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Sample records for richard feynman gave

  1. Professor Richard Feynman colloquium

    CERN Multimedia

    1965-01-01

    Richard P. Feynman received the Nobel Prize for physics in 1965. Following the ceremony in Stockholm, Feynman gave the colloquium "Development of the space-time view of quantum electrodynamics" at CERN on 17th December.

  2. Richard Feynman Quarks, Bombs, and Bongos

    CERN Document Server

    Henderson, Harry

    2010-01-01

    Described by his peers as the "finest physicist of his generation," Richard Feynman defied scientist stereotypes. This brash New York-born American physicist startled the more conservative giants of European physics with his endless ability to improvise. Indeed, later in life, Feynman became an accomplished bongo player. Feynman's legacy to physics was his ability to simplify complex equations and clarify fundamental principles through the use of graphs. He developed the theory of quantum electrodynamics, which illustrates the behavior of electrically charged particles, such as elect

  3. Quantum Man: Richard Feynman's Life in Science

    CERN Document Server

    CERN. Geneva

    2011-01-01

    It took a man who was willing to break all the rules to tame a theory that breaks all the rules. This talk will be based on my new book Quantum Man: Richard Feynman's life in science. I will try and present a scientific overview of the contributions of Richard Feynman, as seen through the arc of his fascinating life. From Quantum Mechanics to Antiparticles, from Rio de Janeiro to Los Alamos, a whirlwind tour will provide insights into the character, life and accomplishments of one of the 20th centuries most important scientists, and provide an object lesson in scientific integrity.

  4. To Have Been a Student of Richard Feynman

    Indian Academy of Sciences (India)

    Excerpt from Most of the Good Stuff: Memories of Richard Feynman, 1993, ... of Feynman, but while it inspired us to try for originality after we left Cornell, it also lowered our productivity to a point that at times was dangerous to our academic careers. In truth .... (However, my actual thesis topic turned out to be a different one.).

  5. Feynman Lectures on Computation

    CERN Document Server

    Feynman, Richard Phillips; Allen, Robin W

    1999-01-01

    "When, in 1984-86, Richard P. Feynman gave his famous course on computation at the California Institute of Technology, he asked Tony Hey to adapt his lecture notes into a book. Although led by Feynman,"

  6. Richard Feynman a life in science

    CERN Document Server

    Gribbin, John

    1998-01-01

    This text is a portrayal of one of the greatest scientists of the late 20th-century, which also provides a picture of the significant physics of the period. It combines personal anecdotes, writings and recollections with narrative. Richard Feynman's career included: war-time work on the atomic bomb at Los Alamos; a theory of quantum mechanics for which he won the Nobel prize; and major contributions to the sciences of gravity, nuclear physics and particle theory. In 1986, he was able to show that the Challenger disaster was due to the effect of cold on the booster rocket rubber sealings.

  7. Richard Phillips Feynman

    Indian Academy of Sciences (India)

    ARTICLE-IN-A-BOX. 797. RESONANCE │ September 2011. The war years interrupted the efforts of both Feynman and Schwinger to tackle the divergence problems in quantum electrodynamics, another of Dirac's pioneering creations from 1927. In 1965 the Physics Nobel Prize was shared by the two of them and Sin-Ichiro ...

  8. Richard Phillips Feynman

    Indian Academy of Sciences (India)

    While the two relativity theories were largely the creation of Albert Einstein, the quantum ... of what may lie in store for anyone who dares to follow the beat of a different drum. ... saw Feynman's exceptional talents and in a special lecture explained to him the beautiful principle ... The Character of Physical Law – 1965. c).

  9. One of the many visiting theoreticians, R P Feynman, who gave lectures at CERN during the year

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    Visiting CERN in January was R P Feynman, who has recently been working on strong interaction theory. On 8 January, he packed the lecture theatre, as usual, when he gave a talk on inelastic hadron collisions and is here caught in a typically graphic pose.

  10. Quantum mechanics in the cold war; Quantenmechanik im Kalten Krieg. David Bohm und Richard Feynman

    Energy Technology Data Exchange (ETDEWEB)

    Forstner, C.

    2007-07-01

    In the middle of the 20th century David Bohm and Richard Feynman developed two fundamentally different approaches of modern quantum mechanics: Bohm a realistic interpretation by means of hidden parameters and Feynman the path-integral formalism. This is by this more remarakable, because both physicists started from similar conditions and originated from similar connections. By its comparing approach this study presents more than a contribution to the history of the quantum theory. By the question for the social and cultural conditions of the formation of theories it is furthermore of science-sociological and science-theoretical interest. The in the beginning similar and later different binding of both scientists into the scientific community allows furthermore to study, which adapting pressure each group puts on the individual scientist and the fundamental parts of his research, and which new degrees of freedom in the formation of theories arise, when this constraint is cancelled.

  11. Coupled oscillators and Feynman's three papers

    International Nuclear Information System (INIS)

    Kim, Y S

    2007-01-01

    According to Richard Feynman, the adventure of our science of physics is a perpetual attempt to recognize that the different aspects of nature are really different aspects of the same thing. It is therefore interesting to combine some, if not all, of Feynman's papers into one. The first of his three papers is on the 'rest of the universe' contained in his 1972 book on statistical mechanics. The second idea is Feynman's parton picture which he presented in 1969 at the Stony Brook conference on high-energy physics. The third idea is contained in the 1971 paper he published with his students, where they show that the hadronic spectra on Regge trajectories are manifestations of harmonic-oscillator degeneracies. In this report, we formulate these three ideas using the mathematics of two coupled oscillators. It is shown that the idea of entanglement is contained in his rest of the universe, and can be extended to a space-time entanglement. It is shown also that his parton model and the static quark model can be combined into one Lorentz-covariant entity. Furthermore, Einstein's special relativity, based on the Lorentz group, can also be formulated within the mathematical framework of two coupled oscillators

  12. Feynman Lectures on Gravitation

    International Nuclear Information System (INIS)

    Borcherds, P

    2003-01-01

    years ago, and since then there have been many discoveries: black holes and the cosmic microwave background have been observed. There have also been theoretical developments. Unless you are a category 1 reader, you will find there are substantial passages you will need to skip over. There are also substantial sections throughout the book accessible to all, such as the following excerpt from lecture 13 (there are 16 lectures) in a section entitled 'Disappearing galaxies and energy conservation'. 'Let me also say something that people who worry about mathematical proofs and inconsistencies seem not to know. There is no way of showing mathematically that a physical conclusion is wrong or inconsistent. All that can be shown is that the mathematical assumptions are wrong. If we find that certain mathematical assumptions lead to a logically inconsistent description of Nature, we change the assumptions, not nature.' If you admire Feynman, then you are likely to enjoy this book. If you want an introduction to gravitation and relativity, there are other more recent and accessible books, but Feynman's insight may help your understanding. Think about buying it for yourself, but make sure there is a copy in your library. (book review: Feynman, Richard P; Morinigo, Fernando B; Wagner, William G - ISBN 0-813-34038-1)

  13. Drawing theories apart the dispersion of Feynman diagrams in postwar physics

    CERN Document Server

    Kaiser, David

    2005-01-01

    Winner of the 2007 Pfizer Prize from the History of Science Society. Feynman diagrams have revolutionized nearly every aspect of theoretical physics since the middle of the twentieth century. Introduced by the American physicist Richard Feynman (1918-88) soon after World War II as a means of simplifying lengthy calculations in quantum electrodynamics, they soon gained adherents in many branches of the discipline. Yet as new physicists adopted the tiny line drawings, they also adapted the diagrams and introduced their own interpretations. Drawing Theories Apart traces how generations of young theorists learned to frame their research in terms of the diagrams—and how both the diagrams and their users were molded in the process.Drawing on rich archival materials, interviews, and more than five hundred scientific articles from the period, Drawing Theories Apart uses the Feynman diagrams as a means to explore the development of American postwar physics. By focusing on the ways young physicists learned new calcul...

  14. Le cours de physique de Feynman

    CERN Document Server

    Feynman, Richard; Sands, Matthew

    L’ampleur du succès qu’a rencontré le « Cours de physique de Feynman » dès sa parution s’explique par son caractère fondamentalement novateur. Richard Feynman, qui fut professeur d’université dès l’âge de vingt-quatre ans, a exprimé dans ce cours, avant d’obtenir le prix Nobel de Physique, une vision expérimentale et extrêmement personnelle de l’enseignement de la physique. Cette vision a, depuis, remporté l’adhésion des physiciens du monde entier, faisant de cet ouvrage un grand classique. Ce cours en cinq volumes (Électromagnétisme 1 et 2, Mécanique 1 et 2, Mécanique quantique) s’adresse aux étudiants de tous niveaux qui y trouveront aussi bien les notions de base débarrassées de tout appareil mathématique inutile, que les avancées les plus modernes de cette science passionnante qu’est la physique. Cette nouvelle édition corrigée bénéficie d’une mise en page plus aérée pour un meilleur confort de lecture.

  15. Vous voulez rire, monsieur Feynman !

    CERN Document Server

    Feynman, Richard P

    2000-01-01

    Richard Feynman fut un scientifique hors norme. Non seulement il contribua en profondeur à la grande aventure de la physique des particules élémentaires, depuis la fabrication de la bombe atomique pendant la guerre alors qu'il n'a pas 25 ans, jusqu'à ses diagrammes qui permettent d'y voir un peu plus clair dans les processus physiques de base. Non seulement il fut un professeur génial, n'hésitant pas à faire le clown pour garder l'attention de ses étudiants et à simplifier pour aller à l'essentiel. Mais il mena une vie excentrique - collectionneur, bouffon, impertinent, joueur de bongo, amateur de strip-tease, séducteur impénitent, déchiffreur de codes secrets et de textes mayas, explorateur en Asie centrale -, qu'il raconte ici avec l'humour du gamin des rues de New York qu'il n'a jamais cessé d'être.

  16. Feynman integral calculus

    CERN Document Server

    Smirnov, Vladimir A

    2006-01-01

    The problem of evaluating Feynman integrals over loop momenta has existed from the early days of perturbative quantum field theory. The goal of the book is to summarize those methods for evaluating Feynman integrals that have been developed over a span of more than fifty years. `Feynman Integral Calculus' characterizes the most powerful methods in a systematic way. It concentrates on the methods that have been employed recently for most sophisticated calculations and illustrates them with numerous examples, starting from very simple ones and progressing to nontrivial examples. It also shows how to choose adequate methods and combine them in a non-trivial way. This is a textbook version of the previous book (Evaluating Feynman integrals, STMP 211) of the author. Problems and solutions have been included, Appendix G has been added, more details have been presented, recent publications on evaluating Feynman integrals have been taken into account and the bibliography has been updated.

  17. Introduction to Feynman diagrams

    CERN Document Server

    Bilenky, Samoil Mikhelevich

    1974-01-01

    Introduction to Feynman Diagrams provides Feynman diagram techniques and methods for calculating quantities measured experimentally. The book discusses topics Feynman diagrams intended for experimental physicists. Topics presented include methods for calculating the matrix elements (by perturbation theory) and the basic rules for constructing Feynman diagrams; techniques for calculating cross sections and polarizations; processes in which both leptons and hadrons take part; and the electromagnetic and weak form factors of nucleons. Experimental physicists and graduate students of physics will

  18. Combinatorial and geometric aspects of Feynman graphs and Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Bergbauer, Christoph

    2009-06-11

    The integrals associated to Feynman graphs must have been a source of frustration for particle physicists ever since. Indeed there is a delicate difference between being able to draw a Feynman graph and being able to compute the associated Feynman integral. Although perturbation theory has brought enormous breakthroughs, many physicists turned to more abstract developments in quantum field theory, looked for other ways to produce perturbational results, or left the field entirely. Nonetheless there is a significant number of physicists, computational and theoretical, who pursue the quest for concepts and algorithms to compute and understand those integrals to higher and higher orders. Their motivation is to help test the validity of the underlying physical theory. For a mathematician, Feynman graphs and their integrals provide a rich subject in their own right, independent of their computability. It was only recently though that the work of Bloch, Esnault and Kreimer has brought a growing interest of mathematicians from various disciplines to the subject. In fact it opened up a completely new direction of research: a motivic interpretation of Feynman graphs that unites their combinatorial, geometric and arithmetic aspects. This idea had been in the air for a while, based on computational results of Broadhurst and Kreimer, and on a theorem of Belkale and Brosnan related to a conjecture of Kontsevich about the generality of the underlying motives. A prerequisite for the motivic approach is a profound understanding of renormalization that was established less recently in a modern language by Connes and Kreimer. This dissertation studies the renormalization of Feynman graphs in position space using an adapted resolution of singularities, and makes two other contributions of mostly combinatorial nature to the subject. I hope this may serve as a reference for somebody who feels comfortable with the traditional position space literature and looks for a transition to the

  19. Combinatorial and geometric aspects of Feynman graphs and Feynman integrals

    International Nuclear Information System (INIS)

    Bergbauer, Christoph

    2009-01-01

    The integrals associated to Feynman graphs must have been a source of frustration for particle physicists ever since. Indeed there is a delicate difference between being able to draw a Feynman graph and being able to compute the associated Feynman integral. Although perturbation theory has brought enormous breakthroughs, many physicists turned to more abstract developments in quantum field theory, looked for other ways to produce perturbational results, or left the field entirely. Nonetheless there is a significant number of physicists, computational and theoretical, who pursue the quest for concepts and algorithms to compute and understand those integrals to higher and higher orders. Their motivation is to help test the validity of the underlying physical theory. For a mathematician, Feynman graphs and their integrals provide a rich subject in their own right, independent of their computability. It was only recently though that the work of Bloch, Esnault and Kreimer has brought a growing interest of mathematicians from various disciplines to the subject. In fact it opened up a completely new direction of research: a motivic interpretation of Feynman graphs that unites their combinatorial, geometric and arithmetic aspects. This idea had been in the air for a while, based on computational results of Broadhurst and Kreimer, and on a theorem of Belkale and Brosnan related to a conjecture of Kontsevich about the generality of the underlying motives. A prerequisite for the motivic approach is a profound understanding of renormalization that was established less recently in a modern language by Connes and Kreimer. This dissertation studies the renormalization of Feynman graphs in position space using an adapted resolution of singularities, and makes two other contributions of mostly combinatorial nature to the subject. I hope this may serve as a reference for somebody who feels comfortable with the traditional position space literature and looks for a transition to the

  20. Feynman formulae and phase space Feynman path integrals for tau-quantization of some Lévy-Khintchine type Hamilton functions

    Energy Technology Data Exchange (ETDEWEB)

    Butko, Yana A., E-mail: yanabutko@yandex.ru, E-mail: kinderknecht@math.uni-sb.de [Bauman Moscow State Technical University, 2nd Baumanskaya street, 5, Moscow 105005, Russia and University of Saarland, Postfach 151150, D-66041 Saarbrücken (Germany); Grothaus, Martin, E-mail: grothaus@mathematik.uni-kl.de [University of Kaiserslautern, 67653 Kaiserslautern (Germany); Smolyanov, Oleg G., E-mail: Smolyanov@yandex.ru [Lomonosov Moscow State University, Vorob’evy gory 1, Moscow 119992 (Russian Federation)

    2016-02-15

    Evolution semigroups generated by pseudo-differential operators are considered. These operators are obtained by different (parameterized by a number τ) procedures of quantization from a certain class of functions (or symbols) defined on the phase space. This class contains Hamilton functions of particles with variable mass in magnetic and potential fields and more general symbols given by the Lévy-Khintchine formula. The considered semigroups are represented as limits of n-fold iterated integrals when n tends to infinity. Such representations are called Feynman formulae. Some of these representations are constructed with the help of another pseudo-differential operator, obtained by the same procedure of quantization; such representations are called Hamiltonian Feynman formulae. Some representations are based on integral operators with elementary kernels; these are called Lagrangian Feynman formulae. Langrangian Feynman formulae provide approximations of evolution semigroups, suitable for direct computations and numerical modeling of the corresponding dynamics. Hamiltonian Feynman formulae allow to represent the considered semigroups by means of Feynman path integrals. In the article, a family of phase space Feynman pseudomeasures corresponding to different procedures of quantization is introduced. The considered evolution semigroups are represented as phase space Feynman path integrals with respect to these Feynman pseudomeasures, i.e., different quantizations correspond to Feynman path integrals with the same integrand but with respect to different pseudomeasures. This answers Berezin’s problem of distinguishing a procedure of quantization on the language of Feynman path integrals. Moreover, the obtained Lagrangian Feynman formulae allow also to calculate these phase space Feynman path integrals and to connect them with some functional integrals with respect to probability measures.

  1. Feynman formulae and phase space Feynman path integrals for tau-quantization of some Lévy-Khintchine type Hamilton functions

    International Nuclear Information System (INIS)

    Butko, Yana A.; Grothaus, Martin; Smolyanov, Oleg G.

    2016-01-01

    Evolution semigroups generated by pseudo-differential operators are considered. These operators are obtained by different (parameterized by a number τ) procedures of quantization from a certain class of functions (or symbols) defined on the phase space. This class contains Hamilton functions of particles with variable mass in magnetic and potential fields and more general symbols given by the Lévy-Khintchine formula. The considered semigroups are represented as limits of n-fold iterated integrals when n tends to infinity. Such representations are called Feynman formulae. Some of these representations are constructed with the help of another pseudo-differential operator, obtained by the same procedure of quantization; such representations are called Hamiltonian Feynman formulae. Some representations are based on integral operators with elementary kernels; these are called Lagrangian Feynman formulae. Langrangian Feynman formulae provide approximations of evolution semigroups, suitable for direct computations and numerical modeling of the corresponding dynamics. Hamiltonian Feynman formulae allow to represent the considered semigroups by means of Feynman path integrals. In the article, a family of phase space Feynman pseudomeasures corresponding to different procedures of quantization is introduced. The considered evolution semigroups are represented as phase space Feynman path integrals with respect to these Feynman pseudomeasures, i.e., different quantizations correspond to Feynman path integrals with the same integrand but with respect to different pseudomeasures. This answers Berezin’s problem of distinguishing a procedure of quantization on the language of Feynman path integrals. Moreover, the obtained Lagrangian Feynman formulae allow also to calculate these phase space Feynman path integrals and to connect them with some functional integrals with respect to probability measures

  2. Detailed balance of the Feynman micromotor

    Science.gov (United States)

    Abbott, Derek; Davis, Bruce R.; Parrondo, Juan M. R.

    1999-09-01

    One existing implication of micromotors is that they can be powered by rectifying non-equilibrium thermal fluctuations or mechanical vibrations via the so-called Feynman- micromotor. An example of mechanical rectification is found in the batteryless wristwatch. The original concept was described in as early as 1912 by Smoluchowski and was later revisited in 1963 by Feynman, in the context of rectifying thermal fluctuations to obtain useful motion. It has been shown that, although rectification is impossible at equilibrium, it is possible for the Feynman-micromotor to perform work under non-equilibrium conditions. These concepts can now be realized by MEMS technology and may have exciting implications in biomedicine - where the Feynman- micromotor can be used to power a smart pill, for example. Previously, Feynman's analysis of the motor's efficiency has been shown to be flawed by Parrondo and Espanol. We now show there are further problems in Feynman's treatment of detailed balance. In order to design and understand this device correctly, the equations of detailed balance must be found. Feynman's approach was to use probabilities based on energies and we show that this is problematic. In this paper, we demonstrate corrected equations using level crossing probabilities instead. A potential application of the Feynman-micromotor is a batteryless nanopump that consists of a small MEMS chip that adheres to the skin of a patient and dispense nanoliter quantities of medication. Either mechanical or thermal rectification via a Feynman- micromotor, as the power source, is open for possible investigation.

  3. Feynman integrals and hyperlogarithms

    Energy Technology Data Exchange (ETDEWEB)

    Panzer, Erik

    2015-02-05

    We study Feynman integrals in the representation with Schwinger parameters and derive recursive integral formulas for massless 3- and 4-point functions. Properties of analytic (including dimensional) regularization are summarized and we prove that in the Euclidean region, each Feynman integral can be written as a linear combination of convergent Feynman integrals. This means that one can choose a basis of convergent master integrals and need not evaluate any divergent Feynman graph directly. Secondly we give a self-contained account of hyperlogarithms and explain in detail the algorithms needed for their application to the evaluation of multivariate integrals. We define a new method to track singularities of such integrals and present a computer program that implements the integration method. As our main result, we prove the existence of infinite families of massless 3- and 4-point graphs (including the ladder box graphs with arbitrary loop number and their minors) whose Feynman integrals can be expressed in terms of multiple polylogarithms, to all orders in the ε-expansion. These integrals can be computed effectively with the presented program. We include interesting examples of explicit results for Feynman integrals with up to 6 loops. In particular we present the first exactly computed counterterm in massless φ{sup 4} theory which is not a multiple zeta value, but a linear combination of multiple polylogarithms at primitive sixth roots of unity (and divided by the √(3)). To this end we derive a parity result on the reducibility of the real- and imaginary parts of such numbers into products and terms of lower depth.

  4. Feynman integrals and hyperlogarithms

    International Nuclear Information System (INIS)

    Panzer, Erik

    2015-01-01

    We study Feynman integrals in the representation with Schwinger parameters and derive recursive integral formulas for massless 3- and 4-point functions. Properties of analytic (including dimensional) regularization are summarized and we prove that in the Euclidean region, each Feynman integral can be written as a linear combination of convergent Feynman integrals. This means that one can choose a basis of convergent master integrals and need not evaluate any divergent Feynman graph directly. Secondly we give a self-contained account of hyperlogarithms and explain in detail the algorithms needed for their application to the evaluation of multivariate integrals. We define a new method to track singularities of such integrals and present a computer program that implements the integration method. As our main result, we prove the existence of infinite families of massless 3- and 4-point graphs (including the ladder box graphs with arbitrary loop number and their minors) whose Feynman integrals can be expressed in terms of multiple polylogarithms, to all orders in the ε-expansion. These integrals can be computed effectively with the presented program. We include interesting examples of explicit results for Feynman integrals with up to 6 loops. In particular we present the first exactly computed counterterm in massless φ 4 theory which is not a multiple zeta value, but a linear combination of multiple polylogarithms at primitive sixth roots of unity (and divided by the √(3)). To this end we derive a parity result on the reducibility of the real- and imaginary parts of such numbers into products and terms of lower depth.

  5. Trochanteric fractures. Classification and mechanical stability in McLaughlin, Ender and Richard osteosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Herrlin, K.; Stroemberg, T.; Lidgren, L.; Walloee, A.; Pettersson, H.

    Four hundred and thirty trochanteric factures operated upon with McLaughlin, Ender or Richard's osteosynthesis were divided into 6 different types based on their radiographic appearance before and immediately after reposition with special reference to the medial cortical support. A significant correlation was found between the fracture type and subsequent mechanical complications where types 1 and 2 gave less, and types 4 and 5 more complications. A comparison of the various osteosyntheses showed that Richard's had significantly fewer complications than either the Ender or McLaughlin types. For Richard's osteosynthesis alone no correlation to fracture type could be made because of the small number of complications in this group.

  6. Baikov-Lee representations of cut Feynman integrals

    International Nuclear Information System (INIS)

    Harley, Mark; Moriello, Francesco; Schabinger, Robert M.

    2017-01-01

    We develop a general framework for the evaluation of d-dimensional cut Feynman integrals based on the Baikov-Lee representation of purely-virtual Feynman integrals. We implement the generalized Cutkosky cutting rule using Cauchy’s residue theorem and identify a set of constraints which determine the integration domain. The method applies equally well to Feynman integrals with a unitarity cut in a single kinematic channel and to maximally-cut Feynman integrals. Our cut Baikov-Lee representation reproduces the expected relation between cuts and discontinuities in a given kinematic channel and furthermore makes the dependence on the kinematic variables manifest from the beginning. By combining the Baikov-Lee representation of maximally-cut Feynman integrals and the properties of periods of algebraic curves, we are able to obtain complete solution sets for the homogeneous differential equations satisfied by Feynman integrals which go beyond multiple polylogarithms. We apply our formalism to the direct evaluation of a number of interesting cut Feynman integrals.

  7. Feynman diagrams without Feynman parameters

    International Nuclear Information System (INIS)

    Mendels, E.

    1978-01-01

    Dimensionally regularized Feynman diagrams are represented by means of products of k-functions. The infinite part of these diagrams is found very easily, also if they are overlapping, and the separation of the several kinds of divergences comes out quite naturally. Ward identities are proven in a transparent way. Series expansions in terms of the external momenta and their inner products are possible

  8. FeynRules - Feynman rules made easy

    OpenAIRE

    Christensen, Neil D.; Duhr, Claude

    2008-01-01

    In this paper we present FeynRules, a new Mathematica package that facilitates the implementation of new particle physics models. After the user implements the basic model information (e.g. particle content, parameters and Lagrangian), FeynRules derives the Feynman rules and stores them in a generic form suitable for translation to any Feynman diagram calculation program. The model can then be translated to the format specific to a particular Feynman diagram calculator via F...

  9. Analytic Tools for Feynman Integrals

    CERN Document Server

    Smirnov, Vladimir A

    2012-01-01

    The goal of this book is to describe the most powerful methods for evaluating multiloop Feynman integrals that are currently used in practice.  This book supersedes the author’s previous Springer book “Evaluating Feynman Integrals” and its textbook version “Feynman Integral Calculus.” Since the publication of these two books, powerful new methods have arisen and conventional methods have been improved on in essential ways. A further qualitative change is the fact that most of the methods and the corresponding algorithms have now been implemented in computer codes which are often public. In comparison to the two previous books, three new chapters have been added:  One is on sector decomposition, while the second describes a new method by Lee. The third new chapter concerns the asymptotic expansions of Feynman integrals in momenta and masses, which were described in detail in another Springer book, “Applied Asymptotic Expansions in Momenta and Masses,” by the author. This chapter describes, on t...

  10. A Hundred Years of Physics on Show

    CERN Multimedia

    2002-01-01

    The New Yorker Richard Feynman, well known to all physicists for his diagrams. Eleven vivid posters have recently been hung along the Theoretical Physics corridor on the first floor of Building 53. They tell the story of a century of physics, between 1900 and the end of the nineteen-nineties, the century that gave us atomic and quantum physics and the great breakthroughs that have rocked our understanding of the world and the universe. The posters are a gift from the American Physical Society to the CERN Library. As they were designed for high school and university book collections in the US, they necessarily have a somewhat American view of the history of science. But it is still instructive to revisit contemporary physics through its great figures, such as Marie Curie, Stephen Hawking, and Richard Feynman, not to mention Albert Einstein and many others. Why not take the time for a little trip down this particular stretch of Memory Lane?

  11. Feynman integral calculus

    International Nuclear Information System (INIS)

    Smirnov, V.A.

    2006-01-01

    The goal of the book is to summarize those methods for evaluating Feynman integrals that have been developed over a span of more than fifty years. The book characterizes the most powerful methods and illustrates them with numerous examples starting from very simple ones and progressing to nontrivial examples. The book demonstrates how to choose adequate methods and combine evaluation methods in a non-trivial way. The most powerful methods are characterized and then illustrated through numerous examples. This is an updated textbook version of the previous book (Evaluating Feynman integrals, STMP 211) of the author. (orig.)

  12. Feynman integral calculus

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, V.A. [Lomonosov Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics

    2006-07-01

    The goal of the book is to summarize those methods for evaluating Feynman integrals that have been developed over a span of more than fifty years. The book characterizes the most powerful methods and illustrates them with numerous examples starting from very simple ones and progressing to nontrivial examples. The book demonstrates how to choose adequate methods and combine evaluation methods in a non-trivial way. The most powerful methods are characterized and then illustrated through numerous examples. This is an updated textbook version of the previous book (Evaluating Feynman integrals, STMP 211) of the author. (orig.)

  13. A note on relativistic Feynman-type integrals

    International Nuclear Information System (INIS)

    Namsrai, Kh.

    1979-01-01

    An attempt is made to generalize the definition of Feynman path integral to the relativistic case within the framework of the Kershaw stochastic model. The Smoluchowski type equations are used which allow one to obtain easily the Schrodinger, Klein-Gordon and Dirac equations. The interaction is introduced by using Weyl's gaude theory. In the model developed the Feynman process may formally by interpreted as a stochastic diffusion process in complex times with a real probability measure which occurs in the Euclidean space. Feynman path integrals themselves are not obtained in the model, nonetheless it represents an interest as one of possibilities of the relativistic generalization of Feynman type integrals

  14. Analytic tools for Feynman integrals

    International Nuclear Information System (INIS)

    Smirnov, Vladimir A.

    2012-01-01

    Most powerful methods of evaluating Feynman integrals are presented. Reader will be able to apply them in practice. Contains numerous examples. The goal of this book is to describe the most powerful methods for evaluating multiloop Feynman integrals that are currently used in practice. This book supersedes the author's previous Springer book ''Evaluating Feynman Integrals'' and its textbook version ''Feynman Integral Calculus.'' Since the publication of these two books, powerful new methods have arisen and conventional methods have been improved on in essential ways. A further qualitative change is the fact that most of the methods and the corresponding algorithms have now been implemented in computer codes which are often public. In comparison to the two previous books, three new chapters have been added: One is on sector decomposition, while the second describes a new method by Lee. The third new chapter concerns the asymptotic expansions of Feynman integrals in momenta and masses, which were described in detail in another Springer book, ''Applied Asymptotic Expansions in Momenta and Masses,'' by the author. This chapter describes, on the basis of papers that appeared after the publication of said book, how to algorithmically discover the regions relevant to a given limit within the strategy of expansion by regions. In addition, the chapters on the method of Mellin-Barnes representation and on the method of integration by parts have been substantially rewritten, with an emphasis on the corresponding algorithms and computer codes.

  15. Mathematical aspects of Feynman integrals

    International Nuclear Information System (INIS)

    Bogner, Christian

    2009-08-01

    In the present dissertation we consider Feynman integrals in the framework of dimensional regularization. As all such integrals can be expressed in terms of scalar integrals, we focus on this latter kind of integrals in their Feynman parametric representation and study their mathematical properties, partially applying graph theory, algebraic geometry and number theory. The three main topics are the graph theoretic properties of the Symanzik polynomials, the termination of the sector decomposition algorithm of Binoth and Heinrich and the arithmetic nature of the Laurent coefficients of Feynman integrals. The integrand of an arbitrary dimensionally regularised, scalar Feynman integral can be expressed in terms of the two well-known Symanzik polynomials. We give a detailed review on the graph theoretic properties of these polynomials. Due to the matrix-tree-theorem the first of these polynomials can be constructed from the determinant of a minor of the generic Laplacian matrix of a graph. By use of a generalization of this theorem, the all-minors-matrix-tree theorem, we derive a new relation which furthermore relates the second Symanzik polynomial to the Laplacian matrix of a graph. Starting from the Feynman parametric parameterization, the sector decomposition algorithm of Binoth and Heinrich serves for the numerical evaluation of the Laurent coefficients of an arbitrary Feynman integral in the Euclidean momentum region. This widely used algorithm contains an iterated step, consisting of an appropriate decomposition of the domain of integration and the deformation of the resulting pieces. This procedure leads to a disentanglement of the overlapping singularities of the integral. By giving a counter-example we exhibit the problem, that this iterative step of the algorithm does not terminate for every possible case. We solve this problem by presenting an appropriate extension of the algorithm, which is guaranteed to terminate. This is achieved by mapping the iterative

  16. Mathematical aspects of Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Bogner, Christian

    2009-08-15

    In the present dissertation we consider Feynman integrals in the framework of dimensional regularization. As all such integrals can be expressed in terms of scalar integrals, we focus on this latter kind of integrals in their Feynman parametric representation and study their mathematical properties, partially applying graph theory, algebraic geometry and number theory. The three main topics are the graph theoretic properties of the Symanzik polynomials, the termination of the sector decomposition algorithm of Binoth and Heinrich and the arithmetic nature of the Laurent coefficients of Feynman integrals. The integrand of an arbitrary dimensionally regularised, scalar Feynman integral can be expressed in terms of the two well-known Symanzik polynomials. We give a detailed review on the graph theoretic properties of these polynomials. Due to the matrix-tree-theorem the first of these polynomials can be constructed from the determinant of a minor of the generic Laplacian matrix of a graph. By use of a generalization of this theorem, the all-minors-matrix-tree theorem, we derive a new relation which furthermore relates the second Symanzik polynomial to the Laplacian matrix of a graph. Starting from the Feynman parametric parameterization, the sector decomposition algorithm of Binoth and Heinrich serves for the numerical evaluation of the Laurent coefficients of an arbitrary Feynman integral in the Euclidean momentum region. This widely used algorithm contains an iterated step, consisting of an appropriate decomposition of the domain of integration and the deformation of the resulting pieces. This procedure leads to a disentanglement of the overlapping singularities of the integral. By giving a counter-example we exhibit the problem, that this iterative step of the algorithm does not terminate for every possible case. We solve this problem by presenting an appropriate extension of the algorithm, which is guaranteed to terminate. This is achieved by mapping the iterative

  17. Analytic tools for Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Vladimir A. [Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics

    2012-07-01

    Most powerful methods of evaluating Feynman integrals are presented. Reader will be able to apply them in practice. Contains numerous examples. The goal of this book is to describe the most powerful methods for evaluating multiloop Feynman integrals that are currently used in practice. This book supersedes the author's previous Springer book ''Evaluating Feynman Integrals'' and its textbook version ''Feynman Integral Calculus.'' Since the publication of these two books, powerful new methods have arisen and conventional methods have been improved on in essential ways. A further qualitative change is the fact that most of the methods and the corresponding algorithms have now been implemented in computer codes which are often public. In comparison to the two previous books, three new chapters have been added: One is on sector decomposition, while the second describes a new method by Lee. The third new chapter concerns the asymptotic expansions of Feynman integrals in momenta and masses, which were described in detail in another Springer book, ''Applied Asymptotic Expansions in Momenta and Masses,'' by the author. This chapter describes, on the basis of papers that appeared after the publication of said book, how to algorithmically discover the regions relevant to a given limit within the strategy of expansion by regions. In addition, the chapters on the method of Mellin-Barnes representation and on the method of integration by parts have been substantially rewritten, with an emphasis on the corresponding algorithms and computer codes.

  18. Analytic continuation of dual Feynman amplitudes

    International Nuclear Information System (INIS)

    Bleher, P.M.

    1981-01-01

    A notion of dual Feynman amplitude is introduced and a theorem on the existence of analytic continuation of this amplitude from the convergence domain to the whole complex is proved. The case under consideration corresponds to massless power propagators and the analytic continuation is constructed on the propagators powers. Analytic continuation poles and singular set of external impulses are found explicitly. The proof of the theorem on the existence of analytic continuation is based on the introduction of α-representation for dual Feynman amplitudes. In proving, the so-called ''trees formula'' and ''trees-with-cycles formula'' are established that are dual by formulation to the trees and 2-trees formulae for usual Feynman amplitudes. (Auth.)

  19. Automated generation of lattice QCD Feynman rules

    Energy Technology Data Exchange (ETDEWEB)

    Hart, A.; Mueller, E.H. [Edinburgh Univ. (United Kingdom). SUPA School of Physics and Astronomy; von Hippel, G.M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Horgan, R.R. [Cambridge Univ. (United Kingdom). DAMTP, CMS

    2009-04-15

    The derivation of the Feynman rules for lattice perturbation theory from actions and operators is complicated, especially for highly improved actions such as HISQ. This task is, however, both important and particularly suitable for automation. We describe a suite of software to generate and evaluate Feynman rules for a wide range of lattice field theories with gluons and (relativistic and/or heavy) quarks. Our programs are capable of dealing with actions as complicated as (m)NRQCD and HISQ. Automated differentiation methods are used to calculate also the derivatives of Feynman diagrams. (orig.)

  20. Automated generation of lattice QCD Feynman rules

    International Nuclear Information System (INIS)

    Hart, A.; Mueller, E.H.; Horgan, R.R.

    2009-04-01

    The derivation of the Feynman rules for lattice perturbation theory from actions and operators is complicated, especially for highly improved actions such as HISQ. This task is, however, both important and particularly suitable for automation. We describe a suite of software to generate and evaluate Feynman rules for a wide range of lattice field theories with gluons and (relativistic and/or heavy) quarks. Our programs are capable of dealing with actions as complicated as (m)NRQCD and HISQ. Automated differentiation methods are used to calculate also the derivatives of Feynman diagrams. (orig.)

  1. Feynman diagram drawing made easy

    International Nuclear Information System (INIS)

    Baillargeon, M.

    1997-01-01

    We present a drawing package optimised for Feynman diagrams. These can be constructed interactively with a mouse-driven graphical interface or from a script file, more suitable to work with a diagram generator. It provides most features encountered in Feynman diagrams and allows to modify every part of a diagram after its creation. Special attention has been paid to obtain a high quality printout as easily as possible. This package is written in Tcl/Tk and in C. (orig.)

  2. Beyond Feynman Diagrams (1/3)

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    For decades the central theoretical tool for computing scattering amplitudes has been the Feynman diagram. However, Feynman diagrams are just too slow, even on fast computers, to be able to go beyond the leading order in QCD, for complicated events with many jets of hadrons in the final state. Such events are produced copiously at the LHC, and constitute formidable backgrounds to many searches for new physics. Over the past few years, alternative methods that go beyond ...

  3. Feynman integrals in QCD made simple

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    A key insight is that important properties of these functions can be predicted by inspecting the singularity structure of the Feynman integrand. Combined with the differential equations technique, this gives a powerful method for computing the necessary Feynman integrals. I will review these ideas, based on Phys.Rev.Lett. 110 (2013) 25, and present recent new results relevant for QCD scattering amplitudes.

  4. (U) Feynman-Y calculations using PARTISN

    Energy Technology Data Exchange (ETDEWEB)

    Favorite, Jeffrey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-31

    A prescription for computing the Feynman Y as a function of coincidence gate width using a deterministic multigroup neutron transport code has been published and the results compared favorably with measurements of the BeRP ball. In this paper, we report on our project to implement the method and reproduce the results. There are several clarifications and corrections of the published prescription. We show results using two multigroup cross section libraries compared with measurements and with Monte Carlo results. Deterministic simulations of the mean count rates compare very favorably with previously published Monte Carlo results, and deterministic simulations of the Feynman Y asymptote compare somewhat favorably. In Feynman beta plots, the deterministic simulations reached the asymptotic value much sooner than did a fit to the measured data.

  5. The Feynman-Dyson view

    International Nuclear Information System (INIS)

    Gill, Tepper L.

    2017-01-01

    This paper is a survey of our work on the mathematical foundations for the Feynman-Dyson program in quantum electrodynamics (QED). After a brief discussion of the history, we provide a representation theory for the Feynman operator calculus. This allows us to solve the general initial-value problem and construct the Dyson series. We show that the series is asymptotic, thus proving Dyson’s second conjecture for quantum electrodynamics. In addition, we show that the expansion may be considered exact to any finite order by producing the remainder term. This implies that every nonperturbative solution has a perturbative expansion. Using a physical analysis of information from experiment versus that implied by our models, we reformulate our theory as a sum over paths. This allows us to relate our theory to Feynman’s path integral, and to prove Dyson’s first conjecture that the divergences are in part due to a violation of Heisenberg’s uncertainly relations. As a by-product, we also prove Feynman’s conjecture about the relationship between the operator calculus and has path integral. Thus, providing the first rigorous justification for the Feynman formulation of quantum mechanics. (paper)

  6. The Feynman-Dyson view

    Science.gov (United States)

    Gill, Tepper L.

    2017-05-01

    This paper is a survey of our work on the mathematical foundations for the Feynman-Dyson program in quantum electrodynamics (QED). After a brief discussion of the history, we provide a representation theory for the Feynman operator calculus. This allows us to solve the general initial-value problem and construct the Dyson series. We show that the series is asymptotic, thus proving Dyson’s second conjecture for quantum electrodynamics. In addition, we show that the expansion may be considered exact to any finite order by producing the remainder term. This implies that every nonperturbative solution has a perturbative expansion. Using a physical analysis of information from experiment versus that implied by our models, we reformulate our theory as a sum over paths. This allows us to relate our theory to Feynman’s path integral, and to prove Dyson’s first conjecture that the divergences are in part due to a violation of Heisenberg’s uncertainly relations. As a by-product, we also prove Feynman’s conjecture about the relationship between the operator calculus and has path integral. Thus, providing the first rigorous justification for the Feynman formulation of quantum mechanics.

  7. Research Capabilities

    Science.gov (United States)

    ; Sponsored Work Regional Economic Development Technology Opportunities User Facilities About Us Metrics In Search Site submit About Us Los Alamos National LaboratoryRichard P. Feynman Center for Innovation Innovation protecting tomorrow Los Alamos National Laboratory The Richard P. Feynman Center for Innovation

  8. Spin wave Feynman diagram vertex computation package

    Science.gov (United States)

    Price, Alexander; Javernick, Philip; Datta, Trinanjan

    Spin wave theory is a well-established theoretical technique that can correctly predict the physical behavior of ordered magnetic states. However, computing the effects of an interacting spin wave theory incorporating magnons involve a laborious by hand derivation of Feynman diagram vertices. The process is tedious and time consuming. Hence, to improve productivity and have another means to check the analytical calculations, we have devised a Feynman Diagram Vertex Computation package. In this talk, we will describe our research group's effort to implement a Mathematica based symbolic Feynman diagram vertex computation package that computes spin wave vertices. Utilizing the non-commutative algebra package NCAlgebra as an add-on to Mathematica, symbolic expressions for the Feynman diagram vertices of a Heisenberg quantum antiferromagnet are obtained. Our existing code reproduces the well-known expressions of a nearest neighbor square lattice Heisenberg model. We also discuss the case of a triangular lattice Heisenberg model where non collinear terms contribute to the vertex interactions.

  9. Some recent results on evaluating Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, V.A. [Nuclear Physics Institute of Moscow State University, Moscow 119992 (Russian Federation)

    2006-07-15

    Some recent results on evaluating Feynman integrals are reviewed. The status of the method based on Mellin-Barnes representation as a powerful tool to evaluate individual Feynman integrals is characterized. A new method based on Groebner bases to solve integration by parts relations in an automatic way is described.

  10. Some recent results on evaluating Feynman integrals

    International Nuclear Information System (INIS)

    Smirnov, V.A.

    2006-01-01

    Some recent results on evaluating Feynman integrals are reviewed. The status of the method based on Mellin-Barnes representation as a powerful tool to evaluate individual Feynman integrals is characterized. A new method based on Groebner bases to solve integration by parts relations in an automatic way is described

  11. A Feynman graph selection tool in GRACE system

    International Nuclear Information System (INIS)

    Yuasa, Fukuko; Ishikawa, Tadashi; Kaneko, Toshiaki

    2001-01-01

    We present a Feynman graph selection tool grcsel, which is an interpreter written in C language. In the framework of GRACE, it enables us to get a subset of Feynman graphs according to given conditions

  12. Numerical evaluation of tensor Feynman integrals in Euclidean kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Gluza, J.; Kajda [Silesia Univ., Katowice (Poland). Inst. of Physics; Riemann, T.; Yundin, V. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2010-10-15

    For the investigation of higher order Feynman integrals, potentially with tensor structure, it is highly desirable to have numerical methods and automated tools for dedicated, but sufficiently 'simple' numerical approaches. We elaborate two algorithms for this purpose which may be applied in the Euclidean kinematical region and in d=4-2{epsilon} dimensions. One method uses Mellin-Barnes representations for the Feynman parameter representation of multi-loop Feynman integrals with arbitrary tensor rank. Our Mathematica package AMBRE has been extended for that purpose, and together with the packages MB (M. Czakon) or MBresolve (A. V. Smirnov and V. A. Smirnov) one may perform automatically a numerical evaluation of planar tensor Feynman integrals. Alternatively, one may apply sector decomposition to planar and non-planar multi-loop {epsilon}-expanded Feynman integrals with arbitrary tensor rank. We automatized the preparations of Feynman integrals for an immediate application of the package sectordecomposition (C. Bogner and S. Weinzierl) so that one has to give only a proper definition of propagators and numerators. The efficiency of the two implementations, based on Mellin-Barnes representations and sector decompositions, is compared. The computational packages are publicly available. (orig.)

