions.

    Science.gov (United States)

    Boushehri, Elham; Soltani Arabshahi, Kamran; Monajemi, Alireza

    2015-01-01

    Exploration into the concept of "medical expert" dates back to more than 50 years ago, yet yielding three leading theories in the area of clinical reasoning, namely, knowledge structure, hypotheticdeductive, and dual process. Each theory defines "medical expert" in a dissimilar way. Therefore, the methods of assessment through which the experts are identified have been changed during the time. In this paper, we tried to categorize and introduce some widely used tests for identification of experts within the framework of existing main theories. Implementation of the proposed categorization for providing future assessment tools is discussed.

  8. From Cicero to Cohen: developmental theories of aging, from antiquity to the present.

    Science.gov (United States)

    Agronin, Marc E

    2014-02-01

    Cicero's famous essay "On Old Age," written in ancient Rome, was one of the first detailed depictions of the challenges and opportunities posed by the aging process. Several modern developmental theories of the life cycle have echoed many of the themes of Cicero, including the existence of unfolding life stages with specific tasks and transitions. Freud's psychoanalytic theory of infantile sexuality provided a limited starting point, as well as a theoretical base for Erik Erikson's proposed eight stages of the life cycle. Unlike Freud, however, Erikson and others including Daniel Levinson, George Vaillant, and Carol Gilligan elaborated on forces in adult development that were distinct from early life experiences. Gene Cohen's theory of human potential phases took middle age as a starting point and proposed an extensive structure for late-life development based on emergent strengths including wisdom and creativity.

  9. A new and self-contained presentation of the theory of boundary operators for slit diffraction and their logarithmic approximations

    Energy Technology Data Exchange (ETDEWEB)

    Gorenflo, Norbert [Beuth Hochschule fuer Technik Berlin (Germany). Fachbereich II; Kunik, Matthias [Magdeburg Univ. (Germany). Inst. fuer Analysis und Numerik

    2009-07-01

    We present a new and self-contained theory for mapping properties of the boundary operators for slit diffraction occurring in Sommerfeld's diffraction theory, covering two different cases of the polarisation of the light. This theory is entirely developed in the context of the boundary operators with a Hankel kernel and not based on the corresponding mixed boundary value problem for the Helmholtz equation. For a logarithmic approximation of the Hankel kernel we also study the corresponding mapping properties and derive explicit solutions together with certain regularity results. (orig.)

  10. EVOLUTION OF THE CIRCULAR FLOW THEORY WITHIN XX CENTURY AND ITS PRESENT-DAY PERSPECTIVES

    Directory of Open Access Journals (Sweden)

    P. Klyukin

    2013-04-01

    Full Text Available In this article new retrospective of elaborating of the circular-flow theory from F. Quesnay (1758 up to P. Sraffa (1960 is proposed. This retrospective is based on organic integration Russian-Ukrainian pre-Revolutionary economic heritage, which has been realized in works written by M.I. Tugan-Baranovsky, V.K. Dmitriev, N.N. Shaposhnikoff, L. von Bortkiewicz, G. von Charasoff, E.E. Slutsky, A.D. Bilimoviĉ. Such an representation of the circular-flow theory interpreted as non-stop evolving thematic tradition (in spirit of post-positivist methodologist Gerald Holton makes it possi-ble to construct a new circular-flow scheme of economy.

  11. The History of Macroeconomics from Keynes’s General Theory to the Present

    OpenAIRE

    De Vroey, Michel; Malgrange, Pierre

    2011-01-01

    This paper is a contribution to the forthcoming Edward Elgar Handbook of the History of Economic Analysis volume edited by Gilbert Faccarello and Heinz Kurz. Its aim is to introduce the reader to the main episodes that have marked the course of modern macroeconomics: its emergence after the publication of Keynes’s General Theory, the heydays of Keynesian macroeconomics based on the IS-LM model, disequilibrium and non-Walrasian equilibrium modelling, the invention of the natural rate of unempl...

  12. The History of Macroeconomics from Keynes’s General Theory to thePresent

    OpenAIRE

    De Vroey, Michel; Malgrange, Pierre

    2011-01-01

    This paper is a contribution to the forthcoming Edward Elgar Handbook of the History of Economic Analysis volume edited by Gilbert Faccarello and Heinz Kurz. Its aim is to introduce the reader to the main episodes that have marked the course of modern macroeconomics: its emergence after the publication of Keynes’s General Theory, the heydays of Keynesian macroeconomics based on the IS-LM model, disequilibrium and non-Walrasian equilibrium modelling, the invention of the natural rate of unempl...

  13. The War on Women in Psychoanalytic Theory Building: Past to Present.

    Science.gov (United States)

    Balsam, Rosemary H

    2015-01-01

    Psychoanalysis has both waged "hot" war on women overtly and "cold" war covertly over the years by colluding with cultural stereotypes offered as "theory," starting with Freud and his Viennese circle. True freedom of thinking, however, broke through in Freud's originality even then, and from time to time subsequently in the history of the movement only to keep retreating. Fritz Wittels's thesis on the "Child Woman" will exemplify Horneys (1924, 1926, 1933) and Jones's (1927) grounds for engaging in the "hot war" in the 1920s and challenging the unselfconscious inbuilt denigration of women. This skirmish had little impact, however, in the New World up till the 1970s. In the aftermath of the second wave of feminism, there were (and are) bursts of new thought about sex and gender that remain fragmented and unintegrated into general acceptance. The contemporary situation has been more like a "cold" war waged by ennui in the field. A sexed and agendered theories of mind as a "no man's land" absorb an intense focus away from the sexual and gender specificities that were alive, contentious, and unresolved in Freud's libido theory. The third sociocultural wave of feminism, since the 1990s, has refocused vitality on individuality, race, and varieties of sexual identity. I identify the latter as the psychoanalytic space for a potential renewed interest in theorizing the female body within heterosexual, homosexual, queer, or transgendered individuals. The "wars" have shown how fruitless for peace and new discovery is the compulsive (but still common) close comparison between males and females developmentally. Female development is as fresh and unsettled a theoretical question as it once was with Freud.

  14. Group theory in quantum mechanics an introduction to its present usage

    CERN Document Server

    Heine, Volker

    2007-01-01

    Geared toward research students in physics and chemistry, this text introduces the three main uses of group theory in quantum mechanics: (1) to label energy levels and the corresponding eigenstates; (2) to discuss qualitatively the splitting of energy levels, starting from an approximate Hamiltonian and adding correction terms; and (3) to aid in the evaluation of matrix elements of all kinds.""The theme,"" states author Volker Heine, ""is to show how all this is achieved by considering the symmetry properties of the Hamiltonian and the way in which these symmetries are reflected in the wave fu

  15. Presentation-Practice-Production and Task-Based Learning in the Light of Second Language Learning Theories.

    Science.gov (United States)

    Ritchie, Graeme

    2003-01-01

    Features of presentation-practice-production (PPP) and task-based learning (TBL) models for language teaching are discussed with reference to language learning theories. Pre-selection of target structures, use of controlled repetition, and explicit grammar instruction in a PPP lesson are given. Suggests TBL approaches afford greater learning…

  16. Presentation-Practice-Production and Task-Based Learning in the Light of Second Language Learning Theories.

    Science.gov (United States)

    Ritchie, Graeme

    2003-01-01

    Features of presentation-practice-production (PPP) and task-based learning (TBL) models for language teaching are discussed with reference to language learning theories. Pre-selection of target structures, use of controlled repetition, and explicit grammar instruction in a PPP lesson are given. Suggests TBL approaches afford greater learning…

  17. The past, present and future of reproductive skew theory and experiments.

    Science.gov (United States)

    Nonacs, Peter; Hager, Reinmar

    2011-05-01

    A major evolutionary question is how reproductive sharing arises in cooperatively breeding species despite the inherent reproductive conflicts in social groups. Reproductive skew theory offers one potential solution: each group member gains or is allotted inclusive fitness equal to or exceeding their expectation from reproducing on their own. Unfortunately, a multitude of skew models with conflicting predictions has led to confusion in both testing and evaluating skew theory. The confusion arises partly because one set of models (the 'transactional' type) answer the ultimate evolutionary question of what ranges of reproductive skew can yield fitness-enhancing solutions for all group members. The second set of models ('compromise') give an evolutionarily proximate, game-theoretic evolutionarily stable state (ESS) solution that determines reproductive shares based on relative competitive abilities. However, several predictions arising from compromise models require a linear payoff to increased competition and do not hold with non-linear payoffs. Given that for most species it may be very difficult or impossible to determine the true relationship between effort devoted to competition and reproductive share gained, compromise models are much less predictive than previously appreciated. Almost all skew models make one quantitative prediction (e.g. realized skew must fall within ranges predicted by transactional models), and two qualitative predictions (e.g. variation in relatedness or competitive ability across groups affects skew). A thorough review of the data finds that these three predictions are relatively rarely supported. As a general rule, therefore, the evolution of cooperative breeding appears not to be dependent on the ability of group members to monitor relatedness or competitive ability in order to adjust their behaviour dynamically to gain reproductive share. Although reproductive skew theory fails to predict within-group dynamics consistently, it does

  18. Global Fits of the Electroweak Standard Theory: Past, Present and Future

    CERN Document Server

    Baak, M; Mönig, K

    2016-01-01

    The last decades have seen tremendous progress in the experimental techniques for measuring key observables of the Standard Theory (ST) as well as in theoretical calculations that has led to highly precise predictions of these observables. Global electroweak fits of the ST compare the precision measurements of electroweak observables from lepton and hadron colliders at CERN and elsewhere with accurate theoretical predictions of the ST calculated at multi-loop level. For a long time, global fits have been used to assess the validity of the ST and to constrain indirectly (by exploiting contributions from quantum loops) the remaining free ST parameters, like the masses of the top quark and Higgs boson before their direct discovery. With the discovery of the Higgs boson at the Large Hadron Collider (LHC), the electroweak sector of the ST is now complete and all fundamental ST parameters are known. Hence the global fits are a powerful tool to probe the internal consistency of the ST, to predict ST parameters with...

  19. PRESENTATIONAL TRAINING LECTURES ON NATURAL-SCIENCE DISCIPLINES: PRACTICE AND THEORY

    Directory of Open Access Journals (Sweden)

    Elena P. Bogomolova

    2014-01-01

    Full Text Available This paper discusses the feasibility of delivering streaming lectures on natural-science disciplines with computer presentations. Typical students’ comments on those are observed. There are analyzed the strengths and weaknesses of this form of delivery of lecture material for students of full-time training. 

  20. Looking forward to the present. [abiogenesis theory illuminated by lunar amino acids

    Science.gov (United States)

    Fox, S. W.

    1975-01-01

    The present understanding of the origin of life based on Oparin's (1924) conception of life as a manifestation of matter in a special stage of its development is outlined. The results of chemical analyses of lunar samples are discussed, and their implications regarding chemical reactions beginning with carbonaceous dust are considered. Amino acids isolated from lunar samples taken from different sites show a high degree of similarity, in agreement with the hypothesis that carbon compounds, including amino acid precursors, were implanted on the lunar surface by components of the solar wind. The amino acid precursors are most likely a cyanide compound. Overlapping amino acid/carbon ratios from lunar samples and samples of meteorites suggest a common cosmochemical state of carbon in the solar system.

  1. Theory and application for the promotion of wheat production in China: past, present and future.

    Science.gov (United States)

    Xu, Zhenzhu; Yu, Zhenwen; Zhao, Junye

    2013-08-15

    Food security is becoming a crucial concern worldwide. In this study, we focus on wheat - a staple crop in China - as a model to review its history, status quo and future scenarios, with regard to key production technologies and management practices for wheat production and associated food security issues since the new era in China: the post-1949 era. First, the dominant technologies and management practices over the past 60 years are reviewed. Secondly, we outline several key innovative technologies and their theoretical bases over the last decade, including (i) prohibiting excessively early senescence at a later growth stage to maintain viable leaves with higher photosynthetic capacity, (ii) postponing top dressing nitrogen application to balance carbon and nitrogen nutrition, and (iii) achieving both high yield and better grain quality mainly by increasing soil productivity and balancing the ratio of nutrient elements. Finally, concerns such as water shortages and excessive application of chemical fertilizers are presented. Nevertheless, under high negative conditions, including global warming, rapid population growth, decreasing amounts of arable land, increasing competition with cash crops and severe environmental pollution, we conclude that domestic food production will be able to meet Chinese demand in the mid to long term, because increasingly innovative technologies and improved management practices have been and may continue to be applied appropriately.

  2. Landau ghost pole problem in quantum field theory: From 50th of last century to the present day

    Science.gov (United States)

    Jafarov, Rauf G.; Mutallimov, Mutallim M.

    2016-03-01

    In this paper we present our results of the investigation of asymptotical behavior of amplitude at short distances in four-dimensional scalar field theory with ϕ4 interaction. To formulate of our calculating model - two-particle approximation of the mean-field expansion we have used an Rochev's iteration scheme of solution of the Schwinger-Dyson equations with the fermion bilocal source. We have considered the nonlinear integral equations in deep-inelastic region of momenta. As result we have a non-trivial behavior of amplitude at large momenta.

  3. Dismantling the present and future threats of testicular cancer: a grounded theory of positive and negative adjustment trajectories.

    Science.gov (United States)

    Matheson, Lauren; Boulton, Mary; Lavender, Verna; Protheroe, Andrew; Brand, Sue; Wanat, Marta; Watson, Eila

    2016-02-01

    Testicular cancer commonly affects men in the prime of their lives. While survival rates are excellent, little previous research has examined men's experiences of adjustment to survivorship. We aimed to explore this issue in younger testicular cancer survivors. In-depth qualitative interviews were conducted with testicular cancer survivors over two time points approximately 6 months apart in the year following treatment completion. Interviews were analysed using a grounded theory approach. The sample included 18 testicular cancer survivors between 22 and 44 years (mean age 34). A grounded theory was developed, which explained the process of positive adjustment over the first year following the treatment completion in terms of men's ability to dismantle the present and future threats of cancer, involving the key transitions of gaining a sense of perspective and striving to get on with life and restore normality. These were facilitated by six key processes. The processes that explained a negative adjustment trajectory are also presented. These findings contribute to the understanding of the psychosocial impact of testicular cancer on younger men's lives and have implications for the provision of support to testicular cancer survivors. Further investigation into the feasibility of one-on-one peer support interventions is warranted, as well as informal support that respects men's desire for independence. Understanding the processes involved in adjustment highlights ways in which health professionals can offer support to those struggling to adjust through challenging illness beliefs, encouraging emotional disclosure and facilitating peer mentoring.

  4. Applications Of Nonclassical Geometry To String Theory

    CERN Document Server

    Zunger, Y

    2003-01-01

    String theory is built on a foundation of geometry. This thesis examines several applications of geometry beyond the classical Riemannian geometry of curved surfaces. The first part considers the use of extended spaces with internal dimensions to each point (“twistors”) to probe systems with a great deal of symmetry but complicated dynamics. These systems are of critical interest in understanding holographic phenomena in string theory and the origins of entropy. We develop a twistor formulation of coset spaces and use this to write simplified actions for particles and strings on anti-de Sitter space, which are easier to quantize than the ordinary (highly nonlinear) actions. In the second part, we consider two aspects of noncommutative geometry, a generalization of ordinary geometry where points are “fuzzed out” and functions of space become noncommuting operators. We first examine strings with one endpoint on a D-brane in a background magnetic field. (Strings with both ...

  5. Present state, basic theories, methods and progresses of investigation and assessment on marine hazardous geology in China

    Institute of Scientific and Technical Information of China (English)

    Li Peiying; Li Ping; Liu Lejun; Du Jun; Zhang Xiaolong; Wang Shengji

    2003-01-01

    The achievement progresses of investigation and studies on marine hazardous geology are summarized and presentsd in the late 20 century in China. The importance, research value and presentday studies of marine hazardous geology, a newly developing branch of geoscience, are well expatiated.Several often confused concepts and theories are explained and redefined here. The comment on the means of investigations, assessment of marine hazardous geology, as well as its evolution, innovation,existing questions and future tasks are also introduced and presented. The concepts of "hazard geology","geohazard", "map of marine hazard geology", "integrated evaluaton on seafloor stablity" are respectively discussed, including their definition, research objects, methods and contents. The types and classification of marine hazardous geology, principles and methods of marine hazardous geology map compilation, the assessment methods and models of marine hazardous geology environment and seafloor stability and so on are also discussed.

  6. The Presentation of an Optimal Transferring Message Model to Reducing Energy Consumption in Wireless Sensor Networks by Games Theory

    Directory of Open Access Journals (Sweden)

    Abdolreza Mohammadzadeh

    2016-06-01

    Full Text Available Wireless Sensor Networks (WSNs because of their limitation in energy consumption in their nodes, high rate of energy consumption and inability interchangeable battery, are always in danger of extiction. The highest energy consumption in these networks is done when communicating of the nodes with the base station (BS and sending infirmation, which itsreason is the limitation of BS in receiving and saving the incoming message. Now, if we will be able to increase the lifespan of these networks. So, a lot of algorithms and modelshas been suggested to reduce the energy consumption of WSNs. In this study, we have tried to present a new model in order to nodes cooperation in communicating with the BS and also reducing the number of messages by using games theory and exclusively enter market game (EMG.

  7. The Coulomb Branch of 3d N= 4 Theories

    Science.gov (United States)

    Bullimore, Mathew; Dimofte, Tudor; Gaiotto, Davide

    2017-09-01

    We propose a construction for the quantum-corrected Coulomb branch of a general 3d gauge theory with N=4 supersymmetry, in terms of local coordinates associated with an abelianized theory. In a fixed complex structure, the holomorphic functions on the Coulomb branch are given by expectation values of chiral monopole operators. We construct the chiral ring of such operators, using equivariant integration over BPS moduli spaces. We also quantize the chiral ring, which corresponds to placing the 3d theory in a 2d Omega background. Then, by unifying all complex structures in a twistor space, we encode the full hyperkähler metric on the Coulomb branch. We verify our proposals in a multitude of examples, including SQCD and linear quiver gauge theories, whose Coulomb branches have alternative descriptions as solutions to Bogomolnyi and/or Nahm equations.

  8. EDITORIAL: Special issue containing papers presented at the 4th IAEA Technical Meeting on the Theory of Plasma Instabilities Special issue containing papers presented at the 4th IAEA Technical Meeting on the Theory of Plasma Instabilities

    Science.gov (United States)

    Itoh, K.; Wilson, H. R.

    2010-05-01

    The 4th IAEA technical meeting (TM) on the Theory of Plasma Instabilities was held in Kyoto, May 18th--20th 2009, following the first (Seeon), second (Trieste) and third (York) meetings in this series. This IAEA-TM was motivated by the recent advances in theoretical methodology, the rapid progress in observations of laboratory and astrophysical plasmas and the evolution of fusion research as we approach the ITER era. The international advisory committee (IAC) and local organizing committee (LOC), the members of which are listed below, collaborated to define the scope and the content of the scientific programme. Young scientists were actively encouraged to participate in this TM to help stimulate their future research careers and raise their international profiles. Through these young scientists, the IAEA-TM planned to identify the future directions of research. About 90 researchers, from 13 countries and the IAEA, participated in this IAEA-TM, with 72 scientific presentations. The talks and posters generated enthusiastic discussions, contributing to the vibrancy of the meeting. This special issue of Nuclear Fusion consists of a cluster of papers, reporting some of the main contributions to the IAEA-TM. The articles in this cluster are representative of the scientific width of presentations at the meeting, spanning topics from micro-turbulence to large-scale MHD dynamics and from transport to detailed analysis of diagnostics. They demonstrate the quality and depth of the research presented at the conference. List of IAC (alphabetical order): B. Breizman (USA), S. Guenter (Germany), T. S. Hahm (USA), K. Itoh (Japan, Chair of 2009), Ya. I. Kolesnichenko (Ukraine), A. G. Peeters (UK), H. Wilson (UK) List of LOC (alphabetical order): A. Fukuyama, R. Horiuchi, S.-I. Itoh, N. Kasuya, Y. Kishimoto (co-chair), K. Kusano, J. Li, K. Mima, S. Murakami, H. Naitou, N. Nakajima, Y. Nakamura, H. Ohtani, S. Okamura, T. Ozeki, S. Sudo (co-chair), H. Sugama, Y. Todo, S. Tokuda, S

  9. Skew-symmetric complex matrices, pure spinors, the twistor space of the conformal $2n$-sphere, and the Fano variety of linear $n$-folds of a non-singular complex quadric hypersurface in $\\mathbb{P}^{2n+1}$

    CERN Document Server

    Puente, Elsa

    2011-01-01

    For $n \\geq 1$, the twistor space $\\mathfrak{Z}(\\mathbb{S}^{2n})$ of the conformal $2n$-sphere is biholomorphic to the Zariski closure, taken in the complex Grassmannian manifold $\\mathbf{G}(n+1, 2n+2)$, of the set of graphs of skew-symmetric linear endomorphism of $\\mathbb{C}^{n+1}$. We use this fact to describe a natural stratification of the twistor space $\\mathfrak{Z}(\\mathbb{S}^{2n})$ with $n \\geq 3$, in terms of what we have called {\\it generalised complex orthogonal Stiefel manifolds} of $\\mathbb{C}^{n+1}$. In particular, the twistor space $\\mathfrak{Z}(\\mathbb{S}^{6})$ is biholomorphic to a non-singular complex quadric hypersurface in $\\mathbb{P}^{7}$. We explicitly construct a real-analytic foliation, by linear 3-folds, of this quadric hypersurface such that the quotient space is isomorphic to the 6-sphere with its standard metric. This foliation is Riemannian with respect to the Fubini-Study metric and isometrically equivalent to the twistor fibration over the 6-sphere.

  10. Development of a Generalized Version of the Poisson-Nernst-Planck Equations Using the Hybrid Mixture Theory: Presentation of 2D Numerical Examples

    DEFF Research Database (Denmark)

    Johannesson, Björn

    2010-01-01

    A numerical scheme for the transient solution of generalized version of the Poisson-Nernst-Planck equations is presented. The finite element method is used to establish the coupled non-linear matrix system of equations capable of solving the present problem iteratively. The Poisson-Nernst-Planck ......A numerical scheme for the transient solution of generalized version of the Poisson-Nernst-Planck equations is presented. The finite element method is used to establish the coupled non-linear matrix system of equations capable of solving the present problem iteratively. The Poisson......, however, coupled in both directions. The governed set of equations is derived from a simplified version of the so-called hybrid mixture theory (HMT). This theory is a special version of the more ‘classical’ continuum mixture theories in the sense that it works with averaged equations at macro...

  11. Focusing on Presentation Instead of Representation: Perspectives on Representational and Non-Representational Language-Games for Educational History and Theory

    Science.gov (United States)

    Fendler, Lynn; Smeyers, Paul

    2015-01-01

    Debates in science seem to depend on referential language-games, but in other senses they do not. This article addresses non-representational theory. It is a branch of newer approaches to cultural geography that strive to get a handle on spatial relationships not by representing them, but rather by presenting them. In this case, present connotes…

  12. Focusing on Presentation Instead of Representation: Perspectives on Representational and Non-Representational Language-Games for Educational History and Theory

    Science.gov (United States)

    Fendler, Lynn; Smeyers, Paul

    2015-01-01

    Debates in science seem to depend on referential language-games, but in other senses they do not. This article addresses non-representational theory. It is a branch of newer approaches to cultural geography that strive to get a handle on spatial relationships not by representing them, but rather by presenting them. In this case, present connotes…

  13. Problem of the Landau Poles in Quantum Field Theory: from N. N. Bogolyubov to the Present Day

    Science.gov (United States)

    Jafarov, R. G.; Agham-Alieva, L. A.; Agha-Kishieva, P. É.; Rahim-zade, S. G.; Mamedova, S. N.; Mutallimov, M. M.

    2017-03-01

    A review of problems associated with the unphysical Landau pole in propagators of quantum particles is given. Approaches to eliminating this pole within the framework of electrodynamics and effective theories of strongly interacting particles are investigated. The asymptotic behavior at large momenta in the scalar theory ϕ4 in the two-particle (bubble) approximation is investigated. To formulate a calculational model in the two-particle approximation, we use an iterative scheme for solving the Schwinger-Dyson equation in the formalism of a bilocal field source. The main problem is to develop a recipe for numerical analysis of the solutions of the obtained nonlinear equation for the amplitude at small interaction distances (large values of the momentum) for different values of the constant. The nontrivial behavior of the amplitude in the deeply inelastic region of momenta is determined. The positions of the unphysical poles (the Landau poles) in the expression for the amplitude in the deeply inelastic region of momenta are identified.

  14. Combining density functional theory calculations, supercomputing, and data-driven methods to design new materials (Conference Presentation)

    Science.gov (United States)

    Jain, Anubhav

    2017-04-01

    Density functional theory (DFT) simulations solve for the electronic structure of materials starting from the Schrödinger equation. Many case studies have now demonstrated that researchers can often use DFT to design new compounds in the computer (e.g., for batteries, catalysts, and hydrogen storage) before synthesis and characterization in the lab. In this talk, I will focus on how DFT calculations can be executed on large supercomputing resources in order to generate very large data sets on new materials for functional applications. First, I will briefly describe the Materials Project, an effort at LBNL that has virtually characterized over 60,000 materials using DFT and has shared the results with over 17,000 registered users. Next, I will talk about how such data can help discover new materials, describing how preliminary computational screening led to the identification and confirmation of a new family of bulk AMX2 thermoelectric compounds with measured zT reaching 0.8. I will outline future plans for how such data-driven methods can be used to better understand the factors that control thermoelectric behavior, e.g., for the rational design of electronic band structures, in ways that are different from conventional approaches.

  15. Theory of Transformation Groups, by S. Lie and F. Engel (Vol. I, 1888). Modern Presentation and English Translation

    CERN Document Server

    Merker, Joel

    2010-01-01

    The goal of this modern presentation, followed by an English translation from the German, is to make available some parts of Lie's very systematic mathematical thought which deserve to join the contemporary literature, and above all also, to be read.

  16. Vocal reaction times to unilaterally presented concrete and abstract words: towards a theory of differential right hemispheric semantic processing.

    Science.gov (United States)

    Rastatter, M; Dell, C W; McGuire, R A; Loren, C

    1987-03-01

    Previous studies investigating hemispheric organization for processing concrete and abstract nouns have provided conflicting results. Using manual reaction time tasks some studies have shown that the right hemisphere is capable of analyzing concrete words but not abstract. Others, however, have inferred that the left hemisphere is the sole analyzer of both types of lexicon. The present study tested these issues further by measuring vocal reaction times of normal subjects to unilaterally presented concrete and abstract items. Results were consistent with a model of functional localization which suggests that the minor hemisphere is capable of differentially processing both types of lexicon in the presence of a dominant left hemisphere.

  17. Topological M-theory as Unification of Form Theories of Gravity

    CERN Document Server

    Dijkgraaf, R; Neitzke, A; Vafa, C; Dijkgraaf, Robbert; Gukov, Sergei; Neitzke, Andrew; Vafa, Cumrun

    2004-01-01

    We introduce a notion of topological M-theory and argue that it provides a unification of form theories of gravity in various dimensions. Its classical solutions involve G_2 holonomy metrics on 7-manifolds, obtained from a topological action for a 3-form gauge field introduced by Hitchin. We show that by reductions of this 7-dimensional theory one can classically obtain 6-dimensional topological A and B models, the topological sector of loop quantum gravity in 4 dimensions, and Chern-Simons gravity in 3 dimensions. We also find that the 7-dimensional M-theory perspective sheds some light on the fact that the topological string partition function is a wavefunction, as well as on S-duality between the A and B models. The degrees of freedom of the A and B models appear as conjugate variables in the 7-dimensional theory. Finally, from the topological M-theory perspective we find hints of an intriguing holographic link between non-supersymmetric Yang-Mills in 4 dimensions and A model topological strings on twistor...

  18. Polar Volatiles on Mars--Theory versus Observation: Excess solid carbon dioxide is probably present in the north residual cap.

    Science.gov (United States)

    Murray, B C; Malin, M C

    1973-11-02

    The residual frost caps of Mars are probably water-ice. They may be the source of the water vapor associated with seasonal polar hoods. A permanent reservoir of solid CO(2) is also probably present within the north residual cap and may comprise a mass of CO(2) some two to five times that of the present atmosphere of Mars. The martian atmospheric pressure is probably regulated by the temperature of the reservoir and not by the annual heat balance of exposed solid CO(2) (37). The present reservoir temperature presumably reflects a long-term average of the polar heat balance. The question of a large permanent north polar cap is reexamined in light of the Mariner 9 data. The lower general elevation of the north polar region compared to the south and the resulting occurrence in the north of a permanent CO(2) deposit are probably responsible for the differences in size and shape of the two residual caps. The details of the processes involved are less apparent, however. It might be argued that the stability of water-ice deposits depends on both insolation and altitude. The present north and south residual caps should be symmetrically located with respect to such a hypothetical stability field. However, the offset of the south cap from the geometrical pole, the non-symmetrical outline of the north cap, and the apparently uniform thickness of the thin, widespread water-ice all argue against control by simple solid-vapor equilibrium of water under present environmental conditions. We think that the present location of the water-ice may reflect, in part, the past location of the permanent CO(2) reservoir. The extreme stability of polar water-ice deposits increases the likelihood that past environmental conditions may be recorded there. Detailed information on elevations in the vicinity of the residual caps is needed before we can further elucidate the nature and history of the residual caps. This, along with measurements of polar infrared emission, should be given high

  19. A Self-determination Theory Approach to the Study of Body Image Concerns, Self-presentation and Self-perceptions in a Sample of Aerobic Instructors

    OpenAIRE

    Thøgersen-Ntoumani, Cecilie; Ntoumanis, Nikos

    2007-01-01

    This study examined motivational predictors of body image concerns, self-presentation and self-perceptions using Self-determination Theory as a guiding framework. Aerobic instructors (N = 149) completed questionnaires measuring general need satisfaction, exercise motivational regulations, body image concerns, social physique anxiety and self-perceptions. Introjected regulation predicted all outcome variables in the expected direction. Intrinsic motivation positively predicted physical self-wo...