  13. Application of difference filter to Feynman-α analysis

    International Nuclear Information System (INIS)

    Mouri, Tomoaki; Ohtani, Nobuo

    1997-11-01

    The Feynman-α method has been developed for monitoring sub-criticality in nuclear fuel facilities. It is difficult to apply the Feynman-α method which estimates statistical variation of the number of neutron counts per unit time, to the system in transient condition such that the averaged neutron flux varies with time. In the application of Feynman-α method to such system, it is suggested to remove the averaged variation of neutron flux from neutron count data by the use of the difference filter. In this study, we applied the difference filter to reactor noise data at sub-criticality near to criticality, where the prompt decay constant was difficult to estimate due to the large effect of delayed neutron. With the difference filter, accurate prompt decay constants for effective multiplication factors from 0.999 to 0.994 were obtained by Feynman-α method. It was cleared that the difference filter is effective to estimate accurate prompt decay constant, so that there is the prospect to be able to apply Feynman-α method having the difference filter to the system in the transient condition. (author)

  14. Feynman diagrams coupled to three-dimensional quantum gravity

    International Nuclear Information System (INIS)

    Barrett, John W

    2006-01-01

    A framework for quantum field theory coupled to three-dimensional quantum gravity is proposed. The coupling with quantum gravity regulates the Feynman diagrams. One recovers the usual Feynman amplitudes in the limit as the cosmological constant tends to zero

  15. Feynman maps without improper integrals

    International Nuclear Information System (INIS)

    Exner, P.; Kolerov, G.I.

    1980-01-01

    The Feynman maps introduced first by Truman are examined. The domain considered here consists of the Fresnel-inteo-rable functions in the sense of Albeverio and Hoegh-Krohn. The original definition of the F-maps is slightly modified: it is started from the underlying measures on the Hilbert space of paths in order to avoid use of improper integrals. Some new properties of the F-maps are derived. In particular, the dominated convergence theorem is shown to be not valid for the F 1 -map (or Feynman integral); this fact is of a certain importance for classical limit of quantum mechanics

  16. Factorization in QCD in Feynman gauge

    International Nuclear Information System (INIS)

    Tucci, R.R.

    1985-01-01

    We present a mass divergence power counting technique for QCD in the Feynman gauge. For the process γ/sup */ → qq, we find the leading regions of integration and show that single diagrams are at worst logarithmically divergent. Using the Weyl representation facilities the γ matrix manipulations necessary for power counting and adds much physical insight. We prove Ward type identities which are needed in the proof of factorization of the Drill Yan process. Previous treatments prove them only for an axial gauge, and the proofs are diagrammatic in nature. We, on the other hand, establish the identities for the Feynman gauge and through symmetry considerations at the Lagrangian level. The strategy is to first derive exact results in a background field gauge and then to show that to leading order in the mass divergences the background field gauge results can be used in the Feynman gauge

  17. Rigorous time slicing approach to Feynman path integrals

    CERN Document Server

    Fujiwara, Daisuke

    2017-01-01

    This book proves that Feynman's original definition of the path integral actually converges to the fundamental solution of the Schrödinger equation at least in the short term if the potential is differentiable sufficiently many times and its derivatives of order equal to or higher than two are bounded. The semi-classical asymptotic formula up to the second term of the fundamental solution is also proved by a method different from that of Birkhoff. A bound of the remainder term is also proved. The Feynman path integral is a method of quantization using the Lagrangian function, whereas Schrödinger's quantization uses the Hamiltonian function. These two methods are believed to be equivalent. But equivalence is not fully proved mathematically, because, compared with Schrödinger's method, there is still much to be done concerning rigorous mathematical treatment of Feynman's method. Feynman himself defined a path integral as the limit of a sequence of integrals over finite-dimensional spaces which is obtained by...

  18. Richard III

    DEFF Research Database (Denmark)

    Lauridsen, Palle Schantz

    2017-01-01

    Kort analyse af Shakespeares Richard III med fokus på, hvordan denne skurk fremstilles, så tilskuere (og læsere) langt henad vejen kan føle sympati med ham. Med paralleller til Netflix-serien "House of Cards"......Kort analyse af Shakespeares Richard III med fokus på, hvordan denne skurk fremstilles, så tilskuere (og læsere) langt henad vejen kan føle sympati med ham. Med paralleller til Netflix-serien "House of Cards"...

  19. Counting the number of Feynman graphs in QCD

    Science.gov (United States)

    Kaneko, T.

    2018-05-01

    Information about the number of Feynman graphs for a given physical process in a given field theory is especially useful for confirming the result of a Feynman graph generator used in an automatic system of perturbative calculations. A method of counting the number of Feynman graphs with weight of symmetry factor was established based on zero-dimensional field theory, and was used in scalar theories and QED. In this article this method is generalized to more complicated models by direct calculation of generating functions on a computer algebra system. This method is applied to QCD with and without counter terms, where many higher order are being calculated automatically.

  20. The Feynman integral for time-dependent anharmonic oscillators

    International Nuclear Information System (INIS)

    Grothaus, M.; Khandekar, D.C.; da Silva, J.L.; Streit, L.

    1997-01-01

    We review some basic notions and results of white noise analysis that are used in the construction of the Feynman integrand as a generalized white noise functional. We show that the Feynman integrand for the time-dependent harmonic oscillator in an external potential is a Hida distribution. copyright 1997 American Institute of Physics

  1. Feynman rules for fermion-number-violating interactions

    International Nuclear Information System (INIS)

    Denner, A.; Eck, H.; Hahn, O.; Kueblbeck, J.

    1992-01-01

    We present simple algorithmic Feynman rules for fermion-number-violating interactions. They do not involve explicit charge-conjugation matrices and resemble closely the familiar rules for Dirac fermions. We insist on a fermion flow through the graphs along fermion lines and get the correct relative signs between different interfering Feynman graphs as in the case of Dirac fermions. We only need the familiar Dirac propagator and fewer vertices than in the usual treatment of fermion-number-violating interactions. (orig.)

  2. The Hellman-Feynman theorem at finite temperature

    International Nuclear Information System (INIS)

    Cabrera, A.; Calles, A.

    1990-01-01

    The possibility of a kind of Hellman-Feynman theorem at finite temperature is discussed. Using the cannonical ensembles, the derivative of the internal energy is obtained when it depends explicitly on a parameter. It is found that under the low temperature regime the derivative of the energy can be obtained as the statistical average of the derivative of the hamiltonian operator. The result allows to speak of the existence of the Hellman-Feynman theorem at finite temperatures (Author)

  3. Near threshold expansion of Feynman diagrams

    International Nuclear Information System (INIS)

    Mendels, E.

    2005-01-01

    The near threshold expansion of Feynman diagrams is derived from their configuration space representation, by performing all x integrations. The general scalar Feynman diagram is considered, with an arbitrary number of external momenta, an arbitrary number of internal lines and an arbitrary number of loops, in n dimensions and all masses may be different. The expansions are considered both below and above threshold. Rules, giving real and imaginary part, are derived. Unitarity of a sunset diagram with I internal lines is checked in a direct way by showing that its imaginary part is equal to the phase space integral of I particles

  4. Feynman path integral and the interaction picture

    International Nuclear Information System (INIS)

    Pugh, R.E.

    1986-01-01

    The role of interaction-picture fields in the construction of coherent states and in the derivation of the Feynman path integral for interacting scalar quantum fields is examined. Special attention is paid to the dependence of the integrand on the intermediate times and it is shown that the Feynman rules are valid prior to taking the limit wherein the number of intermediate times goes to infinity; thus, this number does not act as a cutoff in divergent amplitudes. Specific normalization factors are determined

  5. Feynman versus Bakamjian-Thomas in light-front dynamics

    International Nuclear Information System (INIS)

    Araujo, W.R.B. de; Beyer, M.; Weber, H.J.; Frederico, T.

    1999-01-01

    We compare the Bakamjian-Thomas (BT) formulation of relativistic few-body systems with light-front field theories that maintain closer contact with Feynman diagrams. We find that Feynman diagrams distinguish Melosh rotations and other kinematical quantities belonging to various composite subsystem frames that correspond to different loop integrals. The BT formalism knows only the rest frame of the whole composite system, where everything is evaluated. (author)

  6. The signed permutation group on Feynman graphs

    Energy Technology Data Exchange (ETDEWEB)

    Purkart, Julian, E-mail: purkart@physik.hu-berlin.de [Institute of Physics, Humboldt University, D-12489 Berlin (Germany)

    2016-08-15

    The Feynman rules assign to every graph an integral which can be written as a function of a scaling parameter L. Assuming L for the process under consideration is very small, so that contributions to the renormalization group are small, we can expand the integral and only consider the lowest orders in the scaling. The aim of this article is to determine specific combinations of graphs in a scalar quantum field theory that lead to a remarkable simplification of the first non-trivial term in the perturbation series. It will be seen that the result is independent of the renormalization scheme and the scattering angles. To achieve that goal we will utilize the parametric representation of scalar Feynman integrals as well as the Hopf algebraic structure of the Feynman graphs under consideration. Moreover, we will present a formula which reduces the effort of determining the first-order term in the perturbation series for the specific combination of graphs to a minimum.

  7. A LaTeX graphics routine for drawing Feynman diagrams

    International Nuclear Information System (INIS)

    Levine, M.J.S.

    1990-01-01

    FEYNMAN is a LaTeX macropackage which allows the user to construct a versatile range of Feynman diagrams within the text of a document. Diagrams of publication quality may be drawn with relative ease and rapidity. (orig.)

  8. Electrodynamic metaphors: communicating particle physics with Feynman diagrams

    Directory of Open Access Journals (Sweden)

    Pietroni Massimo

    2002-03-01

    Full Text Available The aim of this project is to communicate the basic laws of particle physics with Feynman diagrams - visual tools which represent elementary particle processes. They were originally developed as a code to be used by physicists and are still used today for calculations and elaborations of theoretical nature. The technical and mathematical rules of Feynman diagrams are obviously the exclusive concern of physicists, but on a pictorial level they can help to popularize many concepts, ranging from matter and the antimatter; the creation, destruction and transformation of particles; the role of ‘virtual’ particles in interactions; the conservation laws, symmetries, etc. Unlike the metaphors often used to describe the microcosm, these graphic representations provide an unequivocal translation of the physical content of the underlying quantum theory. As such they are perfect metaphors, not misleading constructions. A brief introduction on Feynman diagrams will be followed by the practical realization of this project, which will be carried out with the help of an experiment based on three-dimensional manipulable objects. The Feynman rules are expressed in terms of mechanical constraints on the possible conjuctions among the various elements of the experiment. The final part of the project will present the results of this experiment, which has been conducted among high-school students.

  9. On application of analytical transformation system using a computer for Feynman intearal calculation

    International Nuclear Information System (INIS)

    Gerdt, V.P.

    1978-01-01

    Various systems of analytic transformations for the calculation of Feynman integrals using computers are discussed. The hyperspheric technique Which is used to calculate Feynman integrals enables to perform angular integration for a set of diagrams, thus reducing the multiplicity of integral. All calculations based on this method are made with the ASHMEDAL program. Feynman integrals are calculated in Euclidean space using integration by parts and some differential identities. Analytic calculation of Feynman integral is performed by the MACSYMA system. Dispersion method of integral calculation is implemented in the SCHOONSCHIP system, calculations based on features of Nielsen function are made using efficient SINAC and RSIN programs. A tube of basic Feynman integral parameters calculated using the above techniques is given

  10. J. Richard Hackman (1940-2013)

    OpenAIRE

    Wageman, Ruth; Amabile, Teresa M.

    2013-01-01

    When J. Richard Hackman died in Cambridge, Massachusetts, on January 8, 2013, psychology lost a giant. Six and a half feet tall, with an outsize personality to match, Richard was the leading scholar in two distinct areas: work design and team effectiveness. In both domains, his work is foundational. Throughout his career, Richard applied rigorous methods to problems of great social importance, tirelessly championing multi-level analyses of problems that matter. His impact on our field has bee...

  11. Applying Groebner bases to solve reduction problems for Feynman integrals

    International Nuclear Information System (INIS)

    Smirnov, Alexander V.; Smirnov, Vladimir A.

    2006-01-01

    We describe how Groebner bases can be used to solve the reduction problem for Feynman integrals, i.e. to construct an algorithm that provides the possibility to express a Feynman integral of a given family as a linear combination of some master integrals. Our approach is based on a generalized Buchberger algorithm for constructing Groebner-type bases associated with polynomials of shift operators. We illustrate it through various examples of reduction problems for families of one- and two-loop Feynman integrals. We also solve the reduction problem for a family of integrals contributing to the three-loop static quark potential

  12. Applying Groebner bases to solve reduction problems for Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Alexander V. [Mechanical and Mathematical Department and Scientific Research Computer Center of Moscow State University, Moscow 119992 (Russian Federation); Smirnov, Vladimir A. [Nuclear Physics Institute of Moscow State University, Moscow 119992 (Russian Federation)

    2006-01-15

    We describe how Groebner bases can be used to solve the reduction problem for Feynman integrals, i.e. to construct an algorithm that provides the possibility to express a Feynman integral of a given family as a linear combination of some master integrals. Our approach is based on a generalized Buchberger algorithm for constructing Groebner-type bases associated with polynomials of shift operators. We illustrate it through various examples of reduction problems for families of one- and two-loop Feynman integrals. We also solve the reduction problem for a family of integrals contributing to the three-loop static quark potential.

  13. A convergence theorem for asymptotic expansions of Feynman amplitudes

    International Nuclear Information System (INIS)

    Mabouisson, A.P.C.

    1999-06-01

    The Mellin representations of Feynman integrals is revisited. From this representation, and asymptotic expansion for generic Feynman amplitudes, for any set of invariants going to zero or to ∞, may be obtained. In the case of all masses going to zero in Euclidean metric, we show that the truncated expansion has a rest compatible with convergence of the series. (author)

  14. Richard Nixon, 1972-2016 Obituary

    OpenAIRE

    Tom, Brian Dermot; Thompson, Simon Gregory; Duffy, SW; Sweeting, Michael John; Ohlssen, DI

    2017-01-01

    After a year-long journey with cancer, Dr Richard Nixon died on August 26th, 2016, aged only 43 years. He leaves behind his wife of 5 years, Valda, and their 1-year-old baby daughter, Kyra. Richard, a Yorkshireman, was born on September 8th, 1972. He attended Ilkley Grammar School, studied mathematics at Durham University (1991–1994) and was awarded the Diploma in Mathematical Statistics from the University of Cambridge in 1995. Richard then took a career break for a couple of years to...

  15. Mathematical theory of Feynman path integrals an introduction

    CERN Document Server

    Albeverio, Sergio A; Mazzucchi, Sonia

    2008-01-01

    Feynman path integrals, suggested heuristically by Feynman in the 40s, have become the basis of much of contemporary physics, from non-relativistic quantum mechanics to quantum fields, including gauge fields, gravitation, cosmology. Recently ideas based on Feynman path integrals have also played an important role in areas of mathematics like low-dimensional topology and differential geometry, algebraic geometry, infinite-dimensional analysis and geometry, and number theory. The 2nd edition of LNM 523 is based on the two first authors' mathematical approach of this theory presented in its 1st edition in 1976. To take care of the many developments since then, an entire new chapter on the current forefront of research has been added. Except for this new chapter and the correction of a few misprints, the basic material and presentation of the first edition has been maintained. At the end of each chapter the reader will also find notes with further bibliographical information.

  16. Constructive Representation Theory for the Feynman Operator Calculus

    CERN Document Server

    Gill, T L

    2006-01-01

    In this paper, we survey recent progress on the constructive theory of the Feynman operator calculus. We first develop an operator version of the Henstock-Kurzweil integral, and a new Hilbert space that allows us to construct the elementary path integral in the manner originally envisioned by Feynman. After developing our time-ordered operator theory we extend a few of the important theorems of semigroup theory, including the Hille-Yosida theorem. As an application, we unify and extend the theory of time-dependent parabolic and hyperbolic evolution equations. We then develop a general perturbation theory and use it to prove that all theories generated by semigroups are asympotic in the operator-valued sense of Poincar e. This allows us to provide a general theory for the interaction representation of relativistic quantum theory. We then show that our theory can be reformulated as a physically motivated sum over paths, and use this version to extend the Feynman path integral to include more general interaction...

  17. Richard's back: death, scoliosis and myth making.

    Science.gov (United States)

    Lund, Mary Ann

    2015-12-01

    The body of a mediaeval monarch was always under scrutiny, and Richard III's was no exception. In death, however, his body became subject to new forms of examination and interpretation: stripped naked after the battle of Bosworth, his corpse was carried to Leicester and exhibited before being buried. In 2012, it was rediscovered. The revelation that Richard suffered from scoliosis prompts this article to re-evaluate the historical sources about Richard's physique and his posthumous reputation. This article argues that Richard's death and his myth as 'crookback' are inextricably linked and traces attitudes to spinal curvature in the early modern period. It also considers how Shakespeare represented Richard as deformed, and aspects of performance history which suggest physical vulnerability. It then considers Richard's scoliosis from the perspective of medical history, reviewing classical accounts of scoliosis and arguing that Richard was probably treated with a mixture of axial traction and pressure. It demonstrates from the evidence of Richard's medical household that he was well placed to receive hands-on therapies and considers in particular the role of his physician and surgeon, William Hobbes. Finally, it shows how the case of Richard III demonstrates the close relationship between politics and medicine in the period and the contorted process of historical myth making. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  18. Feynman integrals and the moment problem

    International Nuclear Information System (INIS)

    Pusterla, M.; Turchetti, G.; Vitali, G.

    1976-01-01

    In this letter it is illustrated a general procedure, based on the momentum method, to estimate the scalar Feynman integrals. In order to illustrate the various situations discussed, some numerical examples are presented

  19. New framework for the Feynman path integral

    International Nuclear Information System (INIS)

    Shaharir, M.Z.

    1986-01-01

    The well-known Fourier integral solution of the free diffusion equation in an arbitrary Euclidean space is reduced to Feynmannian integrals using the method partly contained in the formulation of the Fresnelian integral. By replacing the standard Hilbert space underlying the present mathematical formulation of the Feynman path integral by a new Hilbert space, the space of classical paths on the tangent bundle to the Euclidean space (and more general to an arbitrary Riemannian manifold) equipped with a natural inner product, we show that our Feynmannian integral is in better agreement with the qualitative features of the original Feynman path integral than the previous formulations of the integral

  20. Richard Lavenham on Future Contingents

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter

    1983-01-01

    Richard Lavenham on Future Contingents’, Cahiers de l’Institut du Moyen-âge Grec et Latin, 44 (1983), p.180-186.......‘Richard Lavenham on Future Contingents’, Cahiers de l’Institut du Moyen-âge Grec et Latin, 44 (1983), p.180-186....

  1. A New Comment on Dyson's Exposition of Feynman's Proof of Maxwell Equations

    International Nuclear Information System (INIS)

    Pombo, Claudia

    2009-01-01

    A paper by Dyson, published nearly two decades ago, describing Feynman's proof of Maxwell equations, has generated many comments, analysis, discussions and generalizations of the proof. Feynman's derivation is assumed to be based on two main sets of equations. One is supposed to be the second law of Newton and the other a set of basic commutation relations from quantum physics.Here we present a new comment on this paper, focusing mainly on the initial arguments and applying a new method of analysis and interpretation of physics, named observational realism. The present discussion does not alter the technical steps of Feynman, but do clarify their basis. We show that Newton's physics is not a starting point in Feynman's derivation, neither is quantum physics involved in it, but the foundations of relativity only.

  2. arXiv Diagrammatic Hopf algebra of cut Feynman integrals: the one-loop case

    CERN Document Server

    Abreu, Samuel; Duhr, Claude; Gardi, Einan

    2017-12-15

    We construct a diagrammatic coaction acting on one-loop Feynman graphs and their cuts. The graphs are naturally identified with the corresponding (cut) Feynman integrals in dimensional regularization, whose coefficients of the Laurent expansion in the dimensional regulator are multiple polylogarithms (MPLs). Our main result is the conjecture that this diagrammatic coaction reproduces the combinatorics of the coaction on MPLs order by order in the Laurent expansion. We show that our conjecture holds in a broad range of nontrivial one-loop integrals. We then explore its consequences for the study of discontinuities of Feynman integrals, and the differential equations that they satisfy. In particular, using the diagrammatic coaction along with information from cuts, we explicitly derive differential equations for any one-loop Feynman integral. We also explain how to construct the symbol of any one-loop Feynman integral recursively. Finally, we show that our diagrammatic coaction follows, in the special case of o...

  3. Path-integral quantization of solitons using the zero-mode Feynman rule

    International Nuclear Information System (INIS)

    Sung Sheng Chang

    1978-01-01

    We propose a direct expansion treatment to quantize solitons without collective coordinates. Feynman's path integral for a free particle subject to an external force is directly used as the generating functional for the zero-frequency mode. The generating functional has no infrared singularity and defines a zero-mode Feynman rule which also gives a correct perturbative expansion for the harmonic-oscillator Green's function by treating the quadratic potential as a perturbation. We use the zero-mode Feynman rule to calculate the energy shift due to the second-order quantum corrections for solitons. Our result agrees with previous predictions using the collective-coordinate method or the method of Goldstone and Jackiw

  4. Feynman variance-to-mean method

    International Nuclear Information System (INIS)

    Dowdy, E.J.; Hansen, G.E.; Robba, A.A.

    1985-01-01

    The Feynman and other fluctuation techniques have been shown to be useful for determining the multiplication of subcritical systems. The moments of the counting distribution from neutron detectors is analyzed to yield the multiplication value. The authors present the methodology and some selected applications and results and comparisons with Monte Carlo calculations

  5. Algorithm FIRE-Feynman Integral REduction

    International Nuclear Information System (INIS)

    Smirnov, A.V.

    2008-01-01

    The recently developed algorithm FIRE performs the reduction of Feynman integrals to master integrals. It is based on a number of strategies, such as applying the Laporta algorithm, the s-bases algorithm, region-bases and integrating explicitly over loop momenta when possible. Currently it is being used in complicated three-loop calculations.

  6. Automatically generating Feynman rules for improved lattice field theories

    International Nuclear Information System (INIS)

    Hart, A.; Hippel, G.M. von; Horgan, R.R.; Storoni, L.C.

    2005-01-01

    Deriving the Feynman rules for lattice perturbation theory from actions and operators is complicated, especially when improvement terms are present. This physically important task is, however, suitable for automation. We describe a flexible algorithm for generating Feynman rules for a wide range of lattice field theories including gluons, relativistic fermions and heavy quarks. We also present an efficient implementation of this in a freely available, multi-platform programming language (PYTHON), optimised to deal with a wide class of lattice field theories

  7. Basics of introduction to Feynman diagrams and electroweak interactions physics

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Mikhov, S.G.

    1994-01-01

    The Feynman diagrams are the main computational method for the evaluation of the matrix elements of different processes. Although it is a perturbative method, its significance is not restricted to perturbation theory only. In this book, the elements of quantum field theory, the Feynman diagram method, the theory of electroweak interactions and other topics are discussed. A number of classical weak and electroweak processes are considered in details. This involves, first of all, the construction of the matrix elements of the process using both the Feynman diagram method (when perturbation theory can be applied) and the invariance principles (when perturbation theory fails). Then the cross sections and the decay probabilities are computed. The text is providing widely used computational techniques and some experimental data. (A.B.). 32 refs., 7 appendix

  8. Feynman's operational calculus and beyond noncommutativity and time-ordering

    CERN Document Server

    Johnson, George W; Nielsen, Lance

    2015-01-01

    This book is aimed at providing a coherent, essentially self-contained, rigorous and comprehensive abstract theory of Feynman's operational calculus for noncommuting operators. Although it is inspired by Feynman's original heuristic suggestions and time-ordering rules in his seminal 1951 paper An operator calculus having applications in quantum electrodynamics, as will be made abundantly clear in the introduction (Chapter 1) and elsewhere in the text, the theory developed in this book also goes well beyond them in a number of directions which were not anticipated in Feynman's work. Hence, the second part of the main title of this book. The basic properties of the operational calculus are developed and certain algebraic and analytic properties of the operational calculus are explored. Also, the operational calculus will be seen to possess some pleasant stability properties. Furthermore, an evolution equation and a generalized integral equation obeyed by the operational calculus are discussed and connections wi...

  9. A multi-region multi-energy formalism for the Feynman-alpha formulas

    International Nuclear Information System (INIS)

    Malinovitch, T.; Dubi, C.

    2015-01-01

    Highlights: • A formalism of N regions and M groups for the Feynman-α method is introduced. • Using a space-energy cell notation the expressions are simplified significantly. • A simple way to incorporate the detectors in the system is used. • The results have been verified by a Monte Carlo simulation in a two-region case. - Abstract: The stochastic transport equation, describing the dynamics in time of the neutron population in a nuclear system, is used to gain expressions for the higher moments of the neutron population in a sub-critical system. Such expressions are the bone structure of the so called Feynman-α method to analyze noise experiments, aimed to determine the reactivity of sub-critical systems. In the present study, a general formalism for the stochastic transport equation in an N regions system, under the M energy groups approximation will be introduced. In particular, expressions for the Feynman variance to mean (or the Feynman-Y function) under the above mentioned restriction will be sought by using the steady state mode of the solution

  10. Simplifying Differential Equations for Multiscale Feynman Integrals beyond Multiple Polylogarithms.

    Science.gov (United States)

    Adams, Luise; Chaubey, Ekta; Weinzierl, Stefan

    2017-04-07

    In this Letter we exploit factorization properties of Picard-Fuchs operators to decouple differential equations for multiscale Feynman integrals. The algorithm reduces the differential equations to blocks of the size of the order of the irreducible factors of the Picard-Fuchs operator. As a side product, our method can be used to easily convert the differential equations for Feynman integrals which evaluate to multiple polylogarithms to an ϵ form.

  11. Extension of a theory of Feynman

    International Nuclear Information System (INIS)

    Blaquiere, Augustin

    1979-01-01

    We propose a relativistic extension of a method through which Feynman derives the Schroedinger equation. The equation of Klein-Gordon for a charged particle in a magnetic field is obtained. Some connections with the nonrelativistic and the classical approximations are discussed [fr

  12. Richards Barrier LA Reference Design Feature Evaluation

    International Nuclear Information System (INIS)

    N.E. Kramer

    1999-01-01

    The Richards Barrier is one of the design features of the repository to be considered for the License Application (LA), Richards was a soil scientist who first described the diversion of moisture between two materials with different hydrologic properties. In this report, a Richards Barrier is a special type of backfill with a fine-grained material (such as sand) overlaying a coarse-grained material (such as gravel). Water that enters an emplacement drift will first encounter the fine-grained material and be transported around the coarse-grained material covering the waste package, thus protecting the waste package from contact with most of the groundwater. The objective of this report is to discuss the benefits and liabilities to the repository by the inclusion of a Richards Barrier type backfill in emplacement drifts. The Richards Barrier can act as a barrier to water flow, can reduce the waste package material dissolution rate, limit mobilization of the radionuclides, and can provide structural protection for the waste package. The scope of this report is to: (1) Analyze the behavior of barrier materials following the intrusion of groundwater for influxes of 1 to 300 mm per year. The report will demonstrate diversion of groundwater intrusions into the barrier over an extended time period when seismic activity and consolidation may cause the potential for liquefaction and settlement of the Richards Barrier. (2) Review the thermal effects of the Richards Barrier on material behavior. (3) Analyze the effect of rockfall on the performance of the Richards Barrier and the depth of the barrier required to protect waste packages under the barrier. (4) Review radiological and heating conditions on placement of multiple layers of the barrier. Subsurface Nuclear Safety personnel will perform calculations to determine the radiation reduction-time relationship and shielding capacity of the barrier. (5) Evaluate the effects of ventilation on cooling of emplacement drifts and

  13. Obituary: Richard Joseph Elston, 1960-2004

    Science.gov (United States)

    Jannuzi, Buell Tomasson; Bechtold, Jill

    2004-12-01

    Richard Joseph Elston, known for his development of innovative astronomical instrumentation, died on 26 January 2004 in Gainesville, Florida, after a four-year battle with Hodgkin's lymphoma. A professor of astronomy at the University of Florida, Richard had an unusually broad range of interests and skills, and a willingness to share his passion for astronomy with others, which made him a highly valued member of the astronomical community. Born 1 July 1960, in Albuquerque, New Mexico, Richard was the son of a geologist father and journalist mother. His childhood interest in astronomy and instrumentation matured as he majored in physics and astronomy at the University of New Mexico (BS, 1983) under the mentorship of Michael Zeilik. Richard pursued his PhD in astronomy at the University of Arizona and earned his degree in 1988. He pioneered the use of IR arrays for deep imaging surveys of the sky to study galaxy formation, and completed his thesis Search for Rapidly Forming Galaxies at High Redshift under the direction of George Rieke. Richard's graduate work included the first detection of galaxies at intermediate redshifts with evolved populations too red to have been identifiable from optical imaging surveys alone. In the Astrophysical Journal Letters in 1988, he, George Rieke, and Marcia Rieke reported the discovery of this new class of galaxies, now known as EROs (Extremely Red Objects), important as the possible progenitors of present day elliptical galaxies. Following post-doctoral positions at Kitt Peak National Observatory from 1988 to 1991 and at the Observatories of the Carnegie Institution of Washington from 1991 to 1992, Richard joined the scientific staff of Cerro Tololo Inter-American Observatory in Chile, part of the NSF's National Optical Astronomy Observatory. By 1994, he had become head of CTIO's IR instrumentation program and was leading the development of new instruments for the US astronomical community. In 1996, Richard married astronomer

  14. Automation of Feynman diagram evaluations

    International Nuclear Information System (INIS)

    Tentyukov, M.N.

    1998-01-01

    A C-program DIANA (DIagram ANAlyser) for the automation of Feynman diagram evaluations is presented. It consists of two parts: the analyzer of diagrams and the interpreter of a special text manipulating language. This language can be used to create a source code for analytical or numerical evaluations and to keep the control of the process in general

  15. Quantum gravitation. The Feynman path integral approach

    International Nuclear Information System (INIS)

    Hamber, Herbert W.

    2009-01-01

    The book covers the theory of Quantum Gravitation from the point of view of Feynman path integrals. These provide a manifestly covariant approach in which fundamental quantum aspects of the theory such as radiative corrections and the renormalization group can be systematically and consistently addressed. The path integral method is suitable for both perturbative as well as non-perturbative studies, and is known to already provide a framework of choice for the theoretical investigation of non-abelian gauge theories, the basis for three of the four known fundamental forces in nature. The book thus provides a coherent outline of the present status of the theory gravity based on Feynman's formulation, with an emphasis on quantitative results. Topics are organized in such a way that the correspondence to similar methods and results in modern gauge theories becomes apparent. Covariant perturbation theory are developed using the full machinery of Feynman rules, gauge fixing, background methods and ghosts. The renormalization group for gravity and the existence of non-trivial ultraviolet fixed points are investigated, stressing a close correspondence with well understood statistical field theory models. Later the lattice formulation of gravity is presented as an essential tool towards an understanding of key features of the non-perturbative vacuum. The book ends with a discussion of contemporary issues in quantum cosmology such as scale dependent gravitational constants and quantum effects in the early universe. (orig.)

  16. Calculation of the pulsed Feynman- and Rossi-alpha formulae with delayed neutrons

    International Nuclear Information System (INIS)

    Kitamura, Y.; Pazsit, I.; Wright, J.; Yamamoto, A.; Yamane, Y.

    2005-01-01

    In previous works, the authors have developed an effective solution technique for calculating the pulsed Feynman- and Rossi-alpha formulae. Through derivation of these formulae, it was shown that the technique can easily handle various pulse shapes of the pulsed neutron source. Furthermore, it was also shown that both the deterministic (i.e., synchronizing with the pulsing of neutron source) and stochastic (non-synchronizing) Feynman-alpha formulae can be obtained with this solution technique. However, for mathematical simplicity and the sake of insight, the formal derivation was performed in a model without delayed neutrons. In this paper, to demonstrate the robustness of the technique, the pulsed Feynman- and Rossi-alpha formulae were re-derived by taking one group of delayed neutrons into account. The results show that the advantages of this technique are retained even by inclusion of the delayed neutrons. Compact explicit formulae are derived for the Feynman- and Rossi-alpha methods for various pulse shapes and pulsing methods

  17. Analytic properties of Feynman diagrams in quantum field theory

    CERN Document Server

    Todorov, I T

    1971-01-01

    Analytic Properties of Feynman Diagrams in Quantum Field Theory deals with quantum field theory, particularly in the study of the analytic properties of Feynman graphs. This book is an elementary presentation of a self-contained exposition of the majorization method used in the study of these graphs. The author has taken the intermediate position between Eden et al. who assumes the physics of the analytic properties of the S-matrix, containing physical ideas and test results without using the proper mathematical methods, and Hwa and Teplitz, whose works are more mathematically inclined with a

  18. Transport coefficients for deeply inelastic scattering from the Feynman path integral method

    International Nuclear Information System (INIS)

    Brink, D.M.; Neto, J.; Weidenmueller, H.A.

    1979-01-01

    Friction and diffusion coefficients can be derived simply by combining statistical arguments with the Feynman path integral method. A transport equation for Feynman's influence functional is obtained, and transport coefficients are deduced from it. The expressions are discussed in the limits of weak, and of strong coupling. (Auth.)

  19. The R{sup ∗}-operation for Feynman graphs with generic numerators

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Franz [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); Ruijl, Ben [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); Leiden University,Niels Bohrweg 1, 2333 CA Leiden (Netherlands)

    2017-05-08

    The R{sup ∗}-operation by Chetyrkin, Tkachov, and Smirnov is a generalisation of the BPHZ R-operation, which subtracts both ultraviolet and infrared divergences of euclidean Feynman graphs with non-exceptional external momenta. It can be used to compute the divergent parts of such Feynman graphs from products of simpler Feynman graphs of lower loops. In this paper we extend the R{sup ∗}-operation to Feynman graphs with arbitrary numerators, including tensors. We also provide a novel way of defining infrared counterterms which closely resembles the definition of its ultraviolet counterpart. We further express both infrared and ultraviolet counterterms in terms of scaleless vacuum graphs with a logarithmic degree of divergence. By exploiting symmetries, integrand and integral relations, which the counterterms of scaleless vacuum graphs satisfy, we can vastly reduce their number and complexity. A FORM implementation of this method was used to compute the five loop beta function in QCD for a general gauge group. To illustrate the procedure, we compute the poles in the dimensional regulator of all top-level propagator graphs at five loops in four dimensional ϕ{sup 3} theory.

  20. Solutions of the Wheeler-Feynman equations with discontinuous velocities.

    Science.gov (United States)

    de Souza, Daniel Câmara; De Luca, Jayme

    2015-01-01

    We generalize Wheeler-Feynman electrodynamics with a variational boundary value problem for continuous boundary segments that might include velocity discontinuity points. Critical-point orbits must satisfy the Euler-Lagrange equations of the action functional at most points, which are neutral differential delay equations (the Wheeler-Feynman equations of motion). At velocity discontinuity points, critical-point orbits must satisfy the Weierstrass-Erdmann continuity conditions for the partial momenta and the partial energies. We study a special setup having the shortest time-separation between the (infinite-dimensional) boundary segments, for which case the critical-point orbit can be found using a two-point boundary problem for an ordinary differential equation. For this simplest setup, we prove that orbits can have discontinuous velocities. We construct a numerical method to solve the Wheeler-Feynman equations together with the Weierstrass-Erdmann conditions and calculate some numerical orbits with discontinuous velocities. We also prove that the variational boundary value problem has a unique solution depending continuously on boundary data, if the continuous boundary segments have velocity discontinuities along a reduced local space.

  1. Richard Florida : loovsektor on majanduskasvu mootor / Richard Florida ; interv. Argo Ideon

    Index Scriptorium Estoniae

    Florida, Richard

    2008-01-01

    USA majandus- ja ühiskonnateadlane Richard Florida loovklassi teooriast, selle osast majanduskasvu tagamisel, seosest ühiskonna tolerantsuse ja ühiskonna majandusliku edukuse vahel, sotsiaalse sidususe takistavast rollist loovuse motiveerimisel

  2. Fulltext PDF

    Indian Academy of Sciences (India)

    shop'. Richard Feynman, in his ... his life, Feynman investigated the mechanical failure in the space shuttle Challenger. There are many more ... Eiffel stands out as tall as the famous tower his company designed and built in 1889. In this issue, we ...

  3. Feynman-Kac equations for reaction and diffusion processes

    Science.gov (United States)

    Hou, Ru; Deng, Weihua

    2018-04-01

    This paper provides a theoretical framework for deriving the forward and backward Feynman-Kac equations for the distribution of functionals of the path of a particle undergoing both diffusion and reaction processes. Once given the diffusion type and reaction rate, a specific forward or backward Feynman-Kac equation can be obtained. The results in this paper include those for normal/anomalous diffusions and reactions with linear/nonlinear rates. Using the derived equations, we apply our findings to compute some physical (experimentally measurable) statistics, including the occupation time in half-space, the first passage time, and the occupation time in half-interval with an absorbing or reflecting boundary, for the physical system with anomalous diffusion and spontaneous evanescence.

  4. QED the strange theory of light and matter

    CERN Document Server

    Feynman, Richard Phillips

    2006-01-01

    Celebrated for his brilliantly quirky insights into the physical world, Nobel laureate Richard Feynman also possessed an extraordinary talent for explaining difficult concepts to the general public. Here Feynman provides a classic and definitive introduction to QED (namely quantum electrodynamics), that part of quantum field theory describing the interactions of light with charged particles. Using everyday language, spatial concepts, visualizations, and his renowned ""Feynman diagrams"" instead of advanced mathematics, Feynman clearly and humorously communicates both the substance and spiri

  5. Systematic approximation of multi-scale Feynman integrals arXiv

    CERN Document Server

    Borowka, Sophia; Hulme, Daniel

    An algorithm for the systematic analytical approximation of multi-scale Feynman integrals is presented. The algorithm produces algebraic expressions as functions of the kinematical parameters and mass scales appearing in the Feynman integrals, allowing for fast numerical evaluation. The results are valid in all kinematical regions, both above and below thresholds, up to in principle arbitrary orders in the dimensional regulator. The scope of the algorithm is demonstrated by presenting results for selected two-loop three-point and four-point integrals with an internal mass scale that appear in the two-loop amplitudes for Higgs+jet production.

  6. Statistical error estimation of the Feynman-α method using the bootstrap method

    International Nuclear Information System (INIS)

    Endo, Tomohiro; Yamamoto, Akio; Yagi, Takahiro; Pyeon, Cheol Ho

    2016-01-01

    Applicability of the bootstrap method is investigated to estimate the statistical error of the Feynman-α method, which is one of the subcritical measurement techniques on the basis of reactor noise analysis. In the Feynman-α method, the statistical error can be simply estimated from multiple measurements of reactor noise, however it requires additional measurement time to repeat the multiple times of measurements. Using a resampling technique called 'bootstrap method' standard deviation and confidence interval of measurement results obtained by the Feynman-α method can be estimated as the statistical error, using only a single measurement of reactor noise. In order to validate our proposed technique, we carried out a passive measurement of reactor noise without any external source, i.e. with only inherent neutron source by spontaneous fission and (α,n) reactions in nuclear fuels at the Kyoto University Criticality Assembly. Through the actual measurement, it is confirmed that the bootstrap method is applicable to approximately estimate the statistical error of measurement results obtained by the Feynman-α method. (author)

  7. Feynman integrals and difference equations

    International Nuclear Information System (INIS)

    Moch, S.; Schneider, C.

    2007-09-01

    We report on the calculation of multi-loop Feynman integrals for single-scale problems by means of difference equations in Mellin space. The solution to these difference equations in terms of harmonic sums can be constructed algorithmically over difference fields, the so-called ΠΣ * -fields. We test the implementation of the Mathematica package Sigma on examples from recent higher order perturbative calculations in Quantum Chromodynamics. (orig.)

  8. Connection between Feynman integrals having different values of the space-time dimension

    International Nuclear Information System (INIS)

    Tarasov, O.V.

    1996-05-01

    A systematic algorithm for obtaining recurrence relations for dimensionally regularized Feynman integrals w.r.t. the space-time dimension d is proposed. The relation between d and d-2 dimensional integrals is given in terms of a differential operator for which an explicit formula can be obtained for each Feynman diagram. We show how the method works for one-, two- and three-loop integrals. The new recurrence relations w.r.t. d are complementary to the recurrence relations which derive from the method of integration by parts. We find that the problem of the irreducible numerators in Feynman integrals can be naturally solved in the framework of the proposed generalized recurrence relations. (orig.)

  9. Lectures on differential equations for Feynman integrals

    International Nuclear Information System (INIS)

    Henn, Johannes M

    2015-01-01

    Over the last year significant progress was made in the understanding of the computation of Feynman integrals using differential equations (DE). These lectures give a review of these developments, while not assuming any prior knowledge of the subject. After an introduction to DE for Feynman integrals, we point out how they can be simplified using algorithms available in the mathematical literature. We discuss how this is related to a recent conjecture for a canonical form of the equations. We also discuss a complementary approach that is based on properties of the space–time loop integrands, and explain how the ideas of leading singularities and d-log representations can be used to find an optimal basis for the DE. Finally, as an application of these ideas we show how single-scale integrals can be bootstrapped using the Drinfeld associator of a DE. (topical review)

  10. A recursive reduction of tensor Feynman integrals

    International Nuclear Information System (INIS)

    Diakonidis, T.; Riemann, T.; Tausk, J.B.; Fleischer, J.

    2009-07-01

    We perform a recursive reduction of one-loop n-point rank R tensor Feynman integrals [in short: (n,R)-integrals] for n≤6 with R≤n by representing (n,R)-integrals in terms of (n,R-1)- and (n-1,R-1)-integrals. We use the known representation of tensor integrals in terms of scalar integrals in higher dimension, which are then reduced by recurrence relations to integrals in generic dimension. With a systematic application of metric tensor representations in terms of chords, and by decomposing and recombining these representations, we find the recursive reduction for the tensors. The procedure represents a compact, sequential algorithm for numerical evaluations of tensor Feynman integrals appearing in next-to-leading order contributions to massless and massive three- and four-particle production at LHC and ILC, as well as at meson factories. (orig.)

  11. A Feynman-Hellmann approach to the spin structure of hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, A.J. [Adelaide Univ., SA (Australia). CSSM, Dept. of Physics; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe (Japan); Collaboration: CSSM and QCDSF/UKQCD Collaborations; and others

    2014-05-15

    We perform a N{sub f}=2+1 lattice QCD simulation to determine the quark spin fractions of hadrons using the Feynman-Hellmann theorem. By introducing an external spin operator to the fermion action, the matrix elements relevant for quark spin fractions are extracted from the linear response of the hadron energies. Simulations indicate that the Feynman-Hellmann method offers statistical precision that is comparable to the standard three-point function approach, with the added benefit that it is less susceptible to excited state contamination. This suggests that the Feynman-Hellmann technique offers a promising alternative for calculations of quark line disconnected contributions to hadronic matrix elements. At the SU(3)-flavour symmetry point, we find that the connected quark spin fractions are universally in the range 55-70% for vector mesons and octet and decuplet baryons. There is an indication that the amount of spin suppression is quite sensitive to the strength of SU(3) breaking.