  20. D-instantons and twistors

    NARCIS (Netherlands)

    Alexandrov, S.; Pioline, B.; Saueressig, F.; Vandoren, S.J.G.

    2009-01-01

    Finding the exact, quantum corrected metric on the hypermultiplet moduli space in Type II string compactifications on Calabi-Yau threefolds is an outstanding open problem. We address this issue by relating the quaternionic-Kähler metric on the hypermultiplet moduli space to the complex contact geome

  1. TV programme presentations: Bang Goes the Theory by BBC (2010) and Beyond the Atom with John Ellis by Redes and Science Networks (2010)

    CERN Multimedia

    Carolyn Lee

    2011-01-01

    BBC’s Bang Goes the Theory explores various aspects of science. In this episode, presenter Dallas Campbell travels to CERN to meet physicist Tara Shears and learn more about antimatter. Other topics include breath-holding techniques such as free diving, and what exactly is horsepower and how is it measured? In addition, Redes and Science Networks have produced "Beyond the Atom with John Ellis", a TV programme presented by Eduard Punset and featuring CERN theorist John Ellis. The aim of this programme is to understand more about what matter is and what the physicists working on the LHC experiments hope to discover, including the Higgs boson, dark matter and supersymmetry. This programme is in English and Spanish with English subtitles. Bang Goes the Theory will be presented on Friday 11 March from 13:00 to 13:30 Language: English Beyond the Atom with John Ellis will be presented on Friday 11 March from 13:30 to 14:00 Language: English and Spanish with English subtitles Both will be...

  2. One-Loop Gauge Theory Amplitudes in N=4 Super Yang-Mills from MHV Vertices

    CERN Document Server

    Brandhuber, A; Travaglini, G; Brandhuber, Andreas; Spence, Bill; Travaglini, Gabriele

    2004-01-01

    We propose a new, twistor string theory inspired formalism to calculate loop amplitudes in N=4 super Yang-Mills theory. In this approach, maximal helicity violating (MHV) tree amplitudes of N=4 super Yang-Mills are used as vertices, using an off-shell prescription introduced by Cachazo, Svrcek and Witten, and combined into effective diagrams that incorporate large numbers of conventional Feynman diagrams. As an example, we apply this formalism to the particular class of MHV one-loop scattering amplitudes with an arbitrary number of external legs in N=4 super Yang-Mills. Remarkably, our approach naturally leads to a representation of the amplitudes as dispersion integrals, which we evaluate exactly. Our results for the MHV amplitudes are in precise agreement with the expressions for this class of amplitudes obtained previously by Bern, Dixon, Dunbar and Kosower using the cut-constructibility approach.

  3. The Present State and Problems of the Theory of the Kinetics of Electrode Reactions Accompanied by the Adsorption of Inactive Substances and Reagents

    Science.gov (United States)

    Krylov, V. S.; Damaskin, B. B.; Kir'yanov, V. A.

    1986-08-01

    Problems in the theoretical description of the influence of the adsorption of dissolved species on the rates of electrode processes have been discussed. Present-day theories of the mechanism of the interaction between adsorbed species and ionic reagents have been used to develop a general statistical-mechanical approach to the quantitative examination of the macrokinetics of heterogeneous transformations complicated by the adsorption of ionic or dipolar components of the solution, including the adsorption of the reagents themselves. The bibliography contains 84 references.

  4. Present time

    CERN Document Server

    Romero, Gustavo E

    2014-01-01

    The idea of a moving present or `now' seems to form part of our most basic beliefs about reality. Such a present, however, is not reflected in any of our theories of the physical world. I show in this article that presentism, the doctrine that only what is present exists, is in conflict with modern relativistic cosmology and recent advances in neurosciences. I argue for a tenseless view of time, where what we call `the present' is just an emergent secondary quality arising from the interaction of perceiving self-conscious individuals with their environment. I maintain that there is no flow of time, but just an ordered system of events.

  5. A Self-determination Theory approach to the study of body image concerns, self-presentation and self-perceptions in a sample of aerobic instructors.

    Science.gov (United States)

    Thøgersen-Ntoumani, Cecilie; Ntoumanis, Nikos

    2007-03-01

    This study examined motivational predictors of body image concerns, self-presentation and self-perceptions using Self-determination Theory as a guiding framework. Aerobic instructors (N = 149) completed questionnaires measuring general need satisfaction, exercise motivational regulations, body image concerns, social physique anxiety and self-perceptions. Introjected regulation predicted all outcome variables in the expected direction. Intrinsic motivation positively predicted physical self-worth. Further, autonomy need satisfaction negatively predicted body image concerns. Finally, differences existed in need satisfaction, introjected regulation, self-perceptions and social physique anxiety between those at risk of developing eating disorders and those not at risk. The results underline the importance of overall and exercise-specific feelings of self-determination in dealing with body image concerns and low self-perceptions of aerobics instructors.

  6. CERN Library | Cecilia Jarlskog presents "Portrait of Gunnar Källén: a physics shooting star and poet of early quantum field theory" | 16 September

    CERN Multimedia

    2014-01-01

    Wolfgang Pauli referred to him as 'my discovery', Robert Oppenheimer described him as 'one of the most gifted theorists' and Niels Bohr found him enormously stimulating. Who was the man in question, Gunnar Källén (1926-1968)?   His appearance in the physics sky was like a shooting star. His contributions to the scientific debate caused excitement among young and old. Similar to his friend and mentor, Wolfgang Pauli, he demanded honesty and rigour in physics - a distinct dividing line between fact and speculation. In his obituary, Arthur S. Wightman would write: "Gunnar Källén was a proud continuer of the tradition in quantum field theory established by Wolfgang Pauli. His papers on quantum electrodynamics in the period 1950-1954 carried the non-perturbative approach to quantum electrodynamics forward to a point beyond which very little essential progress has been made up to the present day. At the time I was trying ...

  7. The Milankovitch theory and climate sensitivity. I - Equilibrium climate model solutions for the present surface conditions. II - Interaction between the Northern Hemisphere ice sheets and the climate system

    Science.gov (United States)

    Neeman, Binyamin U.; Ohring, George; Joseph, Joachim H.

    1988-01-01

    A seasonal climate model was developed to test the climate sensitivity and, in particular, the Milankovitch (1941) theory. Four climate model versions were implemented to investigate the range of uncertainty in the parameterizations of three basic feedback mechanisms: the ice albedo-temperature, the outgoing long-wave radiation-temperature, and the eddy transport-meridional temperature gradient. It was found that the differences between the simulation of the present climate by the four versions were generally small, especially for annually averaged results. The climate model was also used to study the effect of growing/shrinking of a continental ice sheet, bedrock sinking/uplifting, and sea level changes on the climate system, taking also into account the feedback effects on the climate of the building of the ice caps.

  8. Z Theory

    OpenAIRE

    Nekrasov, Nikita

    2004-01-01

    We present the evidence for the existence of the topological string analogue of M-theory, which we call Z-theory. The corners of Z-theory moduli space correspond to the Donaldson-Thomas theory, Kodaira-Spencer theory, Gromov-Witten theory, and Donaldson-Witten theory. We discuss the relations of Z-theory with Hitchin's gravities in six and seven dimensions, and make our own proposal, involving spinor generalization of Chern-Simons theory of three-forms. Based on the talk at Strings'04 in Paris.

  9. Thinking and research on self present theory%对自我呈现理论的思考和研究

    Institute of Scientific and Technical Information of China (English)

    郭晓蓓; 张晨轩

    2015-01-01

    自我呈现理论最早是由美国著名的社会学家戈夫曼提出,指的是藉由调整自己的行为给他人创造某个特殊印象的过程。在日常生活中,自我呈现也是一个常见的现象,个人良好的自我呈现不但有利于自身得到更好的发展,也有利于构建和谐社会伟大目标的实现。本文着重探讨了自我呈现的内涵和机制,动机和过程以及常见策略等,以期为个人实现良性的自我呈现提供一些参考和建议。%The present theory was first put forward by American famous sociologist Goffman, by adjusting their behavior refers to the process of creating a particular impression to others. In daily life, render itself is also a common phenomenon, personal good render themselves not only promotes the development of their own better, and conducive to the realization of great goal to build a harmonious society. This paper discusses the self presents the connotation and mechanism of motivation and process and common strategy, etc., so as to provide some references for individuals to realize benign self present and Suggestions.

  10. String theory

    OpenAIRE

    Marino Beiras, Marcos

    2001-01-01

    We give an overview of the relations between matrix models and string theory, focusing on topological string theory and the Dijkgraaf--Vafa correspondence. We discuss applications of this correspondence and its generalizations to supersymmetric gauge theory, enumerative geometry and mirror symmetry. We also present a brief overview of matrix quantum mechanical models in superstring theory.

  11. Game Theory

    DEFF Research Database (Denmark)

    Game Theory is a collection of short interviews based on 5 questions presented to some of the most influential and prominent scholars in game theory. We hear their views on game theory, its aim, scope, use, the future direction of game theory and how their work fits in these respects....

  12. Jorge A. Swieca's contributions to quantum field theory in the 60s and 70s and their relevance in present research

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Freie Universitaet, Berlin (Germany). Inst. fuer Theoretische Physik

    2010-02-15

    After revisiting some high points of particle physics and QFT of the two decades from 1960 to 1980, I comment on the work by Jorge Andre Swieca. I explain how it fits into the quantum field theory during these two decades and draw attention to its relevance to the ongoing particle physics research. A particular aim of this article is to draw attention to the relevance of what at the time of Swieca was called 'the Schwinger Higgs screening mechanism'. which, together with recent ideas which generalize the concept of gauge theories, have all the ingredients to revolutionize the issue of gauge theories and the standard model. (author)

  13. Grassmannians for scattering amplitudes in 4d $\\mathcal{N}=4$ SYM and 3d ABJM

    CERN Document Server

    Elvang, Henriette; Keeler, Cynthia; Lam, Thomas; Olson, Timothy M; Roland, Samuel B; Speyer, David E

    2014-01-01

    Scattering amplitudes in 4d $\\mathcal{N}=4$ super Yang-Mills theory (SYM) can be described by Grassmannian contour integrals whose form depends on whether the external data is encoded in momentum space, twistor space, or momentum twistor space. After a pedagogical review, we present a new, streamlined proof of the equivalence of the three integral formulations. A similar strategy allows us to derive a new Grassmannian integral for 3d $\\mathcal{N}=6$ ABJM theory amplitudes in momentum twistor space: it is a contour integral in an orthogonal Grassmannian with the novel property that the internal metric depends on the external data. The result can be viewed as a central step towards developing an amplituhedron formulation for ABJM amplitudes. Various properties of Grassmannian integrals are examined, including boundary properties, pole structure, and a homological interpretation of the global residue theorems for $\\mathcal{N}=4$ SYM.

  14. A note on dual MHV diagrams in mathcal{N} = 4 SYM

    Science.gov (United States)

    Brandhuber, Andreas; Spence, Bill; Travaglini, Gabriele; Yang, Gang

    2010-12-01

    Recently a reformulation of the MHV diagram method in mathcal{N} = 4 supersymmetric Yang-Mills theory in momentum twistor space was presented and was shown to be equivalent to the perturbative expansion of the expectation value of a supersymmetric Wilson loop in momentum twistor space. In this note we present related explicit Feynman rules in dual momentum space, which should have the interpretation of Wilson loop diagrams in dual momentum space. We show that these novel rules are completely equivalent to ordinary spacetime MHV rules and can be naturally viewed as their graph dual representation.

  15. A Note on Dual MHV Diagrams in N=4 SYM

    CERN Document Server

    Brandhuber, Andreas; Travaglini, Gabriele; Yang, Gang

    2010-01-01

    Recently a reformulation of the MHV diagram method in N=4 supersymmetric Yang-Mills theory in momentum twistor space was presented and was shown to be equivalent to the perturbative expansion of the expectation value of a supersymmetric Wilson loop in momentum twistor space. In this note we present related explicit Feynman rules in dual momentum space, which should have the interpretation of Wilson loop diagrams in dual momentum space. We show that these novel rules are completely equivalent to ordinary spacetime MHV rules and can be naturally viewed as their graph dual representation.

  16. Packaging Theory.

    Science.gov (United States)

    Williams, Jeffrey

    1994-01-01

    Considers the recent flood of anthologies of literary criticism and theory as exemplifications of the confluence of pedagogical concerns, economics of publishing, and other historical factors. Looks specifically at how these anthologies present theory. Cites problems with their formatting theory and proposes alternative ways of organizing theory…

  17. Evolution of the neuromatrix theory of pain. The Prithvi Raj Lecture: presented at the third World Congress of World Institute of Pain, Barcelona 2004.

    Science.gov (United States)

    Melzack, Ronald

    2005-06-01

    The neuromatrix theory of pain proposes that pain is a multidimensional experience produced by characteristic "neurosignature" patterns of nerve impulses generated by a widely distributed neural network-the "body-self neuromatrix"-in the brain. These neurosignature patterns may be triggered by sensory inputs, but they may also be generated independently of them. Acute pains evoked by brief noxious inputs have been meticulously investigated by neuroscientists, and their sensory transmission mechanisms are generally well understood. In contrast, chronic pain syndromes, which are often characterized by severe pain associated with little or no discernable injury or pathology, remain a mystery. Furthermore, chronic psychological or physical stress is often associated with chronic pain, but the relationship is poorly understood. The neuromatrix theory of pain provides a new conceptual framework to examine these problems. It proposes that the output patterns of the body-self neuromatrix activate perceptual, homeostatic, and behavioral programs after injury, pathology, or chronic stress. Pain, then, is produced by the output of a widely distributed neural network in the brain rather than directly by sensory input evoked by injury, inflammation, or other pathology. The neuromatrix, which is genetically determined and modified by sensory experience, is the primary mechanism that generates the neural pattern that produces pain. Its output pattern is determined by multiple influences, of which the somatic sensory input is only a part, that converge on the neuromatrix.

  18. Practice and Problems in Language Testing 5. Non-Classical Test Theory; Final Examinations in Secondary Schools. Papers Presented at the International Language Testing Symposium (5th, Arnhem, Netherlands, March 25-26, 1982).

    Science.gov (United States)

    van Weeren, J., Ed.

    Presented in this symposium reader are nine papers, four of which deal with the theory and impact of the Rasch model on language testing and five of which discuss final examinations in secondary schools in both general and specific terms. The papers are: "Introduction to Rasch Measurement: Some Implications for Language Testing" (J. J.…

  19. 社会关系网络分析基础理论:现状与展望%Social Network Analysis Basic Theory:Present and Future

    Institute of Scientific and Technical Information of China (English)

    邓小龙; 李欲晓; 曾洁

    2016-01-01

    With very fast developing speed of online social network users and their influence to our daily life, it is urgent for researchers to explore the essential scientific problem, investigate the disciplinary issues and common laws of social network, study the fundamental theory and basic approach to qualitatively or quantitatively researching on social network.And in recent years, researchers always focus on three components of relation structure, network group and network information to explore the essence of social network.To dealing the three essential components above, this paper analyzes and summary the related work of six aspects of social network such as basic concept, classification, components, statistical indicators, community detection algo-rithm in social network.It also looks ahead to the development trends of social network such as structure statistic analysis of new generation in social network, information semantic recognition and sentiment judgment in multilingual and complex sentiments en-vironment, psychological interaction disciplines in information spreading process and so on.%针对关系结构、网络群体、网络信息这3个社会关系网络核心点,总结了社会关系网络的基本概念、分类、组成要素、社会关系网络分析的统计特性指标、社团结构划分算法等5个方面的主要问题和研究现状,并对未来与公共安全紧密相关的社会关系网络上的结构特性判别、多语言复杂情感环境下社会关系网络中信息语义和倾向性判别,以及社会关系网络信息传播过程中心理互动规律等方面的发展趋势进行了展望.

  20. Band-offsets at BaTiO3/Cu2O heterojunction and enhanced photoelectrochemical response: theory and experiment(Conference Presentation)

    Science.gov (United States)

    Sharma, Dipika; Satsangi, Vibha R.; Dass Kaura, Sahab; Shrivastav, Rohit; Waghmare, Umesh V.

    2016-10-01

    Band-offsets at BaTiO3/Cu2O heterojunction and enhanced photoelectrochemical response: theory and experiment Dipika Sharmaa, Vibha R. Satsangib, Rohit Shrivastava, Umesh V. Waghmarec, Sahab Dassa aDepartment of Chemistry, Dayalbagh Educational Institute, Agra-282 110 (India) bDepartment of Physics and Computer Sciences, Dayalbagh Educational Institute, Agra-282 110 (India) cTheoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560 064 (India) * Phone: +91-9219695960. Fax: +91-562-2801226. E-mail: drsahabdas@gmail.com. Study on photoelectrochemical activity of pristine BaTiO3, Cu2O and BaTiO3/Cu2O heterojunction has been carried out using DFT based band offsets and charge carriers effective mass calculations and their experimental verification. The results of DFT calculations show that BaTiO3 and Cu2O have staggered type band alignment after the heterojunction formation and high mobility of electrons in Cu2O as compared to the electrons in BaTiO3. Staggered type band edges alignment and high mobility of electrons and holes improved the separation of photo-generated charge carriers in BaTiO3/Cu2O heterojunction. To validate the theoretical results experiments were carried out on pristine BaTiO3, Cu2O and BaTiO3/Cu2O heterojunction with varying thickness of Cu2O. All samples were characterized by X- Ray Diffractometer, SEM and UV-Vis spectrometry. Nanostructured thin films of pristine BaTiO3, Cu2O and BaTiO3/Cu2O heterojunction were used as photoelectrode in the photoelectrochemical cell for water splitting reaction. Maximum photocurrent density of 1.44 mA/cm2 at 0.90 V/SCE was exhibited by 442 nm thick BaTiO3/Cu2O heterojunction photoelectrode Increased photocurrent density and enhanced photoconversion efficiency, exhibited by the heterojunction may be attributed to improved conductivity and enhanced separation of the photogenerated carriers at the BaTiO3/Cu2O interface. The experimental results and first

  1. 浅议社会表象理论(Social RePresentation Theory)在旅游学研究中的应用%Several Issues on the Application of Social Representation Theory in Tourism Research

    Institute of Scientific and Technical Information of China (English)

    应天煜

    2004-01-01

    旅游作为一门跨多个学科领域的应用科学,其学科发展往往会涉及社会学、心理学、人类学、地理学等各相关学科的研究成果.而目前旅游学研究中具体实证研究有余而基础理论工作相对不足的局面已经阻碍了旅游学作为一个学科体系的确立、完善和向前发展.本文试对社会心理学中新兴的"社会表象理论"(Social Representation Theory)以及近年来国外学术界将该理论引入旅游学研究的基本情况作一个简单的介绍,以期能够为国内旅游学界的相关研究工作起到一点参考作用.

  2. Viability Theory

    CERN Document Server

    Aubin, Jean-Pierre; Saint-Pierre, Patrick

    2011-01-01

    Viability theory designs and develops mathematical and algorithmic methods for investigating the adaptation to viability constraints of evolutions governed by complex systems under uncertainty that are found in many domains involving living beings, from biological evolution to economics, from environmental sciences to financial markets, from control theory and robotics to cognitive sciences. It involves interdisciplinary investigations spanning fields that have traditionally developed in isolation. The purpose of this book is to present an initiation to applications of viability theory, explai

  3. Indications from space geodesy, gravimetry and seismology for slow Earth expansion at present - comment on "The Earth expansion theory and its transition from scientific hypothesis to pseudoscientific belief" by Sudiro (2014)

    Science.gov (United States)

    Edwards, Matthew R.

    2016-12-01

    In a recent article in this journal, Paolo Sudiro (2014) considered the long history of the expanding Earth theory and its recent descent into what he termed "pseudoscientific belief". The expanding Earth theory contends that the radius of the Earth was once one-half to two-thirds of its current value, with the Earth's continents forming a continuous sialic cover over the Earth. The theory has had two main variants: slow expansion at about 0.5 mm yr-1 radial increase since the time of Earth's formation and fast expansion at about 5 mm yr-1 since the Triassic. Focusing on Maxlow's model, Sudiro thoroughly addresses the possibly insurmountable difficulties of the fast version, such as an improbably high density and surface gravity prior to 200 Ma. He omits, however, any discussion of the slow expansion model, which has a longer history and far fewer theoretical difficulties. Moreover, recent evidence from space geodesy, gravimetry and seismology indicates that the Earth at present may be slowly expanding at 0.1-0.4 mm yr-1. It is concluded that Sudiro's obituary of the expanding Earth theory as a whole must be considered premature at this time.

  4. Shielding Theory

    Directory of Open Access Journals (Sweden)

    Ion N.Chiuta

    2009-05-01

    Full Text Available The paper determines relations for shieldingeffectiveness relative to several variables, includingmetal type, metal properties, thickness, distance,frequency, etc. It starts by presenting some relationshipsregarding magnetic, electric and electromagnetic fieldsas a pertinent background to understanding and applyingfield theory. Since literature about electromagneticcompatibility is replete with discussions about Maxwellequations and field theory only a few aspects arepresented.

  5. Field theory

    CERN Document Server

    Roman, Steven

    2006-01-01

    Intended for graduate courses or for independent study, this book presents the basic theory of fields. The first part begins with a discussion of polynomials over a ring, the division algorithm, irreducibility, field extensions, and embeddings. The second part is devoted to Galois theory. The third part of the book treats the theory of binomials. The book concludes with a chapter on families of binomials - the Kummer theory. This new edition has been completely rewritten in order to improve the pedagogy and to make the text more accessible to graduate students.  The exercises have also been im

  6. Theory of thermal stresses

    CERN Document Server

    Boley, Bruno A

    1997-01-01

    Highly regarded text presents detailed discussion of fundamental aspects of theory, background, problems with detailed solutions. Basics of thermoelasticity, heat transfer theory, thermal stress analysis, more. 1985 edition.

  7. On Discrete Differential Geometry in Twistor Space

    OpenAIRE

    2011-01-01

    In this paper we introduce a discrete integrable system generalizing the discrete (real) cross-ratio system in $S^4$ to complex values of a generalized cross-ratio by considering $S^4$ as a real section of the complex Pl\\"ucker quadric, realized as the space of two-spheres in $S^4.$ We develop the geometry of the Pl\\"ucker quadric by examining the novel contact properties of two-spheres in $S^4,$ generalizing classical Lie geometry in $S^3.$ Discrete differential geometry aims to develop disc...

  8. Potential Theory

    CERN Document Server

    Lukeš, Jaroslav; Netuka, Ivan; Veselý, Jiří

    1988-01-01

    Within the tradition of meetings devoted to potential theory, a conference on potential theory took place in Prague on 19-24, July 1987. The Conference was organized by the Faculty of Mathematics and Physics, Charles University, with the collaboration of the Institute of Mathematics, Czechoslovak Academy of Sciences, the Department of Mathematics, Czech University of Technology, the Union of Czechoslovak Mathematicians and Physicists, the Czechoslovak Scientific and Technical Society, and supported by IMU. During the Conference, 69 scientific communications from different branches of potential theory were presented; the majority of them are in­ cluded in the present volume. (Papers based on survey lectures delivered at the Conference, its program as well as a collection of problems from potential theory will appear in a special volume of the Lecture Notes Series published by Springer-Verlag). Topics of these communications truly reflect the vast scope of contemporary potential theory. Some contributions deal...

  9. Researching Stonehenge: Theories Past and Present

    Directory of Open Access Journals (Sweden)

    Mike Parker Pearson

    2013-10-01

    Full Text Available Over the years archaeologists connected with the Institute of Archaeology and UCL have made substantial contributions to the study of Stonehenge, the most enigmatic of all the prehistoric stone circles in Britain. Two of the early researchers were Petrie and Childe. More recently, colleagues in UCL’s Anthropology department – Barbara Bender and Chris Tilley – have also studied and written about the monument in its landscape. Mike Parker Pearson, who joined the Institute in 2012, has been leading a 10-year-long research programme on Stonehenge and, in this paper, he outlines the history and current state of research.

  10. Toward a Theory of Visual Presentation.

    Science.gov (United States)

    Burke, Ken

    Communication is a multi-faceted discipline which has often neglected the study of images as spatial, stylistic experiences in favor of exploring the social impact of their contents. This essay offers an addition to the traditional emphases of communication by building on the concepts of framing (perspectives on how meaning is created) and…

  11. Foundations of Galois theory

    CERN Document Server

    Postnikov, MM; Stark, M; Ulam, S

    1962-01-01

    Foundations of Galois Theory is an introduction to group theory, field theory, and the basic concepts of abstract algebra. The text is divided into two parts. Part I presents the elements of Galois Theory, in which chapters are devoted to the presentation of the elements of field theory, facts from the theory of groups, and the applications of Galois Theory. Part II focuses on the development of general Galois Theory and its use in the solution of equations by radicals. Equations that are solvable by radicals; the construction of equations solvable by radicals; and the unsolvability by radica

  12. CATCHY PRESENTATIONS

    DEFF Research Database (Denmark)

    Eriksen, Kaare; Tollestrup, Christian; Ovesen, Nis

    2011-01-01

    An important competence for designers is the ability to communicate and present ideas and proposals for customers, partners, investors and colleagues. The Pecha Kucha principle, developed by Astrid Klein and Mark Dytham, has become a widely used and easy format for the presentation of new concepts...

  13. Graph theory

    CERN Document Server

    Gould, Ronald

    2012-01-01

    This introduction to graph theory focuses on well-established topics, covering primary techniques and including both algorithmic and theoretical problems. The algorithms are presented with a minimum of advanced data structures and programming details. This thoroughly corrected 1988 edition provides insights to computer scientists as well as advanced undergraduates and graduate students of topology, algebra, and matrix theory. Fundamental concepts and notation and elementary properties and operations are the first subjects, followed by examinations of paths and searching, trees, and networks. S

  14. Information Presentation

    Science.gov (United States)

    Holden, Kritina L.; Thompson, Shelby G.; Sandor, Aniko; McCann, Robert S.; Kaiser, Mary K.; Adelstein, Barnard D.; Begault, Durand R.; Beutter, Brent R.; Stone, Leland S.; Godfroy, Martine

    2009-01-01

    The goal of the Information Presentation Directed Research Project (DRP) is to address design questions related to the presentation of information to the crew. In addition to addressing display design issues associated with information formatting, style, layout, and interaction, the Information Presentation DRP is also working toward understanding the effects of extreme environments encountered in space travel on information processing. Work is also in progress to refine human factors-based design tools, such as human performance modeling, that will supplement traditional design techniques and help ensure that optimal information design is accomplished in the most cost-efficient manner. The major areas of work, or subtasks, within the Information Presentation DRP for FY10 are: 1) Displays, 2) Controls, 3) Procedures and Fault Management, and 4) Human Performance Modeling. The poster will highlight completed and planned work for each subtask.

  15. Information Presentation

    Science.gov (United States)

    Holden, K.L.; Boyer, J.L.; Sandor, A.; Thompson, S.G.; McCann, R.S.; Begault, D.R.; Adelstein, B.D.; Beutter, B.R.; Stone, L.S.

    2009-01-01

    The goal of the Information Presentation Directed Research Project (DRP) is to address design questions related to the presentation of information to the crew. The major areas of work, or subtasks, within this DRP are: 1) Displays, 2) Controls, 3) Electronic Procedures and Fault Management, and 4) Human Performance Modeling. This DRP is a collaborative effort between researchers at Johnson Space Center and Ames Research Center.

  16. Voting Present

    Directory of Open Access Journals (Sweden)

    James Lo

    2013-12-01

    Full Text Available During his time as a state senator in Illinois, Barack Obama voted “Present” 129 times, a deliberate act of nonvoting that subsequently became an important campaign issue during the 2008 presidential elections. In this article, I examine the use of Present votes in the Illinois state senate. I find evidence that Present votes can largely be characterized as protest votes used as a legislative tool by the minority party. Incorporating information from Present votes into a Bayesian polytomous item-response model, I find that this information increases the efficiency of ideal point estimates by approximately 35%. There is little evidence of significant moderation by Obama when Present votes are accounted for, though my results suggest that Obama’s voting record may have moderated significantly before his subsequent election to the U.S. Senate. My results also suggest that because legislative nonvoting may occur for a variety of reasons, naive inclusion of nonvoting behavior into vote choice models may lead to biased results.

  17. Continuity theory

    CERN Document Server

    Nel, Louis

    2016-01-01

    This book presents a detailed, self-contained theory of continuous mappings. It is mainly addressed to students who have already studied these mappings in the setting of metric spaces, as well as multidimensional differential calculus. The needed background facts about sets, metric spaces and linear algebra are developed in detail, so as to provide a seamless transition between students' previous studies and new material. In view of its many novel features, this book will be of interest also to mature readers who have studied continuous mappings from the subject's classical texts and wish to become acquainted with a new approach. The theory of continuous mappings serves as infrastructure for more specialized mathematical theories like differential equations, integral equations, operator theory, dynamical systems, global analysis, topological groups, topological rings and many more. In light of the centrality of the topic, a book of this kind fits a variety of applications, especially those that contribute to ...