  12. Non-planar Feynman diagrams and Mellin-Barnes representations with AMBRE 3.0

    International Nuclear Information System (INIS)

    Dubovyk, Ievgen; Gluza, Janusz; Riemann, Tord

    2016-04-01

    We introduce the Mellin-Barnes representation of general Feynman integrals and discuss their evaluation. The Mathematica package AMBRE has been recently extended in order to cover consistently non-planar Feynman integrals with two loops. Prospects for the near future are outlined. This write-up is an introduction to new results which have also been presented elsewhere.

  13. Solving recurrence relations for multi-loop Feynman integrals

    International Nuclear Information System (INIS)

    Smirnov, Vladimir A.; Steinhauser, Matthias

    2003-01-01

    We study the problem of solving integration-by-parts recurrence relations for a given class of Feynman integrals which is characterized by an arbitrary polynomial in the numerator and arbitrary integer powers of propagators, i.e., the problem of expressing any Feynman integral from this class as a linear combination of master integrals. We show how the parametric representation invented by Baikov [Phys. Lett. B 385 (1996) 404, Nucl. Instrum. Methods A 389 (1997) 347] can be used to characterize the master integrals and to construct an algorithm for evaluating the corresponding coefficient functions. To illustrate this procedure we use simple one-loop examples as well as the class of diagrams appearing in the calculation of the two-loop heavy quark potential

  14. Feynman integrals and difference equations

    Energy Technology Data Exchange (ETDEWEB)

    Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation

    2007-09-15

    We report on the calculation of multi-loop Feynman integrals for single-scale problems by means of difference equations in Mellin space. The solution to these difference equations in terms of harmonic sums can be constructed algorithmically over difference fields, the so-called {pi}{sigma}{sup *}-fields. We test the implementation of the Mathematica package Sigma on examples from recent higher order perturbative calculations in Quantum Chromodynamics. (orig.)

  15. S-bases as a tool to solve reduction problems for Feynman integrals

    International Nuclear Information System (INIS)

    Smirnov, A.V.; Smirnov, V.A.

    2006-01-01

    We suggest a mathematical definition of the notion of master integrals and present a brief review of algorithmic methods to solve reduction problems for Feynman integrals based on integration by parts relations. In particular, we discuss a recently suggested reduction algorithm which uses Groebner bases. New results obtained with its help for a family of three-loop Feynman integrals are outlined

  16. S-bases as a tool to solve reduction problems for Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.V. [Scientific Research Computing Center of Moscow State University, Moscow 119992 (Russian Federation); Smirnov, V.A. [Nuclear Physics Institute of Moscow State University, Moscow 119992 (Russian Federation)

    2006-10-15

    We suggest a mathematical definition of the notion of master integrals and present a brief review of algorithmic methods to solve reduction problems for Feynman integrals based on integration by parts relations. In particular, we discuss a recently suggested reduction algorithm which uses Groebner bases. New results obtained with its help for a family of three-loop Feynman integrals are outlined.

  17. Cuts of Feynman Integrals in Baikov representation

    Energy Technology Data Exchange (ETDEWEB)

    Frellesvig, Hjalte; Papadopoulos, Costas G. [Institute of Nuclear and Particle Physics, NCSR ‘Demokritos’,P.O. Box 60037, Agia Paraskevi, 15310 (Greece)

    2017-04-13

    Based on the Baikov representation, we present a systematic approach to compute cuts of Feynman Integrals, appropriately defined in d dimensions. The information provided by these computations may be used to determine the class of functions needed to analytically express the full integrals.

  18. Cuts of Feynman Integrals in Baikov representation

    International Nuclear Information System (INIS)

    Frellesvig, Hjalte; Papadopoulos, Costas G.

    2017-01-01

    Based on the Baikov representation, we present a systematic approach to compute cuts of Feynman Integrals, appropriately defined in d dimensions. The information provided by these computations may be used to determine the class of functions needed to analytically express the full integrals.

  19. Quadratic forms for Feynman-Kac semigroups

    International Nuclear Information System (INIS)

    Hibey, Joseph L.; Charalambous, Charalambos D.

    2006-01-01

    Some problems in a stochastic setting often involve the need to evaluate the Feynman-Kac formula that follows from models described in terms of stochastic differential equations. Equivalent representations in terms of partial differential equations are also of interest, and these establish the well-known connection between probabilistic and deterministic formulations of these problems. In this Letter, this connection is studied in terms of the quadratic form associated with the Feynman-Kac semigroup. The probability measures that naturally arise in this approach, and thus define how Brownian motion is killed at a specified rate while exiting a set, are interpreted as a random time change of the original stochastic differential equation. Furthermore, since random time changes alter the diffusion coefficients in stochastic differential equations while Girsanov-type measure transformations alter their drift coefficients, their simultaneous use should lead to more tractable solutions for some classes of problems. For example, the minimization of some quadratic forms leads to solutions that satisfy certain partial differential equations and, therefore, the techniques discussed provide a variational approach for finding these solutions

  20. Construction of renormalized coefficient functions of the Feynman diagrams by means of a computer

    International Nuclear Information System (INIS)

    Tarasov, O.V.

    1978-01-01

    An algorithm and short description of computer program, written in SCHOONSCHIP, are given. The program is assigned for construction of integrands of renormalized coefficient functions of the Feynman diagrams in scalar theories in the case of arbitrary subtraction point. For the given Feynman graph computer completely realizes the R-operation of Bogolubov-Parasjuk and gives the result as an integral over Feynman parameters. With the help of the program the time construction of the whole renormalized coefficient function is equal approximately 30 s on the CDC-6500 computer

  1. Feynman and physics. Life and research of an exceptional man; Feynman und die Physik. Leben und Forschung eines aussergewoehnlichen Menschen

    Energy Technology Data Exchange (ETDEWEB)

    Resag, Joerg

    2018-04-01

    The life of Feynman is described together with his work on path integrals, quantum electrodynmaics, helium at low temperatures, the weak interaction, the quark model, and computer-calculation methods, and his contribution to the Manhattan project. (HSI)

  2. Equivariance, Variational Principles, and the Feynman Integral

    Directory of Open Access Journals (Sweden)

    George Svetlichny

    2008-03-01

    Full Text Available We argue that the variational calculus leading to Euler's equations and Noether's theorem can be replaced by equivariance and invariance conditions avoiding the action integral. We also speculate about the origin of Lagrangian theories in physics and their connection to Feynman's integral.

  3. A mapping between Feynman and string motivated one-loop rules in gauge theories

    International Nuclear Information System (INIS)

    Bern, Z.

    1992-01-01

    Recently, computationally efficient rules for one-loop gauge theory amplitudes have been derived from string theory. We demonstrate the relationship of the compact string organization of the amplitude to Feynman diagrams. In particular, we explicitly show how large cancellations inherent in conventional Feynman diagram computations are avoided by the string motivated rules. (orig.)

  4. Feynman Integrals with Absorbing Boundaries

    OpenAIRE

    Marchewka, A.; Schuss, Z.

    1997-01-01

    We propose a formulation of an absorbing boundary for a quantum particle. The formulation is based on a Feynman-type integral over trajectories that are confined to the non-absorbing region. Trajectories that reach the absorbing wall are discounted from the population of the surviving trajectories with a certain weighting factor. Under the assumption that absorbed trajectories do not interfere with the surviving trajectories, we obtain a time dependent absorption law. Two examples are worked ...

  5. The Errors of Feynman and Hibbs

    Indian Academy of Sciences (India)

    rors simply because he was so smart. He would write down equations that got to the gist of the difficult ... work at a level somewhat below Feynman's, these fac- tors and limits and so forth are not obvious, and their ... an interview with Hibbs in which he said he's working on a book to be titled Quantum Mechanics and Path In-.

  6. Probing finite coarse-grained virtual Feynman histories with sequential weak values

    Science.gov (United States)

    Georgiev, Danko; Cohen, Eliahu

    2018-05-01

    Feynman's sum-over-histories formulation of quantum mechanics has been considered a useful calculational tool in which virtual Feynman histories entering into a coherent quantum superposition cannot be individually measured. Here we show that sequential weak values, inferred by consecutive weak measurements of projectors, allow direct experimental probing of individual virtual Feynman histories, thereby revealing the exact nature of quantum interference of coherently superposed histories. Because the total sum of sequential weak values of multitime projection operators for a complete set of orthogonal quantum histories is unity, complete sets of weak values could be interpreted in agreement with the standard quantum mechanical picture. We also elucidate the relationship between sequential weak values of quantum histories with different coarse graining in time and establish the incompatibility of weak values for nonorthogonal quantum histories in history Hilbert space. Bridging theory and experiment, the presented results may enhance our understanding of both weak values and quantum histories.

  7. Exact Maximum-Entropy Estimation with Feynman Diagrams

    Science.gov (United States)

    Netser Zernik, Amitai; Schlank, Tomer M.; Tessler, Ran J.

    2018-02-01

    A longstanding open problem in statistics is finding an explicit expression for the probability measure which maximizes entropy with respect to given constraints. In this paper a solution to this problem is found, using perturbative Feynman calculus. The explicit expression is given as a sum over weighted trees.

  8. Juvenile Cosmology; Or Richard Powers’ Post-Global Doughnut

    Directory of Open Access Journals (Sweden)

    Judith Roof

    2010-02-01

    Full Text Available Le roman de Richard Powers, Operation Wandering Soul (1993, présente le lien subtil qui associe un mondialisme déjà usé et vieillissant à l’enfant perçu comme catégorie dominante. Comme les faces serpentines d’un ruban de Möbius lové autour de l’illimité et de l’intemporel, le texte, tendu entre ses deux infinis – l’univers et l’enfant – révise la portée, la conception, la structure et le style du genre romanesque. Délaissant Aristote pour Einstein, Operation Wandering Soul se place sur le terrain de la cosmologie. Le récit, qui rassemble la kyrielle des grands ralliements juvéniles et leurs vains pèlerinages, concentre l’espace-temps dans une présentation qui évoque la « somme des histoires » de Richard Feynman. La contraction de l’espace-temps opérée par le roman ne fait pas de celui-ci un hymne simpliste au global (catégorie déjà aussi datée que celle des malheureux vétérans du Vietnam, mais capte au contraire la conscience grandissante d’une existence sans origine qui s’étend à perte de vue au-delà de ses coordonnées supposées. Le roman s’enroule sur lui-même tout en s’épanchant au dehors, boucle ses cadres et ses détours tout en desserrant leur emprise. Il fait tourner la roue de ses récits comme des planètes en rotation, la ronde d’un système solaire, le tourbillon d’une galaxie. La conscience que présente Operation Wandering Soul ne se résume donc pas au seul point de vue de l’âme errante qu’est le personnage de Kraft, mais consiste en la somme de tous les temps et de tous les lieux, de leurs strates accumulées comme une conscience en acte, complexe et tissée de réseaux, qui n’appartient à personne et est partagée par tous. Cette accumulation organise le jeu des perspectives multiples qui instaurent l’acte de lecture et sont instaurées par lui. À cet égard, lire constitue ici une physique des oubliés.Richard Powers’ novel Operation Wandering

  9. AMBRE - a mathematica package for the construction of Mellin-Barnes representations for Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Gluza, J.; Kajda, K. [Silesia Univ, Katowice (Poland). Dept. of Field Theory and Particle Physics, Inst. of Phsyics; Riemann, T. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2007-05-15

    The Mathematica toolkit AMBRE derives Mellin-Barnes (MB) representations for Feynman integrals in d=4-2{epsilon} dimensions. It may be applied for tadpoles as well as for multi-leg multi-loop scalar and tensor integrals. AMBRE uses a loop-by-loop approach and aims at lowest dimensions of the final MB representations. The present version of AMBRE works fine for planar Feynman diagrams. The output may be further processed by the package MB for the determination of its singularity structure in {epsilon}. The AMBRE package contains various sample applications for Feynman integrals with up to six external particles and up to four loops. (orig.)

  10. Computer generation of integrands for Feynman parametric integrals

    International Nuclear Information System (INIS)

    Cvitanovic, Predrag

    1973-01-01

    TECO text editing language, available on PDP-10 computers, is used for the generation and simplification of Feynman integrals. This example shows that TECO can be a useful computational tool in complicated calculations where similar algebraic structures recur many times

  11. A complete algebraic reduction of one-loop tensor Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, J. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Bielefeld Univ. (Germany). Fakultaet fuer Physik; Riemann, T. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2010-09-15

    Guided by the need to eliminate inverse Gram determinants (){sub 5} from tensorial 5-point functions and sub-Gram determinants (){sub 4} from tensorial 4-point functions, we set up a new and very efficient approach for the tensor reduction of Feynman integrals. We eliminate all Gram determinants for one-loop 5-point integrals up to tensors of rank R=5 by reducing their tensor coefficients to higherdimensional 4-point tensor coefficients. These in turn are reduced to expressions which are free of inverse powers of (){sub 4}, but depend on higher-dimensional integrals I{sub 4}{sup (d)} with d{<=}2R. Their expression in terms of scalar integrals defined in the generic dimension, I{sub 4}; I{sub 3}; I{sub 2}; I{sub 1}, however, introduces coefficients [1=(){sub 4}]{sup R} for tensors of rank R. For small or vanishing (){sub 4}, an efficient expansion is found so that a stable numerical evaluation of massive and massless Feynman integrals at arbitrary values of the Gram determinants is made possible. Finally, some relations are mentioned which may be useful for analytic simplifications of the original Feynman diagrams. (orig.)

  12. Asymptotic behaviour of Feynman integrals

    International Nuclear Information System (INIS)

    Bergere, M.C.

    1980-01-01

    In these lecture notes, we describe how to obtain the asymptotic behaviour of Feynman amplitudes; this technique has been already applied in several cases, but the general solution for any kind of asymptotic behaviour has not yet been found. From the mathematical point of view, the problem to solve is close to the following problem: find the asymptotic expansion at large lambda of the integral ∫...∫ [dx] esup(-LambdaP[x]) where P[x] is a polynomial of several variables. (orig.)

  13. Feynman path integrals - from the prodistribution definition to the calculation of glory scattering

    International Nuclear Information System (INIS)

    DeWitt-Morette, C.

    1984-01-01

    In these lectures I present a path integral calculation, starting from a global definition of Feynman path integrals and ending at a scattering cross section formula. Along the way I discuss some basic issues which had to be resolved to exploit the computational power of the proposed definition of Feynman integrals. I propose to compute the glory scattering of gravitational waves by black holes. (orig./HSI)

  14. Feynman propagator in curved space-time

    International Nuclear Information System (INIS)

    Candelas, P.; Raine, D.J.

    1977-01-01

    The Wick rotation is generalized in a covariant manner so as to apply to curved manifolds in a way that is independent of the analytic properties of the manifold. This enables us to show that various methods for defining a Feynman propagator to be found in the literature are equivalent where they are applicable. We are also able to discuss the relation between certain regularization methods that have been employed

  15. Perturbation theory via Feynman diagrams in classical mechanics

    OpenAIRE

    Penco, R.; Mauro, D.

    2006-01-01

    In this paper we show how Feynman diagrams, which are used as a tool to implement perturbation theory in quantum field theory, can be very useful also in classical mechanics, provided we introduce also at the classical level concepts like path integrals and generating functionals.

  16. Feynman path integral formulation of quantum mechanics

    International Nuclear Information System (INIS)

    Mizrahi, M.M.

    1975-01-01

    The subject of this investigation is Feynman's path integral quantization scheme, which is a powerful global formalism with great intuitive appeal. It stems from the simple idea that a probability amplitude for a system to make a transition between two states is the ''sum'' of the amplitudes for all the possible ways the transition can take place

  17. A quantum formulation of the Feynman-Kac formula

    International Nuclear Information System (INIS)

    Accardi, L.

    1981-01-01

    The author discusses a formulation, in the general setting of W*- (or C*)-algebras, of the classical Feynman-Kac formula. The equivalence, in the commutative case, of the present formulation and the usual one is based on the identification between stochastic processes and local algebras. (Auth.)

  18. The ε-form of the differential equations for Feynman integrals in the elliptic case

    Science.gov (United States)

    Adams, Luise; Weinzierl, Stefan

    2018-06-01

    Feynman integrals are easily solved if their system of differential equations is in ε-form. In this letter we show by the explicit example of the kite integral family that an ε-form can even be achieved, if the Feynman integrals do not evaluate to multiple polylogarithms. The ε-form is obtained by a (non-algebraic) change of basis for the master integrals.

  19. A partial solution for Feynman's problem: A new derivation of the Weyl equation

    Directory of Open Access Journals (Sweden)

    Atsushi Inoue

    2000-07-01

    Full Text Available Associating classical mechanics to a system of partial differential equations, we give a procedure for Feynman-type quantization of a "Schrodinger-type equation with spin." Mathematically, we construct a "good parametrix" for the Weyl equation with an external electromagnetic field. Main ingredients are (i a new interpretation of the matrix structure using superanalysis and (ii another interpretation of the method of characteristics as a quantization procedure of Feynman type.

  20. Mellin-Barnes representations of Feynman diagrams, linear systems of differential equations, and polynomial solutions

    International Nuclear Information System (INIS)

    Kalmykov, Mikhail Yu.; Kniehl, Bernd A.

    2012-05-01

    We argue that the Mellin-Barnes representations of Feynman diagrams can be used for obtaining linear systems of homogeneous differential equations for the original Feynman diagrams with arbitrary powers of propagators without recourse to the integration-by-parts technique. These systems of differential equation can be used (i) for the differential reductions to sets of basic functions and (ii) for counting the numbers of master-integrals.

  1. Survey and selection of assessment methodologies for GAVE options; Inventarisatie en selectie van beoordelingsmethodieken voor GAVE-opties

    Energy Technology Data Exchange (ETDEWEB)

    Weterings, R. [ed.] [TNO Milieu, Energie en Procesinnovatie TNO-MEP, Apeldoorn (Netherlands)

    1999-05-01

    The Dutch government is interested in the possibilities for a market introduction of new gaseous and liquid energy carriers. To this purpose the GAVE-programme was recently set up. This study is carried out within the framework of the GAVE-programme and aims at the selection of methodologies for assessing the technological, economic, ecological and social perspectives of these new energy options (so-called GAVE-options). Based on the results of these assessments the Dutch ministries of Housing, Planning and Environment (VROM) and Economic Affairs (EZ) will decide at the end of 1999 about starting demonstration projects of promising energy carriers.

  2. Picard-Fuchs equations of dimensionally regulated Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Zayadeh, Raphael

    2013-12-15

    This thesis is devoted to studying differential equations of Feynman integrals. A Feynman integral depends on a dimension D. For integer values of D it can be written as a projective integral, which is called the Feynman parameter prescription. A major complication arises from the fact that for some values of D the integral can diverge. This problem is solved within dimensional regularization by continuing the integral as a meromorphic function on the complex plane and replacing the ill-defined quantity by a Laurent series in a dimensional regularization parameter. All terms in such a Laurent expansion are periods in the sense of Kontsevich and Zagier. We describe a new method to compute differential equations of Feynman integrals. So far, the standard has been to use integration-by-parts (IBP) identities to obtain coupled systems of linear differential equations for the master integrals. Our method is based on the theory of Picard-Fuchs equations. In the case we are interested in, that of projective and quasiprojective families, a Picard-Fuchs equation can be computed by means of the Griffiths-Dwork reduction. We describe a method that is designed for fixed integer dimension. After a suitable integer shift of dimension we obtain a period of a family of hypersurfaces, hence a Picard-Fuchs equation. This equation is inhomogeneous because the domain of integration has a boundary and we only obtain a relative cycle. As a second step we shift back the dimension using Tarasov's generalized dimensional recurrence relations. Furthermore, we describe a method to directly compute the differential equation for general D without shifting the dimension. This is based on the Griffiths-Dwork reduction. The success of this method depends on the ability to solve large systems of linear equations. We give examples of two and three-loop graphs. Tarasov classifies two-loop two-point functions and we give differential equations for these. For us the most interesting example is

  3. Picard-Fuchs equations of dimensionally regulated Feynman integrals

    International Nuclear Information System (INIS)

    Zayadeh, Raphael

    2013-12-01

    This thesis is devoted to studying differential equations of Feynman integrals. A Feynman integral depends on a dimension D. For integer values of D it can be written as a projective integral, which is called the Feynman parameter prescription. A major complication arises from the fact that for some values of D the integral can diverge. This problem is solved within dimensional regularization by continuing the integral as a meromorphic function on the complex plane and replacing the ill-defined quantity by a Laurent series in a dimensional regularization parameter. All terms in such a Laurent expansion are periods in the sense of Kontsevich and Zagier. We describe a new method to compute differential equations of Feynman integrals. So far, the standard has been to use integration-by-parts (IBP) identities to obtain coupled systems of linear differential equations for the master integrals. Our method is based on the theory of Picard-Fuchs equations. In the case we are interested in, that of projective and quasiprojective families, a Picard-Fuchs equation can be computed by means of the Griffiths-Dwork reduction. We describe a method that is designed for fixed integer dimension. After a suitable integer shift of dimension we obtain a period of a family of hypersurfaces, hence a Picard-Fuchs equation. This equation is inhomogeneous because the domain of integration has a boundary and we only obtain a relative cycle. As a second step we shift back the dimension using Tarasov's generalized dimensional recurrence relations. Furthermore, we describe a method to directly compute the differential equation for general D without shifting the dimension. This is based on the Griffiths-Dwork reduction. The success of this method depends on the ability to solve large systems of linear equations. We give examples of two and three-loop graphs. Tarasov classifies two-loop two-point functions and we give differential equations for these. For us the most interesting example is the two

  4. The algebraic locus of Feynman integrals

    OpenAIRE

    Kol, Barak

    2016-01-01

    In the Symmetries of Feynman Integrals (SFI) approach, a diagram's parameter space is foliated by orbits of a Lie group associated with the diagram. SFI is related to the important methods of Integrations By Parts and of Differential Equations. It is shown that sometimes there exist a locus in parameter space where the set of SFI differential equations degenerates into an algebraic equation, thereby enabling a solution in terms of integrals associated with degenerations of the diagram. This i...

  5. Richard von Volkmann

    Science.gov (United States)

    Willy, Christian; Schneider, Peter; Engelhardt, Michael; Hargens, Alan R.

    2008-01-01

    Richard von Volkmann (1830–1889), one of the most important surgeons of the 19th century, is regarded as one of the fathers of orthopaedic surgery. He was a contemporary of Langenbeck, Esmarch, Lister, Billroth, Kocher, and Trendelenburg. He was head of the Department of Surgery at the University of Halle, Germany (1867–1889). His popularity attracted doctors and patients from all over the world. He was the lead physician for the German military during two wars. From this experience, he compared the mortality of civilian and war injuries and investigated the general poor hygienic conditions in civilian hospitals. This led him to introduce the “antiseptic technique” to Germany that was developed by Lister. His powers of observation and creativity led him to findings and achievements that to this day bear his name: Volkmann’s contracture and the Hueter-Volkmann law. Additionally, he was a gifted writer; he published not only scientific literature but also books of children’s fairy tales and poems under the pen name of Richard Leander, assuring him a permanent place in the world of literature as well as orthopaedics. PMID:18196438

  6. Richard Avedon ja Annie Leibovitz laulsid kaanonit / Marika Alver

    Index Scriptorium Estoniae

    Alver, Marika

    2008-01-01

    Richard Avedoni (1923-2004) retrospektiivnäitusest (fotod aastatest 1946-2004) kuraator Helle Crenzien (Lousiana Kaasaegse Kunsti muuseum Taanis), millega kaasnes ka Helen Whitney film "Richard Avedon : darkness and light" ja Annie Leibovitzi (1949) suurprojektist "A photographer's life 1990-2005" Pariisis

  7. Remark on the solution of the Schroedinger equation for anharmonic oscillators via the Feynman path integral

    International Nuclear Information System (INIS)

    Rezende, J.

    1983-01-01

    We give a simple proof of Feynman's formula for the Green's function of the n-dimensional harmonic oscillator valid for every time t with Im t<=0. As a consequence the Schroedinger equation for the anharmonic oscillator is integrated and expressed by the Feynman path integral on Hilbert space. (orig.)

  8. JaxoDraw: A graphical user interface for drawing Feynman diagrams

    Science.gov (United States)

    Binosi, D.; Theußl, L.

    2004-08-01

    JaxoDraw is a Feynman graph plotting tool written in Java. It has a complete graphical user interface that allows all actions to be carried out via mouse click-and-drag operations in a WYSIWYG fashion. Graphs may be exported to postscript/EPS format and can be saved in XML files to be used for later sessions. One of JaxoDraw's main features is the possibility to create ? code that may be used to generate graphics output, thus combining the powers of ? with those of a modern day drawing program. With JaxoDraw it becomes possible to draw even complicated Feynman diagrams with just a few mouse clicks, without the knowledge of any programming language. Program summaryTitle of program: JaxoDraw Catalogue identifier: ADUA Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUA Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Distribution format: tar gzip file Operating system: Any Java-enabled platform, tested on Linux, Windows ME, XP, Mac OS X Programming language used: Java License: GPL Nature of problem: Existing methods for drawing Feynman diagrams usually require some 'hard-coding' in one or the other programming or scripting language. It is not very convenient and often time consuming, to generate relatively simple diagrams. Method of solution: A program is provided that allows for the interactive drawing of Feynman diagrams with a graphical user interface. The program is easy to learn and use, produces high quality output in several formats and runs on any operating system where a Java Runtime Environment is available. Number of bytes in distributed program, including test data: 2 117 863 Number of lines in distributed program, including test data: 60 000 Restrictions: Certain operations (like internal latex compilation, Postscript preview) require the execution of external commands that might not work on untested operating systems. Typical running time: As an interactive program, the running time depends on the complexity

  9. Differential reduction of generalized hypergeometric functions from Feynman diagrams. One-variable case

    Energy Technology Data Exchange (ETDEWEB)

    Bytev, Vladimir V.; Kalmykov, Mikhail Yu.; Kniehl, Bernd A. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

    2010-03-15

    The differential-reduction algorithm, which allows one to express generalized hypergeometric functions with parameters of arbitrary values in terms of such functions with parameters whose values differ from the original ones by integers, is discussed in the context of evaluating Feynman diagrams. Where this is possible, we compare our results with those obtained using standard techniques. It is shown that the criterion of reducibility of multiloop Feynman integrals can be reformulated in terms of the criterion of reducibility of hypergeometric functions. The relation between the numbers of master integrals obtained by differential reduction and integration by parts is discussed. (orig.)

  10. Summing over Feynman histories by functional contour integration

    International Nuclear Information System (INIS)

    Garrison, J.C.; Wright, E.M.

    1986-01-01

    The authors show how complex paths can be consistently introduced into sums for Feynman histories by using the notion of functional contour integration. For a kappa-dimensional system specified by a potential with suitable analyticity properties, each coordinate axis is replaced by a copy of the complex plane, and at each instant of time a contour is chosen in each plane. This map from the time axis into the set of complex contours defines a functional contour. The family of contours labelled by time generates a (kappa+1)-dimensional submanifold of the (2kappa+1)-dimensional space defined by the cartesian product of the time axis and the coordinate planes. The complex Feynman paths lie on this submanifold. An application of this idea to systems described by absorptive potentials yields a simple derivation of the correct WKB result in terms of a complex path that extremalises the action. The method can also be applied to spherically symmetric potentials by using a partial wave expansion and restricting the contours appropriately. (author)

  11. Feynman path integral related to stochastic schroedinger equation

    International Nuclear Information System (INIS)

    Belavkin, V.P.; Smolyanov, O.G.

    1998-01-01

    The derivation of the Schroedinger equation describing the continuous measurement process is presented. The representation of the solution of the stochastic Schroedinger equation for continuous measurements is obtained by means of the Feynman path integral. The connection with the heuristic approach to the description of continuous measurements is considered. The connection with the Senon paradox is established [ru

  12. In conversation with: Professor Richard James

    Directory of Open Access Journals (Sweden)

    John Clarke

    2014-03-01

    Full Text Available In 2011, Richard James wrote in the Foreword to Nelson, Clarke, Kift, and Creagh’s (2012 monograph on Australasian literature on the First Year Experience that:The trend towards universal participation will usher in dramatic changes in the character of the first year in higher education. … (p. iiiIn an interview at the University of Melbourne, Australia in July 2013 between Richard James and John Clarke, Co-editor of the International Journal of the First Year in Higher Education, these and related issues were explored.  The interview picks up where the Foreword left off:  focussing on universal participation.

  13. The power counting theorem for Feynman integrals with massless propagators

    International Nuclear Information System (INIS)

    Lowenstein, J.H.

    2000-01-01

    Dyson's power counting theorem is extended to the case where some of the mass parameters vanish. Weinberg's ultraviolet convergence conditions are supplemented by infrared convergence conditions which combined are sufficient for the convergence of Feynman integrals. (orig.)

  14. Feynman and physics. Life and research of an exceptional man

    International Nuclear Information System (INIS)

    Resag, Joerg

    2018-01-01

    The life of Feynman is described together with his work on path integrals, quantum electrodynmaics, helium at low temperatures, the weak interaction, the quark model, and computer-calculation methods, and his contribution to the Manhattan project. (HSI)

  15. Reactivity determination in accelerator driven nuclear reactors by statistics from neutron detectors (Feynman-Alpha Method)

    International Nuclear Information System (INIS)

    Ceder, M.

    2002-03-01

    The Feynman-alpha method is used in traditional nuclear reactors to determine the subcritical reactivity of a system. The method is based on the measurement of the mean number and the variance of detector counts for different measurement times. The measurement is performed while a steady-state neutron flux is maintained in the reactor by an external neutron source, as a rule a radioactive source. From a plot of the variance-to-mean ratio as a function of measurement time ('gate length'), the reactivity can be determined by fitting the measured curve to the analytical solution. A new situation arises in the planned accelerator driven systems (ADS). An ADS will be run in a subcritical mode, and the steady flux will be maintained by an accelerator based source. Such a source has statistical properties that are different from those of a steady radioactive source. As one example, in a currently running European Community project for ADS research, the MUSE project, the source will be a periodically pulsed neutron generator. The theory of Feynman-alpha method needs to be extended to such nonstationary sources. There are two ways of performing and evaluating such pulsed source experiments. One is to synchronise the detector time gate start with the beginning of an incoming pulse. The Feynman-alpha method has been elaborated for such a case recently. The other method can be called stochastic pulsing. It means that there is no synchronisation between the detector time gate start and the source pulsing, i.e. the start of each measurement is chosen at a random time. The analytical solution to the Feynman-alpha formula from this latter method is the subject of this report. We have obtained an analytical Feynman-alpha formula for the case of stochastic pulsing by two different methods. One is completely based on the use of the symbolic algebra code Mathematica, whereas the other is based on complex function techniques. Closed form solutions could be obtained by both methods

  16. Reactivity determination in accelerator driven nuclear reactors by statistics from neutron detectors (Feynman-Alpha Method)

    Energy Technology Data Exchange (ETDEWEB)

    Ceder, M

    2002-03-01

    The Feynman-alpha method is used in traditional nuclear reactors to determine the subcritical reactivity of a system. The method is based on the measurement of the mean number and the variance of detector counts for different measurement times. The measurement is performed while a steady-state neutron flux is maintained in the reactor by an external neutron source, as a rule a radioactive source. From a plot of the variance-to-mean ratio as a function of measurement time ('gate length'), the reactivity can be determined by fitting the measured curve to the analytical solution. A new situation arises in the planned accelerator driven systems (ADS). An ADS will be run in a subcritical mode, and the steady flux will be maintained by an accelerator based source. Such a source has statistical properties that are different from those of a steady radioactive source. As one example, in a currently running European Community project for ADS research, the MUSE project, the source will be a periodically pulsed neutron generator. The theory of Feynman-alpha method needs to be extended to such nonstationary sources. There are two ways of performing and evaluating such pulsed source experiments. One is to synchronise the detector time gate start with the beginning of an incoming pulse. The Feynman-alpha method has been elaborated for such a case recently. The other method can be called stochastic pulsing. It means that there is no synchronisation between the detector time gate start and the source pulsing, i.e. the start of each measurement is chosen at a random time. The analytical solution to the Feynman-alpha formula from this latter method is the subject of this report. We have obtained an analytical Feynman-alpha formula for the case of stochastic pulsing by two different methods. One is completely based on the use of the symbolic algebra code Mathematica, whereas the other is based on complex function techniques. Closed form solutions could be obtained by both methods

  17. 77 FR 21555 - Manning, Richard W.; Notice of Filing

    Science.gov (United States)

    2012-04-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ID-6835-001] Manning, Richard W.; Notice of Filing Take notice that on April 2, 2012, Richard W. Manning submitted for filing... not serve to make protestants parties to the proceeding. Any person wishing to become a party must...

  18. Quantum cosmology based on discrete Feynman paths

    International Nuclear Information System (INIS)

    Chew, Geoffrey F.

    2002-01-01

    Although the rules for interpreting local quantum theory imply discretization of process, Lorentz covariance is usually regarded as precluding time quantization. Nevertheless a time-discretized quantum representation of redshifting spatially-homogeneous universe may be based on discrete-step Feynman paths carrying causal Lorentz-invariant action--paths that not only propagate the wave function but provide a phenomenologically-promising elementary-particle Hilbert-space basis. In a model under development, local path steps are at Planck scale while, at a much larger ''wave-function scale'', global steps separate successive wave-functions. Wave-function spacetime is but a tiny fraction of path spacetime. Electromagnetic and gravitational actions are ''at a distance'' in Wheeler-Feynman sense while strong (color) and weak (isospin) actions, as well as action of particle motion, are ''local'' in a sense paralleling the action of local field theory. ''Nonmaterial'' path segments and ''trivial events'' collaborate to define energy and gravity. Photons coupled to conserved electric charge enjoy privileged model status among elementary fermions and vector bosons. Although real path parameters provide no immediate meaning for ''measurement'', the phase of the complex wave function allows significance for ''information'' accumulated through ''gentle'' electromagnetic events involving charged matter and ''soft'' photons. Through its soft-photon content the wave function is an ''information reservoir''

  19. Derivation and analysis of the Feynman-alpha formula for deterministically pulsed sources

    International Nuclear Information System (INIS)

    Wright, J.; Pazsit, I.

    2004-03-01

    The purpose or this report is to give a detailed description of the calculation of the Feynman-alpha formula with deterministically pulsed sources. In contrast to previous calculations, Laplace transform and complex function methods are used to arrive at a compact solution in form of a Fourier series-like expansion. The advantage of this method is that it is capable to treat various pulse shapes. In particular, in addition to square- and Dirac delta pulses, a more realistic Gauss-shaped pulse is also considered here. The final solution of the modified variance-to-mean, that is the Feynman Y(t) function, can be quantitatively evaluated fast and with little computational effort. The analytical solutions obtained are then analysed quantitatively. The behaviour of the number or neutrons in the system is investigated in detail, together with the transient that follows the switching on of the source. An analysis of the behaviour of the Feynman Y(t) function was made with respect to the pulse width and repetition frequency. Lastly, the possibility of using me formulae for the extraction of the parameter alpha from a simulated measurement is also investigated

  20. Destructive interferences results in bosons anti bunching: refining Feynman's argument

    Science.gov (United States)

    Marchewka, Avi; Granot, Er'el

    2014-09-01

    The effect of boson bunching is frequently mentioned and discussed in the literature. This effect is the manifestation of bosons tendency to "travel" in clusters. One of the core arguments for boson bunching was formulated by Feynman in his well-known lecture series and has been frequently used ever since. By comparing the scattering probabilities of two bosons and of two distinguishable particles, he concluded: "We have the result that it is twice as likely to find two identical Bose particles scattered into the same state as you would calculate assuming the particles were different" [R.P. Feynman, R.B. Leighton, M. Sands, The Feynman Lectures on Physics: Quantum mechanics (Addison-Wesley, 1965)]. This argument was rooted in the scientific community (see for example [C. Cohen-Tannoudji, B. Diu, F. Laloë, Quantum Mechanics (John Wiley & Sons, Paris, 1977); W. Pauli, Exclusion Principle and Quantum Mechanics, Nobel Lecture (1946)]), however, while this sentence is completely valid, as is proved in [C. Cohen-Tannoudji, B. Diu, F. Laloë, Quantum Mechanics (John Wiley & Sons, Paris, 1977)], it is not a synonym of bunching. In fact, as it is shown in this paper, wherever one of the wavefunctions has a zero, bosons can anti-bunch and fermions can bunch. It should be stressed that zeros in the wavefunctions are ubiquitous in Quantum Mechanics and therefore the effect should be common. Several scenarios are suggested to witness the effect.

  1. The power counting theorem for Feynman integrals with massless propagators

    International Nuclear Information System (INIS)

    Lowenstein, J.H.

    1975-01-01

    Dyson's power counting theorem is extended to the case where some of the mass parameters vanish. Weinberg's ultraviolet convergence conditions are supplemented by infrared convergence conditions which combined are sufficient for the convergence of Feynman integrals. (orig.) [de

  2. FF. A package to evaluate one-loop Feynman diagrams

    International Nuclear Information System (INIS)

    Oldenborgh, G.J. van

    1990-09-01

    A short description and a user's guide of the FF package are given. This package contains routines to evaluate numerically the scalar one-loop integrals occurring in the evaluation in one-loop Feynman diagrams. The algorithms chosen are numerically stable over most parameter space. (author). 5 refs.; 1 tab

  3. Advanced computer algebra algorithms for the expansion of Feynman integrals

    International Nuclear Information System (INIS)

    Ablinger, Jakob; Round, Mark; Schneider, Carsten

    2012-10-01

    Two-point Feynman parameter integrals, with at most one mass and containing local operator insertions in 4+ε-dimensional Minkowski space, can be transformed to multi-integrals or multi-sums over hyperexponential and/or hypergeometric functions depending on a discrete parameter n. Given such a specific representation, we utilize an enhanced version of the multivariate Almkvist-Zeilberger algorithm (for multi-integrals) and a common summation framework of the holonomic and difference field approach (for multi-sums) to calculate recurrence relations in n. Finally, solving the recurrence we can decide efficiently if the first coefficients of the Laurent series expansion of a given Feynman integral can be expressed in terms of indefinite nested sums and products; if yes, the all n solution is returned in compact representations, i.e., no algebraic relations exist among the occurring sums and products.

  4. Advanced computer algebra algorithms for the expansion of Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, Jakob; Round, Mark; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2012-10-15

    Two-point Feynman parameter integrals, with at most one mass and containing local operator insertions in 4+{epsilon}-dimensional Minkowski space, can be transformed to multi-integrals or multi-sums over hyperexponential and/or hypergeometric functions depending on a discrete parameter n. Given such a specific representation, we utilize an enhanced version of the multivariate Almkvist-Zeilberger algorithm (for multi-integrals) and a common summation framework of the holonomic and difference field approach (for multi-sums) to calculate recurrence relations in n. Finally, solving the recurrence we can decide efficiently if the first coefficients of the Laurent series expansion of a given Feynman integral can be expressed in terms of indefinite nested sums and products; if yes, the all n solution is returned in compact representations, i.e., no algebraic relations exist among the occurring sums and products.

  5. Solving differential equations for Feynman integrals by expansions near singular points

    Science.gov (United States)

    Lee, Roman N.; Smirnov, Alexander V.; Smirnov, Vladimir A.

    2018-03-01

    We describe a strategy to solve differential equations for Feynman integrals by powers series expansions near singular points and to obtain high precision results for the corresponding master integrals. We consider Feynman integrals with two scales, i.e. non-trivially depending on one variable. The corresponding algorithm is oriented at situations where canonical form of the differential equations is impossible. We provide a computer code constructed with the help of our algorithm for a simple example of four-loop generalized sunset integrals with three equal non-zero masses and two zero masses. Our code gives values of the master integrals at any given point on the real axis with a required accuracy and a given order of expansion in the regularization parameter ɛ.

  6. Richard Halliburton's Bearded Tales

    Science.gov (United States)

    Morris, Charles E., III

    2009-01-01

    Fusing the concept of "the beard" with the genre of the tall tale to theorize bearded tales deepens our understanding of closet eloquence, or rhetorical repertories of sexual passing in U.S. history. An examination of adventurer-writer-lecturer Richard Halliburton's sexual provenance and bestselling travel tale, "The Royal Road to Romance" (1925),…

  7. Relativistic generalization and extension to the non-Abelian gauge theory of Feynman's proof of the Maxwell equations

    International Nuclear Information System (INIS)

    Tanimura, Shogo

    1992-01-01

    R. P. Feynman showed F. J. Dyson a proof of the Lorentz force law and the homogeneous Maxwell equations, which he obtained starting from Newton's law of motion and the commutation relations between position and velocity for a single nonrelativistic particle. The author formulate both a special relativistic and a general relativistic version of Feynman's derivation. Especially in the general relativistic version they prove that the only possible fields that can consistently act on a quantum mechanical particle are scalar, gauge, and gravitational fields. They also extend Feynman's scheme to the case of non-Abelian gauge theory in the special relativistic context. 8 refs

  8. Mean energy of some interacting bosonic systems derived by virtue of the generalized Hellmann-Feynman theorem

    Science.gov (United States)

    Fan, Hong-yi; Xu, Xue-xiang

    2009-06-01

    By virtue of the generalized Hellmann-Feynman theorem [H. Y. Fan and B. Z. Chen, Phys. Lett. A 203, 95 (1995)], we derive the mean energy of some interacting bosonic systems for some Hamiltonian models without proceeding with diagonalizing the Hamiltonians. Our work extends the field of applications of the Hellmann-Feynman theorem and may enrich the theory of quantum statistics.

  9. Richards Bay effluent pipeline

    CSIR Research Space (South Africa)

    Lord, DA

    1986-07-01

    Full Text Available of major concern identified in the effluent are the large volume of byproduct calcium sulphate (phosphogypsum) which would smother marine life, high concentrations of fluoride highly toxic to marine life, heavy metals, chlorinated organic material... ........................ 9 THE RICHARDS BAY PIPELINE ........................................ 16 Environmental considerations ................................... 16 - Phosphogypsum disposal ................................... 16 - Effects of fluoride on locally occurring...

  10. Some remarks on non-planar Feynman diagrams

    International Nuclear Information System (INIS)

    Bielas, Krzysztof; Dubovyk, Ievgen; Gluza, Janusz

    2013-12-01

    Two criteria for planarity of a Feynman diagram upon its propagators (momentum ows) are presented. Instructive Mathematica programs that solve the problem and examples are provided. A simple geometric argument is used to show that while one can planarize non-planar graphs by embedding them on higher-genus surfaces (in the example it is a torus), there is still a problem with defining appropriate dual variables since the corresponding faces of the graph are absorbed by torus generators.

  11. Some remarks on non-planar Feynman diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Bielas, Krzysztof; Dubovyk, Ievgen; Gluza, Janusz [Silesia Univ., Katowice (Poland). Inst. of Physics; Riemann, Tord [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2013-12-15

    Two criteria for planarity of a Feynman diagram upon its propagators (momentum ows) are presented. Instructive Mathematica programs that solve the problem and examples are provided. A simple geometric argument is used to show that while one can planarize non-planar graphs by embedding them on higher-genus surfaces (in the example it is a torus), there is still a problem with defining appropriate dual variables since the corresponding faces of the graph are absorbed by torus generators.

  12. Huygens-Feynman-Fresnel principle as the basis of applied optics.

    Science.gov (United States)

    Gitin, Andrey V

    2013-11-01

    The main relationships of wave optics are derived from a combination of the Huygens-Fresnel principle and the Feynman integral over all paths. The stationary-phase approximation of the wave relations gives the correspondent relations from the point of view of geometrical optics.

  13. Wars of the holographic world

    Science.gov (United States)

    Preskill, John

    2008-12-01

    In the popular imagination, the iconic American theoretical physicist is Richard Feynman, in all his safe-cracking, bongo-thumping, woman-chasing glory. I suspect that many physicists, if asked to name a living colleague who best captures the spirit of Feynman, would give the same answer as me: Leonard Susskind. As far as I know, Susskind does not crack safes, thump bongos, or chase women, yet he shares Feynman's brash cockiness (which in Susskind's case is leavened by occasional redeeming flashes of self-deprecation) and Feynman's gift for spinning fascinating anecdotes. If you are having a group of physicists over for dinner and want to be sure to have a good time, invite Susskind.

  14. Obituary: Richard D. Schwartz (1941-2011)

    Science.gov (United States)

    Wilking, Bruce

    2011-12-01

    Richard D. Schwartz, Professor Emeritus of Astronomy, died at his home in Sequim, WA, after a nearly 3 year battle against pancreatic cancer. Richard was born in Pretty Prairie, Kansas. He was active in sports and band and graduated in 1959. After completing a BS at Kansas State, and a Master's degree in Divinity at Union Seminary in NY, he further studied astrophysics, receiving his doctorate from University of Washington in 1973. When Dick arrived at the University of Missouri-St. Louis in 1975, he was the only astronomer in the Department of Physics. He built the astronomy program and initiated the B.S. in physics with an astrophysics option that the majority of physics majors choose. Dick was a wonderful teacher and provided outstanding leadership to the campus. He designed and provided oversight on the construction of the campus observatory that was completed in 1981. Since that time the observatory has served as both a teaching and research facility. It is also used for monthly public open houses that draw hundreds of people annually to the campus to view the moon, stars, and planets. Upon his retirement in 2003, the Board of Curators approved naming the campus observatory the "Richard D. Schwartz Observatory" in honor of his distinctive service to the University of Missouri-St. Louis. Just as important as Dick's service to promote public interest in astronomy was his effort to make the campus observatory a research facility. Dick equipped and maintained the observatory with state-of-art detectors that allowed students to get their first taste of scientific research. From 1991-2003, he managed the campus program for the NASA/Missouri Space Grant Consortium and mentored over 30 research students in projects at the observatory. Some of the results have been published in astronomical journals. Many of those students went on to graduate schools and several have achieved tenure and distinction at major universities. In addition to Dick's service to the University

  15. Feynman's path integrals and Bohm's particle paths

    International Nuclear Information System (INIS)

    Tumulka, Roderich

    2005-01-01

    Both Bohmian mechanics, a version of quantum mechanics with trajectories, and Feynman's path integral formalism have something to do with particle paths in space and time. The question thus arises how the two ideas relate to each other. In short, the answer is, path integrals provide a re-formulation of Schroedinger's equation, which is half of the defining equations of Bohmian mechanics. I try to give a clear and concise description of the various aspects of the situation. (letters and comments)

  16. Swearing Used in Richard Wright’s Black Boy

    OpenAIRE

    Giyatmi Giyatmi; Ratih WIjayava; Nunun Tri Widarwati

    2017-01-01

    This research aims at finding the types of swearing expressions and linguistic forms of English swearing used in Richard Wright's Black Boy. This is a descriptive qualitative research since it describes the phenomena of swearing used in the novel. The data of the research are all the conversations or sentences used swearing in the novel written by Richard Wright namely Black Boy as the main data source. The method of collecting data in this research is observation and teknik lanjut catat. Aft...

  17. EDITORIAL: Richard Palmer: celebrating 37 years with Journal of Physics: Condensed Matter Richard Palmer: celebrating 37 years with Journal of Physics: Condensed Matter

    Science.gov (United States)

    Ferry, David

    2009-01-01

    It is with a great deal of both happiness and sadness that I have to announce that we are losing one of the real strengths of the Journal of Physics: Condensed Matter (JPCM). Dr Richard Palmer, our Senior Publisher, announced his retirement, and this issue marks the first without his involvement. Of course, we are happy that he will get to enjoy his retirement, but we are sad to lose such a valuable member of our team. Richard first started work at IOP Publishing in March 1971 as an Editorial Assistant with Journal of Physics B: Atomic and Molecular Physics. After a few months, he transferred to Journal of Physics C: Solid State Physics. During his first year, he was sent on a residential publishing training course and asked to sign an undertaking to stay at IOP Publishing for at least two years. Although Richard refused to sign, as he did not want to commit himself, he has remained with the journal since then. The following year, the Assistant Editor of Journal of Physics C: Solid State Physics, Malcolm Haines, walked out without notice in order to work on his family vineyard in France, and Richard stepped into the breach. In those days, external editors had a much more hands-on role in IOP Publishing and he had to travel to Harwell to be interviewed by Alan Lidiard, the Honorary Editor of Journal of Physics C: Solid State Physics, before being given the job of Assistant Editor permanently. I am told that in those days the job consisted mainly of editing and proofreading and peer review. There was no journal development work. At some point in the early 1980s, production and peer review were split into separate departments and Richard then headed a group of journals consisting of Journal of Physics C: Solid State Physics, Journal of Physics D: Applied Physics and Journal of Physics F: Metal Physics, Semiconductor Science and Technology, Superconductor Science and Technology, Plasma Physics and Controlled Fusion, and later Nanotechnology and Modelling and Simulation

  18. A practical criterion of irreducibility of multi-loop Feynman integrals

    International Nuclear Information System (INIS)

    Baikov, P.A.

    2006-01-01

    A practical criterion for the irreducibility (with respect to integration by part identities) of a particular Feynman integral to a given set of integrals is presented. The irreducibility is shown to be related to the existence of stable (with zero gradient) points of a specially constructed polynomial

  19. Academic Training Lecture | Beyond Feynman Diagrams (1/3) | 24 April

    CERN Multimedia

    2013-01-01

    by Prof. Lance Dixon (SLAC National Accelerator Laboratory (US)). Wednesday 24 April 2013, from 11 a.m. to 12 p.m. at CERN (222-R-001 - Filtration Plant) Description: The search for new physics at the LHC, and accurate measurements of Standard Model processes, all benefit from precise theoretical predictions of collider event rates, which in turn rely on higher order computations in QCD, the theory of the strong interactions. Key ingredients for such computations are scattering amplitudes, the quantum-mechanical transition amplitudes between the incoming quarks and gluons and the outgoing produced particles. To go beyond leading order, we need both classical tree amplitudes and quantum loop amplitudes. For decades the central theoretical tool for computing scattering amplitudes has been the Feynman diagram. However, Feynman diagrams are just too slow, even on fast computers, to be able to go beyond the leading order in QCD, for complicated events with many jets of hadrons in the final state. Such events ...

  20. You err, Einstein.. Newton, Einstein, Heisenberg, and Feynman discuss quantum physics

    International Nuclear Information System (INIS)

    Fritzsch, Harald

    2008-01-01

    Harald Fritzsch and his star physicists Einstein, Heisenberg, and Feynman explain the central concept of nowadays physics, quantum mechanics, without it nothing goes in modern world. And the great Isaac newton puts the questions, which all would put

  1. Orbit-averaged quantities, the classical Hellmann-Feynman theorem, and the magnetic flux enclosed by gyro-motion

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, R. J., E-mail: rperkins@pppl.gov; Bellan, P. M. [Applied Physics and Materials Science, California Institute of Technology, Pasadena, California 91125 (United States)

    2015-02-15

    Action integrals are often used to average a system over fast oscillations and obtain reduced dynamics. It is not surprising, then, that action integrals play a central role in the Hellmann-Feynman theorem of classical mechanics, which furnishes the values of certain quantities averaged over one period of rapid oscillation. This paper revisits the classical Hellmann-Feynman theorem, rederiving it in connection to an analogous theorem involving the time-averaged evolution of canonical coordinates. We then apply a modified version of the Hellmann-Feynman theorem to obtain a new result: the magnetic flux enclosed by one period of gyro-motion of a charged particle in a non-uniform magnetic field. These results further demonstrate the utility of the action integral in regards to obtaining orbit-averaged quantities and the usefulness of this formalism in characterizing charged particle motion.

  2. Convergence theorems for renormalized Feynman integrals with zero-mass propagators

    International Nuclear Information System (INIS)

    Lowenstein, J.H.

    1976-01-01

    A general momentum-space subtraction procedure is proposed for the removal of both ultraviolet and infrared divergences of Feynman integrals. Convergence theorems are proved which allow one to define time-ordered Green functions, as tempered distributions for a wide class of theories with zero-mass propagators. (orig.) [de

  3. Automatic calculation of Feynman amplitude - GRACE/CHANEL

    International Nuclear Information System (INIS)

    Kurihara, Yoshimasa

    1992-01-01

    To investigate feasibility of physics at TeV energy region, cross sections from Feynman amplitudes have to be calculated for processes with multi-particle final state. Event generation and detector simulation must also be carried out to determine a detector design and a requirement of necessary luminosity. The JLC (Japan Linear Collider) working group has developed useful software and hardware tools for above purposes. An overview of the tools developed for the physics study at the JLC is given in this report. (author) 7 refs.; 2 figs

  4. Feynman rules of quantum chromodynamics inside a hadron

    International Nuclear Information System (INIS)

    Lee, T.D.

    1979-01-01

    We start from quantum chromodynamics in a finite volume of linear size L and examine its color-dielectric constant kappa/sub L/, especially the limit kappa/sub infinity/ as L → infinity. By choosing as our standard kappa/sub L/ = 1 when L = some hadron size R, we conclude that kappa/sub infinity/ must be -2 α where α is the fine-structure constant of QCD inside the hadron. A permanent quark confinement corresponds to the limit kappa/sub infinity/ = 0. The hadrons are viewed as small domain structures (with color-dielectric constant = 1) immersed in a perfect, or nearly perfect, color-dia-electric medium, which is the vacuum. The Feynman rules of QCD inside the hadron are derived; they are found to depend on the color-dielectric constant kappa/sub infinity/ of the vacuum that lies outside. We show that, when kappa/sub infinity/ → 0, the mass of any color-nonsinglet state becomes infinity, but for color-singlet states their masses and scattering amplitudes remain finite. These new Feynman rules also depend on the hadron size R. Only at high energy and large four-momentum transfer can such R dependence be neglected and, for color-singlet states, these new rules be reduced to the usual ones

  5. Potshemu medved rõtshit / Richard Pipes

    Index Scriptorium Estoniae

    Pipes, Richard

    2006-01-01

    Harvardi ülikooli ajalooprofessor Richard Pipes arutleb, miks Venemaa viimase aja käitumises väljendub soovimatus koostööks, sageli ka vaenulikkus. Venemaa võimetus rahvusvahelises kontekstis oma kohta leida, selle ajaloolised juured

  6. A guide to Feynman diagrams in the many-body problem

    CERN Document Server

    Mattuck, Richard D

    1976-01-01

    Until this book, most treatments of this topic were inaccessible to nonspecialists. A superb introduction to important areas of modern physics, it covers Feynman diagrams, quasi particles, Fermi systems at finite temperature, superconductivity, vacuum amplitude, Dyson's equation, ladder approximation, and much more. ""A great delight to read."" - Physics Today. 1974 edition.

  7. Richard Peters and Valuing Authenticity

    Science.gov (United States)

    Degenhardt, M. A. B.

    2009-01-01

    Richard Peters has been praised for the authenticity of his philosophy, and inquiry into aspects of the development of his philosophy reveals a profound authenticity. Yet authenticity is something he seems not to favour. The apparent paradox is resolved by observing historical changes in the understanding of authenticity as an important value.…

  8. A power counting theorem for Feynman integrals on the lattice

    International Nuclear Information System (INIS)

    Reisz, T.

    1988-01-01

    A convergence theorem is proved, which states sufficient conditions for the existence of the continuum limit for a wide class of Feynman integrals on a space-time lattice. A new kind of a UV-divergence degree is introduced, which allows the formulation of the theorem in terms of power counting conditions. (orig.)

  9. In Conversation with Paul Richards

    Science.gov (United States)

    Holman, Andrew

    2013-01-01

    Paul Richards is one of those individuals who make a difference and is as far from institutional as one can be. The author met up with him at the Learning Disability Today conference in London to talk more about his work and life. Paul coordinates the service user involvement across Southdown Housing Association, based in Sussex.

  10. Obituary: Dr. Richard Roland Baker

    Directory of Open Access Journals (Sweden)

    Thornton R

    2014-12-01

    Full Text Available Richard Baker died at Easter 2007 after a very short illness. It is sad that he died so soon after his retirement from the British American Tobacco Company at the end of 2005, and just as he was beginning to enjoy his new life, even though tobacco science still had a part to play.

  11. Feynman's Operational Calculi: Spectral Theory for Noncommuting Self-adjoint Operators

    International Nuclear Information System (INIS)

    Jefferies, Brian; Johnson, Gerald W.; Nielsen, Lance

    2007-01-01

    The spectral theorem for commuting self-adjoint operators along with the associated functional (or operational) calculus is among the most useful and beautiful results of analysis. It is well known that forming a functional calculus for noncommuting self-adjoint operators is far more problematic. The central result of this paper establishes a rich functional calculus for any finite number of noncommuting (i.e. not necessarily commuting) bounded, self-adjoint operators A 1 ,..., A n and associated continuous Borel probability measures μ 1 , ?, μ n on [0,1]. Fix A 1 ,..., A n . Then each choice of an n-tuple (μ 1 ,...,μ n ) of measures determines one of Feynman's operational calculi acting on a certain Banach algebra of analytic functions even when A 1 , ..., A n are just bounded linear operators on a Banach space. The Hilbert space setting along with self-adjointness allows us to extend the operational calculi well beyond the analytic functions. Using results and ideas drawn largely from the proof of our main theorem, we also establish a family of Trotter product type formulas suitable for Feynman's operational calculi

  12. The Feynman integrand as a white noise distribution beyond perturbation theory

    International Nuclear Information System (INIS)

    Grothaus, Martin; Vogel, Anna

    2008-01-01

    In this note the concepts of path integrals and techniques how to construct them are presented. Here we concentrate on a White Noise approach. Combining White Noise techniques with a generalized time-dependent Doss' formula Feynman integrands are constructed as white noise distributions beyond perturbation theory

  13. Elementary particles and the laws of physics: The 1986 Dirac Memorial Lectures

    International Nuclear Information System (INIS)

    Feynman, R.P.; Weinberg, S.

    1987-01-01

    Elementary Particles and the Laws of Physics contains transcriptions of the two lectures given in Cambridge, England, in 1986 by Nobel Laureates Richard P. Feynman and Steven Weinberg to commemorate the famous British physicist Paul Dirac. The talks focus on the fundamental problems of physics and the present state of our knowledge. Professor Feynman discusses how the laws of physics require the existence of antiparticles; Professor Weinberg examines the development of the fundamental laws of elementary particle intersection

  14. Foundations for relativistic quantum theory. I. Feynman's operator calculus and the Dyson conjectures

    International Nuclear Information System (INIS)

    Gill, Tepper L.; Zachary, W.W.

    2002-01-01

    In this paper, we provide a representation theory for the Feynman operator calculus. This allows us to solve the general initial-value problem and construct the Dyson series. We show that the series is asymptotic, thus proving Dyson's second conjecture for quantum electrodynamics. In addition, we show that the expansion may be considered exact to any finite order by producing the remainder term. This implies that every nonperturbative solution has a perturbative expansion. Using a physical analysis of information from experiment versus that implied by our models, we reformulate our theory as a sum over paths. This allows us to relate our theory to Feynman's path integral, and to prove Dyson's first conjecture that the divergences are in part due to a violation of Heisenberg's uncertainly relations

  15. Teaching Electron--Positron--Photon Interactions with Hands-on Feynman Diagrams

    Science.gov (United States)

    Kontokostas, George; Kalkanis, George

    2013-01-01

    Feynman diagrams are introduced in many physics textbooks, such as those by Alonso and Finn and Serway, and their use in physics education has been discussed by various authors. They have an appealing simplicity and can give insight into events in the microworld. Yet students often do not understand their significance and often cannot combine the…

  16. Theory of Feynman-alpha technique with masking window for accelerator-driven systems

    International Nuclear Information System (INIS)

    Kitamura, Yasunori; Misawa, Tsuyoshi

    2017-01-01

    Highlights: • A theory of the modified Feynman-alpha technique for the ADS was developed. • The experimental conditions under which this technique works were discussed. • It is expected this technique is applied to the subcriticality monitor for the ADS. - Abstract: Recently, a modified Feynman-alpha technique for the subcritical system driven by periodically triggered neutron bursts was developed. One of the main features of this technique is utilization of a simple formula that is advantageous in evaluating the subcriticality. However, owing to the absence of the theory of this technique, this feature has not been fully investigated yet. In the present study, a theory of this technique is provided. Furthermore, the experimental conditions under which the simple formula works are discussed to apply this technique to the subcriticality monitor for the accelerator-driven system.

  17. Richard W. Ziolkowski Receives Honorary Doctorate

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2012-01-01

    At the annual Commemoration of the Technical University of Denmark (DTU) on April 27, 2012, Prof. Richard W. Ziolkowski, University of Arizona (UoA), received DTU's highest academic degree, the Honorary Doctor degree: Doctor Technices Honoris Causa (Figure 1). Prof. Ziolkowski has been a close...

  18. ALOHA: Automatic libraries of helicity amplitudes for Feynman diagram computations

    Science.gov (United States)

    de Aquino, Priscila; Link, William; Maltoni, Fabio; Mattelaer, Olivier; Stelzer, Tim

    2012-10-01

    We present an application that automatically writes the HELAS (HELicity Amplitude Subroutines) library corresponding to the Feynman rules of any quantum field theory Lagrangian. The code is written in Python and takes the Universal FeynRules Output (UFO) as an input. From this input it produces the complete set of routines, wave-functions and amplitudes, that are needed for the computation of Feynman diagrams at leading as well as at higher orders. The representation is language independent and currently it can output routines in Fortran, C++, and Python. A few sample applications implemented in the MADGRAPH 5 framework are presented. Program summary Program title: ALOHA Catalogue identifier: AEMS_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMS_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: http://www.opensource.org/licenses/UoI-NCSA.php No. of lines in distributed program, including test data, etc.: 6094320 No. of bytes in distributed program, including test data, etc.: 7479819 Distribution format: tar.gz Programming language: Python2.6 Computer: 32/64 bit Operating system: Linux/Mac/Windows RAM: 512 Mbytes Classification: 4.4, 11.6 Nature of problem: An effcient numerical evaluation of a squared matrix element can be done with the help of the helicity routines implemented in the HELAS library [1]. This static library contains a limited number of helicity functions and is therefore not always able to provide the needed routine in the presence of an arbitrary interaction. This program provides a way to automatically create the corresponding routines for any given model. Solution method: ALOHA takes the Feynman rules associated to the vertex obtained from the model information (in the UFO format [2]), and multiplies it by the different wavefunctions or propagators. As a result the analytical expression of the helicity routines is obtained. Subsequently, this expression is

  19. Feynman's thesis: A new approach to quantum theory

    International Nuclear Information System (INIS)

    Das, Ashok

    2007-01-01

    It is not usual for someone to write a book on someone else's Ph.D. thesis, but then Feynman was not a usual physicist. He was without doubt one of the most original physicists of the twentieth century, who has strongly influenced the developments in quantum field theory through his many ingenious contributions. Path integral approach to quantum theories is one such contribution which pervades almost all areas of physics. What is astonishing is that he developed this idea as a graduate student for his Ph.D. thesis which has been printed, for the first time, in the present book along with two other related articles. The early developments in quantum theory, by Heisenberg and Schroedinger, were based on the Hamiltonian formulation, where one starts with the Hamiltonian description of a classical system and then promotes the classical observables to noncommuting quantum operators. However, Dirac had already stressed in an article in 1932 (this article is also reproduced in the present book) that the Lagrangian is more fundamental than the Hamiltonian, at least from the point of view of relativistic invariance and he wondered how the Lagrangian may enter into the quantum description. He had developed this idea through his 'transformation matrix' theory and had even hinted on how the action of the classical theory may enter such a description. However, although the brief paper by Dirac contained the basic essential ideas, it did not fully develop the idea of a Lagrangian description in detail in the functional language. Feynman, on the other hand, was interested in the electromagnetic interactions of the electron from a completely different point of view rooted in a theory involving action-at-a-distance. His theory (along with John Wheeler) did not have a Hamiltonian description and, in order to quantize such a theory, he needed an alternative formulation of quantum mechanics. When the article by Dirac was brought to his attention, he immediately realized what he was

  20. Recensie "The Great Reset" : Richard Florida

    NARCIS (Netherlands)

    Roy van Dalm

    2010-01-01

    Like the Great Depression and the Long Depression before it, experts have viewed prolonged economic downturns as crises. In The Great Reset , bestselling author Richard Florida argues that we should instead see the recent recession as an opportunity to create entirely new ways of working and living

  1. On the classical Maxwell-Lorentz electrodynamics, the electron inertia problem, and the Feynman proper time paradigm

    International Nuclear Information System (INIS)

    Prykarpatsky, A.K.; Bogolubov, J.R.

    2016-01-01

    The classical Maxwell electromagnetic field and the Lorentz-type force equations are rederived in the framework of the Feynman proper time paradigm and the related vacuum field theory approach. The classical Ampere law origin is rederived, and its relationship with the Feynman proper time paradigm is discussed. The electron inertia problem is analyzed in detail within the Lagrangian and Hamiltonian formalisms and the related pressure-energy compensation principle of stochastic electrodynamics. The modified Abraham-Lorentz damping radiation force is derived and the electromagnetic electron mass origin is argued

  2. Seeing Scale: Richard Dunn’s Structuralism

    Directory of Open Access Journals (Sweden)

    Keith Broadfoot

    2012-11-01

    Full Text Available Writing on the occasion of a retrospective of Richard Dunn’s work, Terence Maloon argued that ‘structuralism had an important bearing on virtually all of Richard Dunn’s mature works’, with ‘his modular, “crossed” formats’ being the most obvious manifestation of this. In this article I wish to reconsider this relation, withdrawing from a broad consideration of the framework of structuralism to focus on some of the quite particular ideas that Lacan proposed in response to structuralism. Beginning from a pivotal painting in the 1960s that developed out of Dunn’s experience of viewing the work of Barnett Newman, I wish to suggest a relation between the ongoing exploration of the thematic of scale in Dunn’s work and the idea of the symbolic that Lacan derives from structuralist thought. This relation, I argue, opens up a different way of understanding the art historical transition from Minimalism to Conceptual art.

  3. Theodore William Richards and the Periodic Table

    Science.gov (United States)

    Conant, James B.

    1970-01-01

    Discusses the contribution of Theodore Richards to the accurate determination of atomic weights of copper and other elements; his major contribution was to the building of the definitive periodic table of the elements. (BR)

  4. The Hellmann–Feynman theorem, the comparison theorem, and the envelope theory

    Directory of Open Access Journals (Sweden)

    Claude Semay

    2015-01-01

    Full Text Available The envelope theory is a convenient method to compute approximate solutions for bound state equations in quantum mechanics. It is shown that these approximate solutions obey a kind of Hellmann–Feynman theorem, and that the comparison theorem can be applied to these approximate solutions for two ordered Hamiltonians.

  5. Asymptotic expansions of Feynman diagrams and the Mellin-Barnes representation

    International Nuclear Information System (INIS)

    Friot, Samuel; Greynat, David

    2007-01-01

    In this talk, we describe part of our recent work [S. Friot, D. Greynat and E. de Rafael, Phys. Lett. B 628 (2005) 73 [ (arXiv:hep-ph/0505038)] (see also [S. Friot, PhD Thesis (2005); D. Greynat, PhD Thesis (2005)]) that gives new results in the context of asymptotic expansions of Feynman diagrams using the Mellin-Barnes representation

  6. Relation between Feynman Cycles and Off-Diagonal Long-Range Order

    International Nuclear Information System (INIS)

    Ueltschi, Daniel

    2006-01-01

    The usual order parameter for Bose-Einstein condensation involves the off-diagonal correlation function of Penrose and Onsager, but an alternative is Feynman's notion of infinite cycles. We present a formula that relates both order parameters. We discuss its validity with the help of rigorous results and heuristic arguments. The conclusion is that infinite cycles do not always represent the Bose condensate

  7. Feynman propagator for a particle with arbitrary spin

    International Nuclear Information System (INIS)

    Huang Shi-Zhong; Zhang Peng-Fei; Ruan Tu-Nan; Zhu Yu-Can; Zheng Zhi-Peng

    2005-01-01

    Based on the solution to the Rarita-Schwinger equations, a direct derivation of the projection operator and propagator for a particle with arbitrary spin is worked out. The projection operator constructed by Behrends and Fronsdal is re-deduced and confirmed, and simplified in the case of half-integral spin; the general commutation rules and Feynman propagator for a free particle of any spin are derived, and explicit expressions for the propagators for spins 3/2, 2, 5/2, 3, 7/2, 4 are provided. (orig.)

  8. Closure of the gauge algebra, generalized Lie equations and Feynman rules

    International Nuclear Information System (INIS)

    Batalin, I.A.

    1984-01-01

    A method is given by which an open gauge algebra can always be closed and even made abelian. As a preliminary the generalized Lie equations for the open group are obtained. The Feynman rules for gauge theories with open algebras are derived by reducing the gauge theory to a non-gauge one. (orig.)

  9. Axiomatic derivation of Feynman rules and related topics

    International Nuclear Information System (INIS)

    Dorfmeister, G.K.

    1992-01-01

    Previous results in axiomatic field theory by Steinmann and Epstein-Glaser establish the existence of the retarded and time ordered Green's functions in every order of perturbation. To connect these Green's functions with the ones calculated in canonical field theories via the Feynman rules, one has to consistently build them not just for every order of perturbation but for each specific graph. (open-quotes Consisentlyclose quotes means here that the Green functions associated with two open-quotes smallclose quotes graphs build up to the Green's functions of the open-quotes bigclose quotes graph formed by connecting the two open-quotes smallclose quotes ones). This paper shows that this can indeed be done; that in this sense the Feynman rules of perturbative Lagrangian field theory can be derived from the abstract, but physically very basic, principles of axiomatic field theory. All results hold only for massive field theories. The LSZ formalism, to the best knowledge of the author, has so far not been modified to admit mass zero fields. To make the representation simpler and more transparent, the author restricts the discussion to a single component, scalar Φ 4 interaction which is a part of the Standard Model of Particle Physics. Motivated by its role in particle physics, the author complements the perturbative study of Φ 4 -theory by reviewing the status of non-perturbative solutions to the theory in the final chapter

  10. Hellmann–Feynman connection for the relative Fisher information

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesan, R.C., E-mail: ravi@systemsresearchcorp.com [Systems Research Corporation, Aundh, Pune 411007 (India); Plastino, A., E-mail: plastino@fisica.unlp.edu.ar [IFLP, National University La Plata & National Research (CONICET) C. C., 727 1900, La Plata (Argentina)

    2015-08-15

    The (i) reciprocity relations for the relative Fisher information (RFI, hereafter) and (ii) a generalized RFI–Euler theorem are self-consistently derived from the Hellmann–Feynman theorem. These new reciprocity relations generalize the RFI–Euler theorem and constitute the basis for building up a mathematical Legendre transform structure (LTS, hereafter), akin to that of thermodynamics, that underlies the RFI scenario. This demonstrates the possibility of translating the entire mathematical structure of thermodynamics into a RFI-based theoretical framework. Virial theorems play a prominent role in this endeavor, as a Schrödinger-like equation can be associated to the RFI. Lagrange multipliers are determined invoking the RFI–LTS link and the quantum mechanical virial theorem. An appropriate ansatz allows for the inference of probability density functions (pdf’s, hereafter) and energy-eigenvalues of the above mentioned Schrödinger-like equation. The energy-eigenvalues obtained here via inference are benchmarked against established theoretical and numerical results. A principled theoretical basis to reconstruct the RFI-framework from the FIM framework is established. Numerical examples for exemplary cases are provided. - Highlights: • Legendre transform structure for the RFI is obtained with the Hellmann–Feynman theorem. • Inference of the energy-eigenvalues of the SWE-like equation for the RFI is accomplished. • Basis for reconstruction of the RFI framework from the FIM-case is established. • Substantial qualitative and quantitative distinctions with prior studies are discussed.

  11. The Feynman fluid analogy in e+e- annihilation

    International Nuclear Information System (INIS)

    Hegyi, S.; Krasznovszky, S.

    1990-07-01

    An analysis of the charged particle multiplicity distributions observed in e + e - annihilation is given using the generalized Feynman fluid analogy of multiparticle production. Only the two-and three-particle integrated correlation functions are included into the scheme. It is shown that the model correctly describes the available experimental data from the TASSO and HRS collaborations. Some properties of the fluid of the analogy are computed and a prediction is made for the multiplicity distribution at √s = 91 GeV. (author) 19 refs.; 5 figs.; 1 tab

  12. Method of lines solution of Richards` equation

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, C.T.; Miller, C.T.; Tocci, M.D.

    1996-12-31

    We consider the method of lines solution of Richard`s equation, which models flow through porous media, as an example of a situation in which the method can give incorrect results because of premature termination of the nonlinear corrector iteration. This premature termination arises when the solution has a sharp moving front and the Jacobian is ill-conditioned. While this problem can be solved by tightening the tolerances provided to the ODE or DAE solver used for the temporal integration, it is more efficient to modify the termination criteria of the nonlinear solver and/or recompute the Jacobian more frequently. In this paper we continue previous work on this topic by analyzing the modifications in more detail and giving a strategy on how the modifications can be turned on and off in response to changes in the character of the solution.

  13. Extended Hellmann-Feynman theorem for degenerate eigenstates

    Science.gov (United States)

    Zhang, G. P.; George, Thomas F.

    2004-04-01

    In a previous paper, we reported a failure of the traditional Hellmann-Feynman theorem (HFT) for degenerate eigenstates. This has generated enormous interest among different groups. In four independent papers by Fernandez, by Balawender, Hola, and March, by Vatsya, and by Alon and Cederbaum, an elegant method to solve the problem was devised. The main idea is that one has to construct and diagonalize the force matrix for the degenerate case, and only the eigenforces are well defined. We believe this is an important extension to HFT. Using our previous example for an energy level of fivefold degeneracy, we find that those eigenforces correctly reflect the symmetry of the molecule.

  14. A new approach to the Taylor expansion of multiloop Feynman diagrams

    International Nuclear Information System (INIS)

    Tarasov, O.V.

    1996-01-01

    We present a new method for the Taylor expansion of Feynman integrals with arbitrary masses and any number of loops and external momenta. By using the parametric representation we derive a generating function for the coefficients of the small momentum expansion of an arbitrary diagram. The method is applicable for the expansion with respect to all or a subset of external momenta. The coefficients of the expansion are obtained by applying a differential operator to a given integral with shifted value of the space-time dimension d and the expansion momenta set equal to zero. Integrals with changed d are evaluated by using the generalized recurrence relations recently proposed [O.V. Tarasov, Connection between Feynman integrals having different values of the space-time dimension, preprint DESY 96-068, JINR E2-96-62 (hep-th/9606018), to be published in Phys. Rev. D 54, No. 10 (1996)]. We show how the method works for one- and two-loop integrals. It is also illustrated that our method is simpler and more efficient than others. (orig.)

  15. The dependence of J/ψ-nucleon inelastic cross section on the Feynman variable

    International Nuclear Information System (INIS)

    Duan Chungui; Liu Na; Miao Wendan

    2011-01-01

    By means of two typical sets of nuclear parton distribution functions, meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter in the uniform framework of the Glauber model, a leading order phenomenological analysis is given in the color evaporation model of the E866 experimental data on J/ψ production differential cross section ratios R Fe/Be (x F ). It is shown that the energy loss effect of beam proton on R Fe/Be (x F ) is more important than the nuclear effects on parton distribution functions in the high Feynman variable x F region. It is found that the J/ψ-nucleon inelastic cross section depends on the Feynman variable x F and increases linearly with x F in the region x F > 0.2. (authors)

  16. W. Richard Scott, Institutions and Organizations: Ideas, Interests, and Identities

    DEFF Research Database (Denmark)

    Jakobsen, Michael

    2014-01-01

    Book review of: W. Richard Scott: Institutions and Organizations: Ideas, Interests, and Identities. 4th edition. Thousand Oaks, CA: SAGE Publications, 2014. xiii, 345 pp.......Book review of: W. Richard Scott: Institutions and Organizations: Ideas, Interests, and Identities. 4th edition. Thousand Oaks, CA: SAGE Publications, 2014. xiii, 345 pp....

  17. Survey and selection of assessment methodologies for GAVE options

    International Nuclear Information System (INIS)

    Weterings, R.

    1999-05-01

    The Dutch government is interested in the possibilities for a market introduction of new gaseous and liquid energy carriers. To this purpose the GAVE-programme was recently set up. This study is carried out within the framework of the GAVE-programme and aims at the selection of methodologies for assessing the technological, economic, ecological and social perspectives of these new energy options (so-called GAVE-options). Based on the results of these assessments the Dutch ministries of Housing, Planning and Environment (VROM) and Economic Affairs (EZ) will decide at the end of 1999 about starting demonstration projects of promising energy carriers

  18. Advanced quantum theory and its applications through Feynman diagrams

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1979-01-01

    The two themes of scattering diagrams and the fundamental forces characterize this book. Transformation theory is developed to review the concepts of nonrelativistic quantum mechanics and to formulate the relativistic Klein-Gordon, Maxwell, and Dirac wave equations for relativistic spin-0, massless spin-1, and spin-1/2 particles, respectively. The language of group theory is used to write relativistic Lorentz transformations in a form similar to ordinary rotations and to describe the important discrete symmetries of C, P, and T. Then quantum mechanics is reformulated in the language of scattering theory, with the momentum-space S matrix replacing the coordinate-space hamiltonian as the central dynamical operator. Nonrelativistic perturbation scattering diagrams are then developed, and simple applications given for nuclear, atomic, and solid-state scattering problems. Next, relativistic scattering diagrams built up from covariant Feynman propagators and vertices in a manner consistent with the CPT theorem are considered. The theory is systematically applied to the lowest-order fundamental electromagnetic, strong, weak, and gravitational interactions. Finally, the use of higher-order Feynman diagrams to explain more detailed aspects of quantum electrodynamics (QED) and strong-interaction elementary-particle physics is surveyed. Throughout, the notion of currents is used to exploit the underlying symmetries and dynamical interactions of the various quantum forces. 258 references, 77 figures, 1 table

  19. Specific features of the REDUCE system and calculation of QCD Feynman graphs

    International Nuclear Information System (INIS)

    Dulyan, L.S.

    1990-01-01

    The ways and methods used in calculation of one class of the QCD Feynman graphs with the help of the REDUCE system are described. It is shown how by introducing new constructions and operations the user could avoid difficulties connected with specific restrictions and features of the REDUCE system

  20. Kuues väljasuremine / Richard Leakey, Roger Lewin

    Index Scriptorium Estoniae

    Leakey, Richard

    2002-01-01

    Inimtegevuse hävitavast toimest looduslikule mitmekesisusele, mis tingib loodusliku energiatootmise järsu kahanemise, millest omakorda sõltub inimese enda ellujäämine. Lühidalt Richard Leakey'st

  1. Bridging the Knowledge Gaps between Richards' Equation and Budyko Equation

    Science.gov (United States)

    Wang, D.

    2017-12-01

    The empirical Budyko equation represents the partitioning of mean annual precipitation into evaporation and runoff. Richards' equation, based on Darcy's law, represents the movement of water in unsaturated soils. The linkage between Richards' equation and Budyko equation is presented by invoking the empirical Soil Conservation Service curve number (SCS-CN) model for computing surface runoff at the event-scale. The basis of the SCS-CN method is the proportionality relationship, i.e., the ratio of continuing abstraction to its potential is equal to the ratio of surface runoff to its potential value. The proportionality relationship can be derived from the Richards' equation for computing infiltration excess and saturation excess models at the catchment scale. Meanwhile, the generalized proportionality relationship is demonstrated as the common basis of SCS-CN method, monthly "abcd" model, and Budyko equation. Therefore, the linkage between Darcy's law and the emergent pattern of mean annual water balance at the catchment scale is presented through the proportionality relationship.

  2. Richard A. Werners forskning i pengeskabelse

    DEFF Research Database (Denmark)

    2016-01-01

    Hvilken rolle spiller penge i samfundsøkonomien og hvilken rolle burde penge spille i den økonomiske videnskab? Det forsker Richard Werner i. Han er professor i økonomi ved Southampton University i England, og her præsenteres fire dele af hans forskning i penge: (1) Hvad foregår der egentlig i en...

  3. Do we need Feynman diagrams for higher order perturbation theory?

    International Nuclear Information System (INIS)

    Jora, Renata

    2012-01-01

    We compute the two loop and three loop corrections to the beta function for Yang-Mills theories in the background gauge field method and using the background gauge field as the only source. The calculations are based on the separation of the one loop effective potential into zero and positive modes contributions and are entirely analytical. No two or three loop Feynman diagrams are considered in the process.

  4. Numerical calculations in elementary quantum mechanics using Feynman path integrals

    International Nuclear Information System (INIS)

    Scher, G.; Smith, M.; Baranger, M.

    1980-01-01

    We show that it is possible to do numerical calculations in elementary quantum mechanics using Feynman path integrals. Our method involves discretizing both time and space, and summing paths through matrix multiplication. We give numerical results for various one-dimensional potentials. The calculations of energy levels and wavefunctions take approximately 100 times longer than with standard methods, but there are other problems for which such an approach should be more efficient

  5. Experimental demonstration of the finite measurement time effect on the Feynman-{alpha} technique

    Energy Technology Data Exchange (ETDEWEB)

    Wallerbos, E.J.M.; Hoogenboom, J.E

    1998-09-01

    The reactivity of a subcritical system is determined by fitting two different theoretical models to a measured Feynman-{alpha} curve. The first model is the expression usually found in the literature, which can be shown to be the expectation value of the experimental quality if the measurement time is infinite. The second model is a new expression which is the expectation value of the experimental quantity for a finite measurement time. The reactivity inferred with the new model is seen to be independent of the length of the fitting interval, whereas the reactivity inferred with the conventional model is seen to vary. This difference demonstrates the effect of the finite measurement time. As a reference, the reactivity is also measured with the pulsed-neutron source method. It is seen to be in good agreement with the reactivity obtained with the Feynman-{alpha} technique when the new expression is applied.

  6. The diamond rule for multi-loop Feynman diagrams

    International Nuclear Information System (INIS)

    Ruijl, B.; Ueda, T.; Vermaseren, J.A.M.

    2015-01-01

    An important aspect of improving perturbative predictions in high energy physics is efficiently reducing dimensionally regularised Feynman integrals through integration by parts (IBP) relations. The well-known triangle rule has been used to achieve simple reduction schemes. In this work we introduce an extensible, multi-loop version of the triangle rule, which we refer to as the diamond rule. Such a structure appears frequently in higher-loop calculations. We derive an explicit solution for the recursion, which prevents spurious poles in intermediate steps of the computations. Applications for massless propagator type diagrams at three, four, and five loops are discussed

  7. S-matrix, Feynman zigzag and Einstein correlation

    International Nuclear Information System (INIS)

    Costa de Beauregard, O.

    1978-01-01

    An inherent binding between Einstein correlations and the S-matrix formalism entails full relativistic covariance, complete time symmetry, and spacelike connexions via Feynman zigzags. The relay is in the past for predictive correlations between future measurements, and in the future for retrodictive correlations between past preparations (Pflegor and Mandel). An analogy and a partial binding exist between intrinsic symmetry together with factlike asymmetry of (1) 'blind statistical' prediction and retrodiction (retarded and advanced waves, information as cognizance and as will) and (2) positive and negative frequencies (particles and antiparticles). As advanced waves are required for completeness of expansions, 'antiphysics' obeying blind statistical retrodiction should show up in appropriate contexts, 'parapsychology' being submitted as one of them. (Auth.)

  8. A development of an accelerator board dedicated for multi-precision arithmetic operations and its application to Feynman loop integrals

    International Nuclear Information System (INIS)

    Motoki, S; Ishikawa, T; Yuasa, F; Daisaka, H; Nakasato, N; Fukushige, T; Kawai, A; Makino, J

    2015-01-01

    Higher order corrections in perturbative quantum field theory are required for precise theoretical analysis to investigate new physics beyond the Standard Model. This indicates that we need to evaluate Feynman loop diagrams with multi-loop integrals which may require multi-precision calculation. We developed a dedicated accelerator system for multiprecision calculations (GRAPE9-MPX). We present performance results of our system for the case of Feynman two-loop box and three-loop selfenergy diagrams with multi-precision. (paper)

  9. Hellmann-Feynman theorem and the definition of forces in quantum time-dependent and transport problems

    International Nuclear Information System (INIS)

    Di Ventra, Massimiliano; Pantelides, Sokrates T.

    2000-01-01

    The conventional Hellmann-Feynman theorem for the definition of forces on nuclei is not directly applicable to quantum time-dependent and transport problems. We present a rigorous derivation of a general Hellmann-Feynman-like theorem that applies to all quantum mechanical systems and reduces to well-known results for ground-state problems. It provides a rigorous definition of forces in time-dependent and transport problems. Explicit forms of Pulay-like forces are derived and the conditions for them to be zero are identified. A practical scheme for ab initio calculations of current-induced forces is described and the study of the transfer of a Si atom between two electrodes is presented as an example. (c) 2000 The American Physical Society

  10. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 9. Five Things I Learned from Richard Feynman About Science Education. Kathy Ceceri. Personal Reflections Volume 16 Issue 9 September 2011 pp 879-880. Fulltext. Click here to view fulltext PDF. Permanent link:

  11. Global Estimates of Errors in Quantum Computation by the Feynman-Vernon Formalism

    Science.gov (United States)

    Aurell, Erik

    2018-04-01

    The operation of a quantum computer is considered as a general quantum operation on a mixed state on many qubits followed by a measurement. The general quantum operation is further represented as a Feynman-Vernon double path integral over the histories of the qubits and of an environment, and afterward tracing out the environment. The qubit histories are taken to be paths on the two-sphere S^2 as in Klauder's coherent-state path integral of spin, and the environment is assumed to consist of harmonic oscillators initially in thermal equilibrium, and linearly coupled to to qubit operators \\hat{S}_z . The environment can then be integrated out to give a Feynman-Vernon influence action coupling the forward and backward histories of the qubits. This representation allows to derive in a simple way estimates that the total error of operation of a quantum computer without error correction scales linearly with the number of qubits and the time of operation. It also allows to discuss Kitaev's toric code interacting with an environment in the same manner.