  18. Technical presentation

    CERN Multimedia

    FI Department

    2008-01-01

    RADIOSPARES, the leading catalogue distributor of components (electronic, electrical, automation, etc.) and industrial supplies will be at CERN on Friday 3 October 2008 (Main Building, Room B, from 9.00 a.m. to 3.00 p.m.) to introduce its new 2008/2009 catalogue. This will be the opportunity for us to present our complete range of products in more detail: 400 000 part numbers available on our web site (Radiospares France, RS International, extended range of components from other manufacturers); our new services: quotations, search for products not included in the catalogue, SBP products (Small Batch Production: packaging in quantities adapted to customers’ requirements); partnership with our focus manufacturers; demonstration of the on-line purchasing tool implemented on our web site in conjunction with CERN. RADIOSPARES will be accompanied by representatives of FLUKE and TYCO ELECTRONICS, who will make presentations, demonstrate materials and answer any technical questio...

  19. Overview Presentation

    Science.gov (United States)

    Lytle, John

    2001-01-01

    This report provides an overview presentation of the 2000 NPSS (Numerical Propulsion System Simulation) Review and Planning Meeting. Topics include: 1) a background of the program; 2) 1999 Industry Feedback; 3) FY00 Status, including resource distribution and major accomplishments; 4) FY01 Major Milestones; and 5) Future direction for the program. Specifically, simulation environment/production software and NPSS CORBA Security Development are discussed.

  20. Lattice theory

    CERN Document Server

    Donnellan, Thomas; Maxwell, E A; Plumpton, C

    1968-01-01

    Lattice Theory presents an elementary account of a significant branch of contemporary mathematics concerning lattice theory. This book discusses the unusual features, which include the presentation and exploitation of partitions of a finite set. Organized into six chapters, this book begins with an overview of the concept of several topics, including sets in general, the relations and operations, the relation of equivalence, and the relation of congruence. This text then defines the relation of partial order and then partially ordered sets, including chains. Other chapters examine the properti

  1. Game Theory: 5 Questions

    DEFF Research Database (Denmark)

    Hendricks, Vincent F.

    Game Theory is a collection of short interviews based on 5 questions presented to some of the most influential and prominent scholars in game theory. We hear their views on game theory, its aim, scope, use, the future direction of game theory and how their work fits in these respects....

  2. Game Theory: 5 Questions

    DEFF Research Database (Denmark)

    Hendricks, Vincent F.

    Game Theory is a collection of short interviews based on 5 questions presented to some of the most influential and prominent scholars in game theory. We hear their views on game theory, its aim, scope, use, the future direction of game theory and how their work fits in these respects....

  3. 论《知音》篇理论命题的类型、内涵及当代意义%On the Types,Intensions and Present Significance of the Theory Propositions in "Zhiyin"

    Institute of Scientific and Technical Information of China (English)

    唐萌; 吴建民

    2011-01-01

    "命题"是古代文论的重要构成形式。《知音》篇作为《文心雕龙》关于文学鉴赏和文学批评的专论,刘勰在文中提出了一系列有关文学鉴赏和文学批评的理论命题。这些命题从形式类型上看,主要有四种构成形式;从理论内涵上看,各有不同的思想内涵,构成了刘勰文学欣赏、批评论的基本内容;从价值意义上看,这些理论命题在今天仍然具有切实的应用价值和重要的理论意义。%"Proposition" is an important type of ancient literary theory."Zhiyin",a monography about literary appreciation and criticism in Liuxie's The Literary Mind and the Carving of Dragons,embodies a series of the author's theoretical propositions on literary appreciation and criticism.In terms of form,these propositions can be classified into four types;in terms of content,all the theories contained constitute the basic outlooks of Liuxie's literary appreciation and criticism;in terms of value,many of these propositions are still of practical and theoretical meaning in present time.

  4. Technical presentation

    CERN Multimedia

    FP Department

    2009-01-01

    07 April 2009 Technical presentation by Leuze Electronics: 14.00 – 15.00, Main Building, Room 61-1-017 (Room A) Photoelectric sensors, data identification and transmission systems, image processing systems. We at Leuze Electronics are "the sensor people": we have been specialising in optoelectronic sensors and safety technology for accident prevention for over 40 years. Our dedicated staff are all highly customer oriented. Customers of Leuze Electronics can always rely on one thing – on us! •\tFounded in 1963 •\t740 employees •\t115 MEUR turnover •\t20 subsidiaries •\t3 production facilities in southern Germany Product groups: •\tPhotoelectric sensors •\tIdentification and measurements •\tSafety devices

  5. Matching theory

    CERN Document Server

    Plummer, MD

    1986-01-01

    This study of matching theory deals with bipartite matching, network flows, and presents fundamental results for the non-bipartite case. It goes on to study elementary bipartite graphs and elementary graphs in general. Further discussed are 2-matchings, general matching problems as linear programs, the Edmonds Matching Algorithm (and other algorithmic approaches), f-factors and vertex packing.

  6. Combinatorial Theory

    CERN Document Server

    Hall, Marshall

    2011-01-01

    Includes proof of van der Waerden's 1926 conjecture on permanents, Wilson's theorem on asymptotic existence, and other developments in combinatorics since 1967. Also covers coding theory and its important connection with designs, problems of enumeration, and partition. Presents fundamentals in addition to latest advances, with illustrative problems at the end of each chapter. Enlarged appendixes include a longer list of block designs.

  7. La teoria dell'attivita verbale nella fase attuale e il suo significato nell'insegnamento della lingua russa agli stranieri (The Theory of Verbal Activity in its Present Stage and its Significance in the Teaching of Russian to Foreigners)

    Science.gov (United States)

    Leont'ev, A. A.

    1977-01-01

    Traces the evolution of thought in the field of psycholinguistics ("theory of verbal activity" in Russia) and discusses current research being done in the United States, Europe, and the Soviet Union. A valid method of teaching language cannot be developed without a theory of language acquisition. (Text is in Italian.) (CFM)

  8. La teoria dell'attivita verbale nella fase attuale e il suo significato nell'insegnamento della lingua russa agli stranieri (The Theory of Verbal Activity in its Present Stage and its Significance in the Teaching of Russian to Foreigners)

    Science.gov (United States)

    Leont'ev, A. A.

    1977-01-01

    Traces the evolution of thought in the field of psycholinguistics ("theory of verbal activity" in Russia) and discusses current research being done in the United States, Europe, and the Soviet Union. A valid method of teaching language cannot be developed without a theory of language acquisition. (Text is in Italian.) (CFM)

  9. Teacher's Role in Class Presentation Based on Theory of Mediation:A Case Study on Translation Teaching%教师在课堂陈述中的中介作用研究--以笔译教学为例

    Institute of Scientific and Technical Information of China (English)

    覃慧

    2014-01-01

    随着课堂陈述在外语课堂中越发普遍,教师在课堂陈述中应扮演的角色引起教育者的思考。为了把教学的中心地位归还给学生,一些老师索性把课堂时间都给学生进行课堂陈述,而没有进行任何的指导、干预甚至点评,使课堂效果不尽如人意。该文借用费厄斯坦的中介理论,以笔译课堂为例,分析教师在课堂陈述中四大中介作用的具体表现,总结出提高课堂陈述效果的七大步骤,即发布任务、鼓励与激励、跟踪与反馈、记录、参与讨论、点评和评估打分。该文结论认为教师在课堂陈述中不能对学生袖手旁观,而应充分发挥教师的“中介作用”,成为学生课堂陈述任务的发布者、组织者、鼓励者、资源人、咨询者、管理者、参与者、观察者和评估者。%As class presentations are gaining popularity in English classes, educational experts show keen interests in studying the roles of teachers in class presentations. In order to transfer to stu-dent-centered teaching model, some teachers merely leave the whole class to students to do presentations without any guidance or supervision beforehand, resulting in undesirable teaching out-comes. The paper applies the Theory of Mediation to analyze the roles of teachers as mediators in translation course and thus sum-marizes the approaches to boost class presentation outcomes. It is concluded that teachers are supposed to be the promulgator orga-nizer, motivator, resource, consultant, manager, participant, ob-server and assessor in class presentations.

  10. 空间范畴视域下普列什文生态哲学的诗意呈现%The Poetic Presentation of Pristina’s Ecological Philosophy from the View of Space Theories

    Institute of Scientific and Technical Information of China (English)

    李丽

    2015-01-01

    Ecological philosophy is a kind of philosophical ideas on the basis of ecological crisis. Russian ecological philosophy represents a unique path of thinking in the world. Mikhail Mikhailovich Pristuna man, as the originator of russian ecological literature, formed his own ecological philosophy, which has great effect on the whole Russian ecological literature. In this article, analyzing the poetic presentation of Pristina’s ecological philosophy in three different ways from the view of the space theories, and looking for its origins to find a better way to solve the global ecological crisis.%生态哲学是基于生态危机而产生的一种哲学理念。俄罗斯生态哲学以其独特的风格在世界范围内独树一帜。普列什文作为俄罗斯生态文学的奠基人,其生态哲学理念对俄罗斯生态文学产生了重大影响。试图以空间范畴为视角,从普文中诗意呈现的三个维度解读其生态哲学,追溯其生态哲学诗意呈现的根源,为解决当前全球生态危机提供可借鉴的途径。

  11. Probability theory

    CERN Document Server

    S Varadhan, S R

    2001-01-01

    This volume presents topics in probability theory covered during a first-year graduate course given at the Courant Institute of Mathematical Sciences. The necessary background material in measure theory is developed, including the standard topics, such as extension theorem, construction of measures, integration, product spaces, Radon-Nikodym theorem, and conditional expectation. In the first part of the book, characteristic functions are introduced, followed by the study of weak convergence of probability distributions. Then both the weak and strong limit theorems for sums of independent rando

  12. Galois theory

    CERN Document Server

    Stewart, Ian

    2003-01-01

    Ian Stewart's Galois Theory has been in print for 30 years. Resoundingly popular, it still serves its purpose exceedingly well. Yet mathematics education has changed considerably since 1973, when theory took precedence over examples, and the time has come to bring this presentation in line with more modern approaches.To this end, the story now begins with polynomials over the complex numbers, and the central quest is to understand when such polynomials have solutions that can be expressed by radicals. Reorganization of the material places the concrete before the abstract, thus motivating the g

  13. Elementary particle theory

    Energy Technology Data Exchange (ETDEWEB)

    Marciano, W.J.

    1984-12-01

    The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references. (WHK)

  14. Indications from space geodesy, gravimetry and seismology for slow Earth expansion at present – comment on “The Earth expansion theory and its transition from scientific hypothesis to pseudoscientific belief” by Sudiro (2014)

    OpenAIRE

    Edwards, M R

    2016-01-01

    In a recent article in this journal, Paolo Sudiro (2014) considered the long history of the expanding Earth theory and its recent descent into what he termed “pseudoscientific belief”. The expanding Earth theory contends that the radius of the Earth was once one-half to two-thirds of its current value, with the Earth's continents forming a continuous sialic cover over the Earth. The theory has had two main variants: slow expansion at about 0.5 mm yr−1 radial increase since ...

  15. Presentism meets black holes

    CERN Document Server

    Romero, Gustavo E

    2014-01-01

    Presentism is, roughly, the metaphysical doctrine that maintains that whatever exists, exists in the present. The compatibility of presentism with the theories of special and general relativity was much debated in recent years. It has been argued that at least some versions of presentism are consistent with time-orientable models of general relativity. In this paper we confront the thesis of presentism with relativistic physics, in the strong gravitational limit where black holes are formed. We conclude that the presentist position is at odds with the existence of black holes and other compact objects in the universe. A revision of the thesis is necessary, if it is intended to be consistent with the current scientific view of the universe.

  16. Scattering theory

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Harald [Technische Univ. Muenchen, Garching (Germany). Physik-Department

    2013-08-01

    Written by the author of the widely acclaimed textbook. Theoretical Atomic Physics Includes sections on quantum reflection, tunable Feshbach resonances and Efimov states. Useful for advanced students and researchers. This book presents a concise and modern coverage of scattering theory. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. The level of abstraction is kept as low as at all possible, and deeper questions related to mathematical foundations of scattering theory are passed by. The book should be understandable for anyone with a basic knowledge of nonrelativistic quantum mechanics. It is intended for advanced students and researchers, and it is hoped that it will be useful for theorists and experimentalists alike.

  17. Waltz's Theory of Theory

    DEFF Research Database (Denmark)

    Wæver, Ole

    2009-01-01

    Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism and refle......Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism...... and reflectivism. Yet, ironically, there has been little attention to Waltz's very explicit and original arguments about the nature of theory. This article explores and explicates Waltz's theory of theory. Central attention is paid to his definition of theory as ‘a picture, mentally formed' and to the radical anti......-empiricism and anti-positivism of his position. Followers and critics alike have treated Waltzian neorealism as if it was at bottom a formal proposition about cause-effect relations. The extreme case of Waltz being so victorious in the discipline, and yet being consistently mis-interpreted on the question of theory...

  18. Effective theories of universal theories

    CERN Document Server

    Wells, James D

    2015-01-01

    It is well-known but sometimes overlooked that constraints on the oblique parameters (most notably $S$ and $T$ parameters) are only applicable to a special class of new physics scenarios known as universal theories. In the effective field theory (EFT) framework, the oblique parameters should not be associated with Wilson coefficients in a particular operator basis, unless restrictions have been imposed on the EFT so that it describes universal theories. We work out these restrictions, and present a detailed EFT analysis of universal theories. We find that at the dimension-6 level, universal theories are completely characterized by 16 parameters. They are conveniently chosen to be: 5 oblique parameters that agree with the commonly-adopted ones, 4 anomalous triple-gauge couplings, 3 rescaling factors for the $h^3$, $hff$, $hVV$ vertices, 3 parameters for $hVV$ vertices absent in the Standard Model, and 1 four-fermion coupling of order $y_f^2$. All these parameters are defined in an unambiguous and basis-indepen...

  19. An introduction to information theory

    CERN Document Server

    Reza, Fazlollah M

    1994-01-01

    Graduate-level study for engineering students presents elements of modern probability theory, information theory, coding theory, more. Emphasis on sample space, random variables, capacity, etc. Many reference tables and extensive bibliography. 1961 edition.

  20. Affine connections on involutive G-structures

    OpenAIRE

    Merkulov, Sergey A.

    1995-01-01

    This paper is a review of the twistor theory of irreducible G-structures and affine connections. Long ago, Berger presented a very restricted list of possible irreducibly acting holonomies of torsion-free affine connections. His list was complete in the part of metric connections, while the situation with holonomies of non-metric torsion-free affine connections was and remains rather unclear. One of the results discussed in this review asserts that any torsion-free holomorphic affine connecti...

  1. The Grounded Theory Bookshelf

    Directory of Open Access Journals (Sweden)

    Vivian B. Martin, Ph.D.

    2005-03-01

    Full Text Available Bookshelf will provide critical reviews and perspectives on books on theory and methodology of interest to grounded theory. This issue includes a review of Heaton’s Reworking Qualitative Data, of special interest for some of its references to grounded theory as a secondary analysis tool; and Goulding’s Grounded Theory: A practical guide for management, business, and market researchers, a book that attempts to explicate the method and presents a grounded theory study that falls a little short of the mark of a fully elaborated theory.Reworking Qualitative Data, Janet Heaton (Sage, 2004. Paperback, 176 pages, $29.95. Hardcover also available.

  2. Higher Topos Theory

    CERN Document Server

    Lurie, Jacob

    2009-01-01

    Higher category theory is generally regarded as technical and forbidding, but part of it is considerably more tractable: the theory of infinity-categories, higher categories in which all higher morphisms are assumed to be invertible. In Higher Topos Theory, Jacob Lurie presents the foundations of this theory, using the language of weak Kan complexes introduced by Boardman and Vogt, and shows how existing theorems in algebraic topology can be reformulated and generalized in the theory's new language. The result is a powerful theory with applications in many areas of mathematics. The book's firs

  3. Activity Theory and Ontology

    Science.gov (United States)

    Peim, Nick

    2009-01-01

    This paper seeks to re-examine Yrio Engestrom's activity theory as a technology of knowledge designed to enable positive transformations of specific practices. The paper focuses on a key paper where Engestrom defines the nature and present state of activity theory. Beginning with a brief account of the relations between activity theory and…

  4. Presenting Newtonian gravitation

    Energy Technology Data Exchange (ETDEWEB)

    Counihan, Martin [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)

    2007-11-15

    The basic principles of the Newtonian theory of gravitation are presented in a way which students may find more logically coherent, mathematically accessible and physically interesting than other approaches. After giving relatively simple derivations of the circular hodograph and the elliptical orbit from the inverse-square law, the concept of gravitational energy is developed from vector calculus. It is argued that the energy density of a gravitational field may reasonably be regarded as -g{sup 2}/8{pi}G, and that the inverse-square law may be replaced by a Schwarzschild-like force law without the need to invoke non-Euclidean geometry.

  5. Analyzing in the present

    DEFF Research Database (Denmark)

    Revsbæk, Line; Tanggaard, Lene

    2015-01-01

    The article presents a notion of “analyzing in the present” as a source of inspiration in analyzing qualitative research materials. The term emerged from extensive listening to interview recordings during everyday commuting to university campus. Paying attention to the way different parts...... the interdependency between researcher and researched. On this basis, we advocate an explicit “open-state-of mind” listening as a key aspect of analyzing qualitative material, often described only as a matter of reading transcribed empirical materials, reading theory, and writing. The article contributes...

  6. Information theory and Thermodynamics

    OpenAIRE

    Kafri, Oded

    2006-01-01

    A communication theory for a transmitter broadcasting to many receivers is presented. In this case energetic considerations cannot be neglected as in Shannon theory. It is shown that, when energy is assigned to the information bit, information theory complies with classical thermodynamic and is part of it. To provide a thermodynamic theory of communication it is necessary to define equilibrium for informatics systems that are not in thermal equilibrium and to calculate temperature, heat, and ...

  7. Philosophical theories of probability

    CERN Document Server

    Gillies, Donald

    2000-01-01

    The Twentieth Century has seen a dramatic rise in the use of probability and statistics in almost all fields of research. This has stimulated many new philosophical ideas on probability. Philosophical Theories of Probability is the first book to present a clear, comprehensive and systematic account of these various theories and to explain how they relate to one another. Gillies also offers a distinctive version of the propensity theory of probability, and the intersubjective interpretation, which develops the subjective theory.

  8. RELATIVISTIC TRANSPORT-THEORY

    NARCIS (Netherlands)

    MALFLIET, R

    1993-01-01

    We discuss the present status of relativistic transport theory. Special emphasis is put on problems of topical interest: hadronic features, thermodynamical consistent approximations and spectral properties.

  9. Scattering theory

    CERN Document Server

    Friedrich, Harald

    2016-01-01

    This corrected and updated second edition of "Scattering Theory" presents a concise and modern coverage of the subject. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. The book contains sections on special topics such as near-threshold quantization, quantum reflection, Feshbach resonances and the quantum description of scattering in two dimensions. The level of abstraction is k...

  10. Potential theory

    CERN Document Server

    Helms, Lester L

    2014-01-01

    Potential Theory presents a clear path from calculus to classical potential theory and beyond, with the aim of moving the reader into the area of mathematical research as quickly as possible. The subject matter is developed from first principles using only calculus. Commencing with the inverse square law for gravitational and electromagnetic forces and the divergence theorem, the author develops methods for constructing solutions of Laplace's equation on a region with prescribed values on the boundary of the region. The latter half of the book addresses more advanced material aimed at those with the background of a senior undergraduate or beginning graduate course in real analysis. Starting with solutions of the Dirichlet problem subject to mixed boundary conditions on the simplest of regions, methods of morphing such solutions onto solutions of Poisson's equation on more general regions are developed using diffeomorphisms and the Perron-Wiener-Brelot method, culminating in application to Brownian motion. In ...

  11. Elastoplasticity theory

    CERN Document Server

    Hashiguchi, Koichi

    2014-01-01

    This book was written to serve as the standard textbook of elastoplasticity for students, engineers and researchers in the field of applied mechanics. The present second edition is improved thoroughly from the first edition by selecting the standard theories from various formulations and models, which are required to study the essentials of elastoplasticity steadily and effectively and will remain universally in the history of elastoplasticity. It opens with an explanation of vector-tensor analysis and continuum mechanics as a foundation to study elastoplasticity theory, extending over various strain and stress tensors and their rates. Subsequently, constitutive equations of elastoplastic and viscoplastic deformations for monotonic, cyclic and non-proportional loading behavior in a general rate and their applications to metals and soils are described in detail, and constitutive equations of friction behavior between solids and its application to the prediction of stick-slip phenomena are delineated. In additi...

  12. Rotor theories by Professor Joukowsky: Momentum theories

    DEFF Research Database (Denmark)

    van Kuik, G. A. M.; Sørensen, Jens Nørkær; Okulov, V. L.

    2015-01-01

    This paper is the first of two papers on the history of rotor aerodynamics with special emphasis on the role of Joukowsky. The present one focuses on the development of the momentum theory while the second one surveys the development of vortex theory for rotors. Joukowsky has played a major role ...

  13. Computability theory an introduction to recursion theory

    CERN Document Server

    Enderton, Herbert B

    2010-01-01

    Computability Theory:  An Introduction to Recursion Theory,  provides a concise, comprehensive, and authoritative introduction to contemporary computability theory, techniques, and results. The basic concepts and techniques of computability theory are placed in their historical, philosophical and logical context. This presentation is characterized by an unusual breadth of coverage and the inclusion of advanced topics not to be found elsewhere in the literature at this level.  The text includes both the standard material for a first course in computability and more advanced looks at degree str

  14. Uncertainty theory. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Liu Baoding [Tsinghua Univ., Beijing (China). Uncertainty Theory Lab.

    2007-07-01

    Uncertainty theory is a branch of mathematics based on normality, monotonicity, self-duality, and countable subadditivity axioms. The goal of uncertainty theory is to study the behavior of uncertain phenomena such as fuzziness and randomness. The main topics include probability theory, credibility theory, and chance theory. For this new edition the entire text has been totally rewritten. More importantly, the chapters on chance theory and uncertainty theory are completely new. This book provides a self-contained, comprehensive and up-to-date presentation of uncertainty theory. The purpose is to equip the readers with an axiomatic approach to deal with uncertainty. Mathematicians, researchers, engineers, designers, and students in the field of mathematics, information science, operations research, industrial engineering, computer science, artificial intelligence, and management science will find this work a stimulating and useful reference. (orig.)

  15. Higher spin gauge theories

    CERN Document Server

    Henneaux, Marc; Vasiliev, Mikhail A

    2017-01-01

    Symmetries play a fundamental role in physics. Non-Abelian gauge symmetries are the symmetries behind theories for massless spin-1 particles, while the reparametrization symmetry is behind Einstein's gravity theory for massless spin-2 particles. In supersymmetric theories these particles can be connected also to massless fermionic particles. Does Nature stop at spin-2 or can there also be massless higher spin theories. In the past strong indications have been given that such theories do not exist. However, in recent times ways to evade those constraints have been found and higher spin gauge theories have been constructed. With the advent of the AdS/CFT duality correspondence even stronger indications have been given that higher spin gauge theories play an important role in fundamental physics. All these issues were discussed at an international workshop in Singapore in November 2015 where the leading scientists in the field participated. This volume presents an up-to-date, detailed overview of the theories i...

  16. Introductory graph theory

    CERN Document Server

    Chartrand, Gary

    1984-01-01

    Graph theory is used today in the physical sciences, social sciences, computer science, and other areas. Introductory Graph Theory presents a nontechnical introduction to this exciting field in a clear, lively, and informative style. Author Gary Chartrand covers the important elementary topics of graph theory and its applications. In addition, he presents a large variety of proofs designed to strengthen mathematical techniques and offers challenging opportunities to have fun with mathematics. Ten major topics - profusely illustrated - include: Mathematical Models, Elementary Concepts of Grap

  17. Graph theory

    CERN Document Server

    Diestel, Reinhard

    2017-01-01

    This standard textbook of modern graph theory, now in its fifth edition, combines the authority of a classic with the engaging freshness of style that is the hallmark of active mathematics. It covers the core material of the subject with concise yet reliably complete proofs, while offering glimpses of more advanced methods in each field by one or two deeper results, again with proofs given in full detail. The book can be used as a reliable text for an introductory course, as a graduate text, and for self-study. From the reviews: “This outstanding book cannot be substituted with any other book on the present textbook market. It has every chance of becoming the standard textbook for graph theory.”Acta Scientiarum Mathematiciarum “Deep, clear, wonderful. This is a serious book about the heart of graph theory. It has depth and integrity. ”Persi Diaconis & Ron Graham, SIAM Review “The book has received a very enthusiastic reception, which it amply deserves. A masterly elucidation of modern graph theo...

  18. Model theory and applications

    CERN Document Server

    Belegradek, OV

    1999-01-01

    This volume is a collection of papers on model theory and its applications. The longest paper, "Model Theory of Unitriangular Groups" by O. V. Belegradek, forms a subtle general theory behind Mal‴tsev's famous correspondence between rings and groups. This is the first published paper on the topic. Given the present model-theoretic interest in algebraic groups, Belegradek's work is of particular interest to logicians and algebraists. The rest of the collection consists of papers on various questions of model theory, mainly on stability theory. Contributors are leading Russian researchers in the

  19. Extremal graph theory

    CERN Document Server

    Bollobas, Bela

    2004-01-01

    The ever-expanding field of extremal graph theory encompasses a diverse array of problem-solving methods, including applications to economics, computer science, and optimization theory. This volume, based on a series of lectures delivered to graduate students at the University of Cambridge, presents a concise yet comprehensive treatment of extremal graph theory.Unlike most graph theory treatises, this text features complete proofs for almost all of its results. Further insights into theory are provided by the numerous exercises of varying degrees of difficulty that accompany each chapter. A

  20. f(R Theories

    Directory of Open Access Journals (Sweden)

    Antonio De Felice

    2010-06-01

    Full Text Available Over the past decade, f(R theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R theories to cosmology and gravity – such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans–Dicke theory and Gauss–Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.

  1. Game theory an introduction

    CERN Document Server

    Barron, E N

    2013-01-01

    An exciting new edition of the popular introduction to game theory and its applications The thoroughly expanded Second Edition presents a unique, hands-on approach to game theory. While most books on the subject are too abstract or too basic for mathematicians, Game Theory: An Introduction, Second Edition offers a blend of theory and applications, allowing readers to use theory and software to create and analyze real-world decision-making models. With a rigorous, yet accessible, treatment of mathematics, the book focuses on results that can be used to

  2. Generalization Rough Set Theory

    Institute of Scientific and Technical Information of China (English)

    XIAO Di; ZHANG Jun-feng; HU Shou-song

    2008-01-01

    In order to avoid the discretization in the classical rough set theory, a generlization rough set theory is proposed.At first, the degree of general importance of an attribute and attribute subsets are presented.Then, depending on the degree of general importance of attribute, the space distance can be measured with weighted method.At last, a generalization rough set theory based on the general near neighborhood relation is proposed.The proposed theory partitions the universe into the tolerant modules, and forms lower approximation and upper approximation of the set under general near neighborhood relationship, which avoids the discretization in Pawlak's rough set theory.

  3. Game theory, alive

    CERN Document Server

    Karlin, Anna R

    2016-01-01

    This book presents a rigorous introduction to the mathematics of game theory without losing sight of the joy of the subject. This is done by focusing on theoretical highlights (e.g., at least six Nobel Prize winning results are developed from scratch) and by presenting exciting connections of game theory to other fields, such as computer science, economics, social choice, biology, and learning theory. Both classical topics, such as zero-sum games, and modern topics, such as sponsored search auctions, are covered. Along the way, beautiful mathematical tools used in game theory are introduced, including convexity, fixed-point theorems, and probabilistic arguments. The book is appropriate for a first course in game theory at either the undergraduate or graduate level, whether in mathematics, economics, computer science, or statistics. Game theory's influence is felt in a wide range of disciplines, and the authors deliver masterfully on the challenge of presenting both the breadth and coherence of its underlying ...

  4. On Form Factors in N=4 SYM Theory and Polytopes

    CERN Document Server

    Bork, L V

    2014-01-01

    In this paper we discuss different recursion relations (BCFW and all-line shift) for the form factors of the operators from the $\\mathcal{N}=4$ SYM stress-tensor current supermultiplet $T^{AB}$ in momentum twistor space. We show that cancelations of spurious poles and equivalence between different types of recursion relations can be naturally understood using geometrical interpretation of the form factors as special limit of the volumes of polytopes in $\\mathbb{C}\\mathbb{P}^4$ in close analogy with the amplitude case. We also show how different relations for the IR pole coefficients can be easily derived using momentum twistor representation. This opens an intriguing question - which of powerful on-shell methods and ideas can survive off-shell ?

  5. Radical theory of rings

    CERN Document Server

    Gardner, JW

    2003-01-01

    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  6. Vocabulary of CPH Theory and Modern Physics

    DEFF Research Database (Denmark)

    Javadi, Hossein; Forouzbakhsh, Farshid; Daei Kasmaei, Hamed

    2016-01-01

    Wherefore CPH theory was presented? There are various theories in physics, but nature is unique. This is not nature's problem that we have various theories; nature obeys simple and unique law. So, we should improve our understanding of physical phenomena and unify theories. There is a compare bri...... of CPH Theory (Creative Particles of Higgs Theory) and modern physics in this vocabulary....