  12. Global Estimates of Errors in Quantum Computation by the Feynman-Vernon Formalism

    Science.gov (United States)

    Aurell, Erik

    2018-06-01

    The operation of a quantum computer is considered as a general quantum operation on a mixed state on many qubits followed by a measurement. The general quantum operation is further represented as a Feynman-Vernon double path integral over the histories of the qubits and of an environment, and afterward tracing out the environment. The qubit histories are taken to be paths on the two-sphere S^2 as in Klauder's coherent-state path integral of spin, and the environment is assumed to consist of harmonic oscillators initially in thermal equilibrium, and linearly coupled to to qubit operators \\hat{S}_z. The environment can then be integrated out to give a Feynman-Vernon influence action coupling the forward and backward histories of the qubits. This representation allows to derive in a simple way estimates that the total error of operation of a quantum computer without error correction scales linearly with the number of qubits and the time of operation. It also allows to discuss Kitaev's toric code interacting with an environment in the same manner.

  13. Expressing Solutions of the Dirac Equation in Terms of Feynman Path Integral

    CERN Document Server

    Hose, R D

    2006-01-01

    Using the separation of the variables technique, the free particle solutions of the Dirac equation in the momentum space are shown to be actually providing the definition of Delta function for the Schr dinger picture. Further, the said solution is shown to be derivable on the sole strength of geometrical argument that the Dirac equation for free particle is an equation of a plane in momentum space. During the evolution of time in the Schr dinger picture, the normal to the said Dirac equation plane is shown to be constantly changing in direction due to the uncertainty principle and thereby, leading to a zigzag path for the Dirac particle in the momentum space. Further, the time evolution of the said Delta function solutions of the Dirac equation is shown to provide Feynman integral of all such zigzag paths in the momentum space. Towards the end of the paper, Feynman path integral between two fixed spatial points in the co-ordinate space during a certain time interv! al is shown to be composed, in time sequence...

  14. Richard Mattessich: vida y obra

    OpenAIRE

    Daniel Carrasco Díaz

    2006-01-01

    El texto que se ofrece a continuación constituye el discurso pronunciado por el profesor Daniel Carrasco Díaz, catedrático de Economía Financiera y Contabilidad como padrino del homenajeado, en el solemne acto de investidura del Prof. Dr. Richard Mattessich, profesor emérito de la Sauder School of Commerce, de la University of British Columbia, Vancouver (Canadá), como Doctor honoris causa por la Universidad de Málaga, celebrado el 18 de mayo de 2006.

  15. Failed Mothers, Monster Sons. Reading Shakespeare’S Richard Iii as a Fairy Tale

    Directory of Open Access Journals (Sweden)

    Percec Dana

    2014-03-01

    Full Text Available The paper looks at Shakespeare’s historical play Richard III and its fairy tale-like character given by the configuration of the main character as an arch-villain and the presence of motifs and patterns typically associated with the fairy tale genre. More specifically, it considers the mother-son relationship between the Duchess of York and Richard in the light of the motif of monstrous birth. It is not a coincidence that the emergence of such motifs coincides with the historical contexts of the early modern period. Reading Richard III in this key is related to the revisionist approach to chronicle plays.

  16. Feynman rules and generalized ward identities in phase space functional integral

    International Nuclear Information System (INIS)

    Li Ziping

    1996-01-01

    Based on the phase-space generating functional of Green function, the generalized canonical Ward identities are derived. It is point out that one can deduce Feynman rules in tree approximation without carrying out explicit integration over canonical momenta in phase-space generating functional. If one adds a four-dimensional divergence term to a Lagrangian of the field, then, the propagator of the field can be changed

  17. Richard Weaver's Untraditional Case for Federalism

    OpenAIRE

    Jeremy David Bailey

    2004-01-01

    Although Richard M. Weaver's political writings do not offer a systematic examination of federalism, they include a defense of federalist arrangements. Because Weaver's federalism is central to his conservatism, and because his argument for federalism differs from more common conservative defenses of federalism offered in the twentieth century, his writings allow students of federalism to examine possible connections between federalism and conservative political thought. Copyright 2004, Oxfor...

  18. Interpretation of the evolution parameter of the Feynman parametrization of the Dirac equation

    International Nuclear Information System (INIS)

    Aparicio, J.P.; Garcia Alvarez, E.T.

    1995-01-01

    The Feynman parametrization of the Dirac equation is considered in order to obtain an indefinite mass formulation of relativistic quantum mechanics. It is shown that the parameter that labels the evolution is related to the proper time. The Stueckelberg interpretation of antiparticles naturally arises from the formalism. ((orig.))

  19. Feynman propagator for spin foam quantum gravity.

    Science.gov (United States)

    Oriti, Daniele

    2005-03-25

    We link the notion causality with the orientation of the spin foam 2-complex. We show that all current spin foam models are orientation independent. Using the technology of evolution kernels for quantum fields on Lie groups, we construct a generalized version of spin foam models, introducing an extra proper time variable. We prove that different ranges of integration for this variable lead to different classes of spin foam models: the usual ones, interpreted as the quantum gravity analogue of the Hadamard function of quantum field theory (QFT) or as inner products between quantum gravity states; and a new class of causal models, the quantum gravity analogue of the Feynman propagator in QFT, nontrivial function of the orientation data, and implying a notion of "timeless ordering".

  20. In memoriam: Richard (Rick) G. Harrison—benefactor for ...

    Indian Academy of Sciences (India)

    Professor Richard Harrison (1946–2016), a most influential evolutionary biologist of ... were profoundly important in my development as a scientist and a person. ... observations to infer his love of family, but I am going to risk correction by those ...

  1. PREFACE: Celebrating 20 years of Journal of Physics: Condensed Matter—in honour of Richard Palmer Celebrating 20 years of Journal of Physics: Condensed Matter—in honour of Richard Palmer

    Science.gov (United States)

    Ferry, David; Dowben, Peter; Inglesfield, John

    2009-11-01

    This year marks the 20th anniversary of the launch of Journal of Physics: Condensed Matter in 1989. The journal was formed from the merger of Journal of Physics C: Solid State Physics and Journal of Physics F: Metal Physics which had separated in 1971. In the 20 years since its launch, Journal of Physics: Condensed Matter has more than doubled in size, while raising standards. Indeed, Journal of Physics: Condensed Matter has become one of the leading scientific journals for our field. This could not have occurred without great leadership at the top. No one has been more responsible for this growth in both size and quality than our Senior Publisher, Richard Palmer. Richard first started work at IOP in March 1971 as an Editorial Assistant with J. Phys. B After a few months, he transferred to J. Phys.C The following year, the Assistant Editor of J. Phys. C, Malcolm Haines, left suddenly in order to work on his family vineyard in France, and Richard stepped into the breach. In those days, external editors had a much more hands-on role in IOP Publishing and he had to travel to Harwell to be interviewed by Alan Lidiard, the Honorary Editor of J. Phys. C, before being given the job of Assistant Editor permanently. Since J. Phys. C and J. Phys. F re-merged to form Journal of Physics: Condensed Matter, Richard gradually shed his other journal responsibilities, except for Reports on Progress in Physics, to build up Journal of Physics: Condensed Matter. He has worked closely with four Editors-in-Chief of J. Phys. C and five of Journal of Physics: Condensed Matter. When Richard announced his retirement this past winter, we met it with a great deal of both happiness and sadness. Of course, we are happy that he is going to be allowed to enjoy his retirement, but we remain very sad to lose such a valuable member of our team, especially the one who had provided the heart and soul of the journal over its 20 years. We will be able to rely upon the team which Richard ably trained as

  2. Teaching Basic Quantum Mechanics in Secondary School Using Concepts of Feynman Path Integrals Method

    Science.gov (United States)

    Fanaro, Maria de los Angeles; Otero, Maria Rita; Arlego, Marcelo

    2012-01-01

    This paper discusses the teaching of basic quantum mechanics in high school. Rather than following the usual formalism, our approach is based on Feynman's path integral method. Our presentation makes use of simulation software and avoids sophisticated mathematical formalism. (Contains 3 figures.)

  3. Feynman graphs and gauge theories for experimental physicists. 2. rev. ed.

    International Nuclear Information System (INIS)

    Schmueser, P.

    1995-01-01

    This book is an introduction to the foundations of quantum field theory with special regards to gauge theory. After a general introduction to relativistic wave equations the concept of Feynman graphs is introduced. Then after an introduction to the phenomenology of weak interactions and the principle of gauge invariance the standard model of the electroweak interaction is presented. Finally quantum chromodynamics is described. Every chapter contains exercise problems. (HSI)

  4. Richard Wollheim 1923-2003 / Marek Volt

    Index Scriptorium Estoniae

    Volt, Marek

    2004-01-01

    Järelehüüe anglo-ameerika filosoofile Richard Wollheimile (5. V 1923-4. XI 2003), kes huvitus maalist ja psühhoanalüüsist ning kuulub XX sajandi analüütilist kunstifilosoofiat enim kujundanud filosoofide hulka. Tema peamised tööd: "Art and Its Objects" (1968), "Painting As an Art" (1987), "On Painting and the Self" (1992). Ilmunud ka raamatus: Volt, Marek. Esteetikast. Tallinn : Sirp, 2006

  5. Anomaly detection in random heterogeneous media Feynman-Kac formulae, stochastic homogenization and statistical inversion

    CERN Document Server

    Simon, Martin

    2015-01-01

    This monograph is concerned with the analysis and numerical solution of a stochastic inverse anomaly detection problem in electrical impedance tomography (EIT). Martin Simon studies the problem of detecting a parameterized anomaly in an isotropic, stationary and ergodic conductivity random field whose realizations are rapidly oscillating. For this purpose, he derives Feynman-Kac formulae to rigorously justify stochastic homogenization in the case of the underlying stochastic boundary value problem. The author combines techniques from the theory of partial differential equations and functional analysis with probabilistic ideas, paving the way to new mathematical theorems which may be fruitfully used in the treatment of the problem at hand. Moreover, the author proposes an efficient numerical method in the framework of Bayesian inversion for the practical solution of the stochastic inverse anomaly detection problem.   Contents Feynman-Kac formulae Stochastic homogenization Statistical inverse problems  Targe...

  6. Richard von Volkmann: surgeon and Renaissance man.

    Science.gov (United States)

    Willy, Christian; Schneider, Peter; Engelhardt, Michael; Hargens, Alan R; Mubarak, Scott J

    2008-02-01

    Richard von Volkmann (1830-1889), one of the most important surgeons of the 19(th) century, is regarded as one of the fathers of orthopaedic surgery. He was a contemporary of Langenbeck, Esmarch, Lister, Billroth, Kocher, and Trendelenburg. He was head of the Department of Surgery at the University of Halle, Germany (1867-1889). His popularity attracted doctors and patients from all over the world. He was the lead physician for the German military during two wars. From this experience, he compared the mortality of civilian and war injuries and investigated the general poor hygienic conditions in civilian hospitals. This led him to introduce the "antiseptic technique" to Germany that was developed by Lister. His powers of observation and creativity led him to findings and achievements that to this day bear his name: Volkmann's contracture and the Hueter-Volkmann law. Additionally, he was a gifted writer; he published not only scientific literature but also books of children's fairy tales and poems under the pen name of Richard Leander, assuring him a permanent place in the world of literature as well as orthopaedics.

  7. Complete algebraic reduction of one-loop tensor Feynman integrals

    International Nuclear Information System (INIS)

    Fleischer, J.; Riemann, T.

    2011-01-01

    We set up a new, flexible approach for the tensor reduction of one-loop Feynman integrals. The 5-point tensor integrals up to rank R=5 are expressed by 4-point tensor integrals of rank R-1, such that the appearance of the inverse 5-point Gram determinant is avoided. The 4-point tensor coefficients are represented in terms of 4-point integrals, defined in d dimensions, 4-2ε≤d≤4-2ε+2(R-1), with higher powers of the propagators. They can be further reduced to expressions which stay free of the inverse 4-point Gram determinants but contain higher-dimensional 4-point integrals with only the first power of scalar propagators, plus 3-point tensor coefficients. A direct evaluation of the higher-dimensional 4-point functions would avoid the appearance of inverse powers of the Gram determinants completely. The simplest approach, however, is to apply here dimensional recurrence relations in order to reduce them to the familiar 2- to 4-point functions in generic dimension d=4-2ε, introducing thereby coefficients with inverse 4-point Gram determinants up to power R for tensors of rank R. For small or vanishing Gram determinants--where this reduction is not applicable--we use analytic expansions in positive powers of the Gram determinants. Improving the convergence of the expansions substantially with Pade approximants we close up to the evaluation of the 4-point tensor coefficients for larger Gram determinants. Finally, some relations are discussed which may be useful for analytic simplifications of Feynman diagrams.

  8. The young centre of the Earth

    DEFF Research Database (Denmark)

    Uggerhoj, U. I.; Mikkelsen, R. E.; Faye, J.

    2016-01-01

    We treat, as an illustrative example of gravitational time dilation in relativity, the observation that the centre of the Earth is younger than the surface by an appreciable amount. Richard Feynman first made this insightful point and presented an estimate of the size of the effect in a talk...

  9. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Kathy Ceceri. Articles written in Resonance – Journal of Science Education. Volume 16 Issue 9 September 2011 pp 879-880 Personal Reflections. Five Things I Learned from Richard Feynman About Science Education · Kathy Ceceri · More Details Fulltext PDF ...

  10. Shifts of integration variable within four- and N-dimensional Feynman integrals

    International Nuclear Information System (INIS)

    Elias, V.; McKeon, G.; Mann, R.B.

    1983-01-01

    We resolve inconsistencies between integration in four dimensions, where shifts of integration variable may lead to surface terms, and dimensional regularization, where no surface terms accompany such shifts, by showing that surface terms arise only for discrete values of the dimension parameter. General formulas for variable-of-integration shifts within N-dimensional Feynman integrals are presented, and the VVA triangle anomaly is interpreted as a manifestation of surface terms occurring in exactly four dimensions

  11. Studies of particles statistics in one and two dimensions, based on the quantization methods of Heisenberg, Schroedinger and Feynman

    International Nuclear Information System (INIS)

    Myrheim, J.

    1993-06-01

    The thesis deals with the application of different methods to the quantization problem for system of identical particles in one and two dimensions. The standard method is the analytic quantization method due to Schroedinger, which leads to the concept of fractional statistics in one and two dimensions. Two-dimensional particles with fractional statistics are well known by the name of anyons. Two alternative quantization methods are shown by the author, the algebraic method of Heisenberg and the Feynman path integral method. The Feynman method is closely related to the Schroedinger method, whereas the Heisenberg and Schroedinger methods may give different results. The relation between the Heisenberg and Schroedinger methods is discussed. The Heisenberg method is applied to the equations of motion of vortices in superfluid helium, which have the form of Hamiltonian equations for a one-dimensional system. The same method is also discussed more generally for systems of identical particles in one and two dimensions. An application of the Feynman method to the problem of computing the equation of state for a gas of anyons is presented. 104 refs., 4 figs

  12. 75 FR 53730 - Culturally Significant Objects Imported for Exhibition Determinations: “Richard Hawkins-Third Mind”

    Science.gov (United States)

    2010-09-01

    ... DEPARTMENT OF STATE [Public Notice 7148] Culturally Significant Objects Imported for Exhibition Determinations: ``Richard Hawkins--Third Mind'' SUMMARY: Notice is hereby given of the following determinations... the exhibition ``Richard Hawkins--Third Mind,'' imported from abroad for temporary exhibition within...

  13. Appell functions and the scalar one-loop three-point integrals in Feynman diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Cabral-Rosetti, L G [Departamento de Posgrado, Centro Interdisciplinario de Investigacion y Docencia en Educacion Tecnica (CIIDET), Av. Universidad 282 Pte., Col. Centro, A. Postal 752, C.P. 76000, Santiago de Queretaro, Qro. (Mexico); Sanchis-Lozano, M A [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, 46100 Burjassot, Valencia (Spain)

    2006-05-15

    The scalar three-point function appearing in one-loop Feynman diagrams is compactly expressed in terms of a generalized hypergeometric function of two variables. Use is made of the connection between such Appell function and dilogarithms coming from a previous investigation. Special cases are obtained for particular values of internal masses and external momenta.

  14. Fluid flow in porous media using image-based modelling to parametrize Richards' equation.

    Science.gov (United States)

    Cooper, L J; Daly, K R; Hallett, P D; Naveed, M; Koebernick, N; Bengough, A G; George, T S; Roose, T

    2017-11-01

    The parameters in Richards' equation are usually calculated from experimentally measured values of the soil-water characteristic curve and saturated hydraulic conductivity. The complex pore structures that often occur in porous media complicate such parametrization due to hysteresis between wetting and drying and the effects of tortuosity. Rather than estimate the parameters in Richards' equation from these indirect measurements, image-based modelling is used to investigate the relationship between the pore structure and the parameters. A three-dimensional, X-ray computed tomography image stack of a soil sample with voxel resolution of 6 μm has been used to create a computational mesh. The Cahn-Hilliard-Stokes equations for two-fluid flow, in this case water and air, were applied to this mesh and solved using the finite-element method in COMSOL Multiphysics. The upscaled parameters in Richards' equation are then obtained via homogenization. The effect on the soil-water retention curve due to three different contact angles, 0°, 20° and 60°, was also investigated. The results show that the pore structure affects the properties of the flow on the large scale, and different contact angles can change the parameters for Richards' equation.

  15. A symbolic summation approach to Feynman integral calculus

    International Nuclear Information System (INIS)

    Bluemlein, Johannes; Klein, Sebastian

    2010-11-01

    Given a Feynman parameter integral, depending on a single discrete variable N and a real parameter ε, we discuss a new algorithmic framework to compute the first coefficients of its Laurent series expansion in ε. In a first step, the integrals are expressed by hypergeometric multi sums by means of symbolic transformations. Given this sum format, we develop new summation tools to extract the first coefficients of its series expansion whenever they are expressible in terms of indefinite nested product-sum expressions. In particular, we enhance the known multi-sum algorithms to derive recurrences for sums with complicated boundary conditions, and we present new algorithms to find formal Laurent series solutions of a given recurrence relation. (orig.)

  16. A symbolic summation approach to Feynman integral calculus

    Energy Technology Data Exchange (ETDEWEB)

    Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Klein, Sebastian [Technische Hochschule Aachen (Germany). Inst. fuer Theoretische Teilchenphysik und Kosmologie; Schneider, Carsten; Stan, Flavia [Johannes Kepler Univ. Linz (AT). Research Inst. for Symbolic Computation (RISC)

    2010-11-15

    Given a Feynman parameter integral, depending on a single discrete variable N and a real parameter {epsilon}, we discuss a new algorithmic framework to compute the first coefficients of its Laurent series expansion in {epsilon}. In a first step, the integrals are expressed by hypergeometric multi sums by means of symbolic transformations. Given this sum format, we develop new summation tools to extract the first coefficients of its series expansion whenever they are expressible in terms of indefinite nested product-sum expressions. In particular, we enhance the known multi-sum algorithms to derive recurrences for sums with complicated boundary conditions, and we present new algorithms to find formal Laurent series solutions of a given recurrence relation. (orig.)

  17. Fuchsia. A tool for reducing differential equations for Feynman master integral to epsilon form

    Energy Technology Data Exchange (ETDEWEB)

    Gituliar, Oleksandr [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Magerya, Vitaly

    2017-01-15

    We present Fuchsia - an implementation of the Lee algorithm, which for a given system of ordinary differential equations with rational coefficients ∂{sub x}f(x,ε)=A(x,ε)f(x,ε) finds a basis transformation T(x,ε), i.e., f(x,ε)=T(x,ε)g(x,ε), such that the system turns into the epsilon form: ∂{sub x}g(x,ε)=εS(x)g(x,ε), where S(x) is a Fuchsian matrix. A system of this form can be trivially solved in terms of polylogarithms as a Laurent series in the dimensional regulator ε. That makes the construction of the transformation T(x,ε) crucial for obtaining solutions of the initial system. In principle, Fuchsia can deal with any regular systems, however its primary task is to reduce differential equations for Feynman master integrals. It ensures that solutions contain only regular singularities due to the properties of Feynman integrals.

  18. Fuchsia. A tool for reducing differential equations for Feynman master integral to epsilon form

    International Nuclear Information System (INIS)

    Gituliar, Oleksandr; Magerya, Vitaly

    2017-01-01

    We present Fuchsia - an implementation of the Lee algorithm, which for a given system of ordinary differential equations with rational coefficients ∂ x f(x,ε)=A(x,ε)f(x,ε) finds a basis transformation T(x,ε), i.e., f(x,ε)=T(x,ε)g(x,ε), such that the system turns into the epsilon form: ∂ x g(x,ε)=εS(x)g(x,ε), where S(x) is a Fuchsian matrix. A system of this form can be trivially solved in terms of polylogarithms as a Laurent series in the dimensional regulator ε. That makes the construction of the transformation T(x,ε) crucial for obtaining solutions of the initial system. In principle, Fuchsia can deal with any regular systems, however its primary task is to reduce differential equations for Feynman master integrals. It ensures that solutions contain only regular singularities due to the properties of Feynman integrals.

  19. Analysis and evaluation of GAVE chains. Part 3 of 3. Appendices; Analyse en evaluatie van GAVE-ketens. Deel 3 van 3. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Bosma, W.J.P. [Arthur D. Little International, Rotterdam (Netherlands)

    1999-12-01

    The final report (part 2) contains the detailed findings of the analysis, evaluation, and integration of Novem GAVE options and aims at the reader who is interested in the detailed findings, as well as an overview of the results. For readers who are mainly interested in the high-level results, and are comfortable with Dutch, there is a short text summary of our results, entitled 'Analyse en evaluatie van GAVE-ketens, management summary' (part 1). These appendices is for readers who are interested in the underlying data and detailed assumptions. 70 refs.

  20. 76 FR 10936 - Culturally Significant Objects Imported for Exhibition Determinations: “Richard Serra Drawing: A...

    Science.gov (United States)

    2011-02-28

    ... DEPARTMENT OF STATE [Public Notice: 7348] Culturally Significant Objects Imported for Exhibition Determinations: ``Richard Serra Drawing: A Retrospective'' SUMMARY: Notice is hereby given of the following... objects to be included in the exhibition ``Richard Serra Drawing: A Retrospective,'' imported from abroad...

  1. Feynman variance-to-mean in the context of passive neutron coincidence counting

    Energy Technology Data Exchange (ETDEWEB)

    Croft, S., E-mail: scroft@lanl.gov [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545 (United States); Favalli, A.; Hauck, D.K.; Henzlova, D.; Santi, P.A. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545 (United States)

    2012-09-11

    Passive Neutron Coincidence Counting (PNCC) based on shift register autocorrelation time analysis of the detected neutron pulse train is an important Nondestructive Assay (NDA) method. It is used extensively in the quantification of plutonium and other spontaneously fissile materials for purposes of nuclear materials accountancy. In addition to the totals count rate, which is also referred to as the singles, gross or trigger rate, a quantity known as the reals coincidence rate, also called the pairs or doubles, is obtained from the difference between the measured neutron multiplicities in two measurement gates triggered by the incoming events on the pulse train. The reals rate is a measure of the number of time correlated pairs present on the pulse train and this can be related to the fission rates (and hence material mass) since fissions emit neutrons in bursts which are also detected in characteristic clusters. A closely related measurement objective is the determination of the reactivity of systems as they approach criticality. In this field an alternative autocorrelation signature is popular, the so called Feynman variance-to-mean technique which makes use of the multiplicity histogram formed the periodic, or clock-triggered opening of a coincidence gate. Workers in these two application areas share common challenges and improvement opportunities but are often separated by tradition, problem focus and technical language. The purpose of this paper is to recognize the close link between the Feynman variance-to-mean metric and traditional PNCC using shift register logic applied to correlated pulse trains. We, show using relationships for the late-gate (or accidentals) histogram recorded using a multiplicity shift register, how the Feynman Y-statistic, defined as the excess variance-to-mean ratio, can be expressed in terms of the singles and doubles rates familiar to the safeguards and waste assay communities. These two specialisms now have a direct bridge between

  2. Travelling wave solutions for the Richards equation incorporating non-equilibrium effects in the capillarity pressure

    NARCIS (Netherlands)

    van Duijn, C. J.; Mitra, K.; Pop, I. S.

    2018-01-01

    The Richards equation is a mathematical model for unsaturated flow through porous media. This paper considers an extension of the Richards equation, where non-equilibrium effects like hysteresis and dynamic capillarity are incorporated in the relationship that relates the water pressure and the

  3. Modern Summation Methods and the Computation of 2- and 3-loop Feynman Diagrams

    International Nuclear Information System (INIS)

    Ablinger, Jakob; Bluemlein, Johannes; Klein, Sebastian; Schneider, Carsten

    2010-01-01

    By symbolic summation methods based on difference fields we present a general strategy that transforms definite multi-sums, e.g., in terms of hypergeometric terms and harmonic sums, to indefinite nested sums and products. We succeeded in this task with all our concrete calculations of 2-loop and 3-loop massive single scale Feynman diagrams with local operator insertion.

  4. How oxygen gave rise to eukaryotic sex

    NARCIS (Netherlands)

    Hörandl, Elvira; Speijer, Dave

    2018-01-01

    9years ago. The large amount of ROS coming from a bacterial endosymbiont gave rise to DNA damage and vast increases in host genome mutation rates. Eukaryogenesis and chromosome evolution represent adaptations to oxidative stress. The host, an archaeon, most probably already had repair mechanisms

  5. 78 FR 43093 - Richard C. Theuer; Filing of Food Additive Petition and Citizen Petition

    Science.gov (United States)

    2013-07-19

    ... [Docket Nos. FDA-2013-F-0700 and FDA-2013-P-0472] Richard C. Theuer; Filing of Food Additive Petition and... proposing that the food additive regulations be amended to prohibit the use of carrageenan and salts of... that Richard C. Theuer, Ph.D., 7904 Sutterton Ct., Raleigh, NC 27615, has filed a food additive...

  6. An approach to the calculation of many-loop massless Feynman integrals

    International Nuclear Information System (INIS)

    Gorishnii, S.G.; Isaev, A.P.

    1985-01-01

    A generalization of the identity of dimensionless regular-zation is proposed. The generalization is used to divide the complete set of dimensionally (and analytically) regularized Feynman integrals with one external momentum into classes of equal integrals, and also for calculating some of them. A nontrivial symmetry of the propagator integrals is revealed, on the basis of which a complete system of functional equations for determining two-loop integrals is derived. Possible generalizations of these equations are discussed

  7. Improved parametrization of K+ production in p-Be collisions at low energy using Feynman scaling

    International Nuclear Information System (INIS)

    Mariani, C.; Cheng, G.; Shaevitz, M. H.; Conrad, J. M.

    2011-01-01

    This paper describes an improved parametrization for proton-beryllium production of secondary K + mesons for experiments with primary proton beams from 8.89 to 24 GeV/c. The parametrization is based on Feynman scaling in which the invariant cross section is described as a function of x F and p T . This method is theoretically motivated and provides a better description of the energy dependence of kaon production at low beam energies than other parametrizations such as the commonly used modified Sanford-Wang model. This Feynman scaling parametrization has been used for the simulation of the neutrino flux from the Booster Neutrino Beam at Fermilab and has been shown to agree with the neutrino interaction data from the SciBooNE experiment. This parametrization will also be useful for future neutrino experiments with low primary beam energies, such as those planned for the Project X accelerator.

  8. When Richard Branson wants to build his own facility; Quand Richard Branson veut construire son propre complexe

    Energy Technology Data Exchange (ETDEWEB)

    Cosnard, D

    2005-10-01

    The capacity of petroleum refineries is today insufficient to meet the demand. In front of this shortage, Sir Richard Branson, the owner of Virgin Atlantic Airways, has decided to invest in the building of a refinery in Europe or in Canada. His new company, Virgin Oil, is already launched. However, the setting up of a new facility is very expensive and raises important problems of permits and public contestation which remain to be solved. Short paper. (J.S.)

  9. Numerical Feynman integrals with physically inspired interpolation: Faster convergence and significant reduction of computational cost

    Directory of Open Access Journals (Sweden)

    Nikesh S. Dattani

    2012-03-01

    Full Text Available One of the most successful methods for calculating reduced density operator dynamics in open quantum systems, that can give numerically exact results, uses Feynman integrals. However, when simulating the dynamics for a given amount of time, the number of time steps that can realistically be used with this method is always limited, therefore one often obtains an approximation of the reduced density operator at a sparse grid of points in time. Instead of relying only on ad hoc interpolation methods (such as splines to estimate the system density operator in between these points, I propose a method that uses physical information to assist with this interpolation. This method is tested on a physically significant system, on which its use allows important qualitative features of the density operator dynamics to be captured with as little as two time steps in the Feynman integral. This method allows for an enormous reduction in the amount of memory and CPU time required for approximating density operator dynamics within a desired accuracy. Since this method does not change the way the Feynman integral itself is calculated, the value of the density operator approximation at the points in time used to discretize the Feynamn integral will be the same whether or not this method is used, but its approximation in between these points in time is considerably improved by this method. A list of ways in which this proposed method can be further improved is presented in the last section of the article.

  10. Reading 'blackface': A (narrative) introduction to Richard Kearney's ...

    African Journals Online (AJOL)

    Prominent Irish philosopher Richard Kearney's notion of 'carnal hermeneutics' is introduced by applying it to a case study of a recent event that took place at one of South Africa's university campuses. The narrative assists in illuminating some of the core principles of carnal hermeneutics and illustrates the applicability of ...

  11. H.E. Mr Richard J. Fredericks, Ambassador of the United States of America to Switzerland

    CERN Document Server

    Patrice Loïez

    2001-01-01

    Photo 01 : Prof. L. Maiani, CERN Director-General, gives a piece of LHC super conducting wire to H.E. Mr. Richard J. Fredericks; Photo 02 : Prof. L. Maiani, CERN Director-General, Mr. Jan van der Boon, CERN Director of Administration and H.E. Mr. J. Richard Fredericks

  12. Modern summation methods and the computation of 2- and 3-loop Feynman diagrams

    International Nuclear Information System (INIS)

    Ablinger, Jakob; Schneider, Carsten; Bluemlein, Johannes; Klein, Sebastian

    2010-06-01

    By symbolic summation methods based on difference fields we present a general strategy that transforms definite multi-sums, e.g., in terms of hypergeometric terms and harmonic sums, to indefinite nested sums and products. We succeeded in this task with all our concrete calculations of 2-loop and 3-loop massive single scale Feynman diagrams with local operator insertion. (orig.)

  13. Modern summation methods and the computation of 2- and 3-loop Feynman diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, Jakob; Schneider, Carsten [Linz Univ. (AT). Research Inst. for Symbolic Computation (RISC); Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Klein, Sebastian [RWTH Aachen (Germany). Inst. fuer Theoretische Teilchenphysik und Kosmologie

    2010-06-15

    By symbolic summation methods based on difference fields we present a general strategy that transforms definite multi-sums, e.g., in terms of hypergeometric terms and harmonic sums, to indefinite nested sums and products. We succeeded in this task with all our concrete calculations of 2-loop and 3-loop massive single scale Feynman diagrams with local operator insertion. (orig.)

  14. Nanotechnology: The Incredible Invisible World

    Science.gov (United States)

    Roberts, Amanda S.

    2011-01-01

    The concept of nanotechnology was first introduced in 1959 by Richard Feynman at a meeting of the American Physical Society. Nanotechnology opens the door to an exciting new science/technology/engineering field. The possibilities for the uses of this technology should inspire the imagination to think big. Many are already pursuing such feats…

  15. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 12. The Theory of Positrons. Richard P Feynman. Classics Volume 2 Issue 12 December 1997 pp 107-107. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/002/12/0107-0107. Author Affiliations.

  16. Feynman diagrams sampling for quantum field theories on the QPACE 2 supercomputer

    Energy Technology Data Exchange (ETDEWEB)

    Rappl, Florian

    2016-08-01

    This work discusses the application of Feynman diagram sampling in quantum field theories. The method uses a computer simulation to sample the diagrammatic space obtained in a series expansion. For running large physical simulations powerful computers are obligatory, effectively splitting the thesis in two parts. The first part deals with the method of Feynman diagram sampling. Here the theoretical background of the method itself is discussed. Additionally, important statistical concepts and the theory of the strong force, quantum chromodynamics, are introduced. This sets the context of the simulations. We create and evaluate a variety of models to estimate the applicability of diagrammatic methods. The method is then applied to sample the perturbative expansion of the vertex correction. In the end we obtain the value for the anomalous magnetic moment of the electron. The second part looks at the QPACE 2 supercomputer. This includes a short introduction to supercomputers in general, as well as a closer look at the architecture and the cooling system of QPACE 2. Guiding benchmarks of the InfiniBand network are presented. At the core of this part, a collection of best practices and useful programming concepts are outlined, which enables the development of efficient, yet easily portable, applications for the QPACE 2 system.

  17. A Staged Reading of the Play: Moving Bodies

    Science.gov (United States)

    Schwartz, Brian

    Moving Bodies is about Nobel Prize-winning physicist Richard Feynman as he explores nature, science, sex, anti-Semitism, and the world around him. This epic, comic journey portrays Feynman as an iconoclastic young man, a physicist with the Manhattan Project and confronting the mystery of the Challenger disaster. The Atomic Bomb is central to the play, but it is also very much about human loves and losses. We learn about his (Feynman's) eccentricities: his bongo playing, his penchant for picking locks, and most notably his appreciation for women. Through playwright Arthur Giron's eyes, we see how Feynman became one of the most important scientists of our time. The playwright, Arthur Giron, is the co-playwright of the recent 2015 Broadway Musical, Amazing Grace. The staged reading is performed by the Southern Rep Theatre. http://www.southernrep.com/ The play director and actors as well as a historian-scientist who knew Feynman will be available for a talk-back discussion after the play reading. Produced by Brian Schwartz, CUNY and Gregory Mack, APS. Sponsored by: The Forum on the History of Physics, The Forum on Outreach and Engaging the Public and The Forum on Physics and Society.

  18. Success: Richard Dyer on Diana Ross [and Beyond

    NARCIS (Netherlands)

    Kooijman, J.

    2016-01-01

    In June 1982, film scholar Richard Dyer published a two-page essay on African-American star Diana Ross in the journal Marxism Today. Part of Dyer’s essay focuses on the American conception of success and specifically on how Ross is one of the few black artists who has been "allowed" to be such a

  19. Feynman rules for the Standard Model Effective Field Theory in R ξ -gauges

    Science.gov (United States)

    Dedes, A.; Materkowska, W.; Paraskevas, M.; Rosiek, J.; Suxho, K.

    2017-06-01

    We assume that New Physics effects are parametrized within the Standard Model Effective Field Theory (SMEFT) written in a complete basis of gauge invariant operators up to dimension 6, commonly referred to as "Warsaw basis". We discuss all steps necessary to obtain a consistent transition to the spontaneously broken theory and several other important aspects, including the BRST-invariance of the SMEFT action for linear R ξ -gauges. The final theory is expressed in a basis characterized by SM-like propagators for all physical and unphysical fields. The effect of the non-renormalizable operators appears explicitly in triple or higher multiplicity vertices. In this mass basis we derive the complete set of Feynman rules, without resorting to any simplifying assumptions such as baryon-, lepton-number or CP conservation. As it turns out, for most SMEFT vertices the expressions are reasonably short, with a noticeable exception of those involving 4, 5 and 6 gluons. We have also supplemented our set of Feynman rules, given in an appendix here, with a publicly available Mathematica code working with the FeynRules package and producing output which can be integrated with other symbolic algebra or numerical codes for automatic SMEFT amplitude calculations.

  20. Feynman graph derivation of Einstein quadrupole formula

    International Nuclear Information System (INIS)

    Dass, N.D.H.; Soni, V.

    1980-11-01

    The one graviton transition operator, and consequently, the classical energy loss formula for gravitational radiation are derived from the Feynman graphs of helicity +- 2 theories of gravitation. The calculations are done both for the case of electromagnetic and gravitational scattering. The departure of the in and out states from plane waves owing to the long range nature of gravitation is taken into account to improve the Born approximation calculations. This also includes a long range modification of the graviton wave function which is shown to be equivalent to the classical problem of the true light cones deviating logarithmically at large distances from the flat space light cones. The transition from the S-matrix elements calculated graphically to the graviton transition operator is done by using complimentarity of space-time and momentum descriptions. The energy loss formula derived originally by Einstein is shown to be correct. (Auth.)

  1. Feynman quasi probability distribution for spin-(1/2), and its generalizations

    International Nuclear Information System (INIS)

    Colucci, M.

    1999-01-01

    It has been examined the Feynman's paper Negative probability, in which, after a discussion about the possibility of attributing a real physical meaning to quasi probability distributions, he introduces a new kind of distribution for spin-(1/2), with a possible method of generalization to systems with arbitrary number of states. The principal aim of this article is to shed light upon the method of construction of these distributions, taking into consideration their application to some experiments, and discussing their positive and negative aspects

  2. Advanced Thin Layer Deposition of Materials for Li-ion Batteries via Electrospray

    NARCIS (Netherlands)

    Garcia-Tamayo, E.

    2014-01-01

    The remarkable physicist Richard P. Feynman once said, more than fifty years ago: ”the principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but

  3. Analysis and evaluation of GAVE chains. Part 2 of 3. Final report (sheets presentation); Analyse en evaluatie van GAVE-ketens. Deel 2 van 3. Final report (sheetpresentation)

    Energy Technology Data Exchange (ETDEWEB)

    Bosma, W.J.P. [Arthur D. Little International, Rotterdam (Netherlands)

    1999-12-01

    This report contains the detailed findings of the analysis, evaluation, and integration of Novem GAVE options. This main report is meant for the reader who is interested in the detailed findings, as well as an overview of the results. For readers who are mainly interested in the high-level results, and are comfortable with Dutch, there is a short text summary of our results, entitled 'Analyse en evaluatie van GAVE-ketens, management summary' (part 1). Readers who are interested in the underlying data and detailed assumptions are encouraged to consult the appendix to this report, entitled 'Analyse en evaluatie van GAVE-ketens, appendices' (part 3)

  4. Some remarks on Feynman rules for non-commutative gauge theories based on groups G≠U(N)

    International Nuclear Information System (INIS)

    Dorn, Harald; Sieg, Christoph

    2002-01-01

    We study for subgroups G is a subset of U(N) partial summations of the θ-expanded perturbation theory. On diagrammatic level a summation procedure is established, which in the U(N) case delivers the full star-product induced rules. Thereby we uncover a cancellation mechanism between certain diagrams, which is crucial in the U(N) case, but set out of work for G is a subset of U(N). In addition, an explicit proof is given that for G is a subset of U(N), G≠U(M), M< N there is no partial summation of the θ-expanded rules resulting in new Feynman rules using the U(N) star-product vertices and besides suitable modified propagators at most a finite number of additional building blocks. Finally, we show that certain SO(N) Feynman rules conjectured in the literature cannot be derived from the enveloping algebra approach. (author)

  5. An appreciation of Richard Threlkeld Cox

    Science.gov (United States)

    Tribus, Myron

    2002-05-01

    Richard T. Cox's contributions to the foundations of probability theory and inductive logic are not generally appreciated or understood. This paper reviews his life and accomplishments, especially those in his book The Algebra of Probable Inference and his final publication Inference and Inquiry which, in this author's opinion, has the potential to influence in a significant way the design and analysis of self organizing systems which learn from experience. A simple application to the simulation of a neuron is presented as an example of the power of Cox's contribution.

  6. Infrared finite ghost propagator in the Feynman gauge

    International Nuclear Information System (INIS)

    Aguilar, A. C.; Papavassiliou, J.

    2008-01-01

    We demonstrate how to obtain from the Schwinger-Dyson equations of QCD an infrared finite ghost propagator in the Feynman gauge. The key ingredient in this construction is the longitudinal form factor of the nonperturbative gluon-ghost vertex, which, contrary to what happens in the Landau gauge, contributes nontrivially to the gap equation of the ghost. The detailed study of the corresponding vertex equation reveals that in the presence of a dynamical infrared cutoff this form factor remains finite in the limit of vanishing ghost momentum. This, in turn, allows the ghost self-energy to reach a finite value in the infrared, without having to assume any additional properties for the gluon-ghost vertex, such as the presence of massless poles. The implications of this result and possible future directions are briefly outlined

  7. Calculations in the Wheeler-Feynman absorber theory of radiation

    International Nuclear Information System (INIS)

    Balaji, K.S.

    1986-01-01

    One dimensional computer aided calculations were done to find the self consistent solutions for various absorber configurations in the context of the Wheeler-Feynman absorber theory, wherein every accelerating charge is assumed to produce a time symmetric combination of advanced and retarded fields. These calculations picked out the so called outerface solution for incomplete absorbers and showed that advanced as well as retarded signals interact with matter in the same manner as in the full retarded theory. Based on these calculations, the Partridge experiment and the Schmidt-Newman experiment were ruled out as tests of the absorber theory. An experiment designed to produce and detect advanced effects is proposed, based on more one-dimensional calculations

  8. Mellin-Barnes meets Method of Brackets: a novel approach to Mellin-Barnes representations of Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Prausa, Mario [RWTH Aachen University, Institute for Theoretical Particle Physics and Cosmology, Aachen (Germany)

    2017-09-15

    In this paper, we present a new approach to the construction of Mellin-Barnes representations for Feynman integrals inspired by the Method of Brackets. The novel technique is helpful to lower the dimensionality of Mellin-Barnes representations in complicated cases, some examples are given. (orig.)

  9. Planck's Constant as a Natural Unit of Measurement

    Science.gov (United States)

    Quincey, Paul

    2013-01-01

    The proposed revision of SI units would embed Planck's constant into the definition of the kilogram, as a fixed constant of nature. Traditionally, Planck's constant is not readily interpreted as the size of something physical, and it is generally only encountered by students in the mathematics of quantum physics. Richard Feynman's…

  10. Die grossen Physiker und ihre Entdeckungen von den fallenden Körpern zu den Quarks

    CERN Document Server

    Segrè, Emilio

    1998-01-01

    Von Galileo Galilei bis zu Richard Feynman und Murray Gell-Mann - von den fallenden Körpern zu den Quarks: Der Physiknobelpreisträger Emilio Segre hat seine ganz persönliche Geschichte der Physik geschrieben. Er erzählt von den großen Gestalten und deren wichtigen Entdeckungen mit großer Anschaulichkeit und Lebendigkeit.

  11. Modified Feynman ratchet with velocity-dependent fluctuations

    Directory of Open Access Journals (Sweden)

    Jack Denur

    2004-03-01

    Full Text Available Abstract: The randomness of Brownian motion at thermodynamic equilibrium can be spontaneously broken by velocity-dependence of fluctuations, i.e., by dependence of values or probability distributions of fluctuating properties on Brownian-motional velocity. Such randomness-breaking can spontaneously obtain via interaction between Brownian-motional Doppler effects --- which manifest the required velocity-dependence --- and system geometrical asymmetry. A non random walk is thereby spontaneously superposed on Brownian motion, resulting in a systematic net drift velocity despite thermodynamic equilibrium. The time evolution of this systematic net drift velocity --- and of velocity probability density, force, and power output --- is derived for a velocity-dependent modification of Feynman's ratchet. We show that said spontaneous randomness-breaking, and consequent systematic net drift velocity, imply: bias from the Maxwellian of the system's velocity probability density, the force that tends to accelerate it, and its power output. Maximization, especially of power output, is discussed. Uncompensated decreases in total entropy, challenging the second law of thermodynamics, are thereby implied.