  7. Vocabulary of CPH Theory and Modern Physics

    DEFF Research Database (Denmark)

    Javadi, Hossein; Forouzbakhsh, Farshid; Daei Kasmaei, Hamed

    2016-01-01

    Wherefore CPH theory was presented? There are various theories in physics, but nature is unique. This is not nature's problem that we have various theories; nature obeys simple and unique law. So, we should improve our understanding of physical phenomena and unify theories. There is a compare brief...... of CPH Theory (Creative Particles of Higgs Theory) and modern physics in this vocabulary....

  8. Applied number theory

    CERN Document Server

    Niederreiter, Harald

    2015-01-01

    This textbook effectively builds a bridge from basic number theory to recent advances in applied number theory. It presents the first unified account of the four major areas of application where number theory plays a fundamental role, namely cryptography, coding theory, quasi-Monte Carlo methods, and pseudorandom number generation, allowing the authors to delineate the manifold links and interrelations between these areas.  Number theory, which Carl-Friedrich Gauss famously dubbed the queen of mathematics, has always been considered a very beautiful field of mathematics, producing lovely results and elegant proofs. While only very few real-life applications were known in the past, today number theory can be found in everyday life: in supermarket bar code scanners, in our cars’ GPS systems, in online banking, etc.  Starting with a brief introductory course on number theory in Chapter 1, which makes the book more accessible for undergraduates, the authors describe the four main application areas in Chapters...

  9. Matrix theory of gravitation

    CERN Document Server

    Koehler, Wolfgang

    2011-01-01

    A new classical theory of gravitation within the framework of general relativity is presented. It is based on a matrix formulation of four-dimensional Riemann-spaces and uses no artificial fields or adjustable parameters. The geometrical stress-energy tensor is derived from a matrix-trace Lagrangian, which is not equivalent to the curvature scalar R. To enable a direct comparison with the Einstein-theory a tetrad formalism is utilized, which shows similarities to teleparallel gravitation theories, but uses complex tetrads. Matrix theory might solve a 27-year-old, fundamental problem of those theories (sec. 4.1). For the standard test cases (PPN scheme, Schwarzschild-solution) no differences to the Einstein-theory are found. However, the matrix theory exhibits novel, interesting vacuum solutions.

  10. Vocabulary of CPH Theory and Modern Physics

    DEFF Research Database (Denmark)

    Javadi, Hossein; Forouzbakhsh, Farshid; Daei Kasmaei, Hamed

    2016-01-01

    Wherefore CPH theory was presented? There are various theories in physics, but nature is unique. This is not nature's problem that we have various theories; nature obeys simple and unique law. So, we should improve our understanding of physical phenomena and unify theories. There is a compare bri...... of CPH Theory (Creative Particles of Higgs Theory) and modern physics in this vocabulary.......Wherefore CPH theory was presented? There are various theories in physics, but nature is unique. This is not nature's problem that we have various theories; nature obeys simple and unique law. So, we should improve our understanding of physical phenomena and unify theories. There is a compare brief...

  11. Representation theory of finite monoids

    CERN Document Server

    Steinberg, Benjamin

    2016-01-01

    This first text on the subject provides a comprehensive introduction to the representation theory of finite monoids. Carefully worked examples and exercises provide the bells and whistles for graduate accessibility, bringing a broad range of advanced readers to the forefront of research in the area. Highlights of the text include applications to probability theory, symbolic dynamics, and automata theory. Comfort with module theory, a familiarity with ordinary group representation theory, and the basics of Wedderburn theory, are prerequisites for advanced graduate level study. Researchers in algebra, algebraic combinatorics, automata theory, and probability theory, will find this text enriching with its thorough presentation of applications of the theory to these fields. Prior knowledge of semigroup theory is not expected for the diverse readership that may benefit from this exposition. The approach taken in this book is highly module-theoretic and follows the modern flavor of the theory of finite dimensional ...

  12. The meaning of quantum theory

    CERN Document Server

    Von Weizsäcker, Carl Friedrich

    1988-01-01

    1- presentation of quantum theory in present-day physics. 2- a flash-back on the history : from Planck to Copenhagen. 3- the Copenhagen interpretation. 4- reconstrucction of Abstract Quantum Theory. 5- recent interpretations. 6- the philosophy of the mind. 7- concrete quantum theory. 8- the non-locality. This second tape contains the debate following the talk of the professor.

  13. Topos theory

    CERN Document Server

    Johnstone, PT

    2014-01-01

    Focusing on topos theory's integration of geometric and logical ideas into the foundations of mathematics and theoretical computer science, this volume explores internal category theory, topologies and sheaves, geometric morphisms, other subjects. 1977 edition.

  14. Presentations of groups

    CERN Document Server

    Johnson, D L

    1997-01-01

    The aim of this book is to provide an introduction to combinatorial group theory. Any reader who has completed first courses in linear algebra, group theory and ring theory will find this book accessible. The emphasis is on computational techniques but rigorous proofs of all theorems are supplied. This new edition has been revised throughout, including new exercises and an additional chapter on proving that certain groups are infinite.

  15. Reimagining Critical Theory

    Science.gov (United States)

    Rexhepi, Jevdet; Torres, Carlos Alberto

    2011-01-01

    This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments at a…

  16. Reimagining Critical Theory

    Science.gov (United States)

    Rexhepi, Jevdet; Torres, Carlos Alberto

    2011-01-01

    This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments…

  17. Quantum field theory

    CERN Document Server

    de Wit, Bernard

    1990-01-01

    After a brief and practical introduction to field theory and the use of Feynman diagram, we discuss the main concept in gauge theories and their application in elementary particle physics. We present all the ingredients necessary for the construction of the standard model.

  18. Reimagining Critical Theory

    Science.gov (United States)

    Rexhepi, Jevdet; Torres, Carlos Alberto

    2011-01-01

    This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments…

  19. Discrete gauge theories

    NARCIS (Netherlands)

    de Wild Propitius, M.D.F.; Bais, F.A.

    1999-01-01

    In these lectures, we present a self-contained treatment of planar gauge theories broken down to some finite residual gauge group $H$ via the Higgs mechanism. The main focus is on the discrete $H$ gauge theory describing the long distance physics of such a model. The spectrum features global $H$ cha

  20. Agency Theory

    DEFF Research Database (Denmark)

    Linder, Stefan; Foss, Nicolai Juul

    Agency theory studies the problems and solutions linked to delegation of tasks from principals to agents in the context of conflicting interests between the parties. Beginning from clear assumptions about rationality, contracting and informational conditions, the theory addresses problems of ex...... agency theory to enjoy considerable scientific impact on social science; however, it has also attracted considerable criticism....

  1. What is CPH Theory?

    DEFF Research Database (Denmark)

    Javadi, Hossein; Forouzbakhsh, Farshid; Daei Kasmaei, Hamed

    2016-01-01

    physical events. Emphasizing on these phenomena and presenting the relation between photon's energy and frequency, CPH Theory is to draw attention on the importance of constancy of speed in relation to the mass structure which will be scrutinized in reviewing relativistic Newton's second law. The results......There are various theories in physics, but nature is unique. This is not nature's problem that we have various theories; nature obeys simple and unique law. We should improve our theories. Universal constancy of the speed of light undergoes the question whether the limit on the light speed...

  2. Conformal field theory

    CERN Document Server

    Ketov, Sergei V

    1995-01-01

    Conformal field theory is an elegant and powerful theory in the field of high energy physics and statistics. In fact, it can be said to be one of the greatest achievements in the development of this field. Presented in two dimensions, this book is designed for students who already have a basic knowledge of quantum mechanics, field theory and general relativity. The main idea used throughout the book is that conformal symmetry causes both classical and quantum integrability. Instead of concentrating on the numerous applications of the theory, the author puts forward a discussion of the general

  3. Superspace version of BF theories

    Energy Technology Data Exchange (ETDEWEB)

    Aidaoui, A.; Tahiri, M. [Laboratoire de Physique Theorique, Universite d' Oran Es-senia, 31100 Oran (Algeria)

    2012-06-27

    The BF theory is presented in a superspace formalism. This permits us to see that the necessary fields of the quantized theory enlarged with auxiliary fields naturally occur and lead to a BRST-VSUY exact quantum action.

  4. Gauge Theories of Gravitation

    CERN Document Server

    Blagojević, Milutin

    2012-01-01

    During the last five decades, gravity, as one of the fundamental forces of nature, has been formulated as a gauge field theory of the Weyl-Cartan-Yang-Mills type. The resulting theory, the Poincar\\'e gauge theory of gravity, encompasses Einstein's gravitational theory as well as the teleparallel theory of gravity as subcases. In general, the spacetime structure is enriched by Cartan's torsion and the new theory can accommodate fermionic matter and its spin in a perfectly natural way. The present reprint volume contains articles from the most prominent proponents of the theory and is supplemented by detailed commentaries of the editors. This guided tour starts from special relativity and leads, in its first part, to general relativity and its gauge type extensions a la Weyl and Cartan. Subsequent stopping points are the theories of Yang-Mills and Utiyama and, as a particular vantage point, the theory of Sciama and Kibble. Later, the Poincar\\'e gauge theory and its generalizations are explored and specific topi...

  5. What is CPH Theory?

    DEFF Research Database (Denmark)

    Javadi, Hossein; Forouzbakhsh, Farshid; Daei Kasmaei, Hamed

    2016-01-01

    is the mechanism of increasing in the photon energy that causes increase in its frequency growth? So, in CPH theory (Creative particles of Higgs Theory), it has been attempted to scrutinize the interface between classical mechanics, relativity and quantum mechanics through a novel approach to the established......There are various theories in physics, but nature is unique. This is not nature's problem that we have various theories; nature obeys simple and unique law. We should improve our theories. Universal constancy of the speed of light undergoes the question whether the limit on the light speed...... physical events. Emphasizing on these phenomena and presenting the relation between photon's energy and frequency, CPH Theory is to draw attention on the importance of constancy of speed in relation to the mass structure which will be scrutinized in reviewing relativistic Newton's second law. The results...

  6. Atomic theories

    CERN Document Server

    Loring, FH

    2014-01-01

    Summarising the most novel facts and theories which were coming into prominence at the time, particularly those which had not yet been incorporated into standard textbooks, this important work was first published in 1921. The subjects treated cover a wide range of research that was being conducted into the atom, and include Quantum Theory, the Bohr Theory, the Sommerfield extension of Bohr's work, the Octet Theory and Isotopes, as well as Ionisation Potentials and Solar Phenomena. Because much of the material of Atomic Theories lies on the boundary between experimentally verified fact and spec

  7. Agency Theory

    DEFF Research Database (Denmark)

    Linder, Stefan; Foss, Nicolai Juul

    2015-01-01

    Agency theory studies the problems and solutions linked to delegation of tasks from principals to agents in the context of conflicting interests between the parties. Beginning from clear assumptions about rationality, contracting, and informational conditions, the theory addresses problems of ex ...... agency theory to enjoy considerable scientific impact on social science; however, it has also attracted considerable criticism.......Agency theory studies the problems and solutions linked to delegation of tasks from principals to agents in the context of conflicting interests between the parties. Beginning from clear assumptions about rationality, contracting, and informational conditions, the theory addresses problems of ex...

  8. Agency Theory

    DEFF Research Database (Denmark)

    Linder, Stefan; Foss, Nicolai Juul

    Agency theory studies the problems and solutions linked to delegation of tasks from principals to agents in the context of conflicting interests between the parties. Beginning from clear assumptions about rationality, contracting and informational conditions, the theory addresses problems of ex a...... agency theory to enjoy considerable scientific impact on social science; however, it has also attracted considerable criticism.......Agency theory studies the problems and solutions linked to delegation of tasks from principals to agents in the context of conflicting interests between the parties. Beginning from clear assumptions about rationality, contracting and informational conditions, the theory addresses problems of ex...

  9. Ring theory

    CERN Document Server

    Rowen, Louis H

    1991-01-01

    This is an abridged edition of the author's previous two-volume work, Ring Theory, which concentrates on essential material for a general ring theory course while ommitting much of the material intended for ring theory specialists. It has been praised by reviewers:**""As a textbook for graduate students, Ring Theory joins the best....The experts will find several attractive and pleasant features in Ring Theory. The most noteworthy is the inclusion, usually in supplements and appendices, of many useful constructions which are hard to locate outside of the original sources....The audience of non

  10. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  11. Ramsey theory for product spaces

    CERN Document Server

    Dodos, Pandelis

    2016-01-01

    Ramsey theory is a dynamic area of combinatorics that has various applications in analysis, ergodic theory, logic, number theory, probability theory, theoretical computer science, and topological dynamics. This book is devoted to one of the most important areas of Ramsey theory-the Ramsey theory of product spaces. It is a culmination of a series of recent breakthroughs by the two authors and their students who were able to lift this theory to the infinite-dimensional case. The book presents many major results and methods in the area, such as Szemerédi's regularity method, the hypergraph removal lemma, and the density Hales-Jewett theorem. This book addresses researchers in combinatorics but also working mathematicians and advanced graduate students who are interested in Ramsey theory. The prerequisites for reading this book are rather minimal: it only requires familiarity, at the graduate level, with probability theory and real analysis. Some familiarity with the basics of Ramsey theory would be beneficial, ...

  12. Theory of gravitational interactions

    CERN Document Server

    Gasperini, Maurizio

    2013-01-01

    This reference textbook is an up-to-date and self-contained introduction to the theory of gravitational interactions. The first part of the book follows the traditional presentation of general relativity as a geometric theory of the macroscopic gravitational field. A second, advanced part then discusses the deep analogies (and differences) between a geometric theory of gravity and the gauge theories of the other fundamental interactions. This fills a gap which is present in the context of the traditional approach to general relativity, and which usually makes students puzzled about the role of gravity. The necessary notions of differential geometry are reduced to the minimum, leaving more room for those aspects of gravitational physics of current phenomenological and theoretical interest, such as the properties of gravitational waves, the gravitational interactions of spinors, and the supersymmetric and higher-dimensional generalization of the Einstein equations. Theory of Gravitational Interactions will be o...

  13. Governance and organizational theory

    Directory of Open Access Journals (Sweden)

    Carlos E. Quintero Castellanos

    2017-07-01

    Full Text Available The objective of this essay is to propose a way to link the theoretical body that has been weaved around governance and organizational theory. For this, a critical exposition is done about what is the theoretical core of governance, the opportunity areas are identified for the link of this theory with organizational theory. The essay concludes with a proposal for the organizational analysis of administrations in governance. The essay addresses with five sections. The first one is the introduction. In the second one, I present a synthesis of the governance in its current use. In the next one are presented the work lines of the good governance. In the fourth part, I show the organizational and managerial limits in the governance theory. The last part develops the harmonization proposal for the governance and organizational theories.

  14. Classical Aerodynamic Theory

    Science.gov (United States)

    Jones, R. T. (Compiler)

    1979-01-01

    A collection of papers on modern theoretical aerodynamics is presented. Included are theories of incompressible potential flow and research on the aerodynamic forces on wing and wing sections of aircraft and on airship hulls.

  15. Hadron Spectroscopy -- Theory

    CERN Document Server

    Swanson, E S

    2009-01-01

    A brief review of theoretical progress in hadron spectroscopy and nonperturbative QCD is presented. Attention is focussed on recent lattice gauge theory, the Dyson-Schwinger formalism, unquenching constituent models, and some beyond the Standard Model physics.

  16. Viscous conformal gauge theories

    DEFF Research Database (Denmark)

    Toniato, Arianna; Sannino, Francesco; Rischke, Dirk H.

    2017-01-01

    We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories.......We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories....

  17. Basic Concurrency Theory

    DEFF Research Database (Denmark)

    Løvengreen, Hans Henrik

    2002-01-01

    In this set of notes, we present some of the basic theory underlying the discipline of programming with concurrent processes/threads. The notes are intended to supplement a standard textbook on concurrent programming.......In this set of notes, we present some of the basic theory underlying the discipline of programming with concurrent processes/threads. The notes are intended to supplement a standard textbook on concurrent programming....

  18. Constraints on Extensions of a Default Theory

    Institute of Scientific and Technical Information of China (English)

    SU Kaile

    2001-01-01

    In this paper, the representability of a family of theories as the set of extensions of a default theory is studied. First, a new necessary condition is given for the representability by means of general default theories; then a sufficient one is presented. The families of theories represented by default theories are also fully characterized. Finally, the paper gives an example of denumerable families of mutually inconsistent theories that are represented by a default theory but not by normal ones.

  19. Maslow's theory and its application to librarianship

    OpenAIRE

    Sridhar, M. S.

    1981-01-01

    Explains the basis for Maslow’s theory, enumerates Maslow’s hierarchy of needs, describes implications of the theory and finally presents application of Maslow’s theory to librarianship with suitable examples and illustrations.

  20. Statistical Decision Theory Estimation, Testing, and Selection

    CERN Document Server

    Liese, Friedrich

    2008-01-01

    Suitable for advanced graduate students and researchers in mathematical statistics and decision theory, this title presents an account of the concepts and a treatment of the major results of classical finite sample size decision theory and modern asymptotic decision theory

  1. The nature of the present

    CERN Document Server

    Romero, Gustavo E

    2012-01-01

    The feeling of a moving present or `now' seems to form part of our most basic perceptions about reality. Such a present, however, is not reflected in any of our theories of the physical world. In this short note I argue for a tenseless view of time, where what we call `the present' is just an emergent secondary quality arising from the interaction of perceiving self-conscious individuals with their environment. I maintain that there is no flow of time, but just an ordered system of events.

  2. Principles of copula theory

    CERN Document Server

    Durante, Fabrizio

    2015-01-01

    Principles of Copula Theory explores the state of the art on copulas and provides you with the foundation to use copulas in a variety of applications. Throughout the book, historical remarks and further readings highlight active research in the field, including new results, streamlined presentations, and new proofs of old results.After covering the essentials of copula theory, the book addresses the issue of modeling dependence among components of a random vector using copulas. It then presents copulas from the point of view of measure theory, compares methods for the approximation of copulas,

  3. Generalized etale cohomology theories

    CERN Document Server

    Jardine, John F

    1997-01-01

    A generalized etale cohomology theory is a theory which is represented by a presheaf of spectra on an etale site for an algebraic variety, in analogy with the way an ordinary spectrum represents a cohomology theory for spaces. Examples include etale cohomology and etale K-theory. This book gives new and complete proofs of both Thomason's descent theorem for Bott periodic K-theory and the Nisnevich descent theorem. In doing so, it exposes most of the major ideas of the homotopy theory of presheaves of spectra, and generalized etale homology theories in particular. The treatment includes, for the purpose of adequately dealing with cup product structures, a development of stable homotopy theory for n-fold spectra, which is then promoted to the level of presheaves of n-fold spectra.   This book should be of interest to all researchers working in fields related to algebraic K-theory. The techniques presented here are essentially combinatorial, and hence algebraic. An extensive background in traditional stable hom...

  4. Model theory

    CERN Document Server

    Chang, CC

    2012-01-01

    Model theory deals with a branch of mathematical logic showing connections between a formal language and its interpretations or models. This is the first and most successful textbook in logical model theory. Extensively updated and corrected in 1990 to accommodate developments in model theoretic methods - including classification theory and nonstandard analysis - the third edition added entirely new sections, exercises, and references. Each chapter introduces an individual method and discusses specific applications. Basic methods of constructing models include constants, elementary chains, Sko

  5. Model Theory in Algebra, Analysis and Arithmetic

    CERN Document Server

    Dries, Lou; Macpherson, H Dugald; Pillay, Anand; Toffalori, Carlo; Wilkie, Alex J

    2014-01-01

    Presenting recent developments and applications, the book focuses on four main topics in current model theory: 1) the model theory of valued fields; 2) undecidability in arithmetic; 3) NIP theories; and 4) the model theory of real and complex exponentiation. Young researchers in model theory will particularly benefit from the book, as will more senior researchers in other branches of mathematics.

  6. Abstract Presentations: What Do SGIM Presenters Prefer?

    OpenAIRE

    Tulsky, Asher A.; Kouides, Ruth W

    1998-01-01

    We surveyed physicians presenting abstracts at the 1995 Society of General Internal Medicine annual meeting to determine whether the oral or poster format better achieved their presentation goals. Poster presentations better met respondents' objectives for feedback and criticism and for networking and developing collaborative projects, while oral presentations better met their objectives for national visibility and sharing knowledge within one's field. Sixty-nine percent of respondents prefer...

  7. Elastoplasticity theory

    CERN Document Server

    Hashiguchi, Koichi

    2009-01-01

    This book details the mathematics and continuum mechanics necessary as a foundation of elastoplasticity theory. It explains physical backgrounds with illustrations and provides descriptions of detailed derivation processes..

  8. Galois Theory

    CERN Document Server

    Cox, David A

    2012-01-01

    Praise for the First Edition ". . .will certainly fascinate anyone interested in abstract algebra: a remarkable book!"—Monatshefte fur Mathematik Galois theory is one of the most established topics in mathematics, with historical roots that led to the development of many central concepts in modern algebra, including groups and fields. Covering classic applications of the theory, such as solvability by radicals, geometric constructions, and finite fields, Galois Theory, Second Edition delves into novel topics like Abel’s theory of Abelian equations, casus irreducibili, and the Galo

  9. Game theory.

    Science.gov (United States)

    Dufwenberg, Martin

    2011-03-01

    Game theory is a toolkit for examining situations where decision makers influence each other. I discuss the nature of game-theoretic analysis, the history of game theory, why game theory is useful for understanding human psychology, and why game theory has played a key role in the recent explosion of interest in the field of behavioral economics. WIREs Cogni Sci 2011 2 167-173 DOI: 10.1002/wcs.119 For further resources related to this article, please visit the WIREs website.

  10. EL ORIGEN DE LAS ESPECIES Y SU RELACIÓNCON EL INICIO DE LA ACTUAL TEORÍA DE LA HERENCIA The Origin of Species and its Relation with the Birth of Present Genetic Theory

    Directory of Open Access Journals (Sweden)

    WILLIAM USAQUÉN MARTÍNEZ

    Full Text Available En la primera parte se mostrarán algunos elementos históricos relacionados con la "Philosophie Zoologique" de Jean-Baptiste Lamarck, obra fundamental de la biología moderna merecedora de una mención especial en su aniversario número 200. Esta obra contiene algunos conceptos impor-tantes para "The Origin of species by means of natural selection, or the preservation of favoured races in the struggle for life" el trabajo fundamental de Charles Darwin. Posteriormente se revisará la idea general de la pangénesis y sus diferentes contradicciones en la explicación de la variabilidad necesaria para la acción de la selección natural que culminarían con el nacimiento de la genética. Es importante mostrar la posición particular de los experimentos mendelianos en relación con el paradigma evo-lutivo causado por el origen de las especies.In the first part I present some historical elements related to the "Philosophie Zoologique" by Jean-Baptiste Lamarck, a fundamental work of modern biology. This work deserves a special mention in its 200th anniversary, since it contains some important concepts for "The Origin of Species by Means of Natural Selection, or the Preservation of favored races in the struggle for life" the principal work of Charles Darwin. Subsequently we review the pangenesis and various contradictions in the explanation of the variability required for the action of natural selection that culminate with the birth of genetics. In this paper is important show the particular position of Mendelian experiments in relation with the evolutionary paradigm caused by the origin of species.

  11. Exploring gravitational theories beyond Horndeski

    CERN Document Server

    Gleyzes, Jérôme; Piazza, Federico; Vernizzi, Filippo

    2014-01-01

    We have recently proposed a new class of gravitational scalar-tensor theories free from ghost instabilities. As they generalize Horndeski theories, or "generalized" galileons, we call them G$^3$. These theories possess a simple formulation when the time hypersurfaces are chosen to coincide with the uniform scalar field hypersurfaces. We confirm that they do not suffer from Ostrogradski instabilities by presenting the details of the Hamiltonian formulation. We examine the coupling between these theories and matter. Moreover, we investigate how they transform under a disformal redefinition of the metric. Remarkably, these theories are preserved by disformal transformations, which also allow subfamilies of G$^3$ to be mapped into Horndeski theories.

  12. Dispersion Decay and Scattering Theory

    CERN Document Server

    Komech, Alexander

    2012-01-01

    A simplified, yet rigorous treatment of scattering theory methods and their applications Dispersion Decay and Scattering Theory provides thorough, easy-to-understand guidance on the application of scattering theory methods to modern problems in mathematics, quantum physics, and mathematical physics. Introducing spectral methods with applications to dispersion time-decay and scattering theory, this book presents, for the first time, the Agmon-Jensen-Kato spectral theory for the Schr?dinger equation, extending the theory to the Klein-Gordon equation. The dispersion decay plays a crucial role i

  13. Weak interaction: past answers, present questions

    Energy Technology Data Exchange (ETDEWEB)

    Ne' eman, Y.

    1977-02-01

    A historical sketch of the weak interaction is presented. From beta ray to pion decay, the V-A theory of Marshak and Sudarshan, CVC principle of equivalence, universality as an algebraic condition, PCAC, renormalized weak Hamiltonian in the rehabilitation of field theory, and some current issues are considered in this review. 47 references. (JFP)

  14. Learning theory and gestalt therapy.

    Science.gov (United States)

    Harper, R; Bauer, R; Kannarkat, J

    1976-01-01

    This article discusses the theory and operations of Gestalt Therapy from the viewpoint of learning theory. General comparative issues are elaborated as well as the concepts of introjection, retroflextion, confluence, and projection. Principles and techniques of Gestalt Therapy are discussed in terms of learning theory paradigm. Practical implications of the various Gestalt techniques are presented.

  15. Theory of interacting quantum fields

    CERN Document Server

    Rebenko, Alexei L

    2012-01-01

    This monograph is devoted to the systematic and encyclopedic presentation of the foundations of quantum field theory. It represents mathematical problems of the quantum field theory with regardto the new methods of the constructive and Euclidean field theory formed for the last thirty years of the 20th century on the basis of rigorous mathematical tools of the functional analysis, the theory of operators, and the theory of generalized functions. The book is useful for young scientists who desire to understand not only the formal structure of the quantum field theory but also its basic concepts and connection with classical mechanics, relativistic classical field theory, quantum mechanics, group theory, and the theory of functional integration.

  16. Combinatorial and computational mathematics present and future

    CERN Document Server

    Hong, Sungpyo; Kim, Ki Hang; Roush, Fred W

    2001-01-01

    This book describes and summarizes past work in important areas of combinatorics and computation, as well as gives directions for researchers working in these areas in the 21st century. It contains primarily survey papers and presents original research by Peter Fishburn, Jim Ho Kwak, Jaeun Lee, K H Kim, F W Roush and Susan Williams. The papers deal with some of the most exciting and promising developments in the areas of coding theory in relation to number theory, lattice theory and its applications, graph theory and its applications, topological techniques in combinatorics, symbolic dynamics

  17. Presentation rubric: improving faculty professional presentations.

    Science.gov (United States)

    Hayne, Arlene N; McDaniel, Gretchen S

    2013-01-01

    This article describes the content of a presentation evaluation rubric for use in the development and improvement in faculty performance to enhance learning. Lectures or professional presentations require skills that can be learned through the use of evidence-based practices for all forms of public speaking. A core competency of nursing faculty is to serve as a role model in skilled oral communication. The use of an evaluation presentation rubric can increase faculty competency in this area. © 2013 Wiley Periodicals, Inc.

  18. 6D superconformal theory as the theory of everything

    CERN Document Server

    Smilga, A V

    2005-01-01

    We argue that the fundamental Theory of Everything is a conventional field theory defined in the flat multidimensional bulk. Our Universe should be obtained as a 3-brane classical solution in this theory. The renormalizability of the fundamental theory implies that it involves higher derivatives (HD). It should be supersymmetric (otherwise one cannot get rid of the huge induced cosmological term) and probably conformal (otherwise one can hardly cope with the problem of ghosts) . We present arguments that in conformal HD theories the ghosts (which are inherent for HD theories) might be not so malignant. In particular, we present a nontrivial QM HD model where ghosts are absent and the spectrum has a well defined ground state. The requirement of superconformal invariance restricts the dimension of the bulk to be D < 7. We suggest that the TOE lives in six dimensions and enjoys the maximum N = (2,0) superconformal symmetry. Unfortunately, no renormalizable field theory with this symmetry is presently known. W...

  19. Action Theory Evolution

    CERN Document Server

    Varzinczak, Ivan

    2008-01-01

    Like any other logical theory, domain descriptions in reasoning about actions may evolve, and thus need revision methods to adequately accommodate new information about the behavior of actions. The present work is about changing action domain descriptions in propositional dynamic logic. Its contribution is threefold: first we revisit the semantics of action theory contraction that has been done in previous work, giving more robust operators that express minimal change based on a notion of distance between Kripke-models. Second we give algorithms for syntactical action theory contraction and establish their correctness w.r.t. our semantics. Finally we state postulates for action theory contraction and assess the behavior of our operators w.r.t. them. Moreover, we also address the revision counterpart of action theory change, showing that it benefits from our semantics for contraction.

  20. Extended Theories of Gravity

    CERN Document Server

    Capozziello, Salvatore

    2011-01-01

    Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is aimed to address conceptual and experimental problems recently emerged in Astrophysics, Cosmology and High Energy Physics. In particular, the goal is to encompass, in a self-consistent scheme, problems like Inflation, Dark Energy, Dark Matter, Large Scale Structure and, first of all, to give at least an effective description of Quantum Gravity. We review the basic principles that any gravitational theory has to follow. The geometrical interpretation is discussed in a broad perspective in order to highlight the basic assumptions of General Relativity and its possible extensions in the general framework of gauge theories. Principles of such modifications are presented, focusing on specific classes of theories like f (R)-gravity and scalar-tensor gravity in the metric and Pala...

  1. Dual Double Field Theory

    CERN Document Server

    Bergshoeff, Eric A; Penas, Victor A; Riccioni, Fabio

    2016-01-01

    We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O(D,D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O(D,D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for "exotic" dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

  2. Nonlocal continuum field theories

    CERN Document Server

    2002-01-01

    Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unif...

  3. Quantum Theory

    CERN Document Server

    Manning, Phillip

    2011-01-01

    The study of quantum theory allowed twentieth-century scientists to examine the world in a new way, one that was filled with uncertainties and probabilities. Further study also led to the development of lasers, the atomic bomb, and the computer. This exciting new book clearly explains quantum theory and its everyday uses in our world.

  4. Uncertainty theory

    CERN Document Server

    Liu, Baoding

    2015-01-01

    When no samples are available to estimate a probability distribution, we have to invite some domain experts to evaluate the belief degree that each event will happen. Perhaps some people think that the belief degree should be modeled by subjective probability or fuzzy set theory. However, it is usually inappropriate because both of them may lead to counterintuitive results in this case. In order to rationally deal with belief degrees, uncertainty theory was founded in 2007 and subsequently studied by many researchers. Nowadays, uncertainty theory has become a branch of axiomatic mathematics for modeling belief degrees. This is an introductory textbook on uncertainty theory, uncertain programming, uncertain statistics, uncertain risk analysis, uncertain reliability analysis, uncertain set, uncertain logic, uncertain inference, uncertain process, uncertain calculus, and uncertain differential equation. This textbook also shows applications of uncertainty theory to scheduling, logistics, networks, data mining, c...

  5. Conspiracy Theory

    DEFF Research Database (Denmark)

    Bjerg, Ole; Presskorn-Thygesen, Thomas

    2017-01-01

    The paper is a contribution to current debates about conspiracy theories within philosophy and cultural studies. Wittgenstein’s understanding of language is invoked to analyse the epistemological effects of designating particular questions and explanations as a ‘conspiracy theory......’. It is demonstrated how such a designation relegates these questions and explanations beyond the realm of meaningful discourse. In addition, Agamben’s concept of sovereignty is applied to explore the political effects of using the concept of conspiracy theory. The exceptional epistemological status assigned...... to alleged conspiracy theories within our prevalent paradigms of knowledge and truth is compared to the exceptional legal status assigned to individuals accused of terrorism under the War on Terror. The paper concludes by discussing the relation between conspiracy theory and ‘the paranoid style...

  6. Concept theory

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2009-01-01

      Concept theory is an extremely broad, interdisciplinary and complex field of research related to many deep fields with very long historical traditions without much consensus. However, information science and knowledge organization cannot avoid relating to theories of concepts. Knowledge...... organizing systems (e.g. classification systems, thesauri and ontologies) should be understood as systems basically organizing concepts and their semantic relations. The same is the case with information retrieval systems. Different theories of concepts have different implications for how to construe......, evaluate and use such systems. Based on "a post-Kuhnian view" of paradigms this paper put forward arguments that the best understanding and classification of theories of concepts is to view and classify them in accordance with epistemological theories (empiricism, rationalism, historicism and pragmatism...

  7. Conspiracy Theory

    DEFF Research Database (Denmark)

    Bjerg, Ole; Presskorn-Thygesen, Thomas

    2017-01-01

    The paper is a contribution to current debates about conspiracy theories within philosophy and cultural studies. Wittgenstein’s understanding of language is invoked to analyse the epistemological effects of designating particular questions and explanations as a ‘conspiracy theory......’. It is demonstrated how such a designation relegates these questions and explanations beyond the realm of meaningful discourse. In addition, Agamben’s concept of sovereignty is applied to explore the political effects of using the concept of conspiracy theory. The exceptional epistemological status assigned...... to alleged conspiracy theories within our prevalent paradigms of knowledge and truth is compared to the exceptional legal status assigned to individuals accused of terrorism under the War on Terror. The paper concludes by discussing the relation between conspiracy theory and ‘the paranoid style...

  8. Elementary number theory with programming

    CERN Document Server

    Lewinter, Marty

    2015-01-01

    A successful presentation of the fundamental concepts of number theory and computer programming Bridging an existing gap between mathematics and programming, Elementary Number Theory with Programming provides a unique introduction to elementary number theory with fundamental coverage of computer programming. Written by highly-qualified experts in the fields of computer science and mathematics, the book features accessible coverage for readers with various levels of experience and explores number theory in the context of programming without relying on advanced prerequisite knowledge and con

  9. Quaternionic-like manifolds and homogeneous twistor spaces.

    Science.gov (United States)

    Pantilie, Radu

    2016-12-01

    Motivated by the quaternionic geometry corresponding to the homogeneous complex manifolds endowed with (holomorphically) embedded spheres, we introduce and initiate the study of the 'quaternionic-like manifolds'. These contain, as particular subclasses, the CR quaternionic and the ρ-quaternionic manifolds. Moreover, the notion of 'heaven space' finds its adequate level of generality in this setting: (essentially) any real analytic quaternionic-like manifold admits a (germ) unique heaven space, which is a ρ-quaternionic manifold. We, also, give a natural construction of homogeneous complex manifolds endowed with embedded spheres, thus, emphasizing the abundance of the quaternionic-like manifolds.

  10. Technical presentation: Next Generation Oscilloscopes

    CERN Multimedia

    PH Department

    2011-01-01

      Rohde & Schwarz "Next Generation Oscilloscopes" - Introduction and Presentation Agenda: Wednesday 23 March  -  09:30 to 11:30 (open end) Bldg. 13-2-005 Language: English 09.30 Presentation "Next Generation Oscilloscopes" from Rohde & Schwarz RTO / RTM in theory and practice Gerard Walker 10.15 Technical design details from R&D Dr. Markus Freidhof 10.45 Scope and Probe Roadmap (confidential) Guido Schulze 11.00 Open Discussion Feedback, first impression, wishes, needs and requirements from CERN All 11.30 Expert Talks, Hands on All Mr. Dr. Markus Freidhof, Head of R&D Oscilloscopes, Rohde & Schwarz, Germany; Mr. Guido Schulze, ...

  11. Toward a Unified Consciousness Theory

    Science.gov (United States)

    Johnson, Richard H.

    1977-01-01

    The beginning of a holistic theory that can treat paranormal phenomena as normal human development is presented. Implications for counseling, counselor education, and counselor supervision are discussed. (Author)

  12. Theories in Social Policy and Development Studies

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    Theories in Social Policy and Development Studies Presentation for the PhD Seminar - Theories, Concepts and Methods in Development Studies and Sociology......Theories in Social Policy and Development Studies Presentation for the PhD Seminar - Theories, Concepts and Methods in Development Studies and Sociology...

  13. Making your presentation fun: creative presentation techniques

    Energy Technology Data Exchange (ETDEWEB)

    KEENEN,MARTHA JANE

    2000-05-18

    What possesses someone to volunteer and go through hoops and red tape to make a presentation at a conference? For that matter, why does anyone ever present anything to anyone? Actually, presentations are a fact of life and there are many reasons for doing a presentation and doing it well. New and existing staff need training and orientation to the way things are done here. Handing all of them a manual and hoping they read it is pretty much a waste of paper. On the other hand, an effective, entertaining and upbeat presentation on the relevant topics is more likely to stick with those people. They will even have a name and face to remember and seek out when they have an issue on or with that topic. This can be a very effective beginning for networking with new peers. The presenter is seen as knowledgeable, as a source of information on company topics and possibly evaluated as a potential mentor or future manager. Project staff and/or peers benefit from clear, concise, presentations of topical knowledge. This is one way that a group working on various aspects of the same project or program can stay in touch and in step with each other. Most importantly, presentations may be the best or only door into the minds (and budgets) of management and customers. These presentations are a wonderful opportunity to address legal and compliance issues, budget, staffing, and services. Here is a chance, maybe the only one, to demonstrate and explain the wonderfulness of a program and the benefit they get by using the services offered most effectively. An interactive presentation on legal and compliance issues can be an effective tool in helping customers and/or management make good risk management decisions.

  14. Universality and string theory

    Science.gov (United States)

    Bachlechner, Thomas Christian

    The first run at the Large Hadron Collider has deeply challenged conventional notions of naturalness, and CMB polarization experiments are about to open a new window to early universe cosmology. As a compelling candidate for the ultraviolet completion of the standard model, string theory provides a prime opportunity to study both early universe cosmology and particle physics. However, relating low energy observations to ultraviolet physics requires knowledge of the metastable states of string theory through the study of vacua. While it is difficult to directly obtain infrared data from explicit string theory constructions, string theory imposes constraints on low energy physics. The study of ensembles of low energy theories consistent with ultra-violet constraints provides insight on generic features we might expect to occur in string compactifications. In this thesis we present a statistical treatment of vacuum stability and vacuum properties in the context of random supergravity theories motivated by string theory. Early universe cosmology provides another avenue to high energy physics. From the low energy perspective large field inflation is typically considered highly unnatural: the scale relevant for the diameter of flat regions in moduli space is sub-Planckian in regions of perturbative control. To approach this problem, we consider generic Calabi-Yau compactifications of string theory and find that super-Planckian diameters of axion fundamental domains in fact arise generically. We further demonstrate that such super-Planckian flat regions are plausibly consistent with theWeak Gravity Conjecture.

  15. [United theory of aging].

    Science.gov (United States)

    Trubitsyn, A G

    2012-01-01

    In attempts to develop a means of life prolongation the humankind has created more than three hundred theories of the aging; each of them offers the original cause of aging. However, none of them has given practical result by now. The majority of the theories have now only historical interest. There are several different theories that are mainly under consideration currently. They are based on reliable, proven evidence: the free radical theory, the protein error theory, the replicative senescence theory, the theory of reparation weakening, the immunological theory, several versions of neuroendocrinal theories, and programmed aging theory. The theory presented here is based on conception that the life as the phenomenon represents many of the interconnected physical and chemical processes propelled by energy of the mitochondrial bioenergetical machine. Gradual degradation of all vital processes is caused by the programmed decrease in level of bioenergetics. This theory unites all existing theories of aging constructed on authentic facts: it is shown, that such fundamental phenomena accompanying aging process as the increase in level of reactive oxygen species (ROS), the decrease in the general level of protein synthesis, the limitation of cellular dividing (Haiflick limit), decrease in efficiency of reparation mechanisms are caused by bioenergetics attenuation. Each of these phenomena in turn generates a number of harmful secondary processes. Any of the theories bases on one of these destructive phenomena or their combination. Hence, each of them describes one of sides of process of the aging initially caused by programmed decrease of level of bioenergetics. This united theory gives the chance to understand the nature of aging clock and explains a phenomenon of increase in longevity at the condition of food restriction. Failures of attempts to develop means from aging are explained by that the manipulations with the separate secondary phenomena of attenuation of

  16. Basic ergodic theory

    CERN Document Server

    Nadkarni, M G

    2013-01-01

    This is an introductory book on Ergodic Theory. The presentation has a slow pace and the book can be read by any person with a background in basic measure theory and metric topology. A new feature of the book is that the basic topics of Ergodic Theory such as the Poincare recurrence lemma, induced automorphisms and Kakutani towers, compressibility and E. Hopf's theorem, the theorem of Ambrose on representation of flows are treated at the descriptive set-theoretic level before their measure-theoretic or topological versions are presented. In addition, topics around the Glimm-Effros theorem are discussed. In the third edition a chapter entitled 'Additional Topics' has been added. It gives Liouville's Theorem on the existence of invariant measure, entropy theory leading up to Kolmogorov-Sinai Theorem, and the topological dynamics proof of van der Waerden's theorem on arithmetical progressions.

  17. Strategic Paralysis: An Airpower Theory for the Present

    Science.gov (United States)

    1992-05-01

    Attacks on a Country�s NEVs 94 10. The Enemy�s Alliance Network 97 11. New England Power Associations Electric Grid 105 12. De Seversky�s Octopus ...vulnerabilities, i.e. hidden, buried, or camouflaged . Strategic Paralysis assumes that attacks on these highly prized elements will not only shock and...grappling with those limbs and cannot strike at his heart. ...To grasp the strategic layout, think of Japan as a giant octopus . [See Figure 12]206

  18. Theory of THz harmonic generation in semiconductor superlattices (Conference Presentation)

    Science.gov (United States)

    Pereira, Mauro F.; Winge, David O.; Wacker, Andreas

    2016-10-01

    Superlattices are artificial structures with a wide range of applications and open possibilities for controlling and study transport and optical [M.F. Pereira Jr., Phys. Rev. B 52, (1995)] properties of semiconductors. In this work, we start from the full Nonequilibrium Greens Functions approach [A. Wacker et a, IEEE Journal of Sel. Top. in Quantum Electron.,19 1200611, (2013),T. Schmielau and M.F. Pereira, Appl. Phys. Lett. 95 231111, (2009)] to obtain Voltage-Current curves and compare them with experiments. By adjusting the numerical solutions of the corresponding Dyson equations to a simple model, analytical solutions are given for the nonlinear response of a biased superlattice under sub-THz radiation. The frequency multiplication process leading to multiple harmonicgeneration is described. This hybrid approach leads to predictive simulations and may have important application for a new generation of devices where the superlattices are used as both sources and detectors and may be particular useful for high resolution transient spectroscopy [A.A. Yablokov et at, IEEE Transactions on THz Science and Technology 5, 845 (2015)].

  19. Auditory Processing Theories of Language Disorders: Past, Present, and Future

    Science.gov (United States)

    Miller, Carol A.

    2011-01-01

    Purpose: The purpose of this article is to provide information that will assist readers in understanding and interpreting research literature on the role of auditory processing in communication disorders. Method: A narrative review was used to summarize and synthesize the literature on auditory processing deficits in children with auditory…

  20. Unconfined Aquifer Flow Theory - from Dupuit to present

    CERN Document Server

    Mishra, Phoolendra K

    2013-01-01

    Analytic and semi-analytic solution are often used by researchers and practicioners to estimate aquifer parameters from unconfined aquifer pumping tests. The non-linearities associated with unconfined (i.e., water table) aquifer tests makes their analysis more complex than confined tests. Although analytical solutions for unconfined flow began in the mid-1800s with Dupuit, Thiem was possibly the first to use them to estimate aquifer parameters from pumping tests in the early 1900s. In the 1950s, Boulton developed the first transient well test solution specialized to unconfined flow. By the 1970s Neuman had developed solutions considering both primary transient storage mechanisms (confined storage and delayed yield) without non-physical fitting parameters. In the last decade, research into developing unconfined aquifer test solutions has mostly focused on explicitly coupling the aquifer with the linearized vadose zone. Despite the many advanced solution methods available, there still exists a need for realism ...

  1. Cosmology Theory and Observations

    CERN Document Server

    Dolgov, A D

    1998-01-01

    The comparison of the Standard Cosmological Model (SCM) with astronomical observations, i.e. theory versus experiment, and with the Minimal Standard Model (MSM) in particle physics, i.e. theory versus theory, is discussed. The main issue of this talk is whether cosmology indicates new physics beyond the standard $SU(3)\\times SU(2)\\times U(1)$ model with minimal particle content. The answer to this question is strongly and definitely "YES". New, yet unknown, physics exists and cosmology presents very weighty arguments in its favor.

  2. Generalized Supersymmetric Perturbation Theory

    Institute of Scientific and Technical Information of China (English)

    B. G(o)n(ǖ)l

    2004-01-01

    @@ Using the basic ingredient of supersymmetry, a simple alternative approach is developed to perturbation theory in one-dimensional non-relativistic quantum mechanics. The formulae for the energy shifts and wavefunctions do not involve tedious calculations which appear in the available perturbation theories. The model applicable in the same form to both the ground state and excited bound states, unlike the recently introduced supersymmetric perturbation technique which, together with other approaches based on logarithmic perturbation theory, are involved within the more general framework of the present formalism.

  3. Theory of relations

    CERN Document Server

    Fraïssé, R

    2011-01-01

    The first part of this book concerns the present state of the theory of chains (= total or linear orderings), in connection with some refinements of Ramsey's theorem, due to Galvin and Nash-Williams. This leads to the fundamental Laver's embeddability theorem for scattered chains, using Nash-Williams' better quasi-orderings, barriers and forerunning.The second part (chapters 9 to 12) extends to general relations the main notions and results from order-type theory. An important connection appears with permutation theory (Cameron, Pouzet, Livingstone and Wagner) and with logics (existence criter

  4. Theories of information behavior

    CERN Document Server

    Erdelez, Sandra; McKechnie, Lynne

    2005-01-01

    This unique book presents authoritative overviews of more than 70 conceptual frameworks for understanding how people seek, manage, share, and use information in different contexts. A practical and readable reference to both well-established and newly proposed theories of information behavior, the book includes contributions from 85 scholars from 10 countries. Each theory description covers origins, propositions, methodological implications, usage, links to related conceptual frameworks, and listings of authoritative primary and secondary references. The introductory chapters explain key concepts, theory–method connections, and the process of theory development.

  5. Economic Selection Theory

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn

    2003-01-01

    The present article provides a minimal description of the causal structure of economic selection theory and outlines how the internal selection dynamics of business organisations can be reconciled with selection in competitive markets. In addition to generic similarity in terms of the Darwinian...... principles of variation, continuity and selection, it is argued that economic selection theory should mimic the causal structure of neo-Darwinian theory. Two of the most influential explanations of economic evolution, Alchian's and Nelson and Winter's, are used to illustrate how this could be achieved....

  6. Theory of simple liquids

    CERN Document Server

    Hansen, Jean-Pierre

    1986-01-01

    This book gives a comprehensive and up-to-date treatment of the theory of ""simple"" liquids. The new second edition has been rearranged and considerably expanded to give a balanced account both of basic theory and of the advances of the past decade. It presents the main ideas of modern liquid state theory in a way that is both pedagogical and self-contained. The book should be accessible to graduate students and research workers, both experimentalists and theorists, who have a good background in elementary mechanics.Key Features* Compares theoretical deductions with experimental r

  7. Economic Selection Theory

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn

    2003-01-01

    The present article provides a minimal description of the causal structure of economic selection theory and outlines how the internal selection dynamics of business organisations can be reconciled with selection in competitive markets. In addition to generic similarity in terms of the Darwinian...... principles of variation, continuity and selection, it is argued that economic selection theory should mimic the causal structure of neo-Darwinian theory. Two of the most influential explanations of economic evolution, Alchian's and Nelson and Winter's, are used to illustrate how this could be achieved....

  8. Theory of distributions

    CERN Document Server

    Georgiev, Svetlin G

    2015-01-01

    This book explains many fundamental ideas on the theory of distributions. The theory of partial differential equations is one of the synthetic branches of analysis that combines ideas and methods from different fields of mathematics, ranging from functional analysis and harmonic analysis to differential geometry and topology. This presents specific difficulties to those studying this field. This book, which consists of 10 chapters, is suitable for upper undergraduate/graduate students and mathematicians seeking an accessible introduction to some aspects of the theory of distributions. It can also be used for one-semester course.

  9. Theory of intermolecular forces

    CERN Document Server

    Margenau, H; Ter Haar, D

    1971-01-01

    Theory of Intermolecular Forces deals with the exposition of the principles and techniques of the theory of intermolecular forces. The text focuses on the basic theory and surveys other aspects, with particular attention to relevant experiments. The initial chapters introduce the reader to the history of intermolecular forces. Succeeding chapters present topics on short, intermediate, and long range atomic interactions; properties of Coulomb interactions; shape-dependent forces between molecules; and physical adsorption. The book will be of good use to experts and students of quantum mechanics

  10. Bayesian Theory

    CERN Document Server

    Bernardo, Jose M

    2000-01-01

    This highly acclaimed text, now available in paperback, provides a thorough account of key concepts and theoretical results, with particular emphasis on viewing statistical inference as a special case of decision theory. Information-theoretic concepts play a central role in the development of the theory, which provides, in particular, a detailed discussion of the problem of specification of so-called prior ignorance . The work is written from the authors s committed Bayesian perspective, but an overview of non-Bayesian theories is also provided, and each chapter contains a wide-ranging critica

  11. Psychodynamic Theory

    Directory of Open Access Journals (Sweden)

    Kathleen Holtz Deal

    2007-05-01

    Full Text Available Psychodynamic theory, a theory of personality originated by Sigmund Freud, has a long and complex history within social work and continues to be utilized by social workers. This article traces the theory’s development and explains key concepts with an emphasis on its current relational focus within object relations theory and self-psychology. Empirical support for theoretical concepts and the effectiveness of psychodynamic therapies is reviewed and critiqued. Future directions are discussed, including addressing cultural considerations, increasing research, and emphasizing a relational paradigm

  12. Number theory

    CERN Document Server

    Andrews, George E

    1994-01-01

    Although mathematics majors are usually conversant with number theory by the time they have completed a course in abstract algebra, other undergraduates, especially those in education and the liberal arts, often need a more basic introduction to the topic.In this book the author solves the problem of maintaining the interest of students at both levels by offering a combinatorial approach to elementary number theory. In studying number theory from such a perspective, mathematics majors are spared repetition and provided with new insights, while other students benefit from the consequent simpl

  13. Mapping Theory

    DEFF Research Database (Denmark)

    Smith, Shelley

    This paper came about within the context of a 13-month research project, Focus Area 1 - Method and Theory, at the Center for Public Space Research at the Royal Academy of the Arts School of Architecture in Copenhagen, Denmark. This project has been funded by RealDania. The goals of the research...... project, Focus Area 1 - Method and Theory, which forms the framework for this working paper, are: * To provide a basis from which to discuss the concept of public space in a contemporary architectural and urban context - specifically relating to theory and method * To broaden the discussion of the concept...

  14. Plasticity theory

    CERN Document Server

    Lubliner, Jacob

    2008-01-01

    The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

  15. Present and future in lexicography

    Directory of Open Access Journals (Sweden)

    Félix Bugueño Miranda

    2013-08-01

    Full Text Available The purpose of this lecture is to demonstrate the evolution of lexicography from the practical task of compiling dictionaries to their theoretical approach as reference works. The first issue to be discussed is the status of the discipline itself, since there are lexicographers, like Atkins; Rundell (2008, that deny the existence of a lexicographic theory. Secondly, and accepting that a lexicographical theory does exist, we present the main advances in the area, such as the research on dictionary classification, the criteria used to calculate the number of headwords in a dictionary (macrostructure, the set of comments that appear in each entry (microstructure and the system of cross-references (middlestructure. Finally, the lecture will offer a reflection on the normativity in dictionaries.

  16. Recursion theory for metamathematics

    CERN Document Server

    Smullyan, Raymond M

    1993-01-01

    This work is a sequel to the author''s Godel''s Incompleteness Theorems, though it can be read independently by anyone familiar with Godel''s incompleteness theorem for Peano arithmetic. The book deals mainly with those aspects of recursion theory that have applications to the metamathematics of incompleteness, undecidability, and related topics. It is both an introduction to the theory and a presentation of new results in the field.

  17. Linear network theory

    CERN Document Server

    Sander, K F

    1964-01-01

    Linear Network Theory covers the significant algebraic aspect of network theory, with minimal reference to practical circuits. The book begins the presentation of network analysis with the exposition of networks containing resistances only, and follows it up with a discussion of networks involving inductance and capacity by way of the differential equations. Classification and description of certain networks, equivalent networks, filter circuits, and network functions are also covered. Electrical engineers, technicians, electronics engineers, electricians, and students learning the intricacies

  18. On Action Theory Change

    OpenAIRE

    Varzinczak, Ivan José

    2014-01-01

    As historically acknowledged in the Reasoning about Actions and Change community, intuitiveness of a logical domain description cannot be fully automated. Moreover, like any other logical theory, action theories may also evolve, and thus knowledge engineers need revision methods to help in accommodating new incoming information about the behavior of actions in an adequate manner. The present work is about changing action domain descriptions in multimodal logic. Its contribution is threefold: ...

  19. Action Theory Evolution

    OpenAIRE

    Varzinczak, Ivan

    2008-01-01

    Like any other logical theory, domain descriptions in reasoning about actions may evolve, and thus need revision methods to adequately accommodate new information about the behavior of actions. The present work is about changing action domain descriptions in propositional dynamic logic. Its contribution is threefold: first we revisit the semantics of action theory contraction that has been done in previous work, giving more robust operators that express minimal change based on a notion of dis...

  20. Information field theory

    OpenAIRE

    Enßlin, Torsten

    2013-01-01

    Non-linear image reconstruction and signal analysis deal with complex inverse problems. To tackle such problems in a systematic way, I present information field theory (IFT) as a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms even for non-linear and non-Gaussian signal inference problems. IFT algorithms exploit spatial correlations of the signal fields and b...

  1. Chaos theory in politics

    CERN Document Server

    Erçetin, Şefika; Tekin, Ali

    2014-01-01

    The present work investigates global politics and political implications of social science and management with the aid of the latest complexity and chaos theories. Until now, deterministic chaos and nonlinear analysis have not been a focal point in this area of research. This book remedies this deficiency by utilizing these methods in the analysis of the subject matter. The authors provide the reader a detailed analysis on politics and its associated applications with the help of chaos theory, in a single edited volume.

  2. Evolutionary Theories of Aging and Longevity

    Directory of Open Access Journals (Sweden)

    Leonid A. Gavrilov

    2002-01-01

    Full Text Available The purpose of this article is to provide students and researchers entering the field of aging studies with an introduction to the evolutionary theories of aging, as well as to orient them in the abundant modern scientific literature on evolutionary gerontology. The following three major evolutionary theories of aging are discussed: 1 the theory of programmed death suggested by August Weismann, 2 the mutation accumulation theory of aging suggested by Peter Medawar, and 3 the antagonistic pleiotropy theory of aging suggested by George Williams. We also discuss a special case of the antagonistic pleiotropy theory, the disposable soma theory developed by Tom Kirkwood and Robin Holliday. The theories are compared with each other as well as with recent experimental findings. At present the most viable evolutionary theories are the mutation accumulation theory and the antagonistic pleiotropy theory; these theories are not mutually exclusive, and they both may become a part of a future unifying theory of aging.

  3. Model theory

    CERN Document Server

    Hodges, Wilfrid

    1993-01-01

    An up-to-date and integrated introduction to model theory, designed to be used for graduate courses (for students who are familiar with first-order logic), and as a reference for more experienced logicians and mathematicians.

  4. Activity Theory.

    Science.gov (United States)

    Koschmann, Timothy; Roschelle, Jeremy; Nardi, Bonnie A.

    1998-01-01

    Includes three articles that discuss activity theory, based on "Context and Consciousness." Topics include human-computer interaction; computer interfaces; hierarchical structuring; mediation; contradictions and development; failure analysis; and designing educational technology. (LRW)

  5. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 4th edition of this textbook on linear stochastic vibration...

  6. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 2nd edition of this textbook on linear stochastic vibration th...

  7. Matrix Theory

    Science.gov (United States)

    1988-06-30

    MATRICES . The monograph Nonnegative Matrices [6] is an advanced book on all aspect of the theory of nonnegative matrices and...and on inverse eigenvalue problems for nonnegative matrices . The work explores some of the most recent developments in the theory of nonnegative...k -1, t0 . Define the associated polynomial of type <z>: t t-t 2 t-t 3 t-tk_ 1,X - x - x . . .X- where t = tk . The

  8. Unifying Theories in Isabelle/HOL

    Science.gov (United States)

    Feliachi, Abderrahmane; Gaudel, Marie-Claude; Wolff, Burkhart

    In this paper, we present various extensions of Isabelle/HOL by theories that are essential for several formal methods. First, we explain how we have developed an Isabelle/HOL theory for a part of the Unifying Theories of Programming (UTP). It contains the theories of alphabetized relations and designs. Then we explain how we have encoded first the theory of reactive processes and then the UTP theory for CSP. Our work takes advantage of the rich existing logical core of HOL.

  9. A panorama of discrepancy theory

    CERN Document Server

    Srivastav, Anand; Travaglini, Giancarlo

    2014-01-01

    Discrepancy theory concerns the problem of replacing a continuous object with a discrete sampling. Discrepancy theory is currently at a crossroads between number theory, combinatorics, Fourier analysis, algorithms and complexity, probability theory and numerical analysis. There are several excellent books on discrepancy theory but perhaps no one of them actually shows the present variety of points of view and applications covering the areas "Classical and Geometric Discrepancy Theory", "Combinatorial Discrepancy Theory" and "Applications and Constructions". Our book consists of several chapters, written by experts in the specific areas, and focused on the different aspects of the theory. The book should also be an invitation to researchers and students to find a quick way into the different methods and to motivate interdisciplinary research.

  10. Phonological Derivation in Optimality Theory

    CERN Document Server

    Ellison, T M

    1994-01-01

    Optimality Theory is a constraint-based theory of phonology which allows constraints to be violated. Consequently, implementing the theory presents problems for declarative constraint-based processing frameworks. On the basis of two regularity assumptions, that candidate sets are regular and that constraints can be modelled by transducers, this paper presents and proves correct algorithms for computing the action of constraints, and hence deriving surface forms.

  11. Categorification and higher representation theory

    CERN Document Server

    Beliakova, Anna

    2017-01-01

    The emergent mathematical philosophy of categorification is reshaping our view of modern mathematics by uncovering a hidden layer of structure in mathematics, revealing richer and more robust structures capable of describing more complex phenomena. Categorified representation theory, or higher representation theory, aims to understand a new level of structure present in representation theory. Rather than studying actions of algebras on vector spaces where algebra elements act by linear endomorphisms of the vector space, higher representation theory describes the structure present when algebras act on categories, with algebra elements acting by functors. The new level of structure in higher representation theory arises by studying the natural transformations between functors. This enhanced perspective brings into play a powerful new set of tools that deepens our understanding of traditional representation theory. This volume exhibits some of the current trends in higher representation theory and the diverse te...