  12. Richard H. Thaler: Wirtschaftsnobelpreisträger 2017

    OpenAIRE

    Bruttel, Lisa Verena; Stolley, Florian

    2017-01-01

    Der diesjährige Nobelpreisträger Richard H. Thaler ist einer breiteren Öffentlichkeit vor allem durch sein mit Cass R. Sunstein gemeinsam verfasstes Buch zum Nudging bekannt geworden. Tatsächlich hat er in den vergangenen 40 Jahren die Entwicklung der Verhaltensökonomie entscheidend mitgeprägt und vorangebracht. Thaler hat die Annahmen hinter dem Modell des Homo oeconomicus untersucht und die Abweichungen menschlichen Verhaltens von den Rationalitätsannahmen auf zwei wesentliche Ursachen zurü...

  13. Non-negative Feynman endash Kac kernels in Schroedinger close-quote s interpolation problem

    International Nuclear Information System (INIS)

    Blanchard, P.; Garbaczewski, P.; Olkiewicz, R.

    1997-01-01

    The local formulations of the Markovian interpolating dynamics, which is constrained by the prescribed input-output statistics data, usually utilize strictly positive Feynman endash Kac kernels. This implies that the related Markov diffusion processes admit vanishing probability densities only at the boundaries of the spatial volume confining the process. We discuss an extension of the framework to encompass singular potentials and associated non-negative Feynman endash Kac-type kernels. It allows us to deal with a class of continuous interpolations admitted by general non-negative solutions of the Schroedinger boundary data problem. The resulting nonstationary stochastic processes are capable of both developing and destroying nodes (zeros) of probability densities in the course of their evolution, also away from the spatial boundaries. This observation conforms with the general mathematical theory (due to M. Nagasawa and R. Aebi) that is based on the notion of multiplicative functionals, extending in turn the well known Doob close-quote s h-transformation technique. In view of emphasizing the role of the theory of non-negative solutions of parabolic partial differential equations and the link with open-quotes Wiener exclusionclose quotes techniques used to evaluate certain Wiener functionals, we give an alternative insight into the issue, that opens a transparent route towards applications.copyright 1997 American Institute of Physics

  14. Technical realization of a closure concept for a chamber-system in the underground Richard repository in the Czech Republic

    International Nuclear Information System (INIS)

    Kucerka, Miroslav

    2006-01-01

    The Phare project CZ 632.02.04 'Realization of closure of a chamber in the Richard repository as input for establishing a safety case' is a follow up implementation phase of the Phare project, CZ 01.14.03 'Solution for closure of a chamber in the Richard repository'. Main objective of both projects is to propose and realize a disposal system in selected chambers of the Richard repository, which will eliminate burden from the past practices in waste management during the first phase of the Richard repository operation (1965 - 1980) and which will improve its overall long term safety. This objective will be assured by realization of the concept of so called 'hydraulic cage', which technical solution was developed by DBE Technology within the Phare project CZ 01.14.03. The solution is described in the previous presentation 'Hydraulic Cage Concept for Waste Chambers and its Technical Implementation for the Underground Richard Repository, Litomerice, Czech Republic'. (author)

  15. Equivalence between the Arquès-Walsh sequence formula and the number of connected Feynman diagrams for every perturbation order in the fermionic many-body problem

    Science.gov (United States)

    Castro, E.

    2018-02-01

    From the perturbative expansion of the exact Green function, an exact counting formula is derived to determine the number of different types of connected Feynman diagrams. This formula coincides with the Arquès-Walsh sequence formula in the rooted map theory, supporting the topological connection between Feynman diagrams and rooted maps. A classificatory summing-terms approach is used, in connection to discrete mathematical theory.

  16. Illustrated & Dissected: Professor Richard Sawdon Smith.

    Science.gov (United States)

    2015-06-01

    This Alternative Gallery feature introduces the photographic artist Professor Richard Sawdon Smith. Professor Sawdon Smith's work stems around a fascination with representations of anatomy that have been fuelled by his experience as a hospital patient. The work has allowed him to explore ideas through the use of medical illustrations which include early anatomical drawings, personal medical photography and facial modelling. The work highlights how such imagery can be used in the context of a patient seeking understanding and acceptance of ill health and disease using the body as a canvas on which to translate the experience.

  17. Richard Bright and his neurological studies.

    Science.gov (United States)

    Pearce, J M S

    2009-01-01

    Richard Bright was one of the famous triumvirate of Guy's Hospital physicians in the Victorian era. Remembered for his account of glomerulonephritis (Bright's disease) he also made many important and original contributions to medicine and neurology. These included his work on cortical epileptogenesis, descriptions of simple partial (Jacksonian) seizures, infantile convulsions, and a variety of nervous diseases. Most notable were his reports of neurological studies including papers on traumatic tetanus, syringomyelia, arteries of the brain, contractures of spinal origin, tumours of the base of the brain, and narcolepsy. His career and these contributions are outlined. Copyright 2009 S. Karger AG, Basel.

  18. Polygonal-path approximation on the path spaces of quantum mechanical systems: extended Feynman maps

    International Nuclear Information System (INIS)

    Exner, R.; Kolerov, G.I.

    1981-01-01

    Various types of polygonal-path approximations appearing in the functional-integration theory are discussed. The uniform approximation is applied to extend the definition of the Feynman maps from our previous paper and to prove consistency of this extension. Relations of the extended Fsub(-i)-map to the Wiener integral are given. In particular, the basic theorem about the sequential Wiener integral by Cameron is improved [ru

  19. Integral Hellmann--Feynman analysis of nonisoelectronic processes and the determination of local ionization potentials

    International Nuclear Information System (INIS)

    Simons, G.

    1975-01-01

    The integral Hellmann--Feynmann theorem is extended to apply to nonisoelectronic processes. A local ionization potential formula is proposed, and test calculations on three different approximate helium wavefunctions are reported which suggest that it may be numerically superior to the standard difference of expectation values. Arguments for the physical utility of the new concept are presented, and an integral Hellmann--Feynman analysis of transition energies is begun

  20. Optimized negative dimensional integration method (NDIM) and multiloop Feynman diagram calculation

    International Nuclear Information System (INIS)

    Gonzalez, Ivan; Schmidt, Ivan

    2007-01-01

    We present an improved form of the integration technique known as NDIM (negative dimensional integration method), which is a powerful tool in the analytical evaluation of Feynman diagrams. Using this technique we study a φ 3 +φ 4 theory in D=4-2ε dimensions, considering generic topologies of L loops and E independent external momenta, and where the propagator powers are arbitrary. The method transforms the Schwinger parametric integral associated to the diagram into a multiple series expansion, whose main characteristic is that the argument contains several Kronecker deltas which appear naturally in the application of the method, and which we call diagram presolution. The optimization we present here consists in a procedure that minimizes the series multiplicity, through appropriate factorizations in the multinomials that appear in the parametric integral, and which maximizes the number of Kronecker deltas that are generated in the process. The solutions are presented in terms of generalized hypergeometric functions, obtained once the Kronecker deltas have been used in the series. Although the technique is general, we apply it to cases in which there are 2 or 3 different energy scales (masses or kinematic variables associated to the external momenta), obtaining solutions in terms of a finite sum of generalized hypergeometric series 1 and 2 variables respectively, each of them expressible as ratios between the different energy scales that characterize the topology. The main result is a method capable of solving Feynman integrals, expressing the solutions as hypergeometric series of multiplicity (n-1), where n is the number of energy scales present in the diagram

  1. Fuchsia : A tool for reducing differential equations for Feynman master integrals to epsilon form

    Science.gov (United States)

    Gituliar, Oleksandr; Magerya, Vitaly

    2017-10-01

    We present Fuchsia - an implementation of the Lee algorithm, which for a given system of ordinary differential equations with rational coefficients ∂x J(x , ɛ) = A(x , ɛ) J(x , ɛ) finds a basis transformation T(x , ɛ) , i.e., J(x , ɛ) = T(x , ɛ) J‧(x , ɛ) , such that the system turns into the epsilon form : ∂xJ‧(x , ɛ) = ɛ S(x) J‧(x , ɛ) , where S(x) is a Fuchsian matrix. A system of this form can be trivially solved in terms of polylogarithms as a Laurent series in the dimensional regulator ɛ. That makes the construction of the transformation T(x , ɛ) crucial for obtaining solutions of the initial system. In principle, Fuchsia can deal with any regular systems, however its primary task is to reduce differential equations for Feynman master integrals. It ensures that solutions contain only regular singularities due to the properties of Feynman integrals. Program Files doi:http://dx.doi.org/10.17632/zj6zn9vfkh.1 Licensing provisions: MIT Programming language:Python 2.7 Nature of problem: Feynman master integrals may be calculated from solutions of a linear system of differential equations with rational coefficients. Such a system can be easily solved as an ɛ-series when its epsilon form is known. Hence, a tool which is able to find the epsilon form transformations can be used to evaluate Feynman master integrals. Solution method: The solution method is based on the Lee algorithm (Lee, 2015) which consists of three main steps: fuchsification, normalization, and factorization. During the fuchsification step a given system of differential equations is transformed into the Fuchsian form with the help of the Moser method (Moser, 1959). Next, during the normalization step the system is transformed to the form where eigenvalues of all residues are proportional to the dimensional regulator ɛ. Finally, the system is factorized to the epsilon form by finding an unknown transformation which satisfies a system of linear equations. Additional comments

  2. Feynman-Hellmann theorem for resonances and the quest for QCD exotica

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz de Elvira, J. [University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland); Meissner, U.G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen-und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Juelich Center for Hadron Physics and JARA-HPC, Forschungszentrum Juelich, Institute for Advanced Simulation (IAS-4), Institut fuer Kernphysik (IKP-3), Juelich (Germany); Rusetsky, A. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen-und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Schierholz, G. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany)

    2017-10-15

    The generalization of the Feynman-Hellmann theorem for resonance states in quantum field theory is derived. On the basis of this theorem, a criterion is proposed to study the possible exotic nature of certain hadronic states emerging in QCD. It is shown that this proposal is supported by explicit calculations in chiral perturbation theory and by large-N{sub c} arguments. Analyzing recent lattice data on the quark mass dependence in the pseudoscalar, vector meson, baryon octet and baryon decuplet sectors, we conclude that, as expected, these are predominately quark-model states, albeit the corrections are non-negligible. (orig.)

  3. Theoretical confirmation of Feynman's hypothesis on the creation of circular vortices in Bose-Einstein condensates: II

    Energy Technology Data Exchange (ETDEWEB)

    Senatorski, A; Infeld, E [Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland)

    2004-09-15

    In a recent paper (Infeld and Senatorski 2003 J. Phys.: Condens. Matter 15 5865) we confirmed Feynman's hypothesis on how circular vortices can be created from an oppositely polarized linear pair in a Bose-Einstein condensate. This was done by perturbing the original pair numerically, so that a circular vortex (or array of identical circular vortices) was created as a result of reconnection. These circular vortices were then checked against known theoretical relations binding velocities and radii. Agreement to a high degree of accuracy was found. Here in part II, we give examples of the creation of several different vortices from one linear pair. All are checked as above. We also confirm the limit of separation of the line vortices below which mutual attraction, followed by annihilation, prevents the Feynman metamorphosis. Other possible modes of behaviour are illustrated.

  4. Quasi-constitutional change without intent : A response to Richard Albert

    NARCIS (Netherlands)

    Passchier, Reijer

    2017-01-01

    Recently, Buffalo Law Review published Richard Albert’s article on “quasi-constitutional amendments.” These are, in Albert’s words, “sub-constitutional changes that do not possess the same legal status as a constitutional amendment, that are formally susceptible to statutory repeal or revision, but

  5. Koht, kust tagasi ei tulda / Mark Jenkins ; fotod Cory Richards

    Index Scriptorium Estoniae

    Jenkins, Mark

    2015-01-01

    National Geographicu ekspeditsiooni, mille koosseisu kuulusid Renan Ozturk, Mark Jenkins, Cory Richards, Emily Harrington ja Kilaree O'Neill, püüdlustest tõusta Kagu-Aasia kõrgeima mäe Hkakabo Razi tippu ning mõõta selle täpset kõrgust GPS-i abil

  6. Wooing-Scenes in “Richard III”: A Parody of Courtliness?

    Directory of Open Access Journals (Sweden)

    Agnieszka Stępkowska

    2009-11-01

    Full Text Available In the famous opening soliloquy of Shakespeare’s Richard III, Richard mightily voices his repugnance to “fair well-spoken days” and their “idle pleasures”. He realizes his physical deformity and believes that it sets him apart from others. He openly admits that he is “not shaped for sportive tricks, nor made to court an amorous looking-glass”. Yet, his monstrosity constitutes more perhaps of his aggressive masculine exceptionality rather than of his deformity. Richard’s bullying masculinity manifests itself in his contempt for women. In the wooing scenes we clearly see his pugnacious pursuit of power over effeminate contentment by reducing women to mere objects. Additionally, those scenes are interesting from a psychological viewpoint as they brim over with conflicting emotions. Therefore, the paper explores two wooing encounters of the play, which belong the best examples of effective persuasion and also something we may refer to as ‘the power of eloquence’.

  7. Analysis and evaluation of GAVE chains. Part 1 of 3. Management summary; Analyse en evaluatie van GAVE-ketens. Deel 1 van 3. Management summary

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, E.J.M.T.

    1999-12-01

    This main report contains a summary of the detailed findings of the analysis, evaluation, and integration of Novem GAVE options. The details are presented in the final report (part 2) in the form of copies of overhead sheets. That report aims at the reader who is interested in the detailed findings, as well as an overview of the results. For readers who are mainly interested in the high-level results, and are comfortable with Dutch, there is this short text summary of our results. Readers who are interested in the underlying data and detailed assumptions are encouraged to consult the appendix to this report, entitled 'Analyse en evaluatie van GAVE-ketens, appendices' (part 3)

  8. Richard Kelly: Pioneirismo na iluminação da arquitetura moderna

    Directory of Open Access Journals (Sweden)

    Fernanda Brito Bandeira

    2018-04-01

    Full Text Available Livros resenhado: NEUMANN, Dietrich; STERN, Robert A. M. The structure of light: Richard Kelly and the illumination of modern architecture. New York: Yale University Press, 2010, 214 p. ISBN: 978-0-300-16370-4

  9. Richard Rorty's Conception of Philosophy of Education Revisited

    Science.gov (United States)

    Noaparast, Khosrow Bagheri

    2014-01-01

    In this essay Khosrow Bagheri Noaparast argues that, by focusing on acculturation and edification, Richard Rorty has provided a promising view for education because without acculturation, education turns into a destructive endeavor, and without edification, education risks the danger of being repetitive and reproductive. However, Rorty's view…

  10. The Paradox of the Public Realm in Richard Rorty

    Directory of Open Access Journals (Sweden)

    Martha Palacio Avendaño

    2008-12-01

    Full Text Available The concepto of the public sphere in Richard Rorty's philosophy, inherited of liberal tradition, allows be treated as a part of a game of language called democratic liberalism. One of the rules for validating a move in this game consists in taking for granted the distinction between the public and the private spheres. Richard Rorty thought that democratic liberalism did not need any foundation beyond the way to play it; its only criteria would be the game's practices, according an utopia which would allow us to make more movements in the game. That is, democratic liberalism does not require foundations, but just practices for achieving a social hioe inspired on freedom and pluralism. This kind of utopia, based upon the non-cruelty principle, would make possible an inclusive society where everyone would have a place for their own private vocabulary. In this way, Rorty would have linked freedom and solidarity. However, this language-game reveals the paradox of the link which implies the meaning of the public shere. Herein, freedom is not a sufficient condition of solidarity; hence, there is no place for social inclusion in Rorty's language game.

  11. Has Richard Rorty a moral philosophy?

    Directory of Open Access Journals (Sweden)

    Mohammad Asghari

    2015-06-01

    Full Text Available I try to show that Richard Rorty, although is not a moral philosopher like Kant, nerveless, has moral philosophy that must be taken seriously. Rorty was not engaged with moral philosophy in the systematic manner common among leading modern and contemporary moral philosophers. This paper has two parts: first part, in brief, is concerned with principles of his philosophy such as anti-essentialism, Darwinism, Freudism, and historicism. Second part which be long and detailed, considers many moral themes in Rorty's thought such as critique of Kantian morality, solidarity, moral progress, cruelty and concept of other, etc. Subsequently, I will try to answer the research question of the article namely, has Rorty a moral philosophy?

  12. Whatever Happened to Richard Reid's List of First Programming Languages?

    Science.gov (United States)

    Siegfried, Robert M.; Greco, Daniel M.; Miceli, Nicholas G.; Siegfried, Jason P.

    2012-01-01

    Throughout the 1990s, Richard Reid of Michigan State University maintained a list showing the first programming language used in introductory programming courses taken by computer science and information systems majors; it was updated for several years afterwards by Frances Van Scoy of West Virginia University. However, it has been 5 years since…

  13. Richard Wright, Toni Morrison, and United States book clubs

    Directory of Open Access Journals (Sweden)

    Mark Madigan

    2004-12-01

    Full Text Available This essay focuses on the influence of commercial book clubs in the United States. It will examine the country's oldest commercial book club, the Book-of-the-Month Club (BOMC, Oprah's Book Club (OBC, which bears the name of its founder, television personality Oprah Winfrey, and their roles in the careers of two African-American authors, Richard Wright and Toni Morrison.

  14. Self-consistence equations for extended Feynman rules in quantum chromodynamics

    International Nuclear Information System (INIS)

    Wielenberg, A.

    2005-01-01

    In this thesis improved solutions for Green's functions are obtained. First the for this thesis essential techniques and concepts of QCD as euclidean field theory are presented. After a discussion of the foundations of the extended approach for the Feynman rules of QCD with a systematic approach for the 4-gluon vertex a modified renormalization scheme for the extended approach is developed. Thereafter the resummation of the Dyson-Schwinger equations (DSE) by the appropriately modified Bethe-Salpeter equation is discussed. Then the leading divergences for the 1-loop graphs of the resummed DSE are determined. Thereafter the equation-of-motion condensate is defined as result of an operator-product expansion. Then the self-consistency equations for the extended approaches are defined and numerically solved. (HSI)

  15. Argument from Design in Richard Baxter's Natural Theology

    Directory of Open Access Journals (Sweden)

    Igor Koshelev

    2017-12-01

    Full Text Available The article deals with the teleological argument, or argument from design, as expounded by a famous English Protestant theologian Richard Baxter, one of the leading 17-th century English Puritans, in his work “The Reasons of the Christian Religion”. Natural theology, providing arguments for the existence of God based on reason and without appeal to the Revelation, has always played a vital role throughout the entire history of theological thought. The most popular was the so called teleological argument, or the argument from design, which stands out among all rational arguments for the existence of the Creator. It is mostly known from the “Fifth Way” of the medieval Scholastic philosopher Thomas Aquinas and a famous work “Natural Theology” by an English 19-th century theologian William Paley. The foundation for the modern research in the area was laid during the age of the Scientific Revolution of the 17th century English nature philosophers and theologians, especially Robert Boyle, who believed the teleological argument to be the key element of Natural Theology. His friend and confessor, Richard Baxter, a prominent representative of the Puritan Natural Theology, mostly known by his theological works, paved the way for Natural Theology both in his own time and the following centuries. His work was thought to be the best collection of the evidences for Christianity.

  16. Tight connexion between the Einstein-Podolsky-Rosen non-separability and the non-locality in Feynman's theory of antiparticles

    International Nuclear Information System (INIS)

    Costa de Beauregard, Olivier

    1976-01-01

    The Feynman amplitude for the annihilation transition of an electron-positon pair contains the two polarization correlations of the photons respectively characterizing the 0-1-0 and 1-1-0 cascades. The overall system is in general neither P- nor C-, but is PC-invariant [fr

  17. Departure from the world formula. The new invention of physics

    International Nuclear Information System (INIS)

    Laughlin, Robert B.

    2009-01-01

    Robert B. Laughlin, the most brilliant physicist since Richard Feynman, explains the new theory of emergence: Why all, what we know about physics, must be newly thought and why the greatest physical mysteries ly not at the end of the univers, but in an ice cube ore a salt grain. The Nobel-price carrier draws a clear picture of that, which physics will be in the future

  18. Properties of the Feynman-alpha method applied to accelerator-driven subcritical systems.

    Science.gov (United States)

    Taczanowski, S; Domanska, G; Kopec, M; Janczyszyn, J

    2005-01-01

    A Monte Carlo study of the Feynman-method with a simple code simulating the multiplication chain, confined to pertinent time-dependent phenomena has been done. The significance of its key parameters (detector efficiency and dead time, k-source and spallation neutrons multiplicities, required number of fissions etc.) has been discussed. It has been demonstrated that this method can be insensitive to properties of the zones surrounding the core, whereas is strongly affected by the detector dead time. In turn, the influence of harmonics in the neutron field and of the dispersion of spallation neutrons has proven much less pronounced.

  19. Response to Richard Widdess: Music, Meaning and Culture

    Directory of Open Access Journals (Sweden)

    Jerome Lewis

    2012-09-01

    Full Text Available This commentary discusses the anthropological implications of Richard Widess’ paper by summarizing some anthropological approaches to music, especially focusing on the way musical participation inculcates and transmits an aesthetic orientation that guides action across cultural domains such as politics, economics and religion. The paper ends by suggesting that the heart of human culture is more likely to be an aesthetic orientation than a script or set of rules, and traces out some reasons why music does this so well.

  20. GAVE multi-actor process. A exemplified study with recommendations for a follow-up traject; GAVE multi-actor proces. Een voorbeeldstudie met aanbevelingen voor het vervolgtraject

    Energy Technology Data Exchange (ETDEWEB)

    Diepenmaat, H.B. [Actors Procesmanagement, Zeist (Netherlands)

    2000-02-01

    The focus is on GAVE as an integral multi-actor process, as a collaboration process in which the parties have to find each other. The reason for this multi-actor approach is that the parties themselves have to realise the importance of sustainable energy. A multi-actor approach uses this crucial fact as the starting point. By means of the use of specific multi-actor methods and insights, it is possible during the collaboration process to develop a clear idea of the content of the joint path and the intended collaborative future, while paying specific attention to the individual roles of the players. Based on this, a well- considered and promising realisation path can be followed. The objective of this study is to illustrate - on the basis of two GAVE options - how the multi-actor approach can support the GAVE programme. In doing this, emphasis is placed on examples, the demonstration of added value of such an approach, and making recommendations for the future. Two experiments have been carried out on the basis of the Trinity approach. The Trinity approach is a set of methods specifically developed for supporting change processes which involve many parties (i.e. multi-actor processes). Trinity helps those involved to obtain a clear picture of both the route to be followed and the future situation to be aimed at. The term 'picture' must be understood literally: an important aspect of Trinity is the collaboration and communication with multi-actor models (also referred to as actorprints). By means of a diagram technique (figures and arrows) these models demonstrate the cohesion between the roles and activities of the various parties involved. The modelling process is instrumental in this; the actual result is that the image that is developed is formed and backed up by the participants in the process. Within these experiments, we have, so far, worked mainly in the shadow of the current GAVE process. A forceful participative use of the actor approach is

  1. Review: Lyn Richards (2005. Handling Qualitative Data: A Practical Guide

    Directory of Open Access Journals (Sweden)

    Robert L. Miller

    2006-03-01

    Full Text Available Handling Qualitative Data: A Practical Guide is an introductory textbook covering all stages of qualitative research from the initial conceptualisation of a project, through data collection and analysis, to writing up. The author, Lyn RICHARDS, is a well-known developer of two key qualitative software analysis packages, NUD*IST and NVivo. While RICHARDS clearly advocates the use of qualitative analysis software, the text is "generic" and could be used in tandem with any qualitative software package. The book concentrates on practical advice about the use of software to manage and analyse qualitative data, and provides insights in these areas. The consideration of issues around team-based qualitative research is another strong point. However, due in part to its short length, the overall coverage of topics tends to be superficial. In itself, the book does not provide sufficient detailed support for a student who would like to use it as her/his main source of guidance for carrying out a qualitative research project. URN: urn:nbn:de:0114-fqs0602244

  2. Absolute measurement of β eff based on Feynman-α experiments and the two-region model in the IPEN/MB-01 research reactor

    International Nuclear Information System (INIS)

    Kuramoto, Renato Y.R.; Santos, Adimir dos; Jerez, Rogerio; Diniz, Ricardo

    2007-01-01

    A new methodology for absolute measurement of the effective delayed neutron fraction β eff based on Feynman-α experiments and the two-region model was developed. This method made use of Feynman-α experiments and the two-region model. To examine the present methodology, a series of Feynman-α experiments were conducted at the IPEN/MB-01 research reactor facility. In contrast with other techniques like the slope method, Nelson-number method and 252 Cf-source method, the main advantage of this new methodology is to obtain β eff with the required accuracy and without knowledge of any other parameter. By adopting the present approach, β eff was measured with a 0.67% uncertainty. In addition, the prompt neutron generation time, Λ, and other parameters, was also obtained in an absolute experimental way. In general, the measured parameters are in good agreement with the values found from frequency analysis experiments. The theory-experiment comparison for the β eff measured in this work shows that JENDL3.3 presented the best agreement (within 1%). The reduction of the 235 U thermal yield as proposed by Okajima and Sakurai is completely justified according to the β eff measurements performed in this work

  3. Drawings of fossils by Robert Hooke and Richard Waller

    Science.gov (United States)

    Kusukawa, Sachiko

    2013-01-01

    The drawings of fossils by Robert Hooke and Richard Waller that were the basis of the engravings in Hooke's Posthumous works (1705) are published here for the first time. The drawings show that both Hooke and Waller were proficient draftsmen with a keen eye for the details of petrified objects. These drawings provided Hooke with a polemic edge in making the case for the organic origins of ‘figured stones’.

  4. Parallel Implementation of Numerical Solution of Few-Body Problem Using Feynman's Continual Integrals

    Science.gov (United States)

    Naumenko, Mikhail; Samarin, Viacheslav

    2018-02-01

    Modern parallel computing algorithm has been applied to the solution of the few-body problem. The approach is based on Feynman's continual integrals method implemented in C++ programming language using NVIDIA CUDA technology. A wide range of 3-body and 4-body bound systems has been considered including nuclei described as consisting of protons and neutrons (e.g., 3,4He) and nuclei described as consisting of clusters and nucleons (e.g., 6He). The correctness of the results was checked by the comparison with the exactly solvable 4-body oscillatory system and experimental data.

  5. Comparison of MCNP6 and experimental results for neutron counts, Rossi-α, and Feynman-α distributions

    International Nuclear Information System (INIS)

    Talamo, A.; Gohar, Y.; Sadovich, S.; Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Routkovskaya, C.

    2013-01-01

    MCNP6, the general-purpose Monte Carlo N-Particle code, has the capability to perform time-dependent calculations by tracking the time interval between successive events of the neutron random walk. In fixed-source calculations for a subcritical assembly, the zero time value is assigned at the moment the neutron is emitted by the external neutron source. The PTRAC and F8 cards of MCNP allow to tally the time when a neutron is captured by 3 He(n, p) reactions in the neutron detector. From this information, it is possible to build three different time distributions: neutron counts, Rossi-α, and Feynman-α. The neutron counts time distribution represents the number of neutrons captured as a function of time. The Rossi-a distribution represents the number of neutron pairs captured as a function of the time interval between two capture events. The Feynman-a distribution represents the variance-to-mean ratio, minus one, of the neutron counts array as a function of a fixed time interval. The MCNP6 results for these three time distributions have been compared with the experimental data of the YALINA Thermal facility and have been found to be in quite good agreement. (authors)

  6. Systematic implementation of implicit regularization for multi-loop Feynman Diagrams

    International Nuclear Information System (INIS)

    Cherchiglia, Adriano Lana; Sampaio, Marcos; Nemes, Maria Carolina

    2011-01-01

    Full text: Implicit Regularization (IR) is a candidate to become an invariant framework in momentum space to perform Feynman diagram calculations to arbitrary loop order. The essence of the method is to write the divergences in terms of loop integrals in one internal momentum which do not need to be explicitly evaluated. Moreover it acts in the physical dimension of the theory and gauge invariance is controlled by regularization dependent surface terms which when set to zero define a constrained version of IR (CIR) and deliver gauge invariant amplitudes automatically. Therefore it is in principle applicable to all physical relevant quantum field theories, supersymmetric gauge theories included. A non trivial question is whether we can generalize this program to arbitrary loop order in consonance with locality, unitarity and Lorentz invariance, especially when overlapping divergences occur. In this work we present a systematic implementation of our method that automatically displays the terms to be subtracted by Bogoliubov's recursion formula. Therefore, we achieve a twofold objective: we show that the IR program respects unitarity, locality and Lorentz invariance and we show that our method is consistent since we are able to display the divergent content of a multi-loop amplitude in a well defined set of basic divergent integrals in one internal momentum. We present several examples (from 1-loop to n-loops) using scalar φ 6 3 theory in order to help the reader understand and visualize the essence of the IR program. The choice of a scalar theory does not reduce the generality of the method presented since all other physical theories can be treated within the same strategy after space time and internal algebra are performed. Another result of this contribution is to show that if the surface terms are not set to zero they will contaminate the renormalization group coefficients. Thus, we are forced to adopt CIR which is equivalent to demand momentum routing invariance

  7. Justiça e sociedade liberal em Richard Rorty: justiça como lealdade e o projeto social de uma utopia

    Directory of Open Access Journals (Sweden)

    Marcelo de Almeida Silva

    2014-07-01

    Full Text Available O presente texto pretende explorar o conceito de justiça de Richard Rorty e a proposta da Utopia Liberal que o autor apresenta. Para tanto, explora, dentro da obra de Richard Rorty e de alguns autores com quem dialoga, contribuições para o debate da concepção do termo Justiça como um senso de lealdade ampliada e de sua proposta para uma sociedade mais justa, igualitária e inclusiva.   Abstract: This paper aims to explore the concept of justice from Richard Rorty and his proposal about the idea of a Liberal Utopia. With this goal we seek, within the work of Richard Rorty, and some authors with whom he converses, contributions to the discussion of the conception of justice as an expanded sense of loyalty and his proposal for a fairer, equitable and inclusive society.   Resumen: Este trabajo se propone explorar el concepto de justicia de Richard Rorty y la propuesta de liberal utopía que el autor presenta. Con este objetivo, vamos a buscar en la obra de Richard Rorty, y algunos autores con los que conversa, contribuciones a la discusión sobre la concepción de la justicia como un sentido más amplio de la lealtad y su propuesta de una sociedad más justa, equitativa e incluyente.

  8. Strauss, Richard. Ariane a Naxos: opera seulement, integrale. Miliza Korjus / Michel Parouty

    Index Scriptorium Estoniae

    Parouty, Michel

    1995-01-01

    Uuest heliplaadist "Strauss, Richard. Ariane a Naxos: opera seulement, integrale. Miliza Korjus (Najade). Orchestre de l'Opea l'Efat de Vienne" Arlecchino ARL 14-16, distribution Dante (3 CD: 390 F). 1935, 1944. TT: 3h 46'17"

  9. Making the Road While Walking It: A Conversation with Richard Simpson

    Science.gov (United States)

    Zabel, Robert H.; Kaff, Marilyn; Teagarden, James

    2016-01-01

    Richard Simpson is professor of special education at the University of Kansas (KU). Dr. Simpson's duties at KU have included roles of staff psychologist, teaching associate, assistant professor, project director, associate professor, professor, and chairperson for the Department of Special Education. He has directed numerous University of Kansas…

  10. Lendab nagu kotkas üle maailmas kogutud tarkuse / Richard Aroksaar ; intervjueerinud Ene Riet

    Index Scriptorium Estoniae

    Aroksaar, Richard

    2014-01-01

    Intervjuu eestlase Richard Aroksaarega, kes õppinud psühholoogiat ja raamatukogundust, töötab USA Rahvusparkide Ühenduse raamatukogus (National Park Service Library, NPS) süsteemi raamatukoguhoidja ja administraatorina

  11. Prof. Richard Mattessich at 95. His Research Methodology

    Directory of Open Access Journals (Sweden)

    Giuseppe Galassi

    2017-12-01

    Full Text Available This paper is presented as a tribute to prof. Richard Mattessich. It is written “through the eyes” of a researcher who has worked closely with him over a period of 42 years, starting attending his courses of “Income Determination Theory” and “Research Methodology” at the University of British Columbia in 1975. Among his huge scientific research and publications, I intend to underline these three major contributions: (i Accounting metrics and other mathematical instruments which anticipated computer spreadsheet by 30 years; (ii. The preparation of accountants for information economics by means of analytical methods; and (iii The proposition of the “onion model of reality” to distinguish different Kind of reality. Este trabajo se presenta como un tributo al profesor Richard Mattessich. Está escrito “con los ojos” de un investigador que ha trabajado estrechamente con él durante un período de 42 años, comenzando a asistir a sus cursos de " Income Determination Theory" y "Research Methodology" en la Universidad de British Columbia en 1975. Entre su investigación y publicaciones, más importantes pretendo subrayar estas tres contribuciones principales: (i Accounting metrics and other mathematical instruments which anticipated computer spreadsheet by 30 years; (ii The preparation of accountants for information economics by means of analytical methods; y (iii The proposition of the “onion model of reality” to distinguish different Kind of reality.

  12. Swearing Used in Richard Wright’s Black Boy

    Directory of Open Access Journals (Sweden)

    Giyatmi Giyatmi

    2017-07-01

    Full Text Available This research aims at finding the types of swearing expressions and linguistic forms of English swearing used in Richard Wright’s Black Boy. This is a descriptive qualitative research since it describes the phenomena of swearing used in the novel. The data of the research are all the conversations or sentences used swearing in the novel written by Richard Wright namely Black Boy as the main data source. The method of collecting data in this research is observation and teknik lanjut catat. After all the data had been collected then they are coded using the coding system such as data number/title of novel/chapter/page/data. There is no data reduction since all the data are analyzed in this research. This research used theory triangulation. Kind of swearing expressions found in this novel dealing with God and religion terms, name of  animals and plants, part of body, racial terms, stupidity terms, name of occupation, sexual terms, family terms. The linguistic forms of English swearing used in this novel are word, phrase, and clause. The swearing in the form of words consists of (1 noun referring to place, person, occupation, animal, and idea (2 verb and (3 adjective. Phrase consists of (1 noun phrase with swearing functioning as headword, modifier, and both headword and modifier, (2 adjective phrase with swearing functioning as modifier. Swearing expression is also found in the form of sentence.

  13. Historical Investigations of the Richard B. Russell Multiple Resource Area.

    Science.gov (United States)

    1981-11-01

    period of this project as a contemporary c~lebration and a reiteration of an ancient folk construction, Stonehenge . Appropriately, as this document goes to...55, 56m, 59m, 64m, 65-68, 71- Stonehenge 216 72, 75-76, 79-84, 84m, 91, 94- Sutch, Richard 20 95, 100, lOlm, 102, 103, 121m, Swift, James Y. 195 126

  14. Derivation of the Schrodinger Equation from the Hamilton-Jacobi Equation in Feynman's Path Integral Formulation of Quantum Mechanics

    Science.gov (United States)

    Field, J. H.

    2011-01-01

    It is shown how the time-dependent Schrodinger equation may be simply derived from the dynamical postulate of Feynman's path integral formulation of quantum mechanics and the Hamilton-Jacobi equation of classical mechanics. Schrodinger's own published derivations of quantum wave equations, the first of which was also based on the Hamilton-Jacobi…

  15. Review of Richard Bausch, Hello to the Cannibals

    Directory of Open Access Journals (Sweden)

    Géraldine Chouard

    2006-03-01

    Full Text Available Richard Bausch is credited with five collections of short stories and nine novels that have received various awards in the United States. His latest work, Hello to the Cannibals, blends a historical epic and a more intimate tale. Watch out‑this is a voracious novel.Other CarnageAn ethnologist investigating cannibalistic rites in Africa asks the head of the tribe : « Do you still have cannibals in your tribe ? » « No, we ate the last one yesterday, » answers the head of the tribe. Undoubtedly,...

  16. El vocabulario sechurano de Richard Spruce

    Directory of Open Access Journals (Sweden)

    Matthias Urban

    2015-12-01

    Full Text Available This paper makes accesible a new transcription of Richard Spruce’s vocabulary of the Sechura language. Collected in the mid-19th century by the British botanist, it constitutes one of only two sources of data for this language of northernmost Peru. A comparison of the original with previously published versions shows serious errors in transcription, in particular in those of Otto von Buchwald and Jacinto Jijón y Camaaño. The article also discusses the probable circumstances of data collection and the publication history of the hitherto known version, and concludes with some first observations on the significance of Spruce’s wordlist for elucidating the linguistic history of the region, in particular with regard to the question of the linguistic situation at Olmos.

  17. Transforming Faith: H. Richard Niebuhr and Paulo Freire on Moral Education

    Science.gov (United States)

    Daniel, Joshua Leonard

    2013-01-01

    Through a contextual comparison of the theological ethics of H. Richard Niebuhr and the educational theory of Paulo Freire, I argue that socialization, while an essential task of moral education, is an insufficient aim. The proper aim of moral education is individual development. The intention of my argument is address tendencies towards…

  18. When Richard Branson wants to build his own facility

    International Nuclear Information System (INIS)

    Cosnard, D.

    2005-01-01

    The capacity of petroleum refineries is today insufficient to meet the demand. In front of this shortage, Sir Richard Branson, the owner of Virgin Atlantic Airways, has decided to invest in the building of a refinery in Europe or in Canada. His new company, Virgin Oil, is already launched. However, the setting up of a new facility is very expensive and raises important problems of permits and public contestation which remain to be solved. Short paper. (J.S.)

  19. Richard Carwardine and Jay Sexton, eds., The Global Lincoln.

    Directory of Open Access Journals (Sweden)

    Hans Krabbendam

    2012-06-01

    Full Text Available Most countries have their export heroes that transcend their national origin: India has its Ghandi, South Africa its Mandela, England its Churchill, and the US has Abraham Lincoln. While particularly known for his role in the American Civil War, he has developed into an international beacon for liberalism and democracy, especially for nationals deprived of this liberties.This collection of essays, edited by Corpus Christi College (Oxford, UK colleagues Richard Carwardine and Jay Sexton, puts...

  20. Generalized internal multiple imaging (GIMI) using Feynman-like diagrams

    KAUST Repository

    Zuberi, M. A. H.; Alkhalifah, Tariq Ali

    2014-01-01

    Single scattering events recorded in surface seismic data do not fully illuminate the subsurface structure, especially if it is complicated. In such cases, multiple internal scatterings (internal multiples) can help improve the illumination. We devise a generalized internal multiple imaging (GIMI) procedure that maps internal multiple energy to their true location with a relatively mild addition to the computational cost. GIMI theory relies heavily on seismic interferometry, which often involves cumbersome algebra, especially when one is dealing with high-order terms in the perturbation series. To make the derivations, and inference of the results easier, we introduce Feynman-like diagrams to represent different terms of the perturbation series (solution to the Lippman–Schwinger equation). The rules we define for the diagrams allow operations like convolution and cross-correlation in the series to be compressed in diagram form. The application of the theory to a double scattering example demonstrates the power of the method.

  1. Generalized internal multiple imaging (GIMI) using Feynman-like diagrams

    KAUST Repository

    Zuberi, M. A. H.

    2014-05-19

    Single scattering events recorded in surface seismic data do not fully illuminate the subsurface structure, especially if it is complicated. In such cases, multiple internal scatterings (internal multiples) can help improve the illumination. We devise a generalized internal multiple imaging (GIMI) procedure that maps internal multiple energy to their true location with a relatively mild addition to the computational cost. GIMI theory relies heavily on seismic interferometry, which often involves cumbersome algebra, especially when one is dealing with high-order terms in the perturbation series. To make the derivations, and inference of the results easier, we introduce Feynman-like diagrams to represent different terms of the perturbation series (solution to the Lippman–Schwinger equation). The rules we define for the diagrams allow operations like convolution and cross-correlation in the series to be compressed in diagram form. The application of the theory to a double scattering example demonstrates the power of the method.

  2. Gravitational lensing of the CMB: A Feynman diagram approach

    Directory of Open Access Journals (Sweden)

    Elizabeth E. Jenkins

    2014-09-01

    Full Text Available We develop a Feynman diagram approach to calculating correlations of the Cosmic Microwave Background (CMB in the presence of distortions. As one application, we focus on CMB distortions due to gravitational lensing by Large Scale Structure (LSS. We study the Hu–Okamoto quadratic estimator for extracting lensing from the CMB and derive the noise of the estimator up to O(ϕ4 in the lensing potential ϕ. By identifying the diagrams responsible for the previously noted large O(ϕ4 term, we conclude that the lensing expansion does not break down. The convergence can be significantly improved by a reorganization of the ϕ expansion. Our approach makes it simple to obtain expressions for quadratic estimators based on any CMB channel, including many previously unexplored cases. We briefly discuss other applications to cosmology of this diagrammatic approach, such as distortions of the CMB due to patchy reionization, or due to Faraday rotation from primordial axion fields.

  3. New results for algebraic tensor reduction of Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, Jochem [Bielefeld Univ. (Germany). Fakultaet fuer Physik; Riemann, Tord [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Yundin, Valery [Copenhagen Univ. (Denmark). Niels Bohr International Academy and Discovery Center

    2012-02-15

    We report on some recent developments in algebraic tensor reduction of one-loop Feynman integrals. For 5-point functions, an efficient tensor reduction was worked out recently and is now available as numerical C++ package, PJFry, covering tensor ranks until five. It is free of inverse 5- point Gram determinants and inverse small 4-point Gram determinants are treated by expansions in higher-dimensional 3-point functions. By exploiting sums over signed minors, weighted with scalar products of chords (or, equivalently, external momenta), extremely efficient expressions for tensor integrals contracted with external momenta were derived. The evaluation of 7-point functions is discussed. In the present approach one needs for the reductions a (d +2)-dimensional scalar 5-point function in addition to the usual scalar basis of 1- to 4-point functions in the generic dimension d=4-2{epsilon}. When exploiting the four-dimensionality of the kinematics, this basis is sufficient. We indicate how the (d+2)-dimensional 5-point function can be evaluated. (orig.)

  4. New results for algebraic tensor reduction of Feynman integrals

    International Nuclear Information System (INIS)

    Fleischer, Jochem; Yundin, Valery

    2012-02-01

    We report on some recent developments in algebraic tensor reduction of one-loop Feynman integrals. For 5-point functions, an efficient tensor reduction was worked out recently and is now available as numerical C++ package, PJFry, covering tensor ranks until five. It is free of inverse 5- point Gram determinants and inverse small 4-point Gram determinants are treated by expansions in higher-dimensional 3-point functions. By exploiting sums over signed minors, weighted with scalar products of chords (or, equivalently, external momenta), extremely efficient expressions for tensor integrals contracted with external momenta were derived. The evaluation of 7-point functions is discussed. In the present approach one needs for the reductions a (d +2)-dimensional scalar 5-point function in addition to the usual scalar basis of 1- to 4-point functions in the generic dimension d=4-2ε. When exploiting the four-dimensionality of the kinematics, this basis is sufficient. We indicate how the (d+2)-dimensional 5-point function can be evaluated. (orig.)

  5. The Feynman lectures on physics

    International Nuclear Information System (INIS)

    Feynman, R.P.