  12. Modern graph theory

    CERN Document Server

    Bollobás, Béla

    1998-01-01

    The time has now come when graph theory should be part of the education of every serious student of mathematics and computer science, both for its own sake and to enhance the appreciation of mathematics as a whole. This book is an in-depth account of graph theory, written with such a student in mind; it reflects the current state of the subject and emphasizes connections with other branches of pure mathematics. The volume grew out of the author's earlier book, Graph Theory -- An Introductory Course, but its length is well over twice that of its predecessor, allowing it to reveal many exciting new developments in the subject. Recognizing that graph theory is one of several courses competing for the attention of a student, the book contains extensive descriptive passages designed to convey the flavor of the subject and to arouse interest. In addition to a modern treatment of the classical areas of graph theory such as coloring, matching, extremal theory, and algebraic graph theory, the book presents a detailed ...

  13. Set theory and physics

    Energy Technology Data Exchange (ETDEWEB)

    Svozil, K. [Univ. of Technology, Vienna (Austria)

    1995-11-01

    Inasmuch as physical theories are formalizable, set theory provides a framework for theoretical physics. Four speculations about the relevance of set theoretical modeling for physics are presented: the role of transcendental set theory (i) in chaos theory, (ii) for paradoxical decompositions of solid three-dimensional objects, (iii) in the theory of effective computability (Church-Turing thesis) related to the possible {open_quotes}solution of supertasks,{close_quotes} and (iv) for weak solutions. Several approaches to set theory and their advantages and disadvantages for physical applications are discussed: Cantorian {open_quotes}naive{close_quotes} (i.e., nonaxiomatic) set theory, contructivism, and operationalism. In the author`s opinion, an attitude, of {open_quotes}suspended attention{close_quotes} (a term borrowed from psychoanalysis) seems most promising for progress. Physical and set theoretical entities must be operationalized wherever possible. At the same time, physicists should be open to {open_quotes}bizarre{close_quotes} or {open_quotes}mindboggling{close_quotes} new formalisms, which need not be operationalizable or testable at the time of their creation, but which may successfully lead to novel fields of phenomenology and technology.

  14. Compatible quantum theory.

    Science.gov (United States)

    Friedberg, R; Hohenberg, P C

    2014-09-01

    Formulations of quantum mechanics (QM) can be characterized as realistic, operationalist, or a combination of the two. In this paper a realistic theory is defined as describing a closed system entirely by means of entities and concepts pertaining to the system. An operationalist theory, on the other hand, requires in addition entities external to the system. A realistic formulation comprises an ontology, the set of (mathematical) entities that describe the system, and assertions, the set of correct statements (predictions) the theory makes about the objects in the ontology. Classical mechanics is the prime example of a realistic physical theory. A straightforward generalization of classical mechanics to QM is hampered by the inconsistency of quantum properties with classical logic, a circumstance that was noted many years ago by Birkhoff and von Neumann. The present realistic formulation of the histories approach originally introduced by Griffiths, which we call 'compatible quantum theory (CQT)', consists of a 'microscopic' part (MIQM), which applies to a closed quantum system of any size, and a 'macroscopic' part (MAQM), which requires the participation of a large (ideally, an infinite) system. The first (MIQM) can be fully formulated based solely on the assumption of a Hilbert space ontology and the noncontextuality of probability values, relying in an essential way on Gleason's theorem and on an application to dynamics due in large part to Nistico. Thus, the present formulation, in contrast to earlier ones, derives the Born probability formulas and the consistency (decoherence) conditions for frameworks. The microscopic theory does not, however, possess a unique corpus of assertions, but rather a multiplicity of contextual truths ('c-truths'), each one associated with a different framework. This circumstance leads us to consider the microscopic theory to be physically indeterminate and therefore incomplete, though logically coherent. The completion of the theory

  15. Compatible quantum theory

    Science.gov (United States)

    Friedberg, R.; Hohenberg, P. C.

    2014-09-01

    Formulations of quantum mechanics (QM) can be characterized as realistic, operationalist, or a combination of the two. In this paper a realistic theory is defined as describing a closed system entirely by means of entities and concepts pertaining to the system. An operationalist theory, on the other hand, requires in addition entities external to the system. A realistic formulation comprises an ontology, the set of (mathematical) entities that describe the system, and assertions, the set of correct statements (predictions) the theory makes about the objects in the ontology. Classical mechanics is the prime example of a realistic physical theory. A straightforward generalization of classical mechanics to QM is hampered by the inconsistency of quantum properties with classical logic, a circumstance that was noted many years ago by Birkhoff and von Neumann. The present realistic formulation of the histories approach originally introduced by Griffiths, which we call ‘compatible quantum theory (CQT)’, consists of a ‘microscopic’ part (MIQM), which applies to a closed quantum system of any size, and a ‘macroscopic’ part (MAQM), which requires the participation of a large (ideally, an infinite) system. The first (MIQM) can be fully formulated based solely on the assumption of a Hilbert space ontology and the noncontextuality of probability values, relying in an essential way on Gleason's theorem and on an application to dynamics due in large part to Nistico. Thus, the present formulation, in contrast to earlier ones, derives the Born probability formulas and the consistency (decoherence) conditions for frameworks. The microscopic theory does not, however, possess a unique corpus of assertions, but rather a multiplicity of contextual truths (‘c-truths’), each one associated with a different framework. This circumstance leads us to consider the microscopic theory to be physically indeterminate and therefore incomplete, though logically coherent. The

  16. Develop your presentation skills

    CERN Document Server

    Theobald, Theo

    2016-01-01

    Going beyond handling nerves and presenting PowerPoint slides, the third edition of "Develop Your Presentation Skills "offers practical advice on developing a captivating presentation, constructing compelling content, and boosting self-confidence. The book includes three new chapters on delivering a "stripped down"presentation, using new media to engage with the audience, and handling being asked to present on short notice."

  17. Teaching Presentation Skills

    Science.gov (United States)

    Baker, William H.; Thompson, Michael P.

    2004-01-01

    Effective teaching of presentation skills focuses on the most important element of the presentation--the message itself. Some instructors place the heaviest emphasis on the messenger (the presenter) and focus their presentation feedback on all the presenter is doing wrong--saying "um," gesturing awkwardly, and so forth. When students receive this…

  18. Theory of gravitational interactions

    CERN Document Server

    Gasperini, Maurizio

    2017-01-01

    This is the second edition of a well-received book that is a modern, self-contained introduction to the theory of gravitational interactions. The new edition includes more details on gravitational waves of cosmological origin, the so-called brane world scenario, and gravitational time-delay effects. The first part of the book follows the traditional presentation of general relativity as a geometric theory of the macroscopic gravitational field, while the second, more advanced part discusses the deep analogies (and differences) between a geometric theory of gravity and the “gauge” theories of the other fundamental interactions. This fills a gap within the traditional approach to general relativity which usually leaves students puzzled about the role of gravity. The required notions of differential geometry are reduced to the minimum, allowing room for aspects of gravitational physics of current phenomenological and theoretical interest, such as the properties of gravitational waves, the gravitational inter...

  19. Theories of everything

    CERN Document Server

    Close, Frank

    2017-01-01

    Physicist Frank Close takes the reader to the frontiers of science in a vividly told investigation of revolutionary science and enterprise from the seventeenth century to the present. He looks at what has been meant by theories of everything, explores the scientific breakthroughs they have allowed, and shows the far-reaching effects they have had on crucial aspects of life and belief. Theories of everything, he argues, can be described as those which draw on all relevant branches of knowledge to explain everything known about the universe. Such accounts may reign supreme for centuries. Then, often as a result of the advances they themselves have enabled, a new discovery is made which the current theory cannot explain. A new theory is needed which inspiration, sometimes, supplies. Moving from Isaac Newton's work on gravity and motion in the seventeenth century to thermodynamics and James Clerk Maxwell's laws of electromagnetism in the nineteenth to Max Planck's and Paul Dirac's quantum physics in the twentiet...

  20. Possibility Theory versus Probability Theory in Fuzzy Measure Theory

    Directory of Open Access Journals (Sweden)

    Parul Agarwal

    2015-05-01

    Full Text Available The purpose of this paper is to compare probability theory with possibility theory, and to use this comparison in comparing probability theory with fuzzy set theory. The best way of comparing probabilistic and possibilistic conceptualizations of uncertainty is to examine the two theories from a broader perspective. Such a perspective is offered by evidence theory, within which probability theory and possibility theory are recognized as special branches. While the various characteristic of possibility theory within the broader framework of evidence theory are expounded in this paper, we need to introduce their probabilistic counterparts to facilitate our discussion.

  1. Evolution as Fact and Theory.

    Science.gov (United States)

    Gould, Stephen Jay

    1981-01-01

    This essay by a Harvard evolutionist presents viewpoints concerning the creationists' arguments against evolutionary biology. Semantics regarding "facts" and "theory" of evolution are examined, examples are cited of creationist argument, and arguments for evolution are presented. (CS)

  2. Theories of computational complexity

    CERN Document Server

    Calude, C

    1988-01-01

    This volume presents four machine-independent theories of computational complexity, which have been chosen for their intrinsic importance and practical relevance. The book includes a wealth of results - classical, recent, and others which have not been published before.In developing the mathematics underlying the size, dynamic and structural complexity measures, various connections with mathematical logic, constructive topology, probability and programming theories are established. The facts are presented in detail. Extensive examples are provided, to help clarify notions and constructions. The lists of exercises and problems include routine exercises, interesting results, as well as some open problems.

  3. Biocultural Theory

    DEFF Research Database (Denmark)

    Carroll, Joseph; Clasen, Mathias; Jonsson, Emelie

    2017-01-01

    Biocultural theory is an integrative research program designed to investigate the causal interactions between biological adaptations and cultural constructions. From the biocultural perspective, cultural processes are rooted in the biological necessities of the human life cycle: specifically human...... and ideological beliefs, and artistic practices such as music, dance, painting, and storytelling. Establishing biocultural theory as a program that self-consciously encompasses the different particular forms of human evolutionary research could help scholars and scientists envision their own specialized areas...... of research as contributions to a coherent, collective research program. This article argues that a mature biocultural paradigm needs to be informed by at least 7 major research clusters: (a) gene-culture coevolution; (b) human life history theory; (c) evolutionary social psychology; (d) anthropological...

  4. Fundamentals of queueing theory

    CERN Document Server

    Gross, Donald; Thompson, James M; Harris, Carl M

    2013-01-01

    Praise for the Third Edition ""This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented.""-IIE Transactions on Operations Engineering Thoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than pre

  5. [From the cell theory to the neuron theory].

    Science.gov (United States)

    Tixier-Vidal, Andrée

    2010-01-01

    The relationship between the cell theory formulated by Schwann (1839) and by Virchow (1855) on the one hand, and, on the other hand, the neuron theory, as formulated by Waldeyer (1891) and by Cajal (1906), are discussed from a historical point of view. Both of them are the result of technical and conceptuel progress. Both of them had to fight against the dominant dogma before being accepted. The cell theory opposed the school of Bichat, the vitalist philosophy and the positivist philosophy of Auguste Comte. The neuron theory, which is clearly based on the cell theory, was mostly concerned with the mode of interneuronal communication; it opposed the concept of contiguity to Golgi's concept of continuity. At present, the cell theory remains central in every field of Biology. By contrast, the neuron theory, which until the middle of the XXth century opened the study of the nervous system to a necessary reductionnist approach, is no longer central to recent developments of neurosciences.

  6. Between Theory and Practice

    DEFF Research Database (Denmark)

    Dindler, Christian; Dalsgaard, Peter

    2014-01-01

    We present the notion of ‘bridging concepts’ as a particular form of intermediary knowledge in HCI research, residing between theory and practice. We argue that bridging concepts address the challenge of facilitating exchange between theory and practice in HCI, and we compare it to other intermed....... These constituents specify how bridging concepts, as a form of knowledge, are accountable to both theory and practice. We present an analysis of the concept of ‘peepholes’ as an example of a bridging concept aimed at spurring user curiosity and engagement.......We present the notion of ‘bridging concepts’ as a particular form of intermediary knowledge in HCI research, residing between theory and practice. We argue that bridging concepts address the challenge of facilitating exchange between theory and practice in HCI, and we compare it to other...... intermediary forms of knowledge such as strong concepts and conceptual constructs. We propose that bridging concepts have three defining constituents: a theoretical foundation, a set of design articulations and a range of exemplars that demonstrate the scope and potential of their application...

  7. Deweyan Inquiry: From Education Theory to Practice

    Science.gov (United States)

    Johnston, James Scott

    2009-01-01

    This book presents John Dewey's theory of inquiry and applies it to various areas of the primary, middle, and secondary school curricula. "Deweyan Inquiry" brings Dewey's theory of inquiry together with educational theory and practice. James Scott Johnston uses Dewey's late masterpiece "Logic: The Theory of Inquiry" as a guide…

  8. Mathematical Methods of Game and Economic Theory

    CERN Document Server

    Aubin, J-P

    1982-01-01

    This book presents a unified treatment of optimization theory, game theory and a general equilibrium theory in economics in the framework of nonlinear functional analysis. It not only provides powerful and versatile tools for solving specific problems in economics and the social sciences but also serves as a unifying theme in the mathematical theory of these subjects as well as in pure mathematics itself.

  9. Situation-specific theories from the middle-range transitions theory.

    Science.gov (United States)

    Im, Eun-Ok

    2014-01-01

    The purpose of this article was to analyze the theory development process of the situation-specific theories that were derived from the middle-range transitions theory. This analysis aims to provide directions for future development of situation-specific theories. First, transitions theory is concisely described with its history, goal, and major concepts. Then, the approach that was used to retrieve the situation-specific theories derived from transitions theory is described. Next, an analysis of 6 situation-specific theories is presented. Finally, 4 themes reflecting commonalities and variances in the theory development process are discussed with implications for future theoretical development.

  10. Theory Overview

    CERN Document Server

    Lenz, Alexander

    2016-01-01

    We set the scene for theoretical issues in charm physics that were discussed at CHARM 2016 in Bologna. In particular we emphasize the importance of improving our understanding of standard model contributions to numerous charm observables and we discuss also possible tests of our theory tools, like the Heavy Quark Expansion via the lifetime ratios of $D$-mesons

  11. Livability theory

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    2014-01-01

    markdownabstract__Abstract__ Assumptions Livability theory involves the following six key assumptions: 1. Like all animals, humans have innate needs, such as for food, safety, and companionship. 2. Gratification of needs manifests in hedonic experience. 3. Hedonic experience determines how much we

  12. Theory U

    DEFF Research Database (Denmark)

    Monthoux, Pierre Guillet de; Statler, Matt

    2014-01-01

    The recent Carnegie report (Colby, et al., 2011) characterizes the goal of business education as the development of practical wisdom. In this chapter, the authors reframe Scharmer’s Theory U as an attempt to develop practical wisdom by applying certain European philosophical concepts. Specificall...

  13. Theory U

    DEFF Research Database (Denmark)

    Guillet de Monthoux, Pierre; Statler, Matt

    2017-01-01

    The recent Carnegie report (Colby, et al., 2011) characterizes the goal of business education as the development of practical wisdom. In this chapter, the authors reframe Scharmer's Theory U as an attempt to develop practical wisdom by applying certain European philosophical concepts. Specificall...

  14. Framing theory

    NARCIS (Netherlands)

    de Vreese, C.H.; Lecheler, S.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.

    2016-01-01

    Political issues can be viewed from different perspectives and they can be defined differently in the news media by emphasizing some aspects and leaving others aside. This is at the core of news framing theory. Framing originates within sociology and psychology and has become one of the most used th

  15. Activity Theory

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege; Bødker, Susanne

    2003-01-01

    the young HCI research tradition. But HCI was already facing problems: lack of consideration for other aspects of human behavior, for interaction with other people, for culture. Cognitive science-based theories lacked means to address several issues that came out of the empirical projects....

  16. Theory U

    DEFF Research Database (Denmark)

    Monthoux, Pierre Guillet de; Statler, Matt

    2014-01-01

    The recent Carnegie report (Colby, et al., 2011) characterizes the goal of business education as the development of practical wisdom. In this chapter, the authors reframe Scharmer’s Theory U as an attempt to develop practical wisdom by applying certain European philosophical concepts. Specifically...

  17. Essentials of measure theory

    CERN Document Server

    Kubrusly, Carlos S

    2015-01-01

    Classical in its approach, this textbook is thoughtfully designed and composed in two parts. Part I is meant for a one-semester beginning graduate course in measure theory, proposing an “abstract” approach to measure and integration, where the classical concrete cases of Lebesgue measure and Lebesgue integral are presented as an important particular case of general theory. Part II of the text is more advanced and is addressed to a more experienced reader. The material is designed to cover another one-semester graduate course subsequent to a first course, dealing with measure and integration in topological spaces. The final section of each chapter in Part I presents problems that are integral to each chapter, the majority of which consist of auxiliary results, extensions of the theory, examples, and counterexamples. Problems which are highly theoretical have accompanying hints. The last section of each chapter of Part II consists of Additional Propositions containing auxiliary and complementary results. Th...

  18. Problems in equilibrium theory

    CERN Document Server

    Aliprantis, Charalambos D

    1996-01-01

    In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

  19. Quantum Field Theory

    CERN Document Server

    Zeidler, Eberhard

    This is the first volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists ranging from advanced undergraduate students to professional scientists. The book tries to bridge the existing gap between the different languages used by mathematicians and physicists. For students of mathematics it is shown that detailed knowledge of the physical background helps to motivate the mathematical subjects and to discover interesting interrelationships between quite different mathematical topics. For students of physics, fairly advanced mathematics is presented, which is beyond the usual curriculum in physics. It is the author's goal to present the state of the art of realizing Einstein's dream of a unified theory for the four fundamental forces in the universe (gravitational, electromagnetic, strong, and weak interaction). From the reviews: "… Quantum field theory is one of the great intellectual edifices in the history of human thought. … This volume differs from othe...

  20. Applications of polyfold theory I

    CERN Document Server

    Hofer, H; Zehnder, E

    2017-01-01

    In this paper the authors start with the construction of the symplectic field theory (SFT). As a general theory of symplectic invariants, SFT has been outlined in Introduction to symplectic field theory (2000), by Y. Eliashberg, A. Givental and H. Hofer who have predicted its formal properties. The actual construction of SFT is a hard analytical problem which will be overcome be means of the polyfold theory due to the present authors. The current paper addresses a significant amount of the arising issues and the general theory will be completed in part II of this paper. To illustrate the polyfold theory the authors use the results of the present paper to describe an alternative construction of the Gromov-Witten invariants for general compact symplectic manifolds.

  1. Workshop Presentations: Overviews

    Data.gov (United States)

    National Aeronautics and Space Administration — These slides were presented at the AePW, April 21-22, 2012. Additional presentations can be found on each of the associated analysis webpages. Separate pages contain...

  2. Marketing through Video Presentations.

    Science.gov (United States)

    Newhart, Donna

    1989-01-01

    Discusses the advantages of using video presentations as marketing tools. Includes information about video news releases, public service announcements, and sales/marketing presentations. Describes the three stages in creating a marketing video: preproduction planning; production; and postproduction. (JOW)

  3. Crystallography: past and present

    Science.gov (United States)

    Hodeau, J.-L.; Guinebretiere, R.

    2007-12-01

    In the 19th century, crystallography referred to the study of crystal shapes. Such studies by Haüy and Bravais allowed the establishment of important hypotheses such as (i) “les molécules intégrantes qui sont censées être les plus petits solides que l’on puisse extraire d’un minéral” [1], (ii) the definition of the crystal lattice and (iii) “le cristal est clivable parallèlement à deux ou trois formes cristallines” [2]. This morphological crystallography defined a crystal like “a chemically homogeneous solid, wholly or partly bounded by natural planes that intersect at predetermined angles” [3]. It described the main symmetry elements and operations, nomenclatures of different crystal forms and also the theory of twinning. A breakthrough appeared in 1912 with the use of X-rays by M. von Laue and W.H. and W.L. Bragg. This experimental development allowed the determination of the atomic content of each unit cell constituting the crystal and defined a crystal as “any solid in which an atomic pattern is repeated periodically in three dimensions, that is, any solid that “diffracts” an incident X-ray beam” [3]. Mathematical tools like the Patterson methods, the direct methods, were developed. The way for solving crystalline structure was opened first for simple compounds and at that time crystallography was associated mainly with perfect crystals. In the fifties, crystallographers already had most apparatus and fundamental methods at their disposal; however, we had to wait for the development of computers to see the full use of these tools. Furthermore the development of new sources of neutrons, electrons and synchrotron X-rays allowed the studies of complex compounds like large macromolecules in biology. Nowadays, one of the new frontiers for crystallographers is to relate the crystal structure to its physical-chemical-biological properties, this means that an accurate structural determination is needed to focus on a selective part of the

  4. Make Your Presentation Powerful

    Science.gov (United States)

    Palmer, Erik

    2015-01-01

    "I was planning on doing a lot of work today during your presentation, but I couldn't get anything done. I just had to pay attention!" The author received this unexpected feedback from a teacher at the end of a presentation he gave, and although he considered it a compliment, it made him reflect on the dire state of presentations in…

  5. Presenting Food Science Effectively

    Science.gov (United States)

    Winter, Carl K.

    2016-01-01

    While the need to present food science information effectively is viewed as a critical competency for food scientists by the Institute of Food Technologists, most food scientists may not receive adequate training in this area. Effective presentations combine both scientific content and delivery mechanisms that demonstrate presenter enthusiasm for…

  6. Rotating Poster Presentations

    Science.gov (United States)

    Lagares, Manuel; Reisenleutner, Sandra

    2017-01-01

    Oral presentations are a common practice in foreign language classes, often used to assess students' speaking skills. Usually, the presentations are delivered by students in front of the class, often with PowerPoint slides or Prezi as support. However, frequently the audience does not engage with the presentation and thus, the benefits of this…

  7. Induced QCD I: Theory

    CERN Document Server

    Brandt, Bastian B; Wettig, Tilo

    2016-01-01

    We explore an alternative discretization of continuum SU(N_c) Yang-Mills theory on a Euclidean spacetime lattice, originally introduced by Budzcies and Zirnbauer. In this discretization the self-interactions of the gauge field are induced by a path integral over N_b auxiliary boson fields, which are coupled linearly to the gauge field. The main progress compared to earlier approaches is that N_b can be as small as N_c. In the present paper we (i) extend the proof that the continuum limit of the new discretization reproduces Yang-Mills theory in two dimensions from gauge group U(N_c) to SU(N_c), (ii) derive refined bounds on N_b for non-integer values, and (iii) perform a perturbative calculation to match the bare parameter of the induced gauge theory to the standard lattice coupling. In follow-up papers we will present numerical evidence in support of the conjecture that the induced gauge theory reproduces Yang-Mills theory also in three and four dimensions, and explore the possibility to integrate out the ga...

  8. Basic operator theory

    CERN Document Server

    Gohberg, Israel

    2001-01-01

    rii application of linear operators on a Hilbert space. We begin with a chapter on the geometry of Hilbert space and then proceed to the spectral theory of compact self adjoint operators; operational calculus is next presented as a nat­ ural outgrowth of the spectral theory. The second part of the text concentrates on Banach spaces and linear operators acting on these spaces. It includes, for example, the three 'basic principles of linear analysis and the Riesz­ Fredholm theory of compact operators. Both parts contain plenty of applications. All chapters deal exclusively with linear problems, except for the last chapter which is an introduction to the theory of nonlinear operators. In addition to the standard topics in functional anal­ ysis, we have presented relatively recent results which appear, for example, in Chapter VII. In general, in writ­ ing this book, the authors were strongly influenced by re­ cent developments in operator theory which affected the choice of topics, proofs and exercises. One ...

  9. Induced QCD I: theory

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Bastian B. [Institute for Theoretical Physics, Goethe-University of Frankfurt,60438 Frankfurt (Germany); Institute for Theoretical Physics, University of Regensburg,93040 Regensburg (Germany); Lohmayer, Robert; Wettig, Tilo [Institute for Theoretical Physics, University of Regensburg,93040 Regensburg (Germany)

    2016-11-14

    We explore an alternative discretization of continuum SU(N{sub c}) Yang-Mills theory on a Euclidean spacetime lattice, originally introduced by Budzcies and Zirnbauer. In this discretization the self-interactions of the gauge field are induced by a path integral over N{sub b} auxiliary boson fields, which are coupled linearly to the gauge field. The main progress compared to earlier approaches is that N{sub b} can be as small as N{sub c}. In the present paper we (i) extend the proof that the continuum limit of the new discretization reproduces Yang-Mills theory in two dimensions from gauge group U(N{sub c}) to SU(N{sub c}), (ii) derive refined bounds on N{sub b} for non-integer values, and (iii) perform a perturbative calculation to match the bare parameter of the induced gauge theory to the standard lattice coupling. In follow-up papers we will present numerical evidence in support of the conjecture that the induced gauge theory reproduces Yang-Mills theory also in three and four dimensions, and explore the possibility to integrate out the gauge fields to arrive at a dual formulation of lattice QCD.

  10. Ideal Theory, Real Rationality

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent

    Understanding rationality and power are key to understanding actual political and administrative behavior. Political and administrative theory that ignores this fact stand in danger of being at best irrelevant or, at worst part of the problem it whishes to solve. The paper presents Jürgen Haberma...

  11. Use of Bowen Theory.

    Science.gov (United States)

    Gibson, Joan M.; Donigian, Jeremiah

    1993-01-01

    Notes that theory-based approach to treatment of codependency is missing in fields of chemical dependency and mental health. Presents Bowen family systems therapy as foundation and framework for treatment goals and interventions. Illustrates similarities between characteristics of low levels of differentiation of self and codependency. (Author/NB)

  12. Basic Microfluidics Theory

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith

    2015-01-01

    ,000 m−1, which is a huge difference and has a large impact on flow behavior. In this chapter the basic microfluidic theory will be presented, enabling the reader to gain a comprehensive understanding of how liquids behave at the microscale, enough to be able to engage in design of micro systems...

  13. Use of Bowen Theory.

    Science.gov (United States)

    Gibson, Joan M.; Donigian, Jeremiah

    1993-01-01

    Notes that theory-based approach to treatment of codependency is missing in fields of chemical dependency and mental health. Presents Bowen family systems therapy as foundation and framework for treatment goals and interventions. Illustrates similarities between characteristics of low levels of differentiation of self and codependency. (Author/NB)

  14. Theory into Practice

    Science.gov (United States)

    Kaplan, Sandra N.

    2012-01-01

    The importance of putting theory into practice can be addressed and advocated to educators and gifted students through the presentation of a Continuum of Practice. Articulating the sequence and phases of practice can underscore how practice can take place; it also can change the perspective and meaning of practice.

  15. Hedges and Politeness Theory

    Institute of Scientific and Technical Information of China (English)

    王俊

    2015-01-01

    Leech’s Politeness Principle and Brown &Levinson’s Theory of Politeness accept widely ac-knowledgement.They serve as the most systematic basis for a pragmatic analysis of hedges in present study.This paper,aiming at explaining politeness function in hedges,mainly discusses the relationship between them.

  16. Experimental quantum field theory

    CERN Document Server

    Bell, J S

    1977-01-01

    Presented here, is, in the opinion of the author, the essential minimum of quantum field theory that should be known to cultivated experimental particle physicists. The word experimental describes not only the audience aimed at but also the level of mathematical rigour aspired to. (0 refs).

  17. Incorporating Feminist Standpoint Theory

    DEFF Research Database (Denmark)

    Ahlström, Kristoffer

    2005-01-01

    As has been noted by Alvin Goldman, there are some very interesting similarities between his Veritistic Social Epistemology (VSE) and Sandra Harding’s Feminist Standpoint Theory (FST). In the present paper, it is argued that these similarities are so significant as to motivate an incorporation...

  18. Ideal Theory, Real Rationality

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent

    Understanding rationality and power are key to understanding actual political and administrative behavior. Political and administrative theory that ignores this fact stand in danger of being at best irrelevant or, at worst part of the problem it whishes to solve. The paper presents Jürgen Habermas...

  19. Group theory in physics

    CERN Document Server

    Cornwell, J F

    1989-01-01

    Recent devopments, particularly in high-energy physics, have projected group theory and symmetry consideration into a central position in theoretical physics. These developments have taken physicists increasingly deeper into the fascinating world of pure mathematics. This work presents important mathematical developments of the last fifteen years in a form that is easy to comprehend and appreciate.

  20. Algorithm Theory - SWAT 2006

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the 10th Scandinavian Workshop on Algorithm Theory, SWAT 2006, held in Riga, Latvia, in July 2006. The 36 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 154 submissions. The papers address all...

  1. Ideal Theory and Utopia

    NARCIS (Netherlands)

    V. Ruitinga (Volker)

    2011-01-01

    textabstractJohn Rawls presents his work on social justice as Ideal Theory. By taking an idealized scenario, he is able to consider the compatibility of different concepts relating to social justice without being hampered by all the complexities of society and its actors; an approach to social theor

  2. Stochastic processes and filtering theory

    CERN Document Server

    Jazwinski, Andrew H

    2007-01-01

    This unified treatment of linear and nonlinear filtering theory presents material previously available only in journals, and in terms accessible to engineering students. Its sole prerequisites are advanced calculus, the theory of ordinary differential equations, and matrix analysis. Although theory is emphasized, the text discusses numerous practical applications as well.Taking the state-space approach to filtering, this text models dynamical systems by finite-dimensional Markov processes, outputs of stochastic difference, and differential equations. Starting with background material on probab

  3. Innovative presentations for dummies

    CERN Document Server

    Anthony, Ray

    2014-01-01

    Be the speaker they follow with breakthrough innovative presentations Innovative Presentations For Dummies is a practical guide to engaging your audience with superior, creative, and ultra-compelling presentations. Using clear language and a concise style, this book goes way beyond PowerPoint to enable you to reimagine, reinvent, and remake your presentations. Learn how to stimulate, capture, and hold your audience in the palm of your hand with sound, sight, and touch, and get up to speed on the latest presentation design methods that make you a speaker who gets audiences committed and acting

  4. Communication theory

    DEFF Research Database (Denmark)

    Stein, Irene F.; Stelter, Reinhard

    2011-01-01

    Communication theory covers a wide variety of theories related to the communication process (Littlejohn, 1999). Communication is not simply an exchange of information, in which we have a sender and a receiver. This very technical concept of communication is clearly outdated; a human being...... is not a data processing device. In this chapter, communication is understood as a process of shared meaning-making (Bruner, 1990). Human beings interpret their environment, other people, and themselves on the basis of their dynamic interaction with the surrounding world. Meaning is essential because people...... ascribe specific meanings to their experiences, their actions in life or work, and their interactions. Meaning is reshaped, adapted, and transformed in every communication encounter. Furthermore, meaning is cocreated in dialogues or in communities of practice, such as in teams at a workplace or in school...

  5. Operator theory

    CERN Document Server

    2015-01-01

    A one-sentence definition of operator theory could be: The study of (linear) continuous operations between topological vector spaces, these being in general (but not exclusively) Fréchet, Banach, or Hilbert spaces (or their duals). Operator theory is thus a very wide field, with numerous facets, both applied and theoretical. There are deep connections with complex analysis, functional analysis, mathematical physics, and electrical engineering, to name a few. Fascinating new applications and directions regularly appear, such as operator spaces, free probability, and applications to Clifford analysis. In our choice of the sections, we tried to reflect this diversity. This is a dynamic ongoing project, and more sections are planned, to complete the picture. We hope you enjoy the reading, and profit from this endeavor.

  6. The Lorentz Theory of Electrons and Einstein's Theory of Relativity

    Science.gov (United States)

    Goldberg, Stanley

    1969-01-01

    Traces the development of Lorentz's theory of electrons as applied to the problem of the electrodynamics of moving bodies. Presents evidence that the principle of relativity did not play an important role in Lorentz's theory, and that though Lorentz eventually acknowledged Einstein's work, he was unwilling to completely embrace the Einstein…

  7. Quantitative graph theory mathematical foundations and applications

    CERN Document Server

    Dehmer, Matthias

    2014-01-01

    The first book devoted exclusively to quantitative graph theory, Quantitative Graph Theory: Mathematical Foundations and Applications presents and demonstrates existing and novel methods for analyzing graphs quantitatively. Incorporating interdisciplinary knowledge from graph theory, information theory, measurement theory, and statistical techniques, this book covers a wide range of quantitative-graph theoretical concepts and methods, including those pertaining to real and random graphs such as:Comparative approaches (graph similarity or distance)Graph measures to characterize graphs quantitat

  8. The electroweak theory

    Energy Technology Data Exchange (ETDEWEB)

    Chris Quigg

    2001-08-10

    After a short essay on the current state of particle physics, the author reviews the antecedents of the modern picture of the weak and electromagnetic interactions and then undertakes a brief survey of the SU(2){sub L} {circle_times} U(1){sub Y} electroweak theory. The authors reviews the features of electroweak phenomenology at tree level and beyond, presents an introduction to the Higgs boson and the 1-TeV scale, and examines arguments for enlarging the electroweak theory. The author concludes with a brief look at low-scale gravity.

  9. Solid state theory

    CERN Document Server

    Harrison, Walter A

    2011-01-01

    ""A well-written text . . . should find a wide readership, especially among graduate students."" - Dr. J. I. Pankove, RCA.The field of solid state theory, including crystallography, semi-conductor physics, and various applications in chemistry and electrical engineering, is highly relevant to many areas of modern science and industry. Professor Harrison's well-known text offers an excellent one-year graduate course in this active and important area of research. While presenting a broad overview of the fundamental concepts and methods of solid state physics, including the basic quantum theory o

  10. Elements of probability theory

    CERN Document Server

    Rumshiskii, L Z

    1965-01-01

    Elements of Probability Theory presents the methods of the theory of probability. This book is divided into seven chapters that discuss the general rule for the multiplication of probabilities, the fundamental properties of the subject matter, and the classical definition of probability. The introductory chapters deal with the functions of random variables; continuous random variables; numerical characteristics of probability distributions; center of the probability distribution of a random variable; definition of the law of large numbers; stability of the sample mean and the method of moments

  11. Quantum kinetic theory

    CERN Document Server

    Bonitz, Michael

    2016-01-01

    This book presents quantum kinetic theory in a comprehensive way. The focus is on density operator methods and on non-equilibrium Green functions. The theory allows to rigorously treat nonequilibrium dynamics in quantum many-body systems. Of particular interest are ultrafast processes in plasmas, condensed matter and trapped atoms that are stimulated by rapidly developing experiments with short pulse lasers and free electron lasers. To describe these experiments theoretically, the most powerful approach is given by non-Markovian quantum kinetic equations that are discussed in detail, including computational aspects.

  12. Algebraic number theory

    CERN Document Server

    Weiss, Edwin

    1998-01-01

    Careful organization and clear, detailed proofs characterize this methodical, self-contained exposition of basic results of classical algebraic number theory from a relatively modem point of view. This volume presents most of the number-theoretic prerequisites for a study of either class field theory (as formulated by Artin and Tate) or the contemporary treatment of analytical questions (as found, for example, in Tate's thesis).Although concerned exclusively with algebraic number fields, this treatment features axiomatic formulations with a considerable range of applications. Modem abstract te

  13. Quantum field theory competitive models

    CERN Document Server

    Tolksdorf, Jürgen; Zeidler, Eberhard

    2009-01-01

    For more than 70 years, quantum field theory (QFT) can be seen as a driving force in the development of theoretical physics. Equally fascinating is the fruitful impact which QFT had in rather remote areas of mathematics. The present book features some of the different approaches, different physically viewpoints and techniques used to make the notion of quantum field theory more precise. For example, the present book contains a discussion including general considerations, stochastic methods, deformation theory and the holographic AdS/CFT correspondence. It also contains a discussion of more recent developments like the use of category theory and topos theoretic methods to describe QFT. The present volume emerged from the 3rd 'Blaubeuren Workshop: Recent Developments in Quantum Field Theory', held in July 2007 at the Max Planck Institute of Mathematics in the Sciences in Leipzig/Germany. All of the contributions are committed to the idea of this workshop series: 'To bring together outstanding experts working in...

  14. Behavioural present value

    OpenAIRE

    Krzysztof Piasecki

    2013-01-01

    Impact of chosen behavioural factors on imprecision of present value is discussed here. The formal model of behavioural present value is offered as a result of this discussion. Behavioural present value is described here by fuzzy set. These considerations were illustrated by means of extensive numerical case study. Finally there are shown that in proposed model the return rate is given, as a fuzzy probabilistic set.

  15. CERN Electronics Pool presentations

    CERN Multimedia

    2011-01-01

    The CERN Electronics Pool has organised a series of presentations in collaboration with oscilloscope manufacturers. The last one will take place according to the schedule below.   Time will be available at the end of the presentation to discuss your personal needs. The Agilent presentation had to be postponed and will be organised later. -     Lecroy: Thursday, 24 November 2011, in 530-R-030, 14:00 to 16:30.

  16. Presentation skills for nurses.

    Science.gov (United States)

    Foulkes, Mark

    2015-02-20

    This article emphasises the importance of effective presentation skills. Such skills allow nurses to share knowledge and expertise and to communicate clearly in a range of workplace scenarios. Nurses are increasingly being asked to present in formal and informal situations, such as conferences, poster presentations, job interviews, case reports and ward-based teaching. This article explores the principles underpinning the development of these skills, discusses the situations in which they could be applied and demonstrates how nurses might improve and develop as presenters.

  17. Categorical constructions in graph theory

    Directory of Open Access Journals (Sweden)

    Richard T. Bumby

    1986-01-01

    Full Text Available This paper presents some graph-theoretic questions from the viewpoint of the portion of category theory which has become common knowledge. In particular, the reader is encouraged to consider whether there is only one natural category of graphs and how theories of directed graphs and undirected graphs are related.

  18. The Future of Microeconomic Theory

    OpenAIRE

    2000-01-01

    The question of what constitutes good economic theory is analyzed. Current good and bad aspects of its methodologies are discussed. Interdisciplinary work that goes beyond the social sciences is advocated. The future predictions are presented concerning research in game theory and the economics of information. Finally, the importance of technology and the need for microeconomists to understand it better are argued.

  19. Theory of Test Translation Error

    Science.gov (United States)

    Solano-Flores, Guillermo; Backhoff, Eduardo; Contreras-Nino, Luis Angel

    2009-01-01

    In this article, we present a theory of test translation whose intent is to provide the conceptual foundation for effective, systematic work in the process of test translation and test translation review. According to the theory, translation error is multidimensional; it is not simply the consequence of defective translation but an inevitable fact…

  20. The Interpersonal Theory of Suicide

    Science.gov (United States)

    Van Orden, Kimberly A.; Witte, Tracy K.; Cukrowicz, Kelly C.; Braithwaite, Scott R.; Selby, Edward A.; Joiner, Thomas E., Jr.

    2010-01-01

    Suicidal behavior is a major problem worldwide and, at the same time, has received relatively little empirical attention. This relative lack of empirical attention may be due in part to a relative absence of theory development regarding suicidal behavior. The current article presents the interpersonal theory of suicidal behavior. We propose that…

  1. Electron Theory in Alloy Design

    CERN Document Server

    Pettifor, DG

    1992-01-01

    Presents recent developments in electron theory which have impacted upon the search for novel alloys with improved mechanical or magnetic properties. The ten chapters outline the ability of electron theory to make quantitative predictions (such as heats of formation, planar fault energies, shear moduli and magnetic anisotropy), and to provide simplifying concepts for understanding trends in alloy behaviour.

  2. Conjugando el presente

    Directory of Open Access Journals (Sweden)

    Héctor Rojas Herazo

    1968-06-01

    Full Text Available La añoranza suele ser, casi siempre, la línea critica de menor resistencia. El lema de que "todo tiempo pasado fue mejor" tiene un poco la culpa. En cualquier orden del conocimiento el pasado sigue el verdadero presente. Ese presente en que nos gusta respirar y vivir. Nada de compromiso circundante. Nada de inmediatez.

  3. Supersymmetric gauge theories from string theory; Theorie de jauge supersymetrique de la theorie des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, St

    2005-12-15

    This thesis presents various ways to construct four-dimensional quantum field theories from string theory. In a first part we study the generation of a supersymmetric Yang-Mills theory, coupled to an adjoint chiral superfield, from type IIB string theory on non-compact Calabi-Yau manifolds, with D-branes wrapping certain sub-cycles. Properties of the gauge theory are then mapped to the geometric structure of the Calabi-Yau space. Even if the Calabi-Yau geometry is too complicated to evaluate the geometric integrals explicitly, one can then always use matrix model perturbation theory to calculate the effective superpotential. The second part of this work covers the generation of four-dimensional super-symmetric gauge theories, carrying several important characteristic features of the standard model, from compactifications of eleven-dimensional supergravity on G{sub 2}-manifolds. If the latter contain conical singularities, chiral fermions are present in the four-dimensional gauge theory, which potentially lead to anomalies. We show that, locally at each singularity, these anomalies are cancelled by the non-invariance of the classical action through a mechanism called 'anomaly inflow'. Unfortunately, no explicit metric of a compact G{sub 2}-manifold is known. Here we construct families of metrics on compact weak G{sub 2}-manifolds, which contain two conical singularities. Weak G{sub 2}-manifolds have properties that are similar to the ones of proper G{sub 2}-manifolds, and hence the explicit examples might be useful to better understand the generic situation. Finally, we reconsider the relation between eleven-dimensional supergravity and the E{sub 8} x E{sub 8}-heterotic string. This is done by carefully studying the anomalies that appear if the supergravity theory is formulated on a ten-manifold times the interval. Again we find that the anomalies cancel locally at the boundaries of the interval through anomaly inflow, provided one suitably modifies the

  4. Commercial Conspiracy Theories

    Directory of Open Access Journals (Sweden)

    Adrian eFurnham

    2013-06-01

    Full Text Available There are many ways to categorise conspiracy theories. In the present study, we examined individual and demographic predictors of beliefs in commercial conspiracy theories among a British sample of over 300 women and men. Results showed people were cynical and sceptical with regard to advertising tricks, as well as the tactics of organisations like banks and alcohol, drug and tobacco companies. Beliefs sorted into four identifiable clusters, labelled sneakiness, manipulative, change-the-rules and suppression/prevention. The high alpha for the overall scale suggested general beliefs in commercial conspiracy. Regressions suggested that those people who were less religious, more left-wing, more pessimistic, less (self-defined as wealthy, less Neurotic and less Open-to-Experience believed there was more commercial conspiracy. Overall the individual difference variables explained relatively little of the variance in these beliefs.The implications of these findings for the literature on conspiracy theories are discussed.

  5. Lattice gauge theories

    Science.gov (United States)

    Weisz, Peter; Majumdar, Pushan

    2012-03-01

    Lattice gauge theory is a formulation of quantum field theory with gauge symmetries on a space-time lattice. This formulation is particularly suitable for describing hadronic phenomena. In this article we review the present status of lattice QCD. We outline some of the computational methods, discuss some phenomenological applications and a variety of non-perturbative topics. The list of references is severely incomplete, the ones we have included are text books or reviews and a few subjectively selected papers. Kronfeld and Quigg (2010) supply a reasonably comprehensive set of QCD references. We apologize for the fact that have not covered many important topics such as QCD at finite density and heavy quark effective theory adequately, and mention some of them only in the last section "In Brief". These topics should be considered in further Scholarpedia articles.

  6. Applied multidimensional systems theory

    CERN Document Server

    Bose, Nirmal K

    2017-01-01

    Revised and updated, this concise new edition of the pioneering book on multidimensional signal processing is ideal for a new generation of students. Multidimensional systems or m-D systems are the necessary mathematical background for modern digital image processing with applications in biomedicine, X-ray technology and satellite communications. Serving as a firm basis for graduate engineering students and researchers seeking applications in mathematical theories, this edition eschews detailed mathematical theory not useful to students. Presentation of the theory has been revised to make it more readable for students, and introduce some new topics that are emerging as multidimensional DSP topics in the interdisciplinary fields of image processing. New topics include Groebner bases, wavelets, and filter banks.

  7. Probability theory and applications

    CERN Document Server

    Hsu, Elton P

    1999-01-01

    This volume, with contributions by leading experts in the field, is a collection of lecture notes of the six minicourses given at the IAS/Park City Summer Mathematics Institute. It introduces advanced graduates and researchers in probability theory to several of the currently active research areas in the field. Each course is self-contained with references and contains basic materials and recent results. Topics include interacting particle systems, percolation theory, analysis on path and loop spaces, and mathematical finance. The volume gives a balanced overview of the current status of probability theory. An extensive bibliography for further study and research is included. This unique collection presents several important areas of current research and a valuable survey reflecting the diversity of the field.

  8. Geometric group theory

    CERN Document Server

    Bestvina, Mladen; Vogtmann, Karen

    2014-01-01

    Geometric group theory refers to the study of discrete groups using tools from topology, geometry, dynamics and analysis. The field is evolving very rapidly and the present volume provides an introduction to and overview of various topics which have played critical roles in this evolution. The book contains lecture notes from courses given at the Park City Math Institute on Geometric Group Theory. The institute consists of a set of intensive short courses offered by leaders in the field, designed to introduce students to exciting, current research in mathematics. These lectures do not duplicate standard courses available elsewhere. The courses begin at an introductory level suitable for graduate students and lead up to currently active topics of research. The articles in this volume include introductions to CAT(0) cube complexes and groups, to modern small cancellation theory, to isometry groups of general CAT(0) spaces, and a discussion of nilpotent genus in the context of mapping class groups and CAT(0) gro...

  9. Digital lattice gauge theories

    CERN Document Server

    Zohar, Erez; Reznik, Benni; Cirac, J Ignacio

    2016-01-01

    We propose a general scheme for a digital construction of lattice gauge theories with dynamical fermions. In this method, the four-body interactions arising in models with $2+1$ dimensions and higher, are obtained stroboscopically, through a sequence of two-body interactions with ancillary degrees of freedom. This yields stronger interactions than the ones obtained through pertubative methods, as typically done in previous proposals, and removes an important bottleneck in the road towards experimental realizations. The scheme applies to generic gauge theories with Lie or finite symmetry groups, both Abelian and non-Abelian. As a concrete example, we present the construction of a digital quantum simulator for a $\\mathbb{Z}_{3}$ lattice gauge theory with dynamical fermionic matter in $2+1$ dimensions, using ultracold atoms in optical lattices, involving three atomic species, representing the matter, gauge and auxiliary degrees of freedom, that are separated in three different layers. By moving the ancilla atoms...

  10. Stochastic processes inference theory

    CERN Document Server

    Rao, Malempati M

    2014-01-01

    This is the revised and enlarged 2nd edition of the authors’ original text, which was intended to be a modest complement to Grenander's fundamental memoir on stochastic processes and related inference theory. The present volume gives a substantial account of regression analysis, both for stochastic processes and measures, and includes recent material on Ridge regression with some unexpected applications, for example in econometrics. The first three chapters can be used for a quarter or semester graduate course on inference on stochastic processes. The remaining chapters provide more advanced material on stochastic analysis suitable for graduate seminars and discussions, leading to dissertation or research work. In general, the book will be of interest to researchers in probability theory, mathematical statistics and electrical and information theory.

  11. Finite Temperature Matrix Theory

    CERN Document Server

    Meana, M L; Peñalba, J P; Meana, Marco Laucelli; Peñalba, Jesús Puente

    1998-01-01

    We present the way the Lorentz invariant canonical partition function for Matrix Theory as a light-cone formulation of M-theory can be computed. We explicitly show how when the eleventh dimension is decompactified, the N=1 eleven dimensional SUGRA partition function appears. From this particular analysis we also clarify the question about the discernibility problem when making statistics with supergravitons (the N! problem) in Matrix black hole configurations. We also provide a high temperature expansion which captures some structure of the canonical partition function when interactions amongst D-particles are on. The connection with the semi-classical computations thermalizing the open superstrings attached to a D-particle is also clarified through a Born-Oppenheimer approximation. Some ideas about how Matrix Theory would describe the complementary degrees of freedom of the massless content of eleven dimensional SUGRA are also discussed.

  12. Systems Theory in Immunology

    CERN Document Server

    Doria, Gino; Koch, Giorgio; Strom, Roberto

    1979-01-01

    This volume collects the contributions presented at the "Working Conference on System Theory in Immunology", held in Rome, May 1978. The aim of the Conference was to bring together immunologists on one side and experts in system theory and applied mathematics on the other, in order to identify problems of common interest and to establish a network of joint effort toward their solution. The methodologies of system theory for processing experimental data and for describing dynamical phenomena could indeed contribute significantly to the under­ standing of basic immunological facts. Conversely, the complexity of experimental results and of interpretative models should stimulate mathematicians to formulate new problems and to design appropriate procedures of analysis. The multitude of scientific publications in theoretical biology, appeared in recent years, confirms this trend and calls for extensive interaction between mat- matics and immunology. The material of this volume is divided into five sections, along ...

  13. A book of set theory

    CERN Document Server

    Pinter, Charles C

    2014-01-01

    Suitable for upper-level undergraduates, this accessible approach to set theory poses rigorous but simple arguments. Each definition is accompanied by commentary that motivates and explains new concepts. Starting with a repetition of the familiar arguments of elementary set theory, the level of abstract thinking gradually rises for a progressive increase in complexity.A historical introduction presents a brief account of the growth of set theory, with special emphasis on problems that led to the development of the various systems of axiomatic set theory. Subsequent chapters explore classes and

  14. A seminar on graph theory

    CERN Document Server

    Harary, Frank

    2015-01-01

    Presented in 1962-63 by experts at University College, London, these lectures offer a variety of perspectives on graph theory. Although the opening chapters form a coherent body of graph theoretic concepts, this volume is not a text on the subject but rather an introduction to the extensive literature of graph theory. The seminar's topics are geared toward advanced undergraduate students of mathematics.Lectures by this volume's editor, Frank Harary, include ""Some Theorems and Concepts of Graph Theory,"" ""Topological Concepts in Graph Theory,"" ""Graphical Reconstruction,"" and other introduc

  15. Algebraic and structural automata theory

    CERN Document Server

    Mikolajczak, B

    1991-01-01

    Automata Theory is part of computability theory which covers problems in computer systems, software, activity of nervous systems (neural networks), and processes of live organisms development.The result of over ten years of research, this book presents work in the following areas of Automata Theory: automata morphisms, time-varying automata, automata realizations and relationships between automata and semigroups.Aimed at those working in discrete mathematics and computer science, parts of the book are suitable for use in graduate courses in computer science, electronics, telecommunications, and control engineering. It is assumed that the reader is familiar with the basic concepts of algebra and graph theory.

  16. Lectures on quantum field theory

    CERN Document Server

    Das, Ashok

    2008-01-01

    This book consists of the lectures for a two-semester course on quantum field theory, and as such is presented in a quite informal and personal manner. The course starts with relativistic one-particle systems, and develops the basics of quantum field theory with an analysis of the representations of the Poincaré group. Canonical quantization is carried out for scalar, fermion, Abelian and non-Abelian gauge theories. Covariant quantization of gauge theories is also carried out with a detailed description of the BRST symmetry. The Higgs phenomenon and the standard model of electroweak interactio

  17. Scalar strong interaction hadron theory

    CERN Document Server

    Hoh, Fang Chao

    2015-01-01

    The scalar strong interaction hadron theory, SSI, is a first principles' and nonlocal theory at quantum mechanical level that provides an alternative to low energy QCD and Higgs related part of the standard model. The quark-quark interaction is scalar rather than color-vectorial. A set of equations of motion for mesons and another set for baryons have been constructed. This book provides an account of the present state of a theory supposedly still at its early stage of development. This work will facilitate researchers interested in entering into this field and serve as a basis for possible future development of this theory.

  18. Surveillance theory and its implications for law

    NARCIS (Netherlands)

    Timan, Tjerk; Galic, Masa; Koops, Bert-Jaap; Yeung, Karen; Brownsword, Roger; Scotford, Eloise

    2016-01-01

    This chapter provides an overview of key surveillance theories and their implications for law and regulation. It presents three stages of theories that characterise changes in thinking about surveillance in society and the disciplining, controlling, and entertaining functions of surveillance.

  19. Introductory Lectures on Quantum Field Theory

    CERN Document Server

    Alvarez-Gaumé, Luís

    2014-01-01

    In these lectures we present a few topics in Quantum Field Theory in detail. Some of them are conceptual and some more practical. They have been selected because they appear frequently in current applications to Particle Physics and String Theory.

  20. GNSS remote sensing theory, methods and applications

    CERN Document Server

    Jin, Shuanggen; Xie, Feiqin

    2014-01-01

    This book presents the theory and methods of GNSS remote sensing as well as its applications in the atmosphere, oceans, land and hydrology. It contains detailed theory and study cases to help the reader put the material into practice.

  1. Action Theory, Control and Motivation: A Symposium.

    Science.gov (United States)

    Eckensberger, L. H.; Meacham, J. A., Eds.

    1984-01-01

    Describes the symposium on action theory presented at the 1983 meeting of the International Society for the Study of Behavioral Development in Munich. The symposium included reactions to action theory from a variety of theoretical perspectives. (Author/RH)

  2. 建构主义理论视角下的言说观--我省新建本科英文教学与人文教育交融互构现状及启示%A Discourse Theory from Constructivism Perspective--Present Situation & Enlightenment on How to Combine Humanistic Education with English Teaching in New Universities in Fujianc

    Institute of Scientific and Technical Information of China (English)

    郑竹群

    2013-01-01

    Based on Piaget 's constructivism and Vygotsky's social constructivism , a discourse theory can im-prove the present situation where knowledge is measured by numbers , teachers are lack of humanistic accomplish-ment and students are short of classics learning cases in Fujian new universities .The theory describes why to dis-course , who to discourse , what to discourse , how to make a discourse effect and how to discourse in the teaching process when teachers and students are both subjects .This can provide a practical way for the combination between English teaching and humanistic education .%我省新建本科院校英文教育呈现知识量化衡量、教师人文素养不足以及缺乏经典学习的现状,从皮亚杰的建构主义理论和维果茨基的社会建构主义理论发展而来的言说观对上述问题的解决具有实际的意义。在英文教学与人文教育交融互构中,教师与学生互为主体的同时,围绕为何言说、由谁言说、言说什么、以言取效、如何言说等五个言说层次,进行人文意义上的教学实践活动,为探究英文教学与人文教育的交融互构提供一个可行的思路。

  3. Kraepelin and degeneration theory.

    Science.gov (United States)

    Hoff, Paul

    2008-06-01

    Emil Kraepelin's contribution to the clinical and scientific field of psychiatry is recognized world-wide. In recent years, however, there have been a number of critical remarks on his acceptance of degeneration theory in particular and on his political opinion in general, which was said to have carried "overtones of proto-fascism" by Michael Shepherd [28]. The present paper discusses the theoretical cornerstones of Kraepelinian psychiatry with regard to their relevance for Kraepelin's attitude towards degeneration theory. This theory had gained wide influence not only in scientific, but also in philosophical and political circles in the last decades of the nineteenth century. There is no doubt that Kraepelin, on the one hand, accepted and implemented degeneration theory into the debate on etiology and pathogenesis of mental disorders. On the other hand, it is not appropriate to draw a simple and direct line from early versions of degeneration theory to the crimes of psychiatrists and politicians during the rule of national socialism. What we need, is a differentiated view, since this will be the only scientific one. Much research needs to be done here in the future, and such research will surely have a significant impact not only on the historical field, but also on the continuous debate about psychiatry, neuroscience and neurophilosophy.

  4. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  5. Graph theory

    CERN Document Server

    Diestel, Reinhard

    2012-01-01

    HauptbeschreibungThis standard textbook of modern graph theory, now in its fourth edition, combinesthe authority of a classic with the engaging freshness of style that is the hallmarkof active mathematics. It covers the core material of the subject with concise yetreliably complete proofs, while offering glimpses of more advanced methodsin each field by one or two deeper results, again with proofs given in full detail.The book can be used as a reliable text for an introductory course, as a graduatetext, and for self-study. Rezension"Deep, clear, wonderful. This is a serious book about the

  6. Design theory

    CERN Document Server

    2009-01-01

    This book deals with the basic subjects of design theory. It begins with balanced incomplete block designs, various constructions of which are described in ample detail. In particular, finite projective and affine planes, difference sets and Hadamard matrices, as tools to construct balanced incomplete block designs, are included. Orthogonal latin squares are also treated in detail. Zhu's simpler proof of the falsity of Euler's conjecture is included. The construction of some classes of balanced incomplete block designs, such as Steiner triple systems and Kirkman triple systems, are also given.

  7. Communication theory

    CERN Document Server

    Goldie, Charles M

    1991-01-01

    This book is an introduction, for mathematics students, to the theories of information and codes. They are usually treated separately but, as both address the problem of communication through noisy channels (albeit from different directions), the authors have been able to exploit the connection to give a reasonably self-contained treatment, relating the probabilistic and algebraic viewpoints. The style is discursive and, as befits the subject, plenty of examples and exercises are provided. Some examples and exercises are provided. Some examples of computer codes are given to provide concrete illustrations of abstract ideas.

  8. Graph theory

    CERN Document Server

    Merris, Russell

    2001-01-01

    A lively invitation to the flavor, elegance, and power of graph theoryThis mathematically rigorous introduction is tempered and enlivened by numerous illustrations, revealing examples, seductive applications, and historical references. An award-winning teacher, Russ Merris has crafted a book designed to attract and engage through its spirited exposition, a rich assortment of well-chosen exercises, and a selection of topics that emphasizes the kinds of things that can be manipulated, counted, and pictured. Intended neither to be a comprehensive overview nor an encyclopedic reference, th

  9. Wages in Labour Market Theories

    Directory of Open Access Journals (Sweden)

    Kryńska Elżbieta

    2015-12-01

    Full Text Available Already classical economists took interest in the role of wages and wage formation mechanisms, as well as in their influence on other components of the labour market. This article aims to systematise contemporary approaches to wages as one of the labour market components that have been developed within major economic theories. The systemization will serve as a basis for identifying main interactions between wages and other labour market components, such as labour supply and demand and labour market disequilibrium. The article presents major concepts formulated within neo-classical and Keynesian theories, labour market segmentation theories, efficiency wage theory, rent-sharing and rent-extraction theories, theory of job search, and search-and-matching models. One of the conclusions arising from the discussion is that the evolution of contemporary labour markets is a challenge for researchers seeking wage formation models adequately describing the real-life circumstances.