    1979-01-01

    This set of lectures tries to elucidate from the beginning those features of the quantum mechanics which are most general. The first lectures tackle head on the ideas of a probability amplitude, the interference of amplitudes, the abstract notion of a state, and the superposition and resolution of states - and the Dirac notation is used from the start. In each instance the ideas are introduced together with a detailed discussion of some specific examples - to try to make the physical ideas as real as possible. The time dependence of states including states of definite energy comes next, and the ideas are applied at once to the study of two-state systems. A detailed discussion of the ammonia maser provides the framework for the introduction to radiation absorption and induced transitions. The lectures then go on to consider more complex systems, leading to a discussion of the propagation of electrons in a crystal, and to a rather complete treatment of the quantum mechanics of angular momentum. Our introduction to quantum mechanics ends in Chapter 20 with a discussion of the Schroedinger wave function, its differential equation, and the solution for the hydrogen atom. The last Chapter of this volume is not intended to be a part of the 'course.' It is a 'seminar' on superconductivity and was given in the spirit of some of the entertainment lectures of the first two volumes, with the intent of opening to the students a broader view of the relation of what they were learning to the general culture of physics. Feynman's 'epilogue' serves as the period to the three-volume series [fr

  6. Comparison of MCNP6 and experimental results for neutron counts, Rossi-{alpha}, and Feynman-{alpha} distributions

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, A.; Gohar, Y. [Argonne National Laboratory, 9700 S. Cass Ave., Lemont, IL 60439 (United States); Sadovich, S.; Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Routkovskaya, C. [Joint Institute for Power and Nuclear Research-Sosny, 99 Academician A.K. Krasin Str., Minsk 220109 (Belarus)

    2013-07-01

    MCNP6, the general-purpose Monte Carlo N-Particle code, has the capability to perform time-dependent calculations by tracking the time interval between successive events of the neutron random walk. In fixed-source calculations for a subcritical assembly, the zero time value is assigned at the moment the neutron is emitted by the external neutron source. The PTRAC and F8 cards of MCNP allow to tally the time when a neutron is captured by {sup 3}He(n, p) reactions in the neutron detector. From this information, it is possible to build three different time distributions: neutron counts, Rossi-{alpha}, and Feynman-{alpha}. The neutron counts time distribution represents the number of neutrons captured as a function of time. The Rossi-a distribution represents the number of neutron pairs captured as a function of the time interval between two capture events. The Feynman-a distribution represents the variance-to-mean ratio, minus one, of the neutron counts array as a function of a fixed time interval. The MCNP6 results for these three time distributions have been compared with the experimental data of the YALINA Thermal facility and have been found to be in quite good agreement. (authors)

  7. Ripples from a Passing Ship: Memories; and a Legacy of Richard Peters

    Science.gov (United States)

    Harris, Kevin

    2013-01-01

    This paper outlines aspects and dimensions of my "relationship" with Richard Peters from 1966 onward. The underlying suggestion is that, while Peters' contribution to philosophy of education was undeniably of major proportions, both that contribution and his legacy are institutional rather than substantive. (Contains 15 notes.)

  8. Nano materials for Renewable Energy Storage: Synthesis, Characterization, and Applications

    International Nuclear Information System (INIS)

    Rather, S.U.; Zacharia, R.; Stephan, A.M.; Petrov, L.A.; Nair, J.R.

    2015-01-01

    Nano technology and nano scale materials have been part of human history and in use since centuries. Staining of glass windows hundreds of years ago is one of the examples where people created beautiful works without knowing that they are using nano processing. The beginning of modern era of nano technology dates back to the talk of the Nobel laureate Professor Richard Feynman in There plenty of room at the bottom. Professor Feynman hypothesized that in near future scientists would be able to control and modulate individual molecules and atoms. After a decade, Professor Norio Taniguchi introduced the magical word nano technology. However, in 1981, the introduction of scanning tunnelling microscope enabled the scientists to see the materials in nano scale that propagated the new age of nano technology.

  9. Süütuse kaotamine / Richard Branson ; intervjueerinud Peter Fisk ; tõlkinud Endrik Randoja

    Index Scriptorium Estoniae

    Branson, Richard

    2009-01-01

    Turunduskirjanik Peter Fiski intervjuu Suurbritannia ärimagnaadi Sir Richard Bransoniga, milles arutletakse ettevõtja suurimate saavutuste ja suurimate pettuste üle, uuritakse Bransoni võimet juhtida oma 450 ettevõtet, tema suhtumist konkurentsi ning uutesse äriideedesse, samuti tema ajakasutust

  10. Efficacy Quotient Tindakan ESWL Piezolith Richard Wolf 3000 pada Penderita Batu Ureter di RSUPN Dr. Cipto Mangunkusumo, 2008–2011

    Directory of Open Access Journals (Sweden)

    Vinny Verdini

    2017-01-01

    Full Text Available Extracorporeal shockwave lithotripsy (ESWL saat ini telah menjadi metode yang paling umum dalam tatalaksana aktif batu ureter. Sejak Maret 2008, RSCM telah menggunakan mesin ESWL piezolith 3000 richard wolf dan belum diketahui nilai efficacy quotient (EQ. Penelitian ini bertujuan untuk menentukan nilai EQ dari tindakan ESWL menggunakan mesin piezolith richard wolf 3000 pada batu ureter dan hubungan angka bebas batu dengan lokasi batu, jumlah batu, beban batu, opasitas batu, obstruksi, dan fungsi ginjal. Studi cross sectional ini dilakukan pada bulan Januari 2008-Desember 2011 dan data dianalisis dengan statistik multivariat. Terdapat 113 (95 % dari 119 pasien yang dinyatakan bebas batu setelah tindakan ESWL pertama. Didapatkan nilai EQ 0,89. Hanya ukuran batu yang mempengaruhi angka bebas batu dalam penelitian ini (p<0,05. Disimpulkan bahwa prosedur ESWL menggunakan mesin richard wolf piezolith 3000 memiliki nilai EQ dan angka bebas batu yang lebih baik daripada mesin-mesin sebelumnya dan mesin lain yang sejenis. Faktor yang mempengaruhi keberhasilan adalah ukuran batu ureter yang ditatalaksana.Kata Kunci: batu ureter, ESWL, efficacy quotient, angka bebas batu. Efficacy Quotient of ESWL Piezolith Richard Wolf 3000 Machine in Patientswith Ureteral Stones in Dr. Cipto MangunkusumoNational Hospital 2008 - 2011AbstractExtracorporeal shockwave lithotripsy (ESWL is the most common method of ureteral stone management. Since 2008, RSCM has ben using ESWL piezolith 3000 richard wolf and efficacy quotient (EQ value have not yet studied. The study aims was to determine the efficacy quotient (EQ of ESWL using piezolith richard wolf 3000 machine for ureteral stone by analyzing free-stone rate with location of stones, number of stones, stone burden, stone opacity, obstruction and kidney function. This cross sectional study was carried out in January 2008-December 2011, with multivariate analytical study. Ninety five percent (n=113 of 119 patients were

  11. Richard Wollheim über die Metapher in der Malerei

    OpenAIRE

    Heinrich, Richard

    1993-01-01

    Es handelt sich um den Text eines Vortrages, den ich Jänner 1993 im Rahmen einer Vortragsreihe am Institut für Kunstgeschichte der Universität Wien gehalten habe. Er ist bisher unpubliziert und nicht redigiert. Das worüber ich spreche ist ein Artikel von Richard Wollheim mit dem Titel "Die Metapher in der Malerei". Diesen Artikel habe ich herausgegeben, gemeinsam mit meinem Kollegen Helmuth Vetter, 1991 in dem Band "Bilder der Philosophie". Ursprünglich handelt es sich um einen Vortrag, d...

  12. Automatic numerical integration methods for Feynman integrals through 3-loop

    International Nuclear Information System (INIS)

    De Doncker, E; Olagbemi, O; Yuasa, F; Ishikawa, T; Kato, K

    2015-01-01

    We give numerical integration results for Feynman loop diagrams through 3-loop such as those covered by Laporta [1]. The methods are based on automatic adaptive integration, using iterated integration and extrapolation with programs from the QUADPACK package, or multivariate techniques from the ParInt package. The Dqags algorithm from QuadPack accommodates boundary singularities of fairly general types. PARINT is a package for multivariate integration layered over MPI (Message Passing Interface), which runs on clusters and incorporates advanced parallel/distributed techniques such as load balancing among processes that may be distributed over a network of nodes. Results are included for 3-loop self-energy diagrams without IR (infra-red) or UV (ultra-violet) singularities. A procedure based on iterated integration and extrapolation yields a novel method of numerical regularization for integrals with UV terms, and is applied to a set of 2-loop self-energy diagrams with UV singularities. (paper)

  13. RICHARD WAGNER E O ROMANTISMO ALEMÃO

    Directory of Open Access Journals (Sweden)

    Rainer Câmara Patriota

    2015-07-01

    Full Text Available A cultura musical romântica encontra em Richard Wagner– em sua obra musical e teórica – um de seus maiores protagonistas.A rejeição da Aufklärung e a exaltação da supremacia germânica –elementos constituidores da Weltanschauung romântica alemã –caracterizam fortemente o pensamento e a atitude de Wagner frenteà vida, assumindo conotações ainda mais radicais através de seucontumaz antissemitismo. De modo que pensar Wagner por ocasiãode seu bicentenário também significa retomar uma discussão crucialsobre o romantismo alemão e suas implicações políticas eideológicas.

  14. Conoscenza e etica in Richard Rorty

    Directory of Open Access Journals (Sweden)

    Emilia Romano

    2011-12-01

    Full Text Available The era in which we live, characterized by multiculturalism and complexity, it is a time when it is clear the difficulty of man to orient and to choose their own way. It’s the time of the fall of every certainty, is the era of “post”, after the tradition, after metaphysics, after the truth, and that requires more effort than any other constant reflection. The neopragmatismo seems to be an effective investigative tool for conducting this reflection and a vantage point to carry on a conversation around the issues of education. In particular, the author intended to refer to the work of Richard Rorty, the author who more than others reflected on the encounter between two important pragmatist tradition: that of classical pragmatism and the “continental” or responsible for the development of a new European concept of truth, understood as a critical and interpretative.

  15. Resisting Biopolitics through “Diaphanous Wonder”: Richard Flanagan's Gould's Book of Fish

    NARCIS (Netherlands)

    Wiese, Doro|info:eu-repo/dai/nl/304842699

    2014-01-01

    In Gould's Book of Fish (2003), author Richard Flanagan manages to invent a format in which content and style account for historical events on Sarah Island, Tasmania in the 1820s, yet he does so in a manner that is not in the least objective, disinterested or fact-orientated. The perspective of

  16. "Symposium" by Richard Dawkins, Gerard 't Hooft, Alain Connes

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    Richard Dawkins will speak on biology, Gerard ‘t Hooft will focus on physics, and Alain Connes will discuss mathematics. CERN scientists probe ever-deeper levels of matter and their interactions, but can we say that the patterns they see are truly fundamental? Does the universe obey the same laws throughout? Since mathematical constructions can be true in the absence of any relation to the physical world, is mathematics more fundamental than physics? Extraterrestrial life would probably look much different from that on Earth, but natural selection still be fundamental to their evolution?

  17. Quantum leap from Dirac and Feynman, across the universe, to human body and mind

    CERN Document Server

    Ivancevic, Vladimir G

    2008-01-01

    This is a unique 21st-century monograph that reveals a basic, yet deep understanding of the universe, as well as the human mind and body - all from the perspective of quantum mechanics and quantum field theory.This book starts with both non-mathematical and mathematical preliminaries. It presents the basics of both non-relativistic and relativistic quantum mechanics, and introduces Feynman path integrals and their application to quantum fields and string theory, as well as some non-quantum applications. It then describes the quantum universe in the form of loop quantum gravity and quantum cosm

  18. Critical exponents predicted by grouping of Feynman diagrams in φ4 model

    International Nuclear Information System (INIS)

    Kaupuzs, J.

    2001-01-01

    Different perturbation theory treatments of the Ginzburg-Landau phase transition model are discussed. This includes a criticism of the perturbative renormalization group (RG) approach and a proposal of a novel method providing critical exponents consistent with the known exact solutions in two dimensions. The usual perturbation theory is reorganized by appropriate grouping of Feynman diagrams of φ 4 model with O(n) symmetry. As a result, equations for calculation of the two-point correlation function are obtained which allow to predict possible exact values of critical exponents in two and three dimensions by proving relevant scaling properties of the asymptotic solution at (and near) the criticality. The new values of critical exponents are discussed and compared to the results of numerical simulations and experiments. (orig.)

  19. Generalized conditions for the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space

    International Nuclear Information System (INIS)

    Manoukian, E.B.

    1986-01-01

    Generalized conditions (rules) are set up for the existence of the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space. These rules are generalizations of rules that have been set up earlier by us and hence are applicable to a larger class of graphs. The study is very general as the vanishing masses are led to vanish at different rates. All subtractions of renormalization are carried out directly in momentum space, about the origin, with the degree of divergence of a subtraction coinciding with the dimensionality of the corresponding subdiagram

  20. A newly designed multichannel scaling system: Validated by Feynman-α experiment in EHWZPR

    Energy Technology Data Exchange (ETDEWEB)

    Arkani, Mohammad, E-mail: markani@aeoi.org.ir; Mataji-Kojouri, Naimeddin

    2016-08-15

    Highlights: • An embedded measuring system with enhanced operational capabilities is introduced to the scientists. • The design is low cost and reprogrammable. • The system design is dedicated to multi-detector experiments with huge data collection. • Non count loss effect Feynman-α experiment is performed in EHWZPR. • The results is compared with endogenous/inherent pulsed neutron source experiment. - Abstract: In this work, an embedded multi-input multi-million-channel MCS in a newly design is constructed for multi-detector experimental research applications. Important characteristics of the system are possible to be tuned based on experimental case studies utilizing the reprogrammable nature of the silicon. By means of differentiation of the integrated counts registered in memory, this system is featured as a zero channel advance time measuring tool ideal for experiments on time correlated random processes. Using this equipment, Feynman-α experiment is performed in Esfahan Heavy Water Zero Power Reactor (EHWZPR) utilizing three different in-core neutron detectors. One million channel data is collected by the system in 5 ms gate time from each neutron detector simultaneously. As heavy water moderated reactors are significantly slow systems, a huge number of data channels is required to be collected. Then, by making in use of bunching method, the data is analyzed and prompt neutron decay constant of the system is estimated for each neutron detector positioned in the core. The results are compared with the information provided by endogenous pulsed neutron source experiment and a good agreement is seen within the statistical uncertainties of the results. This equipment makes further research in depth possible in a range of stochastic experiments in nuclear physics such as cross correlation analysis of multi-detector experiments.

  1. Kitchenette: Hell or Home? Different"Kitchenette"Images Created by Richard Wright and Gwendolyn Brooks%Kitchenette:Hell or Home?Different"Kitchenette"Images Created by Richard Wright and Gwendolyn Brooks

    Institute of Scientific and Technical Information of China (English)

    肖志宏

    2017-01-01

    How the southern black migrants navigate and survive the northern urban space is a question profoundly explored and realistically documented in many migration narratives in African American literature. This paper concentrates on the image of Chicago"kitchenette"in the works of Richard Wright and Gwendolyn Brooks, in an attempt to demonstrate the different inter-pretations of migrant spaces on the urban landscape.

  2. Editorial, Forum and Book Reviews

    Science.gov (United States)

    Caulfield, H. J.

    1983-12-01

    In his usual delightful fashion, Professor Richard Feynman recently recounted stories, insights, and observations from his life in science during a one hour interview on U.S. public television. All of what he said was enjoyable, but I think he erred in at least one judgment. He expressed disdain for organizations that form committees to determine who is worthy of an honor. With due deference to his insight, let me offer my own analysis in support of another view.

  3. Measurement of Feynman-x spectra of photons and neutrons in the very forward direction in deep-inelastic scattering at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, V.; Belousov, A.; Fomenko, A.; Gogitidze, N.; Lebedev, A.; Malinovski, E.; Rusakov, S.; Vazdik, Y. [Lebedev Physical Institute, Moscow (Russian Federation); Baghdasaryan, A.; Zohrabyan, H. [Yerevan Physics Institute, Yerevan (Armenia); Begzsuren, K.; Ravdandorj, T.; Tseepeldorj, B. [Institute of Physics and Technology of the Mongolian Academy of Sciences, Ulaanbaatar (Mongolia); Belov, P.; Brinkmann, M.; Britzger, D.; Campbell, A.J.; Dodonov, V.; Eckerlin, G.; Elsen, E.; Fleischer, M.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Gouzevitch, M.; Haidt, D.; Kleinwort, C.; Krueger, K.; Levonian, S.; Lipka, K.; List, B.; List, J.; Lobodzinski, B.; Meyer, A.B.; Meyer, J.; Niebuhr, C.; Olsson, J.E.; Ozerov, D.; Pahl, P.; Petrukhin, A.; Pirumov, H.; Pitzl, D.; Placakyte, R.; Radescu, V.; Schmitt, S.; Sefkow, F.; Shushkevich, S.; South, D.; Steder, M.; Wuensch, E. [DESY, Hamburg (Germany); Boudry, V.; Specka, A. [LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau (France); Brandt, G. [Oxford University, Department of Physics, Oxford (United Kingdom); Brisson, V.; Jacquet, M.; Pascaud, C.; Zhang, Z.; Zomer, F. [LAL, Universite Paris-Sud, CNRS/IN2P3, Orsay (France); Buniatyan, A.; Huber, F.; Sauter, M.; Schoening, A. [Universitaet Heidelberg, Physikalisches Institut, Heidelberg (Germany); Bylinkin, A.; Bystritskaya, L.; Fedotov, A.; Rostovtsev, A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Cantun Avila, K.B.; Contreras, J.G. [CINVESTAV, Departamento de Fisica Aplicada, Merida, Yucatan (Mexico); Ceccopieri, F.; Favart, L.; Grebenyuk, A.; Hreus, T.; Janssen, X.; Roosen, R.; Mechelen, P. van [Brussels and Universiteit Antwerpen, Inter-University Institute for High Energies ULB-VUB, Antwerp (Belgium); Cerny, K.; Pokorny, B.; Polifka, R.; Salek, D.; Valkarova, A.; Zacek, J.; Zlebcik, R. [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Chekelian, V.; Grindhammer, G.; Kiesling, C. [Max-Planck-Institut fuer Physik, Munich (Germany); Dainton, J.B.; Gabathuler, E.; Greenshaw, T.; Klein, M.; Kostka, P.; Kretzschmar, J.; Laycock, P.; Maxfield, S.J.; Mehta, A.; Patel, G.D. [University of Liverpool, Department of Physics, Liverpool (United Kingdom); Daum, K.; Meyer, H. [Fachbereich C, Universitaet Wuppertal, Wuppertal (Germany); Diaconu, C.; Hoffmann, D.; Sauvan, E.; Vallee, C. [CPPM, Aix-Marseille Univ, CNRS/IN2P3, Marseille (France); Dobre, M.; Rotaru, M. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Dossanov, A. [Universitaet Hamburg, Institut fuer Experimentalphysik, Hamburg (Germany); Max-Planck-Institut fuer Physik, Munich (Germany); Egli, S.; Horisberger, R. [Paul Scherrer Institut, Villigen (Switzerland); Feltesse, J.; Perez, E.; Schoeffel, L. [CEA, DSM/Irfu, CE-Saclay, Gif-sur-Yvette (France); Ferencei, J. [Slovak Academy of Sciences, Institute of Experimental Physics, Kosice (Slovakia); Goerlich, L.; Mikocki, S.; Nowak, G.; Sopicki, P.; Turnau, J. [Institute for Nuclear Physics, Cracow (Poland); Grab, C. [Institut fuer Teilchenphysik, ETH, Zurich (Switzerland); Henderson, R.C.W. [University of Lancaster, Department of Physics, Lancaster (United Kingdom); Herbst, M.; Schultz-Coulon, H.C. [Kirchhoff-Institut fuer Physik, Universitaet Heidelberg, Heidelberg (Germany); Hladky, J.; Reimer, P. [Academy of Sciences of the Czech Republic, Institute of Physics, Prague (Czech Republic); Jung, H. [Brussels and Universiteit Antwerpen, Inter-University Institute for High Energies ULB-VUB, Antwerp (Belgium); DESY, Hamburg (Germany); Kapichine, M.; Lytkin, L.; Morozov, A.; Spaskov, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kogler, R.; Nowak, K. [Universitaet Hamburg, Institut fuer Experimentalphysik, Hamburg (Germany); Landon, M.P.J.; Rizvi, E.; Traynor, D. [University of London, School of Physics and Astronomy, Queen Mary, London (GB); Lange, W.; Naumann, T. [DESY, Zeuthen (DE); Martyn, H.U. [I. Physikalisches Institut der RWTH, Aachen (DE); Mueller, K.; Robmann, P.; Straumann, U.; Truoel, P. [Physik-Institut der Universitaet Zuerich, Zurich (CH); Newman, P.R.; Thompson, P.D. [School of Physics and Astronomy, University of Birmingham, Birmingham (GB); Picuric, I.; Raicevic, N. [University of Montenegro, Faculty of Science, Podgorica (ME); Povh, B. [Max-Planck-Institut fuer Kernphysik, Heidelberg (DE); Sankey, D.P.C. [STFC, Rutherford Appleton Laboratory, Didcot, Oxfordshire (GB); Soloviev, Y. [DESY, Hamburg (DE); Lebedev Physical Institute, Moscow (RU); Stella, B. [Dipartimento di Fisica Universita di Roma Tre (IT); INFN Roma 3, Rome (IT); Sykora, T. [Brussels and Universiteit Antwerpen, Inter-University Institute for High Energies ULB-VUB, Antwerp (BE); Charles University, Faculty of Mathematics and Physics, Prague (CZ); Tsakov, I. [Institute for Nuclear Research and Nuclear Energy, Sofia (BG); Wegener, D. [Institut fuer Physik, TU Dortmund, Dortmund (DE); Collaboration: H1 Collaboration

    2014-06-15

    Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic ep scattering at HERA are presented as a function of the Feynman variable x{sub F} and of the centre-of-mass energy of the virtual photon-proton system W. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 131 pb{sup -1}. The measurement is restricted to photons and neutrons in the pseudorapidity range η > 7.9 and covers the range of negative four momentum transfer squared at the positron vertex 6 < Q{sup 2} < 100 GeV{sup 2}, of inelasticity 0.05 < y < 0.6 and of 70 < W < 245 GeV. To test the Feynman scaling hypothesis the W dependence of the x{sub F} dependent cross sections is investigated. Predictions of deep-inelastic scattering models and of models for hadronic interactions of high energy cosmic rays are compared to the measured cross sections. (orig.)

  4. Astronomical fire: Richard Carrington and the solar flare of 1859.

    Science.gov (United States)

    Clark, Stuart

    2007-09-01

    An explosion on the Sun in 1859, serendipitously witnessed by amateur astronomer Richard Carrington, plunged telegraphic communications into chaos and bathed two thirds of the Earth's skies in aurorae. Explaining what happened to the Sun and how it could affect Earth, 93 million miles away, helped change the direction of astronomy. From being concerned principally with charting the stars to aid navigation, astronomers became increasingly concerned with what the celestial objects were, how they behaved and how they might affect life on Earth.

  5. Racial Shame and the Pleasure of Transformation: Richard Rodriguez's Queer Aesthetics of Assimilation

    Science.gov (United States)

    Beltran, Cristina

    2012-01-01

    This essay analyzes Latino conservative thought by rethinking the logics of assimilation through a simultaneous exploration of aesthetic possibility and negative affect. Focusing on the writings of Richard Rodriguez, the essay considers how creative forms of self-individuation and political agency cannot easily be decoupled from negative forms of…

  6. La paradoja de lo público en Richard Rorty

    Directory of Open Access Journals (Sweden)

    Martha Palacio Avendaño

    2008-01-01

    Full Text Available El concepto de lo público en Richard Rorty, heredero de la tradición liberal, admite ser tratado como parte de un juego del lenguaje denominado liberalismo democrático. En ese sentido, una de las reglas de este juego para saber si una jugada es válida consiste en asumir la distinción entre esfera pública y privada. Richard Rorty pensó que este juego no requería fundamentación más allá de la forma de jugarlo, que el criterio en que se apoyaría estaba en las prácticas que tienen lugar dentro del mismo con arreglo a sostener una utopía que permitiera hacer cada vez más jugadas. Esto es, el liberalismo democrático no requería basarse en algo más allá de las prácticas conducentes a lograr una esperanza social alentada por la libertad en defensa del pluralismo. Su utopía liberal, guiada por el principio de la no-crueldad, haría posible una sociedad inclusiva en la que todos tuvieran espacio para su léxico privado. De este modo, Rorty habría vinculado libertad y solidaridad, pero su juego del lenguaje permite advertir la paradoja del vínculo que implicaría el sentido de lo público. Aquí, la libertad no es condición suficiente de la solidaridad, de modo que la inclusión social no tiene cabida en su juego del lenguaje.

  7. Equivalence between the real-time Feynman histories and the quantum-shutter approaches for the 'passage time' in tunneling

    International Nuclear Information System (INIS)

    Garcia-Calderon, Gaston; Villavicencio, Jorge; Yamada, Norifumi

    2003-01-01

    We show the equivalence of the functions G p (t) and vertical bar Ψ(d,t) vertical bar 2 for the 'passage time' in tunneling. The former, obtained within the framework of the real-time Feynman histories approach to the tunneling time problem, uses the Gell-Mann and Hartle's decoherence functional, and the latter involves an exact analytical solution to the time-dependent Schroedinger equation for cutoff initial waves

  8. Salecker-Wigner-Peres clock, Feynman paths, and a tunneling time that should not exist

    Science.gov (United States)

    Sokolovski, D.

    2017-08-01

    The Salecker-Wigner-Peres (SWP) clock is often used to determine the duration a quantum particle is supposed to spend in a specified region of space Ω . By construction, the result is a real positive number, and the method seems to avoid the difficulty of introducing complex time parameters, which arises in the Feynman paths approach. However, it tells little about the particle's motion. We investigate this matter further, and show that the SWP clock, like any other Larmor clock, correlates the rotation of its angular momentum with the durations τ , which the Feynman paths spend in Ω , thereby destroying interference between different durations. An inaccurate weakly coupled clock leaves the interference almost intact, and the need to resolve the resulting "which way?" problem is one of the main difficulties at the center of the "tunnelling time" controversy. In the absence of a probability distribution for the values of τ , the SWP results are expressed in terms of moduli of the "complex times," given by the weighted sums of the corresponding probability amplitudes. It is shown that overinterpretation of these results, by treating the SWP times as physical time intervals, leads to paradoxes and should be avoided. We also analyze various settings of the SWP clock, different calibration procedures, and the relation between the SWP results and the quantum dwell time. The cases of stationary tunneling and tunnel ionization are considered in some detail. Although our detailed analysis addresses only one particular definition of the duration of a tunneling process, it also points towards the impossibility of uniting various time parameters, which may occur in quantum theory, within the concept of a single tunnelling time.

  9. Schouten identities for Feynman graph amplitudes; The Master Integrals for the two-loop massive sunrise graph

    International Nuclear Information System (INIS)

    Remiddi, Ettore; Tancredi, Lorenzo

    2014-01-01

    A new class of identities for Feynman graph amplitudes, dubbed Schouten identities, valid at fixed integer value of the dimension d is proposed. The identities are then used in the case of the two-loop sunrise graph with arbitrary masses for recovering the second-order differential equation for the scalar amplitude in d=2 dimensions, as well as a chained set of equations for all the coefficients of the expansions in (d−2). The shift from d≈2 to d≈4 dimensions is then discussed

  10. Richard Rorty, o la posibilidad de un etnocentrismo universal

    Directory of Open Access Journals (Sweden)

    Isabel Gamero Cabrera

    2010-04-01

    Full Text Available En el presente artículo intentaremos comprender y analizar las implicaciones actuales de dos tesis del filósofo estadounidense Richard Rorty en relación con su etnocentrismo: La expansión global del sistema democrático liberal como horizonte de su teoría política y la restricción de las creencias de importancia última a la esfera privada. Compararemos esta teoría con las aportaciones de otros dos autores: una interpretación antropológica de los juegos de lenguaje de Wittgenstein y la democracia radical de Mouffe.

  11. Feynman-α correlation analysis by prompt-photon detection

    International Nuclear Information System (INIS)

    Hashimoto, Kengo; Yamada, Sumasu; Hasegawa, Yasuhiro; Horiguchi, Tetsuo

    1998-01-01

    Two-detector Feynman-α measurements were carried out using the UTR-KINKI reactor, a light-water-moderated and graphite-reflected reactor, by detecting high-energy, prompt gamma rays. For comparison, the conventional measurements by detecting neutrons were also performed. These measurements were carried out in the subcriticality range from 0 to $1.8. The gate-time dependence of the variance-and covariance-to-mean ratios measured by gamma-ray detection were nearly identical with those obtained using standard neutron-detection techniques. Consequently, the prompt-neutron decay constants inferred from the gamma-ray correlation data agreed with those from the neutron data. Furthermore, the correlated-to-uncorrelated amplitude ratios obtained by gamma-ray detection significantly depended on the low-energy discriminator level of the single-channel analyzer. The discriminator level was determined as optimum for obtaining a maximum value of the amplitude ratio. The maximum amplitude ratio was much larger than that obtained by neutron detection. The subcriticality dependence of the decay constant obtained by gamma-ray detection was consistent with that obtained by neutron detection and followed the linear relation based on the one-point kinetic model in the vicinity of delayed critical. These experimental results suggest that the gamma-ray correlation technique can be applied to measure reactor kinetic parameters more efficiently

  12. A soil moisture accounting-procedure with a Richards' equation-based soil texture-dependent parameterization

    Science.gov (United States)

    Given a time series of potential evapotranspiration and rainfall data, there are at least two approaches for estimating vertical percolation rates. One approach involves solving Richards' equation (RE) with a plant uptake model. An alternative approach involves applying a simple soil moisture accoun...

  13. Transforming differential equations of multi-loop Feynman integrals into canonical form

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Christoph [Institut für Physik, Humboldt-Universität zu Berlin,12489 Berlin (Germany)

    2017-04-03

    The method of differential equations has been proven to be a powerful tool for the computation of multi-loop Feynman integrals appearing in quantum field theory. It has been observed that in many instances a canonical basis can be chosen, which drastically simplifies the solution of the differential equation. In this paper, an algorithm is presented that computes the transformation to a canonical basis, starting from some basis that is, for instance, obtained by the usual integration-by-parts reduction techniques. The algorithm requires the existence of a rational transformation to a canonical basis, but is otherwise completely agnostic about the differential equation. In particular, it is applicable to problems involving multiple scales and allows for a rational dependence on the dimensional regulator. It is demonstrated that the algorithm is suitable for current multi-loop calculations by presenting its successful application to a number of non-trivial examples.

  14. Transforming differential equations of multi-loop Feynman integrals into canonical form

    Science.gov (United States)

    Meyer, Christoph

    2017-04-01

    The method of differential equations has been proven to be a powerful tool for the computation of multi-loop Feynman integrals appearing in quantum field theory. It has been observed that in many instances a canonical basis can be chosen, which drastically simplifies the solution of the differential equation. In this paper, an algorithm is presented that computes the transformation to a canonical basis, starting from some basis that is, for instance, obtained by the usual integration-by-parts reduction techniques. The algorithm requires the existence of a rational transformation to a canonical basis, but is otherwise completely agnostic about the differential equation. In particular, it is applicable to problems involving multiple scales and allows for a rational dependence on the dimensional regulator. It is demonstrated that the algorithm is suitable for current multi-loop calculations by presenting its successful application to a number of non-trivial examples.

  15. Transforming differential equations of multi-loop Feynman integrals into canonical form

    International Nuclear Information System (INIS)

    Meyer, Christoph

    2017-01-01

    The method of differential equations has been proven to be a powerful tool for the computation of multi-loop Feynman integrals appearing in quantum field theory. It has been observed that in many instances a canonical basis can be chosen, which drastically simplifies the solution of the differential equation. In this paper, an algorithm is presented that computes the transformation to a canonical basis, starting from some basis that is, for instance, obtained by the usual integration-by-parts reduction techniques. The algorithm requires the existence of a rational transformation to a canonical basis, but is otherwise completely agnostic about the differential equation. In particular, it is applicable to problems involving multiple scales and allows for a rational dependence on the dimensional regulator. It is demonstrated that the algorithm is suitable for current multi-loop calculations by presenting its successful application to a number of non-trivial examples.

  16. Off-diagonal coefficients of the DeWitt-Schwinger and Hadamard representations of the Feynman propagator

    International Nuclear Information System (INIS)

    Decanini, Yves; Folacci, Antoine

    2006-01-01

    Having in mind applications to gravitational wave theory (in connection with the radiation reaction problem), stochastic semiclassical gravity (in connection with the regularization of the noise kernel) and quantum field theory in higher-dimensional curved spacetime (in connection with the Hadamard regularization of the stress-energy tensor), we improve the DeWitt-Schwinger and Hadamard representations of the Feynman propagator of a massive scalar field theory defined on an arbitrary gravitational background by deriving higher-order terms for the covariant Taylor series expansions of the geometrical coefficients--i.e., the DeWitt and Hadamard coefficients--that define them

  17. JaxoDraw: A graphical user interface for drawing Feynman diagrams. Version 2.0 release notes

    Science.gov (United States)

    Binosi, D.; Collins, J.; Kaufhold, C.; Theussl, L.

    2009-09-01

    A new version of the Feynman graph plotting tool JaxoDraw is presented. Version 2.0 is a fundamental re-write of most of the JaxoDraw core and some functionalities, in particular importing graphs, are not backward-compatible with the 1.x branch. The most prominent new features include: drawing of Bézier curves for all particle modes, on-the-fly update of edited objects, multiple undo/redo functionality, the addition of a plugin infrastructure, and a general improved memory performance. A new LaTeX style file is presented that has been written specifically on top of the original axodraw.sty to meet the needs of this new version. New version program summaryProgram title: JaxoDraw Catalogue identifier: ADUA_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUA_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL No. of lines in distributed program, including test data, etc.: 103 544 No. of bytes in distributed program, including test data, etc.: 3 745 814 Distribution format: tar.gz Programming language: Java Computer: Any Java-enabled platform Operating system: Any Java-enabled platform, tested on Linux, Windows XP, Mac OS X Classification: 14 Catalogue identifier of previous version: ADUA_v1_0 Journal reference of previous version: Comput. Phys. Comm. 161 (2004) 76 Does the new version supersede the previous version?: Yes Nature of problem: Existing methods for drawing Feynman diagrams usually require some hard-coding in one or the other programming or scripting language. It is not very convenient and often time consuming, to generate relatively simple diagrams. Solution method: A program is provided that allows for the interactive drawing of Feynman diagrams with a graphical user interface. The program is easy to learn and use, produces high quality output in several formats and runs on any operating system where a Java Runtime Environment is available. Reasons for new version: A

  18. Effective multiplication factor measurement by feynman-α method. 3

    International Nuclear Information System (INIS)

    Mouri, Tomoaki; Ohtani, Nobuo

    1998-06-01

    The sub-criticality monitoring system has been developed for criticality safety control in nuclear fuel handling plants. In the past experiments performed with the Deuterium Critical Assembly (DCA), it was confirmed that the detection of sub-criticality was possible to k eff = 0.3. To investigate the applicability of the method to more generalized system, experiments were performed in the light-water-moderated system of the modified DCA core. From these experiments, it was confirmed that the prompt decay constant (α), which was a index of the sub-criticality, was detected between k eff = 0.623 and k eff = 0.870 and the difference of 0.05 - 0.1Δk could be distinguished. The α values were numerically calculated with 2D transport code TWODANT and monte carlo code KENO V.a, and the results were compared with the measured values. The differences between calculated and measured values were proved to be less than 13%, which was sufficient accuracy in the sub-criticality monitoring system. It was confirmed that Feynman-α method was applicable to sub-critical measurement of the light-water-moderated system. (author)

  19. [Sir William Richard Gowers: author of the "bible of neurology"].

    Science.gov (United States)

    Hirose, Genjiro

    2014-11-01

    William Richard Gowers is one of the great pioneers in neurology and the author of the well-known neurology textbook, "A Manual of Diseases of the Nervous System." His concepts of neurology are based on meticulously and carefully accumulated knowledge of history, observations, and neurological examinations of patients with various neurological diseases. He is not only a great neurologist but also a great teacher who loves teaching students and physicians through well-prepared lectures. We can glean the essence of the field of neurology through his life story and numerous writings concerning neurological diseases.

  20. Of poetics and possibility: Richard Kearney’s post-metaphysical God

    Directory of Open Access Journals (Sweden)

    Yolande Steenkamp

    2017-11-01

    Full Text Available This article provides an overview of Richard Kearney’s attempt at re-imagining God post-metaphysically. In the context of a continental dialogue on the topic, Kearney has responded to onto-theology with a hermeneutic and phenomenologically informed attempt to rethink God post-metaphysically. This eschatological understanding of God is expounded in the article and is placed in relation to Kearney’s more recent concept of Anatheism. The article closes with a few remarks on what may be gained by Kearney’s work, as well as outlining a few critical questions.

  1. Understanding Richard Wright's "Black Boy": A Student Casebook to Issues, Sources, and Historical Documents.

    Science.gov (United States)

    Felgar, Robert

    In "Black Boy," Richard Wright triumphs over an ugly, racist world by fashioning an inspiring, powerful, beautiful, and fictionalized autobiography. To help students understand and appreciate his story in the cultural, political, racial, social, and literary contexts of its time, this casebook provides primary historical documents,…

  2. Il concetto di medium artistico: Richard Wollheim interprete di Ludwig Wittgenstein

    OpenAIRE

    Maistrello, Andrea

    2016-01-01

    The aim of the dissertation is twofold: (i) analyzing the notion (well known by aestheticians, but not so intensively studied) of artistic medium; (ii) showing the relevance of such notion for aesthetics through the examination of some relevant aspects of Richard Wollheim’s philosophy of art, maybe the main figure in Anglo-American philosophy as for considering artistic medium central in art-theorizing. Artistic media, according to Wollheim, can develop only if properly connected to a cultura...

  3. Gamma radiation and radon concentration levels at the radioactive waste repositories 'Richard' and 'Bratrstvi'

    International Nuclear Information System (INIS)

    Berka, Z.; Sabol, J.; Janu, M.

    1998-01-01

    Owing to the fact that cosmic rays are shielded off, the photon equivalent dose rates in the corridors of the Richard repository are usually slightly lower than outside. However, in points close to barrels containing radioactive waste, the dose rates can reach values as high as tens of μSv/h. Because of high concentrations of natural radionuclides, the dose rates in the Bratrstvi repository is generally considerably higher, as much as 5 times the normal background value. Radon concentrations exhibit specific time variations which are modified by ventilation. Where ventilation is poor or absent, the radon concentrations are extremely high, viz. up to 30 and 300 kBq/m 3 in the Richard and Bratrstvi repositories, respectively. Personal exposure of workers depend on the total time spent underground and on the ventilation rate. While the contribution from photons can be kept below the relevant limits, the radon-related doses may be significant and even exceed the professional limits if no precautions are taken. (P.A.)

  4. Somaesthetic Training, Aesthetics, Ethics, and the Politics of Difference in Richard Shusterman's "Body Consciousness"

    Science.gov (United States)

    Powell, Kimberly

    2010-01-01

    In this essay, the author first addresses the theme of disciplined somatic training and its relationship to self-awareness and transformation. Her attention is focused specifically on the chapter on Ludwig Wittgenstein, in which Richard Shusterman presents and then elaborates upon the philosopher's connections between conscious bodily feelings and…

  5. Richard III in Russian Theatre at the Twilight of the "Thaw"

    OpenAIRE

    Sokolyansky, Mark

    2007-01-01

    Richard III was very rarely staged in Russian theatre in tsarist and Stalin’s times, because the story of inhuman tyranny provoked associations with Russian political reality. In the period of the so-called “Thaw” (1954ß1964) the play became very popular in the USSR and several scenic productions of it were real events in Russian (and Soviet) theatrical life. In the essay three most original and successful performances (in Kujbyshev, Gorkij and Erevan) are discussed and compare...

  6. Metaforos populiarojo mokslo literatūroje: Richard Dawkins knygos analizė

    OpenAIRE

    Urbanavičiūtė, Dovilė

    2017-01-01

    The following paper discusses metaphor usage in the genre of popular science. The object of this analysis is a chapter called ‘Immortal coils’ taken from Richard Dawkins’ book The Selfish Gene. The study discusses the impact of creative conceptual metaphors on the construction of the overall meaning of the text, as well as the significance of their linguistic manifestations and context. In focusing on the genre of popular science, it also makes an attempt at defining potential difficulties of...

  7. Coupled inflaton and electromagnetic fields from Gravitoelectromagnetic Inflation with Lorentz and Feynman gauges

    International Nuclear Information System (INIS)

    Membiela, Federico Agustín; Bellini, Mauricio

    2010-01-01

    Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of electric and magnetic field modes during the early inflationary epoch of the universe on cosmological scales. This is the first time that solutions for the electric field fluctuations are investigated in a systematic way as embeddings for inflationary models in 4D. An important and new result here obtained is that the spectrum of the electric field fluctuations depend with the scale, such that the spectral index increases quadratically as the scale decreases

  8. Coupled inflaton and electromagnetic fields from Gravitoelectromagnetic Inflation with Lorentz and Feynman gauges

    Energy Technology Data Exchange (ETDEWEB)

    Membiela, Federico Agustín; Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar, E-mail: membiela@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina)

    2010-10-01

    Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of electric and magnetic field modes during the early inflationary epoch of the universe on cosmological scales. This is the first time that solutions for the electric field fluctuations are investigated in a systematic way as embeddings for inflationary models in 4D. An important and new result here obtained is that the spectrum of the electric field fluctuations depend with the scale, such that the spectral index increases quadratically as the scale decreases.

  9. Free as in Freedom Richard Stallman's Crusade for Free Software

    CERN Document Server

    Williams, Sam

    2011-01-01

    Free as in Freedom interweaves biographical snapshots of GNU project founder Richard Stallman with the political, social and economic history of the free software movement. It examines Stallman's unique personality and how that personality has been at turns a driving force and a drawback in terms of the movement's overall success. Free as in Freedom examines one man's 20-year attempt to codify and communicate the ethics of 1970s era "hacking" culture in such a way that later generations might easily share and build upon the knowledge of their computing forebears. The book documents Stallman'

  10. Naturalismo e existencialismo na teoria moral de Richard Hare

    Directory of Open Access Journals (Sweden)

    Marco Antônio Oliveira de Azevedo

    2009-08-01

    Full Text Available http://dx.doi.org/10.5007/1677-2954.2009v8n2p247 Em um artigo de 1966, Amartya Sen procurou mostrar que mesmo Richard Hare, um devoto explícitodo antinaturalismo em ética, ainda que inadvertidamente, incorreu num tipo de naturalismo que Senintitulou de existencial. Neste breve artigo, traço um resumo dessa crítica à teoria de Hare, em especial,da chamada “Lei de Hume”, a qual Sen preferiu apropriadamente intitular “Regra de Hare”. Pretendomostrar como esse tipo peculiar de “existencialismo” nos conduz, ainda que sob o possível protesto deHare e seus seguidores, a conclusões subjetivistas e relativistas sobre a moralidade.

  11. Richard Swedberg, The Art of Social Theory

    DEFF Research Database (Denmark)

    Carleheden, Mikael

    2015-01-01

    to systematic consideration. Swedberg attributes this strange absence to what he sees as the miserable state of contemporary social theory. We must, he claims, avoid two misconceptions: ‘empiricism’ and ‘abstract theory’. In the first case, theory is reduced to the task of summarizing the outcome of empirical......It is a rare event when a new general field of research opens up within sociology. However, with this book, Richard Swedberg intends to do just that. It is not just another book on social theory. It is a book on ‘theorizing’. And that makes all the difference. Swedberg has chosen the term ‘art......’, but also ‘craft’, to emphasize the practical side of doing theory. This topic has been strangely absent, not just in sociology but in the social sciences in general. In order to see this absence, we should ask ourselves how education in sociology is conventionally organized. The answer is by a taken...