  10. Exploring gravitational theories beyond Horndeski

    Science.gov (United States)

    Gleyzes, Jérôme; Langlois, David; Piazza, Federico; Vernizzi, Filippo

    2015-02-01

    We have recently proposed a new class of gravitational scalar-tensor theories free from Ostrogradski instabilities, in ref. [1]. As they generalize Horndeski theories, or "generalized" galileons, we call them G3. These theories possess a simple formulation when the time hypersurfaces are chosen to coincide with the uniform scalar field hypersurfaces. We confirm that they contain only three propagating degrees of freedom by presenting the details of the Hamiltonian formulation. We examine the coupling between these theories and matter. Moreover, we investigate how they transform under a disformal redefinition of the metric. Remarkably, these theories are preserved by disformal transformations that depend on the scalar field gradient, which also allow to map subfamilies of G3 into Horndeski theories.

  11. Some geometry of de Sitter space

    CERN Document Server

    Tod, Paul

    2015-01-01

    In this expository note, I present some basic geometric and twistor theoretic facts about de Sitter space leading up to a discussion of Penrose's quasi-local mass construction for linear gravity theory in the de Sitter background. The corresponding results for Minkowski space and anti--de Sitter space are familiar and can be found in \\cite{PR} or \\cite{HT} for the former and \\cite{KT} for the latter. Some of the formulas given here are also quite familiar, but some are thought to be new and it is convenient to have these facts collected in one place.

  12. Workshop Presentations: BSCW Analysts

    Data.gov (United States)

    National Aeronautics and Space Administration — These slides were presented at the AePW, April 21-22, 2012. They detail the analytical results generated by each of the participating analysis teams for the...

  13. Workshop Presentations: RSW Analysts

    Data.gov (United States)

    National Aeronautics and Space Administration — These slides were presented at the AePW, April 21-22, 2012. They detail the analytical results generated by each of the participating analysis teams for the...

  14. Workshop Presentations: HIRENASD Analysts

    Data.gov (United States)

    National Aeronautics and Space Administration — These slides were presented at the AePW, April 21-22, 2012. They detail the analytical results generated by each of the participating analysis teams for the HIRENASD.

  15. Fostering oral presentation performance

    NARCIS (Netherlands)

    Ginkel, van Stan; Gulikers, Judith; Biemans, Harm; Mulder, Martin

    2016-01-01

    Previous research revealed significant differences in the effectiveness of various feedback sources for encouraging students’ oral presentation performance. While former studies emphasised the superiority of teacher feedback, it remains unclear whether the quality of feedback actually differs bet

  16. Blade Testing Trends (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Desmond, M.

    2014-08-01

    As an invited guest speaker, Michael Desmond presented on NREL's NWTC structural testing methods and capabilities at the 2014 Sandia Blade Workshop held on August 26-28, 2014 in Albuquerque, NM. Although dynamometer and field testing capabilities were mentioned, the presentation focused primarily on wind turbine blade testing, including descriptions and capabilities for accredited certification testing, historical methodology and technology deployment, and current research and development activities.

  17. Presenting New Grammar

    Institute of Scientific and Technical Information of China (English)

    WU Cai-ling; WANG Xi

    2015-01-01

    More and more researchers have now agreed upon the necessity of teaching grammar, but it still remains controversial as how to teach the forms, with the central consideration of not to harm the meaning-focused communicative teaching method. In this essay, one of the issues in grammar teaching will be discussed as how to present new grammar to learners, through evaluating and modifying a particular presentation activity in a grammar-teaching textbook.

  18. Communication and presentation skills

    OpenAIRE

    Lorencová, Ivana

    2014-01-01

    This bachelor thesis deals with individual factors of communication and basic presentations skills. The theoretical part specifies the basic elements of verbal and non-verbal communication and basic factors connected with preparation and realisation of a presentation. The practical part of the thesis comprises an analysis of impacts of speaker's visual and other communication influences over an audience. The results are applied to a Multimedia Display exhibition taking place during the bachel...

  19. Developing a paper presentation.

    Science.gov (United States)

    Pierce, L L; Gregg, M M

    1994-01-01

    The purpose of this article is to provide suggestions for developing and presenting papers at an educational conference or other professional meeting. The authors offer suggestions on how to write an abstract, deal with rejection or success, develop an outline, construct a lecture, select audiovisual materials, and use public-speaking skills. The practical strategies described in this article are intended to enable rehabilitation nurses and other readers to develop and/or enhance their paper presentations.

  20. Stellar Presentations (Abstract)

    Science.gov (United States)

    Young, D.

    2015-12-01

    (Abstract only) The AAVSO is in the process of expanding its education, outreach and speakers bureau program. powerpoint presentations prepared for specific target audiences such as AAVSO members, educators, students, the general public, and Science Olympiad teams, coaches, event supervisors, and state directors will be available online for members to use. The presentations range from specific and general content relating to stellar evolution and variable stars to specific activities for a workshop environment. A presentation—even with a general topic—that works for high school students will not work for educators, Science Olympiad teams, or the general public. Each audience is unique and requires a different approach. The current environment necessitates presentations that are captivating for a younger generation that is embedded in a highly visual and sound-bite world of social media, twitter and U-Tube, and mobile devices. For educators, presentations and workshops for themselves and their students must support the Next Generation Science Standards (NGSS), the Common Core Content Standards, and the Science Technology, Engineering and Mathematics (STEM) initiative. Current best practices for developing relevant and engaging powerpoint presentations to deliver information to a variety of targeted audiences will be presented along with several examples.

  1. Hidden figures are ever present.

    Science.gov (United States)

    Mens, L H; Leeuwenberg, E L

    1988-11-01

    Preference judgments about alternative interpretations of unambiguous patterns can be explained in terms of a rivalry between a preferred and a second-best interpretation (cf. Leeuwenberg & Buffart, 1983). We tested whether this second-best interpretation corresponds to a suppressed but concurrently present interpretation or whether it merely reflects an alternative view that happens to be preferred less often. Two patterns were present immediately following each other with a very short onset asynchrony: a complete pattern and one out of three possible subpatterns of it, corresponding to the best, the second best, or an odd interpretation of the complete pattern. Subjects indicated which subpattern was presented by choosing among the three subpatterns shown after each trial. The scores, corrected for response-bias effects, indicated a relative facilitation of the second-best interpretation, in agreement with its predicted "hidden" presence. This result is more in line with theories that capitalize on the quality of the finally selected representation than with processing models aimed at reaching one single solution as fast and as economically as possible.

  2. Testing gauge-invariant perturbation theory

    CERN Document Server

    Törek, Pascal

    2016-01-01

    Gauge-invariant perturbation theory for theories with a Brout-Englert-Higgs effect, as developed by Fr\\"ohlich, Morchio and Strocchi, starts out from physical, exactly gauge-invariant quantities as initial and final states. These are composite operators, and can thus be considered as bound states. In case of the standard model, this reduces almost entirely to conventional perturbation theory. This explains the success of conventional perturbation theory for the standard model. However, this is due to the special structure of the standard model, and it is not guaranteed to be the case for other theories. Here, we review gauge-invariant perturbation theory. Especially, we show how it can be applied and that it is little more complicated than conventional perturbation theory, and that it is often possible to utilize existing results of conventional perturbation theory. Finally, we present tests of the predictions of gauge-invariant perturbation theory, using lattice gauge theory, in three different settings. In ...

  3. A synthetic axiomatization of Map Theory

    DEFF Research Database (Denmark)

    Berline, Chantal; Grue, Klaus Ebbe

    2016-01-01

    of ZFC set theory including the axiom of foundation are provable in Map Theory, and if one omits Hilbert's epsilon operator from Map Theory then one is left with a computer programming language. Map Theory fulfills Church's original aim of lambda calculus. Map Theory is suited for reasoning about......”. The class of wellfounded maps in Map Theory corresponds to the universe of sets in ZFC. The first axiomatization MT 0 of Map Theory had axioms which populated the class of wellfounded maps, much like the power set axiom along with others populate the universe of ZFC. The new axiomatization MT of Map Theory......This paper presents a substantially simplified axiomatization of Map Theory and proves the consistency of this axiomatization (called MT) in ZFC under the assumption that there exists an inaccessible ordinal. Map Theory axiomatizes lambda calculus plus Hilbert's epsilon operator. All theorems...

  4. Information theory and rate distortion theory for communications and compression

    CERN Document Server

    Gibson, Jerry

    2013-01-01

    This book is very specifically targeted to problems in communications and compression by providing the fundamental principles and results in information theory and rate distortion theory for these applications and presenting methods that have proved and will prove useful in analyzing and designing real systems. The chapters contain treatments of entropy, mutual information, lossless source coding, channel capacity, and rate distortion theory; however, it is the selection, ordering, and presentation of the topics within these broad categories that is unique to this concise book. While the cover

  5. Scattering theory. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Harald [Technische Univ. Muenchen, Garching (Germany). Physik-Department

    2016-07-01

    This corrected and updated second edition of ''Scattering Theory'' presents a concise and modern coverage of the subject. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. The book contains sections on special topics such as near-threshold quantization, quantum reflection, Feshbach resonances and the quantum description of scattering in two dimensions. The level of abstraction is kept as low as at all possible and deeper questions related to the mathematical foundations of scattering theory are passed by. It should be understandable for anyone with a basic knowledge of nonrelativistic quantum mechanics. The book is intended for advanced students and researchers, and it is hoped that it will be useful for theorists and experimentalists alike.

  6. Geometric scalar theory of gravity

    Energy Technology Data Exchange (ETDEWEB)

    Novello, M.; Bittencourt, E.; Goulart, E.; Salim, J.M.; Toniato, J.D. [Instituto de Cosmologia Relatividade Astrofisica ICRA - CBPF Rua Dr. Xavier Sigaud 150 - 22290-180 Rio de Janeiro - Brazil (Brazil); Moschella, U., E-mail: novello@cbpf.br, E-mail: eduhsb@cbpf.br, E-mail: Ugo.Moschella@uninsubria.it, E-mail: egoulart@cbpf.br, E-mail: jsalim@cbpf.br, E-mail: toniato@cbpf.br [Università degli Studi dell' Insubria - Dipartamento di Fisica e Matematica Via Valleggio 11 - 22100 Como - Italy (Italy)

    2013-06-01

    We present a geometric scalar theory of gravity. Our proposal will be described using the ''background field method'' introduced by Gupta, Feynman, Deser and others as a field theory formulation of general relativity. We analyze previous criticisms against scalar gravity and show how the present proposal avoids these difficulties. This concerns not only the theoretical complaints but also those related to observations. In particular, we show that the widespread belief of the conjecture that the source of scalar gravity must be the trace of the energy-momentum tensor — which is one of the main difficulties to couple gravity with electromagnetic phenomenon in previous models — does not apply to our geometric scalar theory. From the very beginning this is not a special relativistic scalar gravity. The adjective ''geometric'' pinpoints its similarity with general relativity: this is a metric theory of gravity. Some consequences of this new scalar theory are explored.

  7. The psychological present.

    Science.gov (United States)

    Hayes, L J

    1992-01-01

    The present paper compares behavior-analytic and cognitive treatments of the concept of psychological history with regard to its role in current action. Both treatments take the position that the past bears some responsibility for the present, and are thereby obligated to find a means of actualizing the past in the present. Both do so by arguing that the past is brought to bear in the present via the organism. Although the arguments of the two positions differ on this issue, neither provides a complete account. An unconventional treatment of psychological history is proposed, the logic of which is exemplified in anthropological, biological, and psychological perspectives. The unconventional treatment in psychological perspective holds that (a) the organism's interaction with its environment, not the organism itself, changes with experience; and (b) the past interactions of an organism exist as, and only as, the present interactions of that organism. This solution to the problem of psychological history provides obligations and opportunities for analysis that are not available when the more conventional positions of cognitivism and behavior analysis are adopted.

  8. Elementary Concepts of Quantum Theory

    Science.gov (United States)

    Warren, J. W.

    1974-01-01

    Discusses the importance and difficulties of teaching basic quantum theory. Presents a discussion of wave-particle duality, indeterminacy, the nature of a quantized state of a system, and the exclusion principle. (MLH)

  9. Matrix Theory of Small Oscillations

    Science.gov (United States)

    Chavda, L. K.

    1978-01-01

    A complete matrix formulation of the theory of small oscillations is presented. Simple analytic solutions involving matrix functions are found which clearly exhibit the transients, the damping factors, the Breit-Wigner form for resonances, etc. (BB)

  10. Quantum mechanics theory and experiment

    CERN Document Server

    Beck, Mark

    2012-01-01

    This textbook presents quantum mechanics at the junior/senior undergraduate level. It is unique in that it describes not only quantum theory, but also presents five laboratories that explore truly modern aspects of quantum mechanics. These laboratories include "proving" that light contains photons, single-photon interference, and tests of local realism. The text begins by presenting the classical theory of polarization, moving on to describe the quantum theory of polarization. Analogies between the two theories minimize conceptual difficulties that students typically have when first presented with quantum mechanics. Furthermore, because the laboratories involve studying photons, using photon polarization as a prototypical quantum system allows the laboratory work to be closely integrated with the coursework. Polarization represents a two-dimensional quantum system, so the introduction to quantum mechanics uses two-dimensional state vectors and operators. This allows students to become comfortable with the mat...

  11. Review of chiral perturbation theory

    Indian Academy of Sciences (India)

    B Ananthanarayan

    2003-11-01

    A review of chiral perturbation theory and recent developments on the comparison of its predictions with experiment is presented. Some interesting topics with scope for further elaboration are touched upon.

  12. TUBERCULOSIS PRESENTING AS EPIGLOTTITIS

    Directory of Open Access Journals (Sweden)

    FAHIM AHMED SHAH

    2015-03-01

    Full Text Available We report a rare case of laryngeal tuberculosis in Oman Tuberculous affection of larynx is un-common in Oman and is rarely been reported. Tuberculosis is a chronic illness, acute clinical presentation is unusual. We report the case of a thirty One year old lady, post renal transplant with tuberculous involvement of the larynx, who presented with symptoms and clinical signs of acute epiglottitis. ENT examination showed initially a severely swollen epiglottis which turned nodular in about two weeks. The patient had been on immunosuppressive medications and glucocorticoids post renal trans-plant. Tuberculosis still presents sporadically in countries where the overall incidence of tuber-culosis is much lower as compared to developing countries. A strong index of suspicion is needed in immunocompromised patients with suboptimal response to routine medications. Diagnostic difficulty in this peculiar situation with differential diagnosis and management of laryngeal tuberculosis is discussed along with review of literature.

  13. [Atypical presentation of preeclampsia].

    Science.gov (United States)

    Ditisheim, A; Boulvain, M; Irion, O; Pechère-Bertschi, A

    2015-09-09

    Preeclampsia is a pregnancy-related syndrome, which still represents one of the major causes of maternal-fetal mortality and morbidity. Diagnosis can be made difficult due to the complexity of the disorder and its wide spectrum of clinical manifestations. In order to provide an efficient diagnostic tool to the clinician, medical societies regularly rethink the definition criteria. However, there are still clinical presentations of preeclampsia that escape the frame of the definition. The present review will address atypical forms of preeclampsia, such as preeclampsia without proteinuria, normotensive preeclampsia, preeclampsia before 20 weeks of gestation and post-partum preeclampsia.

  14. Milk: Past and Present

    Science.gov (United States)

    Bulajić, S.; Đorđević, J.; Ledina, T.; Šarčević, D.; Baltić, M. Ž.

    2017-09-01

    Although milk/dairy consumption is part of many cultures and is recommended in most dietary guidelines around the world, its contribution to overall diet quality remains a matter of controversy, leading to a highly polarized debate within the scientific community, media and public sector. The present article, at first, describes the evolutionary roots of milk consumption, then reviews the milk-derived bioactive peptides as health-promoting components. The third part of the article, in general, presents the associations between milk nutrients, disease prevention, and health promotion.

  15. Book Presentation | 27 February

    CERN Multimedia

    The CERN Library

    2013-01-01

    "A caccia del bosone di Higgs. Magneti, governi, scienziati e particelle nell'impresa scientifica del secolo" by Luciano Maiani and Romeo Bassoli, published by Mondadori. On Wednesday 27 February Luciano Maiani will present the book "A caccia del bosone di Higgs. Magneti, governi, scienziati e particelle nell'impresa scientifica del secolo". More information here. The presentation will take place in the Council Chamber at 16.00 and will be followed by a debate and book signing. The book will be on sale. You are cordially invited.

  16. Effective lecture presentation skills.

    Science.gov (United States)

    Gelula, M H

    1997-02-01

    Lectures are the most popular form of teaching in medical education. As much as preparation and organization are key to the lecture's success, the actual presentation also depends upon the presenter's ability to reach the audience. Teaching is a lively activity. It calls for more than just offering ideas and data to an audience. It calls for direct contact with the audience, effective use of language, capability to use limited time effectively, and the ability to be entertaining. This article offers a structure to effective lecturing by highlighting the importance of voice clarity and speaking speed, approaches to using audiovisual aids, effectively using the audience to the lecture, and ways to be entertaining.

  17. Evolutionary theories of aging and longevity.

    Science.gov (United States)

    Gavrilov, Leonid A; Gavrilova, Natalia S

    2002-02-07

    The purpose of this article is to provide students and researchers entering the field of aging studies with an introduction to the evolutionary theories of aging, as well as to orient them in the abundant modern scientific literature on evolutionary gerontology. The following three major evolutionary theories of aging are discussed: 1) the theory of programmed death suggested by August Weismann, 2) the mutation accumulation theory of aging suggested by Peter Medawar, and 3) the antagonistic pleiotropy theory of aging suggested by George Williams. We also discuss a special case of the antagonistic pleiotropy theory, the disposable soma theory developed by Tom Kirkwood and Robin Holliday. The theories are compared with each other as well as with recent experimental findings. At present the most viable evolutionary theories are the mutation accumulation theory and the antagonistic pleiotropy theory; these theories are not mutually exclusive, and they both may become a part of a future unifying theory of aging. Evolutionary theories of aging are useful because they open new opportunities for further research by suggesting testable predictions, but they have also been harmful in the past when they were used to impose limitations on aging studies. At this time, the evolutionary theories of aging are not ultimate completed theories, but rather a set of ideas that themselves require further elaboration and validation. This theoretical review article is written for a wide readership.

  18. Subjective Illness theory and coping

    Directory of Open Access Journals (Sweden)

    Gessmann H.-W.

    2015-03-01

    Full Text Available The article presents a view of a problem of subjective illness theory in context of coping behavior. The article compiles the results of the latest studies of coping; discloses the way subjective illness theory affects the illness coping and patient's health; presents the study of differences in coping behaviour of patients at risk of heart attack and oncology. The article is recommended for specialists, concerned with psychological reasons of pathogenic processes and coping strategies of patients.

  19. A Narrative Theory of Games

    DEFF Research Database (Denmark)

    Aarseth, Espen

    2012-01-01

    In this article I present a narrative theory of games, building on standard narra-tology, as a solution to the conundrum that has haunted computer game studies from the start: How to approach software that combines games and stories?......In this article I present a narrative theory of games, building on standard narra-tology, as a solution to the conundrum that has haunted computer game studies from the start: How to approach software that combines games and stories?...

  20. A Narrative Theory of Games

    DEFF Research Database (Denmark)

    Aarseth, Espen

    2012-01-01

    In this article I present a narrative theory of games, building on standard narra-tology, as a solution to the conundrum that has haunted computer game studies from the start: How to approach software that combines games and stories?......In this article I present a narrative theory of games, building on standard narra-tology, as a solution to the conundrum that has haunted computer game studies from the start: How to approach software that combines games and stories?...

  1. Imagined futures, present lives

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Line; Wildermuth, Norbert

    2006-01-01

    is discussed centrally in this attempt to contribute to an empirically grounded understanding of the role that media play for youth in their striving to ‘find a place in life'. In the empirical context presented in the article, imaginations, expanded and circulated by a globalized media circuit...

  2. Generating Embodied Information Presentations

    NARCIS (Netherlands)

    Theune, M.; Heylen, D.; Nijholt, A.; Stock, O.; Zancanaro, M.

    2005-01-01

    The output modalities available for information presentation by embodied, human-like agents include both language and various nonverbal cues such as pointing and gesturing. These human, nonverbal modalities can be used to emphasize, extend or even replace the language output produced by the agent. T

  3. Presentation design: pecha kucha

    OpenAIRE

    Aníbal, J.

    2011-01-01

    Global presentation phenomena has started in 2003. Pecha Kucha: change in attitude • wonderfully creative • unconventional way “to do PowerPoint". Design is about people creating solutions that help or improve the lives of other people. "Design is not an art although there is art in it", Garr Reynolds.

  4. Creating Meaningful Multimedia Presentations

    NARCIS (Netherlands)

    Hardman, L.; Ossenbruggen, J.R. van

    2006-01-01

    Finding relevant information is one step in the chain of understanding information. Presenting material to a user in a suitable way is a further step. Our research focuses on using semantic annotations of multimedia elements to increase the ”presentability” of retrieved info

  5. The Persistence of Presentism

    Science.gov (United States)

    Hargreaves, Andy; Shirley, Dennis

    2009-01-01

    Background/Context: This study draws on the voluminous research on teachers' workplace orientations and especially on Dan Lortie's documentation of conservatism, individualism, and presentism among teachers. Purpose/Objective/Research Question/Focus of Study: This study investigated a school reform network of over 300 secondary schools entitled…

  6. Presentation of 2004 earnings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-03-01

    This presentation offers financial information on the AREVA Group earnings for the year 2004. With manufacturing facilities in over 40 countries and a sales network in over 100, Areva offers customers technological solutions for nuclear power generation and electricity transmission and distribution. The Group also provides interconnect systems to the telecommunications, computer and automotive markets. (A.L.B.)

  7. Neurosyphilis: Various Presentations

    Directory of Open Access Journals (Sweden)

    Kezban Aslan

    2012-12-01

    Full Text Available Neurosphylisis develops in about 5 % of untreated patients infected with Treponema pallidum. Spirocet, disseminates systemically hours to days after inoculation. Early invasion to central nervous system can be seen in infected patients without symptomatic. In these lecture we presented three patients with different complain. The patients have had; diplopia, headache and blurred vision, numness and slimming of legs.

  8. Presentation design: pecha kucha

    OpenAIRE

    Aníbal, J.

    2011-01-01

    Global presentation phenomena has started in 2003. Pecha Kucha: change in attitude • wonderfully creative • unconventional way “to do PowerPoint". Design is about people creating solutions that help or improve the lives of other people. "Design is not an art although there is art in it", Garr Reynolds.

  9. Presentism and black holes

    NARCIS (Netherlands)

    Sengers, G. (Geurt)

    2017-01-01

    textabstractIn a recent publication in the European Journal for Philosophy of Science (Romero and Pérez, European Journal for Philosophy of Science, 4, 293–308, 2014), Romero and Pérez claim to reveal new trouble for the already difficult life of presentism in relativistic spacetimes. Their argument

  10. Managing Presentation Anxiety

    Science.gov (United States)

    Hartman, Jackie L.; LeMay, Elaine

    2004-01-01

    All business communication professors struggle with anxiety-ridden students when discussing public speaking. To alleviate students' fears of speaking in public a process was designed to allow business communication students to acknowledge, address, and annul their presentation fears. A six-year comparative study using qualitative methods and…

  11. Econophysics: Past and present

    Science.gov (United States)

    de Area Leão Pereira, Eder Johnson; da Silva, Marcus Fernandes; Pereira, H. B. B.

    2017-05-01

    This paper provides a brief historical review of the relationship between economics and physics, beginning with Adam Smith being influenced by Isaac Newton's ideas up to the present day including the new econophysics discipline and some of the tools applied to the economy. Thus, this work is expected to motivate new researchers who are interested in this new discipline.

  12. Classical Theory, Postmodernism, and the Sociology Liberal Arts Curriculum.

    Science.gov (United States)

    Lembcke, Jerry Lee

    1993-01-01

    Discusses classical theory as a modernist endeavor to apprehend the phenomenon of "unity of disunity." Presents three ways that classical theory approaches the philosophy views of Durkheim, Marx, and Weber. Concludes that postmodernism validates the relevancy of classical theory. (CFR)

  13. General systems theory: implications for theory and action in occupational therapy.

    Science.gov (United States)

    Kielhofner, G

    1978-11-01

    This paper presents a description of the transformation of science under General Systems Theory, and the relationship of this transformation to the field of occupational therapy. Changes in scientific methods of proof and in scientific laws that underlie theory are discussed. The paper presents a scale for recognizing complexity in phenomena and for analyzing the appropriateness of theories designed to explain the phenomena. It also presents the theory of open systems as an alternative to mechanistic explanations of human behavior.

  14. Graph theory

    CERN Document Server

    Diestel, Reinhard

    2000-01-01

    This book is a concise, yet carefully written, introduction to modern graph theory, covering all its major recent developments. It can be used both as a reliable textbook for an introductory course and as a graduate text: on each topic it covers all the basic material in full detail, and adds one or two deeper results (again with detailed proofs) to illustrate the more advanced methods of that field. This second edition extends the first in two ways. It offers a thoroughly revised and updated chapter on graph minors, which now includes full new proofs of two of the central Robertson-Seymour theorems (as well as a detailed sketch of the entire proof of their celebrated Graph Minor Theorem). Second, there is now a section of hints for all the exercises, to enhance their value for both individual study and classroom use.

  15. Teratology - past, present and future.

    Science.gov (United States)

    Ujházy, Eduard; Mach, Mojmír; Navarová, Jana; Brucknerová, Ingrid; Dubovický, Michal

    2012-12-01

    Teratology is the science that studies the causes, mechanisms, and patterns of abnormal development. The authors present an updated overview of the most important milestones and stages of the development of modern teratology. Development of knowledge and society led to the recognition that causes of congenital developmental disorders (CDDs) might be caused by various mechanical effects, foetal diseases, and retarded or arrested development of the embryo and foetus. Based on the analysis of the historical development of hypotheses and theories representing a decisive contribution to this field, we present a survey of the six Wilson's fundamental principles of teratology. The aim of observing these principles is to get insight into developmental relations and to understand mechanisms of action on the level of cell populations (elementary morphogenetic processes), tissues and organs. It is important to realise that any negative intervention into the normal course of these processes, either on genetic or non-genetic basis, inevitably leads to a sequence of subsequent changes resulting in CDDs. Moreover, the classical toxicologic monotonic dose-response paradigm recently has been challenged by the so-called "low dose-hypothesis", particularly in the case of endocrine active substances. These include some pesticides, dioxins, polychlorobiphenyls (PCBs), and bisphenol A. Despite modern approaches of molecular biology and genetics, along with top diagnostic techniques, we are still not able to identify the actual cause in more than 65 to 70% of all congenital defects classified as having an unknown etiology. Today CDDs include any birth defect, either morphological, biochemical, or behavioural.

  16. Applied electromagnetic scattering theory

    CERN Document Server

    Osipov, Andrey A

    2017-01-01

    Besides classical applications (radar and stealth, antennas, microwave engineering), scattering and diffraction are enabling phenomena for some emerging research fields (artificial electromagnetic materials or metamaterials, terahertz technologies, electromagnetic aspects of nano-science). This book is a tutorial for advanced students who need to study diffraction theory. The textbook gives fundamental knowledge about scattering and diffraction of electromagnetic waves and provides some working examples of solutions for practical high-frequency scattering and diffraction problems. The book focuses on the most important diffraction effects and mechanisms influencing the scattering process and describes efficient and physically justified simulation methods - physical optics (PO) and the physical theory of diffraction (PTD) - applicable in typical remote sensing scenarios. The material is presented in a comprehensible and logical form, which relates the presented results to the basic principles of electromag...

  17. Cystosarcoma phyllodess. Case presentation

    Directory of Open Access Journals (Sweden)

    Lidia Torres Ajá

    2006-08-01

    Full Text Available A 12 year-old patient is presented, with tumor of the left breast of 11,7 cms, of quick growth, without another accompanying sintomatology, which was diagnosed as cystosarcoma phyllodess benign. In the twenty-five years of existence of our hospital, it is the first tumor phyllodes detected in girl, for that is considered a curious and interesting case that can enrich the experience of other professionals of the health.

  18. Ground Vehicle Robotics Presentation

    Science.gov (United States)

    2012-08-14

    Mr. Jim Parker Associate Director Ground Vehicle Robotics Distribution Statement A. Approved for public release Report Documentation Page...Briefing 3. DATES COVERED 01-07-2012 to 01-08-2012 4. TITLE AND SUBTITLE Ground Vehicle Robotics Presentation 5a. CONTRACT NUMBER 5b. GRANT...ABSTRACT Provide Transition-Ready, Cost-Effective, and Innovative Robotics and Control System Solutions for Manned, Optionally-Manned, and Unmanned

  19. EPIDEMIOLOGY LENSES : A PRESENTATION

    Directory of Open Access Journals (Sweden)

    Prakash V. Kotecha

    2010-07-01

    Full Text Available The presentation started with his nostalgic memory with Professor NR Mehta, Professor DH Trivedi and Professor AK Niyogi with whom he had the opportunity to work as a student and then as a colleague. He refreshed his memory as warden of Dr. Jivraj Mehta Hall where his predecessors were Prof NR Mehta and Professor DH Trivedi and he remembered to be the first time examiner with Prof. Niyogi who was examiner with him for the last time in his career .....

  20. Scleroderma. A case presentation.

    Directory of Open Access Journals (Sweden)

    Rubén Bembibre Taboada

    2005-08-01

    Full Text Available This article presents a brief review about generalized sclerosis (sclerodermia and reports a case with such disease talking into consideration that the patient received clinical intensive care assistaance and had a clinical diagnosis supoported by lab test for a clinical and differential diagnosis. Medical treatment was applied for the disease and for the possible complications, but the patients follow up was wrong due to multi organ failure as a consequence of derlying disease.