  12. Missing Kettles and Too Few Toasters: The Forecasting Methodology at Morphy Richards

    OpenAIRE

    Lane, D; Hughes, D

    2002-01-01

    Faced with problems in forecasting at Morphy Richards, this research represents an investigation into their forecasting methodology following the hypothesis that the current forecasting system was no longer sufficient to ensure guaranteed supply to customers, or to enable forward planning.\\ud \\ud The purpose of the research was to identify any requirements for change within the forecasting system and to identify the ‘best practice’ within the industry. Primary research was carried out using a...

  13. Feynman amplitude and the Meijer's function. A unified representation for divergent and convergent graphs

    Energy Technology Data Exchange (ETDEWEB)

    Kucheryavyi, V I

    1974-12-31

    A parametric alpha -representation of Feynman amplitude for any spinor graph, which is expressed in terms of the Meijer's G functions, is obtained. This representation is valid both for divergent and convergent graphs. The available ChisholmNakanishi-Symanzik alpha -representation for convergent scalar graph turns out to be a special of the formula obtained. Besides that, the expression has a number of useful features. This representation automatically removes the infrared divergencies connected with zero photon mass. The expression has a form in which the scale-invariant terms are explicitly separated from the terms breaking the invariance. It is shown by considering the simplest graphs of quantum electrodynamics that this representation keeps gauge invariance and Ward's identity for renormalized amplitudes. (auth)

  14. The 1D Richards' equation in two layered soils: a Filippov approach to treat discontinuities

    Science.gov (United States)

    Berardi, Marco; Difonzo, Fabio; Vurro, Michele; Lopez, Luciano

    2018-05-01

    The infiltration process into the soil is generally modeled by the Richards' partial differential equation (PDE). In this paper a new approach for modeling the infiltration process through the interface of two different soils is proposed, where the interface is seen as a discontinuity surface defined by suitable state variables. Thus, the original 1D Richards' PDE, enriched by a particular choice of the boundary conditions, is first approximated by means of a time semidiscretization, that is by means of the transversal method of lines (TMOL). In such a way a sequence of discontinuous initial value problems, described by a sequence of second order differential systems in the space variable, is derived. Then, Filippov theory on discontinuous dynamical systems may be applied in order to study the relevant dynamics of the problem. The numerical integration of the semidiscretized differential system will be performed by using a one-step method, which employs an event driven procedure to locate the discontinuity surface and to adequately change the vector field.

  15. Richard Murphy: a life in writing

    Directory of Open Access Journals (Sweden)

    E. Meihuizen

    2006-07-01

    Full Text Available The Irish poet Richard Murphy published his autobiography “The kick: a life among writers” in 2003. From a slightly different perspective the subtitle of this work could be rewritten as “A life in writing” since it is an account of the agencies that moulded a life devoted to creative writing which forms the book’s essential impetus. The memoir is based on notebooks which Murphy kept throughout his life “to hold the scraps of verse, elusive images, dreams, desires and revelations” to be developed into poetry. Apart from contextualising his poetry by registering the relationships, circumstances and landscapes from which it germinated, Murphy also tells of the creative process itself and the personal poetics underlying this process. This article explores what is regarded as the central determining feature of Murphy’s identity as poet, namely the relationship between the creative self and a particular place, where the concept of “place” is seen as a cultural palimpsest which represents not only physical qualities, but also the shaping and development of the landscape through time according to a certain way of life.

  16. Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine

    OpenAIRE

    Marye O'Reilly-Knapp

    2015-01-01

    Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine. Published by Karnac Books: London, 2015 Paperback, Pages 366, ISBN 13: 978-1-78220-190-8

  17. Astronaut Richard H. Truly in training session RMS for STS-2 bldg 9A

    Science.gov (United States)

    1981-01-01

    Astronaut Richard H. Truly in training session with the Remote Manipulator System (RMS) for STS-2 bldg 9A. Views show Truly working at the command console while watching out the windows. Karen Ehlers, an RMS procedures specialist, can be seen at left side of frame (34314); view from behind Truly as he trains at the RMS console (34315).

  18. X-ray cross-sections and crossroads (The International Radiation Physics Society) - Richard Pratt's contributions to both

    International Nuclear Information System (INIS)

    Hubbell, J.H.

    2000-01-01

    Some examples of the impact of the theoretical contributions by Richard Pratt and his collaborators on photon cross section compilations at NBS/NIST and elsewhere over the past several decades are presented. Both the theoretical and measurement works which combine to provide this data base, and the contact with the varied user groups in medical applications, nuclear engineering, crystallography and X-ray astronomy, have formed a global crossroads of researchers now embodied in the International Radiation Physics Society (IRPS). Since the founding of the IRPS at the 3 rd International Symposium on Radiation Physics (ISRP-3) in Ferrara, Italy, in 1985, the Secretariat for this 'global radiation physics family' (the IRPS) has resided at the University of Pittsburgh under the direction of Richard Pratt. A brief account of the origins and history of the IRPS, beginning with ISRP-1 in Calcutta in 1974, is presented.

  19. X-ray cross-sections and crossroads (The International Radiation Physics Society) - Richard Pratt's contributions to both

    Science.gov (United States)

    Hubbell, J. H.

    2000-08-01

    Some examples of the impact of the theoretical contributions by Richard Pratt and his collaborators on photon cross section compilations at NBS/NIST and elsewhere over the past several decades are presented. Both the theoretical and measurement works which combine to provide this data base, and the contact with the varied user groups in medical applications, nuclear engineering, crystallography and X-ray astronomy, have formed a global crossroads of researchers now embodied in the International Radiation Physics Society (IRPS). Since the founding of the IRPS at the 3rd International Symposium on Radiation Physics (ISRP-3) in Ferrara, Italy, in 1985, the Secretariat for this ``global radiation physics family'' (the IRPS) has resided at the University of Pittsburgh under the direction of Richard Pratt. A brief account of the origins and history of the IRPS, beginning with ISRP-1 in Calcutta in 1974, is presented.

  20. Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine

    Directory of Open Access Journals (Sweden)

    Marye O'Reilly-Knapp

    2015-12-01

    Full Text Available Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine. Published by Karnac Books: London, 2015 Paperback, Pages 366, ISBN 13: 978-1-78220-190-8

  1. Prologue to super quantum mechanics something is rotten in the state of quantum mechanics

    CERN Document Server

    Vaguine, Victor

    2012-01-01

    Since its foundation more than eight decades ago, quantum mechanics has been plagued by enigmas, mysteries and paradoxes and held hostage by quantum positivism. This fact strongly suggests that something is fundamentally wrong with the quantum mechanics paradigm. The best scientific minds, such as Albert Einstein, Louis de Broglie, David Bohm, Richard Feynman and others have spent years of their professional lives attempting to find resolution to the quantum mechanics predicament, with not much success. A shift of the quantum mechanics paradigm toward a deeper physics theory is long overdue.

  2. In the Dirac tradition

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1988-04-15

    It was Paul Dirac who cast quantum mechanics into the form we now use, and many generations of theoreticians openly acknowledge his influence on their thinking. When Dirac died in 1984, St. John's College, Cambridge, his base for most of his lifetime, instituted an annual lecture in his memory at Cambridge. The first lecture, in 1986, attracted two heavyweights - Richard Feynman and Steven Weinberg. Far from using the lectures as a platform for their own work, in the Dirac tradition they presented stimulating material on deep underlying questions.

  3. In the Dirac tradition

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    It was Paul Dirac who cast quantum mechanics into the form we now use, and many generations of theoreticians openly acknowledge his influence on their thinking. When Dirac died in 1984, St. John's College, Cambridge, his base for most of his lifetime, instituted an annual lecture in his memory at Cambridge. The first lecture, in 1986, attracted two heavyweights - Richard Feynman and Steven Weinberg. Far from using the lectures as a platform for their own work, in the Dirac tradition they presented stimulating material on deep underlying questions

  4. An elementary treatise on electricity

    CERN Document Server

    Maxwell, James Clerk

    2011-01-01

    Albert Einstein characterized the work of James Clerk Maxwell as the ""most profound and the most fruitful that physics has experienced since the time of Newton."" Max Planck went even further, declaring that ""he achieved greatness unequalled,"" and Richard Feynman asserted that ""From a long view of the history of mankind - seen from, say, ten thousand years from now - there can be little doubt that the most significant event of the nineteenth century will be judged as Maxwell's discovery of the laws of electrodynamics."" Maxwell made numerous other contributions to the advancement of scien

  5. Muusikamaailm : Suur klaveripidu Ruhrimaal. Kissingeni festival tippudega. Sulasoli 80. aastapäev. Richard Rodgers 100 / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2002-01-01

    6. juuni-17. augustini Ruhrimaal toimuvast klaverifestivalist. Bad Kissingenis toimuvatest suvepidustustest. Soome Lauljate ja Mängijate Liit tähistab asutamise 80. aastapäeva. Helilooja Richard Rodgersi sünnist möödub 100 aastat

  6. On the maximal cut of Feynman integrals and the solution of their differential equations

    Directory of Open Access Journals (Sweden)

    Amedeo Primo

    2017-03-01

    Full Text Available The standard procedure for computing scalar multi-loop Feynman integrals consists in reducing them to a basis of so-called master integrals, derive differential equations in the external invariants satisfied by the latter and, finally, try to solve them as a Laurent series in ϵ=(4−d/2, where d are the space–time dimensions. The differential equations are, in general, coupled and can be solved using Euler's variation of constants, provided that a set of homogeneous solutions is known. Given an arbitrary differential equation of order higher than one, there exists no general method for finding its homogeneous solutions. In this paper we show that the maximal cut of the integrals under consideration provides one set of homogeneous solutions, simplifying substantially the solution of the differential equations.

  7. Construction of Fluid - solid Coupling Model with Improved Richards - BP & Its Engineering Application

    Science.gov (United States)

    Xie, Chengyu; Jia, Nan; Shi, Dongping; Lu, Hao

    2017-10-01

    In order to study the slurry diffusion law during grouting, Richards unsaturated-saturated model was introduced, the definition of the grouting model is clear, the Richards model control equation was established, And the BP neural network was introduced, the improved fluid-solid coupling model was constructed, Through the use of saturated - unsaturated seepage flow model, As well as the overflow boundary iterative solution of the mixed boundary conditions, the free surface is calculated. Engineering practice for an example, with the aid of multi - field coupling analysis software, the diffusion law of slurry was simulated numerically. The results show that the slurry diffusion rule is affected by grouting material, initial pressure and other factors. When the slurry starts, it flows in the cracks along the upper side of the grouting hole, when the pressure gradient is reduced to the critical pressure, that is, to the lower side of the flow, when the slurry diffusion stability, and ultimately its shape like an 8. The slurry is spread evenly from the overall point of view, from the grouting mouth toward the surrounding evenly spread, it gradually reaches saturation by non-saturation, and it is not a purely saturated flow, when the slurry spread and reach a saturated state, the diffusion time is the engineering grouting time.

  8. Nuclear physics aspects in the parton model of Feynman

    International Nuclear Information System (INIS)

    Pauchy Hwang, W.Y.

    1995-01-01

    The basic fact that pions couple strongly to nucleons has dominated various nuclear physics thinkings since the birth of the field more than sixty years ago. The parton model of Feynman, in which the structure of a nucleon (or a hadron) is characterized by a set of parton distributions, was proposed originally in late 1960's to treat high energy deep inelastic scattering, and later many other high energy physics experiments involving hadrons. Introduction of the concept of parton distributions signifies the departure of particle physics from nuclear physics. Following the suggestion that the sea quark distributions in a nucleon, at low and moderate Q 2 (at least up to a few GeV 2 ), can be attributed primarily to the probability of finding such quarks or antiquarks in the mesons (or recoiling baryons) associated with the nucleon, the author examines how nuclear physics aspects offer quantitative understanding of several recent experimental results, including the observed violation of the Gotfried sum rule and the so-called open-quotes proton spin crisisclose quotes. These results suggest that determination of parton distributions of a hadron at Q 2 of a few GeV 2 (and at small x) must in general take into account nuclear physics aspects. Implication of these results for other high-energy reactions, such as semi-inclusive hadron production in deep inelastic scattering, are also discussed

  9. Real time alpha value measurement with Feynman-α method utilizing time series data acquisition on low enriched uranium system

    International Nuclear Information System (INIS)

    Tonoike, Kotaro; Yamamoto, Toshihiro; Watanabe, Shoichi; Miyoshi, Yoshinori

    2003-01-01

    As a part of the development of a subcriticality monitoring system, a system which has a time series data acquisition function of detector signals and a real time evaluation function of alpha value with the Feynman-alpha method was established, with which the kinetic parameter (alpha value) was measured at the STACY heterogeneous core. The Hashimoto's difference filter was implemented in the system, which enables the measurement at a critical condition. The measurement result of the new system agreed with the pulsed neutron method. (author)

  10. Newtonian nudging for a Richards equation-based distributed hydrological model

    Science.gov (United States)

    Paniconi, Claudio; Marrocu, Marino; Putti, Mario; Verbunt, Mark

    The objective of data assimilation is to provide physically consistent estimates of spatially distributed environmental variables. In this study a relatively simple data assimilation method has been implemented in a relatively complex hydrological model. The data assimilation technique is Newtonian relaxation or nudging, in which model variables are driven towards observations by a forcing term added to the model equations. The forcing term is proportional to the difference between simulation and observation (relaxation component) and contains four-dimensional weighting functions that can incorporate prior knowledge about the spatial and temporal variability and characteristic scales of the state variable(s) being assimilated. The numerical model couples a three-dimensional finite element Richards equation solver for variably saturated porous media and a finite difference diffusion wave approximation based on digital elevation data for surface water dynamics. We describe the implementation of the data assimilation algorithm for the coupled model and report on the numerical and hydrological performance of the resulting assimilation scheme. Nudging is shown to be successful in improving the hydrological simulation results, and it introduces little computational cost, in terms of CPU and other numerical aspects of the model's behavior, in some cases even improving numerical performance compared to model runs without nudging. We also examine the sensitivity of the model to nudging term parameters including the spatio-temporal influence coefficients in the weighting functions. Overall the nudging algorithm is quite flexible, for instance in dealing with concurrent observation datasets, gridded or scattered data, and different state variables, and the implementation presented here can be readily extended to any of these features not already incorporated. Moreover the nudging code and tests can serve as a basis for implementation of more sophisticated data assimilation

  11. Richard Rufus's theory of mixture: a medieval explanation of chemical combination.

    Science.gov (United States)

    Weisberg, Michael; Wood, Rega

    2003-05-01

    Richard Rufus of Cornwall offered a novel solution to the problem of mixture raised by Aristotle. The puzzle is that mixts or mixed bodies (blood, flesh, wood, etc.) seem to be unexplainable through logic, even though the world is full of them. Rufus's contribution to this long-standing theoretical debate is the development of a modal interpretation of certain Averroistic doctrines. Rufus's account, which posits that the elemental forms in a mixt are in accidental potential, avoids many of the problems that plagued non-atomistic medieval theories of mixture. This paper is an initial examination of Rufus' account.

  12. Maxwell–Lorentz Electrodynamics Revisited via the Lagrangian Formalism and Feynman Proper Time Paradigm

    Directory of Open Access Journals (Sweden)

    Nikolai N. Bogolubov

    2015-04-01

    Full Text Available We review new electrodynamics models of interacting charged point particles and related fundamental physical aspects, motivated by the classical A.M. Ampère magnetic and H. Lorentz force laws electromagnetic field expressions. Based on the Feynman proper time paradigm and a recently devised vacuum field theory approach to the Lagrangian and Hamiltonian, the formulations of alternative classical electrodynamics models are analyzed in detail and their Dirac type quantization is suggested. Problems closely related to the radiation reaction force and electron mass inertia are analyzed. The validity of the Abraham-Lorentz electromagnetic electron mass origin hypothesis is argued. The related electromagnetic Dirac–Fock–Podolsky problem and symplectic properties of the Maxwell and Yang–Mills type dynamical systems are analyzed. The crucial importance of the remaining reference systems, with respect to which the dynamics of charged point particles is framed, is explained and emphasized.

  13. Süüme sundis vabrikujuhti palgatööliseks jääma / Richard Mutso ; interv. Jüri Saar

    Index Scriptorium Estoniae

    Mutso, Richard, 1933-

    2003-01-01

    Intervjuu Võru mööblitehase Wermo peadirektorina töötanud, praeguse tehase nõukogu liikme Richard Mutsoga tehase juhtimisest, euroreferendumist, eraelust. Kommenteerivad: Silva Mutso, Veljo Ipits

  14. Richard Wright's Thematic Treatment of Women in "Uncle Tom's Children,""Black Boy," and "Native Son."

    Science.gov (United States)

    Brewton, Butler E.

    Richard Wright's literary work emphasizes a contrast between black women and white women. Although both are "givers" to black boys, the nature of what they give is different. The black woman gives physical life, feeds it, and protects it at the expense of spiritual or creative vitality. Her goal is to survive bodily, to breathe, to have…

  15. Finding new relationships between hypergeometric functions by evaluating Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, Bernd A. [Santa Barbara Univ., CA (United States). Kavli Inst. for Theoretical Physics; Tarasov, Oleg V. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2011-08-15

    Several new relationships between hypergeometric functions are found by comparing results for Feynman integrals calculated using different methods. A new expression for the one-loop propagator-type integral with arbitrary masses and arbitrary powers of propagators is derived in terms of only one Appell hypergeometric function F{sub 1}. From the comparison of this expression with a previously known one, a new relation between the Appell functions F{sub 1} and F{sub 4} is found. By comparing this new expression for the case of equal masses with another known result, a new formula for reducing the F{sub 1} function with particular arguments to the hypergeometric function {sub 3}F{sub 2} is derived. By comparing results for a particular one-loop vertex integral obtained using different methods, a new relationship between F{sub 1} functions corresponding to a quadratic transformation of the arguments is established. Another reduction formula for the F{sub 1} function is found by analysing the imaginary part of the two-loop self-energy integral on the cut. An explicit formula relating the F{sub 1} function and the Gaussian hypergeometric function {sub 2}F{sub 1} whose argument is the ratio of polynomials of degree six is presented. (orig.)

  16. Regularizing Feynman path integrals using the generalized Kontsevich-Vishik trace

    Science.gov (United States)

    Hartung, Tobias

    2017-12-01

    A fully regulated definition of Feynman's path integral is presented here. The proposed re-formulation of the path integral coincides with the familiar formulation whenever the path integral is well defined. In particular, it is consistent with respect to lattice formulations and Wick rotations, i.e., it can be used in Euclidean and Minkowski space-time. The path integral regularization is introduced through the generalized Kontsevich-Vishik trace, that is, the extension of the classical trace to Fourier integral operators. Physically, we are replacing the time-evolution semi-group by a holomorphic family of operators such that the corresponding path integrals are well defined in some half space of C . The regularized path integral is, thus, defined through analytic continuation. This regularization can be performed by means of stationary phase approximation or computed analytically depending only on the Hamiltonian and the observable (i.e., known a priori). In either case, the computational effort to evaluate path integrals or expectations of observables reduces to the evaluation of integrals over spheres. Furthermore, computations can be performed directly in the continuum and applications (analytic computations and their implementations) to a number of models including the non-trivial cases of the massive Schwinger model and a φ4 theory.

  17. Pimping climate change: Richard Branson, global warming, and the performance of green capitalism

    OpenAIRE

    Scott Prudham

    2009-01-01

    On 21 September 2006 UK über-entrepreneur and Virgin Group Chairman Richard Branson pledged approximately £1.6 billion, the equivalent of all the profits from Virgin Atlantic and Virgin Trains for the next ten years, to fighting climate change. Since then, Branson has restated his commitment to action on global warming, including investment in technologies for sequestering carbon dioxide from the atmosphere. In this paper, I critically examine and engage with Branson’s announcements as a spec...

  18. Feynman-α technique for measurement of detector dead time using a 30 kW tank-in-pool research reactor

    International Nuclear Information System (INIS)

    Akaho, E.H.K.; Intsiful, J.D.K.; Maakuu, B.T.; Anim-Sampong, S.; Nyarko, B.J.B.

    2002-01-01

    Reactor noise analysis was carried out for Ghana Research Reactor-1 GHARR-1, a tank-in-pool type reactor using the Feynman-α technique (variance-to-mean method). Measurements made at different detector positions and under subcritical conditions showed that the technique could not be used to determine the prompt decay constant for the reactor which is Be reflected with photo-neutron background. However, for very low dwell times the technique was used to measure the dead time of the detector which compares favourably with the value obtained using the α-conventional method

  19. Feynman-alpha technique for measurement of detector dead time using a 30 kW tank-in-pool research reactor

    CERN Document Server

    Akaho, E H K; Intsiful, J D K; Maakuu, B T; Nyarko, B J B

    2002-01-01

    Reactor noise analysis was carried out for Ghana Research Reactor-1 GHARR-1, a tank-in-pool type reactor using the Feynman-alpha technique (variance-to-mean method). Measurements made at different detector positions and under subcritical conditions showed that the technique could not be used to determine the prompt decay constant for the reactor which is Be reflected with photo-neutron background. However, for very low dwell times the technique was used to measure the dead time of the detector which compares favourably with the value obtained using the alpha-conventional method.

  20. A semi-classical treatment of dissipative processes based on Feynman's influence functional method

    International Nuclear Information System (INIS)

    Moehring, K.; Smilansky, U.

    1980-01-01

    We develop a semi-classical treatment of dissipative processes based on Feynman's influence functional method. Applying it to deep inelastic collisions of heavy ions we study inclusive transition probabilities corresponding to a situation when only a set of collective variables is specified in the initial and final states. We show that the inclusive probabilities as well as the final energy distributions can be expressed in terms of properly defined classical paths and their corresponding stability fields. We present a uniform approximation for the study of quantal interference and focussing phenomena and discuss the conditions under which they are to be expected. For the dissipation mechanism we study three approximations - the harmonic model for the internal system, the weak coupling (diabatic) and the adiabatic coupling. We show that these three limits can be treated in the same manner. We finally compare the present formalism with other methodes as were introduced for the description of dissipation in deep inelastic collisions. (orig.)

  1. Acceleration of Feynman loop integrals in high-energy physics on many core GPUs

    International Nuclear Information System (INIS)

    Yuasa, F; Ishikawa, T; Hamaguchi, N; Koike, T; Nakasato, N

    2013-01-01

    The current and future colliders in high-energy physics require theorists to carry out a large scale computation for a precise comparison between experimental results and theoretical ones. In a perturbative approach several methods to evaluate Feynman loop integrals which appear in the theoretical calculation of cross-sections are well established in the one-loop level, however, more studies are necessary for higher-order levels. Direct Computation Method (DCM) is developed to evaluate multi-loop integrals. DCM is based on a combination of multidimensional numerical integration and extrapolation on a sequence of integrals. It is a fully numerical method and is applicable to a wide class of integrals with various physics parameters. The computation time depends on physics parameters and the topology of loop diagrams and it becomes longer for the two-loop integrals. In this paper we present our approach to the acceleration of the two-loop integrals by DCM on multiple GPU boards

  2. Triassic marine reptiles gave birth to live young.

    Science.gov (United States)

    Cheng, Yen-Nien; Wu, Xiao-Chun; Ji, Qiang

    2004-11-18

    Sauropterygians form the largest and most diverse group of ancient marine reptiles that lived throughout nearly the entire Mesozoic era (from 250 to 65 million years ago). Although thousands of specimens of this group have been collected around the world since the description of the first plesiosaur in 1821 (ref. 3), no direct evidence has been found to determine whether any sauropterygians came on shore to lay eggs (oviparity) like sea turtles, or gave birth in the water to live young (viviparity) as ichthyosaurs and mosasauroids (marine lizards) did. Viviparity has been proposed for plesiosaur, pachypleurosaur and nothosaur sauropterygians, but until now no concrete evidence has been advanced. Here we report two gravid specimens of Keichousaurus hui Young from the Middle Triassic of China. These exquisitely preserved specimens not only provide the first unequivocal evidence of reproductive mode and sexual dimorphism in sauropterygians, but also indicate that viviparity could have been expedited by the evolution of a movable pelvis in pachypleurosaurs. By extension, this has implications for the reproductive pattern of other sauropterygians and Mesozoic marine reptiles that possessed a movable pelvis.

  3. Iterated elliptic and hypergeometric integrals for Feynman diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, J.; Radu, C.S.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Van Hoeij, M.; Imamoglu, E. [Florida State Univ., Tallahassee, FL (United States). Dept. of Mathematics; Raab, C.G. [Linz Univ. (Austria). Inst. for Algebra

    2017-05-15

    We calculate 3-loop master integrals for heavy quark correlators and the 3-loop QCD corrections to the ρ-parameter. They obey non-factorizing differential equations of second order with more than three singularities, which cannot be factorized in Mellin-N space either. The solution of the homogeneous equations is possible in terms of convergent close integer power series as {sub 2}F{sub 1} Gauss hypergeometric functions at rational argument. In some cases, integrals of this type can be mapped to complete elliptic integrals at rational argument. This class of functions appears to be the next one arising in the calculation of more complicated Feynman integrals following the harmonic polylogarithms, generalized polylogarithms, cyclotomic harmonic polylogarithms, square-root valued iterated integrals, and combinations thereof, which appear in simpler cases. The inhomogeneous solution of the corresponding differential equations can be given in terms of iterative integrals, where the new innermost letter itself is not an iterative integral. A new class of iterative integrals is introduced containing letters in which (multiple) definite integrals appear as factors. For the elliptic case, we also derive the solution in terms of integrals over modular functions and also modular forms, using q-product and series representations implied by Jacobi's θ{sub i} functions and Dedekind's η-function. The corresponding representations can be traced back to polynomials out of Lambert-Eisenstein series, having representations also as elliptic polylogarithms, a q-factorial 1/η{sup κ}(τ), logarithms and polylogarithms of q and their q-integrals. Due to the specific form of the physical variable x(q) for different processes, different representations do usually appear. Numerical results are also presented.

  4. Iterated elliptic and hypergeometric integrals for Feynman diagrams

    International Nuclear Information System (INIS)

    Ablinger, J.; Radu, C.S.; Schneider, C.; Bluemlein, J.; Freitas, A. de; Van Hoeij, M.; Imamoglu, E.; Raab, C.G.

    2017-05-01

    We calculate 3-loop master integrals for heavy quark correlators and the 3-loop QCD corrections to the ρ-parameter. They obey non-factorizing differential equations of second order with more than three singularities, which cannot be factorized in Mellin-N space either. The solution of the homogeneous equations is possible in terms of convergent close integer power series as _2F_1 Gauss hypergeometric functions at rational argument. In some cases, integrals of this type can be mapped to complete elliptic integrals at rational argument. This class of functions appears to be the next one arising in the calculation of more complicated Feynman integrals following the harmonic polylogarithms, generalized polylogarithms, cyclotomic harmonic polylogarithms, square-root valued iterated integrals, and combinations thereof, which appear in simpler cases. The inhomogeneous solution of the corresponding differential equations can be given in terms of iterative integrals, where the new innermost letter itself is not an iterative integral. A new class of iterative integrals is introduced containing letters in which (multiple) definite integrals appear as factors. For the elliptic case, we also derive the solution in terms of integrals over modular functions and also modular forms, using q-product and series representations implied by Jacobi's θ_i functions and Dedekind's η-function. The corresponding representations can be traced back to polynomials out of Lambert-Eisenstein series, having representations also as elliptic polylogarithms, a q-factorial 1/η"κ(τ), logarithms and polylogarithms of q and their q-integrals. Due to the specific form of the physical variable x(q) for different processes, different representations do usually appear. Numerical results are also presented.

  5. Selfish memes: An update of Richard Dawkins’ bibliometric analysis of key papers in sociobiology

    OpenAIRE

    Aaen-Stockdale, Craig

    2017-01-01

    This is an Open Access journal available from http://www.mdpi.com/ In the second edition of The Selfish Gene, Richard Dawkins included a short bibliometric analysis of key papers instrumental to the sociobiological revolution, the intention of which was to support his proposal that ideas spread within a population in an epidemiological manner. In his analysis, Dawkins primarily discussed the influence of an article by British evolutionary biologist William Donald Hamilton which had introdu...

  6. Nothing Risked, Nothing Gained: Richard Powers' Gain and the Horizon of Risk

    Directory of Open Access Journals (Sweden)

    Aaron Jaffe

    2010-02-01

    Full Text Available Cet article interprète Gain, sixième roman de Richard Powers, à la lumière du concept de « seconde modernité » proposé par le sociologue allemand Ulrich Beck. Ce concept souligne la dissémination du risque et la manière dont celle-ci invalide les marchés conclus par la « première modernité » entre l’avenir et le présent, entre l’intérieur du corps et l’extérieur. Cet article entend montrer que Beck fournit un cadre interprétatif utile à la compréhension de ces rapports, hors des impasses catégorielles que suscite l’opposition entre les deux régimes narratifs à l’œuvre dans le texte : le récit biographique, local et individuel, de la maladie de Laura Rowen Bodey, et l’histoire collective de l’entreprise Clare devenue conglomérat.This essay interprets Richard Powers' sixth novel Gain with reference to the German sociologist Ulrich Beck's concept of “second modernity.” The concept underscores the dispersal of risk and how it shreds promissory notes understood in “first modernity” between the future and present and the insides and outsides of the body. It argues that Beck supplies an apt interpretive framework for understanding these relationships and overcoming the categorical impasses between the two narrative words at work in Power's novel, the biographical situatedness of Laura Rowen Bodey's illness and the corporate history of the Clare conglomerate.

  7. Richards Bay Mesometeorological Data – Vertical profiles of air temperature and wind velocity and surface wind statistics.

    CSIR Research Space (South Africa)

    Scholtz, MT

    1978-03-01

    Full Text Available This report details the experimental methods and data obtained in the course of a study of the movement of stable air over a complex region. The field work was carried out in the Richards Bay area on the Natal Coast during the period May to August...

  8. Assets and liabilities are the momentum of particles and antiparticles displayed in Feynman-graphs

    Science.gov (United States)

    Braun, Dieter

    2001-02-01

    An analogy between assets and liabilities and the momentum of particles and antiparticles (called actons and passons) is proposed. It allows physicists to use physical methods in economy for the analysis of monetary systems and for the analysis of double entry bookkeeping. Economists can use it to subdivide and discuss complicated balance transactions in terms of Feynman-graphs which introduce the time dimension to bookkeeping. Within the analogy, assets and liabilities come into existence by pair creation. Conservation of momentum is fulfilled whereas the conservation of energy corresponds to the regulation of a constant amount of money. Interest rates accelerate the particles by imposing a negative friction. The statistical description of an ideal money gas is derived and the transcription to semiconductor physics is given. The analogy is hoped to open a new field for physics and to reveal new insights on monetary systems.

  9. Popular science - common ground. A literary critique of Richard Dawkins's The Selfish Gene

    OpenAIRE

    Nilsen, Helene

    2012-01-01

    This thesis aims to perform a literary reading of Richard Dawkins's The Selfish Gene from a perspective situated outside of the 'battle of the two cultures'. Chapter 1 takes Foucault's article What is an author?" as its point of departure. After discussing how Dawkins may be seen as a reader of Darwin, I will go on to discuss Foucault's concept of the author-function, before I move on to consider some different readings of and approaches to The Selfish Gene. With reference to a polemic bet...

  10. Feynman perturbation expansion for the price of coupon bond options and swaptions in quantum finance. I. Theory.

    Science.gov (United States)

    Baaquie, Belal E

    2007-01-01

    European options on coupon bonds are studied in a quantum field theory model of forward interest rates. Swaptions are briefly reviewed. An approximation scheme for the coupon bond option price is developed based on the fact that the volatility of the forward interest rates is a small quantity. The field theory for the forward interest rates is Gaussian, but when the payoff function for the coupon bond option is included it makes the field theory nonlocal and nonlinear. A perturbation expansion using Feynman diagrams gives a closed form approximation for the price of coupon bond option. A special case of the approximate bond option is shown to yield the industry standard one-factor HJM formula with exponential volatility.

  11. The Need For ``Pleasure in Finding Things Out:'' The Use of History and Our Greatest Scientists for Human Survival and Scientific Integrity

    Science.gov (United States)

    Borchardt, Joshua

    2011-03-01

    Why Homo sapiens search for interesting things and the methods of which we do so. The use of philosophical, theoretical, and demonstrated processes for exploration of the natural, and not so natural world are presented based on the ideas and wishes of some of History's greatest scientists, with concentration on Richard P. Feynman's lens on scientific discovery and pursuit, for which the abstract gets its title. This talk is presented towards the layman as well as the physicist, and gives insight to the nature of discovery and what it means to have pleasure in finding things out for the betterment of all mankind.

  12. The backstairs to the quantum jump. The research of the smallest particles from Max Planck to Anton Zeilinger

    International Nuclear Information System (INIS)

    Fischer, Ernst Peter

    2015-01-01

    It's madness, yet there is method. The physical phenomenon of the quantum jump has already brought some well-known physicists at the edge of dispair. Then nothing seems to be such illogical, undetermined, and unpredictable as the behaviour of the atoms that ultimatively form our world. The renowned historian of sciences Ernst Peter Fischer tells the fascinating story of quantum physics by means of poignant portraits of selected researchers like Max Planck, Werner Heisenberg, Richard P. Feynman, and ''Mr. Beam'' Anton Zeilinger. A great story of science a bout the smallest particles of the nature.

  13. The backstairs to the quantum jump. The research of the smallest particles from Max Planck to Anton Zeilinger; Die Hintertreppe zum Quantensprung. Die Erforschung der kleinsten Teilchen von Max Planck bis Anton Zeilinger

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Ernst Peter

    2015-07-01

    It's madness, yet there is method. The physical phenomenon of the quantum jump has already brought some well-known physicists at the edge of dispair. Then nothing seems to be such illogical, undetermined, and unpredictable as the behaviour of the atoms that ultimatively form our world. The renowned historian of sciences Ernst Peter Fischer tells the fascinating story of quantum physics by means of poignant portraits of selected researchers like Max Planck, Werner Heisenberg, Richard P. Feynman, and ''Mr. Beam'' Anton Zeilinger. A great story of science a bout the smallest particles of the nature.

  14. The effects of coal dust on photosynthetic performance of the mangrove, Avicennia marina in Richards Bay, South Africa

    International Nuclear Information System (INIS)

    Naidoo, G.; Chirkoot, D.

    2004-01-01

    Richards Bay, on the northern KwaZulu-Natal coast, is the largest coal exporting port in South Africa. The coal is stored at the Richards Bay Coal Terminal (RBCT) prior to export. Dust from coal operations is a major problem in the Richards Bay area. In this study, we tested the hypothesis that coal dust adversely affects photosynthetic performance of Avicennia marina (Forssk.) Vierh., the dominant mangrove species in the harbour. Photosynthetic performance was determined on 10 trees by measuring carbon dioxide uptake and chlorophyll fluorescence parameters at two elevation sites and on upper and lower leaf surfaces that were covered or uncovered with coal dust. Measurements were made on five clear, sunny days at saturating light (>1000 μmol m -2 s -1 ) and high temperature (28-30 deg. C). Coal dust significantly reduced carbon dioxide exchange of upper and lower leaf surfaces by 17-39%, the reduction being generally greater on the lower leaf surface that is covered by a dense mat of trichomes and salt glands. The reduction in carbon dioxide exchange by coal dust was higher at the high elevation site that supported isolated dwarfed trees. The chlorophyll fluorescence data indicated that leaves coated with dust exhibited significantly lower photosystem II (PS II) quantum yield, lower electron transport rate (ETR) through PSII and reduced quantum efficiency of PSII (F v F m ). The chlorophyll fluorescence data supported the gas exchange measurements and are consistent with reduced photosynthetic performance of leaves coated with coal dust. - Coal dust reduced photosynthetic performance of the mangrove, Avicennia marina

  15. Marie-Christine Agosto. Richard Brautigan. Les fleurs de néant.

    Directory of Open Access Journals (Sweden)

    Jean-Bernard Basse

    2006-04-01

    Full Text Available Richard Brautigan, si on lui reconnaît un certain humour, est souvent associé avec condescendance au phénomène hippy et considéré comme un auteur démodé, superficiel. Celui qui écrivait dans Cahier d’un Retour de Troie : « Les mots sont des fleurs de néant » est pourtant l’un de ces écrivains que l’on pourrait qualifier de mineurs essentiels, et seuls ceux qui l’ont peu ou mal lu s’étonneront de ce que Marie-Christine Agosto ait choisi de donner comme sous-titre « Les fleurs de néant » au pet...

  16. Transcendence, Taxis, Trust: Richard Kearney and Jacques Derrida

    Directory of Open Access Journals (Sweden)

    Ulrich Schmiedel

    2017-03-01

    Full Text Available Whatever else it takes to drive a taxi, it takes trust. Day after day, the driver has to decide whether the other is or is not trustworthy. I take the taxi as a test case to analyze and assess Richard Kearney’s diacritical hermeneutics of the other. I argue that Kearney functionalizes the concept of transcendence in order to connect the transcendence of the finite other to the transcendence of the infinite other. However, in his central critique of the deconstructionists following Jacques Derrida, Kearney counters his connection. While Kearney’s critique of Derrida’s account of absolute alterity is correct and compelling, I argue that Derrida’s critique of a distinction between the trustworthy other and the non-trustworthy other might be more crucial than Kearney contends. Insisting on openness to the other’s otherness, Derrida provokes any hermeneutic of the other to trust in transcendence. The taxi is taken as a test to illustrate the implications which diacritical and deconstructive drivers might have for evaluating the entanglement of ethics and eschatology—inside and outside the taxi.

  17. Richard J. Bernstein on Ethics and Philosophy between the Linguistic and the Pragmatic Turn

    OpenAIRE

    Marchetti, Sarin

    2017-01-01

    1. In his compelling article American Pragmatism: The Conflict of Narratives, Richard Bernstein quotes a perceptive line by Alasdair MacIntyre that goes [A] tradition not only embodies the narrative of an argument, but is only recovered by an argumentative retelling of that narrative which will itself be in conflict with other argumentative retellings. Bernstein, in the essay mentioned, works through MacIntyre’s passage in order to “engage in the ‘argumentative retelling’ of a metanarrative –...

  18. A Case of Resistant SUNCT that Gave Response to Steroid Treatment

    Directory of Open Access Journals (Sweden)

    Hakan Levent Gül

    2014-03-01

    Full Text Available Conjunctival injection and tearing with unilateral short lasting neuralgiform headache syndrome is called as SUNCT. Even though these headaches are reported seldomly, the prevalence is possibly higher than known. It is of importance to recognize these uncommon disorder, since its management differs from common primary headaches. Until today, it was reported to be treated with different types of drugs. We here reported a 30 years old male patient with normal neurological examination, blood examination and neuroimaging. Our patient gave no response to indomethacin, gabapentine and carbamazepine treatments. This case is an example of SUNCT case treated with steroid

  19. Diagnosis and treatment of polycystic ovary syndrome (PCOS): an interview with Richard Legro.

    Science.gov (United States)

    Legro, Richard

    2015-03-27

    In this podcast, we talk to Professor Richard Legro about the recommendations for the diagnosis and treatment of polycystic ovary syndrome (PCOS) based on clinical practice guidelines and discuss the challenges of diagnosis PCOS at specific age groups. The controversies associated with treatment of PCOS, including therapies for infertility as this is a problem commonly observed in PCOS subjects, are highlighted together with future directions on the topic. The podcast for this interview is available at. http://www.biomedcentral.com/content/supplementary/s12916-015-0299-2-s1.mp3.

  20. Numerical evaluation of Feynman loop integrals by reduction to tree graphs

    International Nuclear Information System (INIS)

    Kleinschmidt, T.

    2007-12-01

    We present a method for the numerical evaluation of loop integrals, based on the Feynman Tree Theorem. This states that loop graphs can be expressed as a sum of tree graphs with additional external on-shell particles. The original loop integral is replaced by a phase space integration over the additional particles. In cross section calculations and for event generation, this phase space can be sampled simultaneously with the phase space of the original external particles. Since very sophisticated matrix element generators for tree graph amplitudes exist and phase space integrations are generically well understood, this method is suited for a future implementation in a fully automated Monte Carlo event generator. A scheme for renormalization and regularization is presented. We show the construction of subtraction graphs which cancel ultraviolet divergences and present a method to cancel internal on-shell singularities. Real emission graphs can be naturally included in the phase space integral of the additional on-shell particles to cancel infrared divergences. As a proof of concept, we apply this method to NLO Bhabha scattering in QED. Cross sections are calculated and are in agreement with results from conventional methods. We also construct a Monte Carlo event generator and present results. (orig.)

  1. Numerical evaluation of Feynman loop integrals by reduction to tree graphs

    Energy Technology Data Exchange (ETDEWEB)

    Kleinschmidt, T.

    2007-12-15

    We present a method for the numerical evaluation of loop integrals, based on the Feynman Tree Theorem. This states that loop graphs can be expressed as a sum of tree graphs with additional external on-shell particles. The original loop integral is replaced by a phase space integration over the additional particles. In cross section calculations and for event generation, this phase space can be sampled simultaneously with the phase space of the original external particles. Since very sophisticated matrix element generators for tree graph amplitudes exist and phase space integrations are generically well understood, this method is suited for a future implementation in a fully automated Monte Carlo event generator. A scheme for renormalization and regularization is presented. We show the construction of subtraction graphs which cancel ultraviolet divergences and present a method to cancel internal on-shell singularities. Real emission graphs can be naturally included in the phase space integral of the additional on-shell particles to cancel infrared divergences. As a proof of concept, we apply this method to NLO Bhabha scattering in QED. Cross sections are calculated and are in agreement with results from conventional methods. We also construct a Monte Carlo event generator and present results. (orig.)

  2. Richard J. Hill, Picturing Scotland through the Waverley Novels: Walter Scott and the Origins of the Victorian Illustrated Novel.

    Directory of Open Access Journals (Sweden)

    Jacqueline Irene Cannata

    2012-10-01

    Full Text Available Richard J. Hill, Picturing Scotland through the Waverley Novels: Walter Scott and the Origins of the Victorian Illustrated Novel . Farnham, Surrey, and Burlington, VT: Ashgate, 2010. Pp. 236. ISBN 978-0-7546-6806-0. US$99.99.

  3. On the presentation of wave phenomena of electrons with the Young-Feynman experiment

    International Nuclear Information System (INIS)

    Matteucci, Giorgio

    2011-01-01

    The Young-Feynman two-hole interferometer is widely used to present electron wave-particle duality and, in particular, the buildup of interference fringes with single electrons. The teaching approach consists of two steps: (i) electrons come through only one hole but diffraction effects are disregarded and (ii) electrons come through both holes and interference fringes are described. Therefore, a student might believe that wave phenomena are not revealed in case (i), but they arise only by the combined effect of electrons from the two holes. To avoid misunderstanding regarding the distribution of electrons passing through one hole, Fresnel and Fraunhofer diffraction patterns are discussed. In particular, an original experiment, realized with a standard electron microscope and a sample with round holes, is presented to introduce the wave nature of electrons. The experimental results clearly show that a careful discussion of electron diffraction phenomena from one hole provides students with the evidence that the interference experiment from both holes is not strictly required to show the superposition of electron waves.

  4. Trochanteric fractures

    International Nuclear Information System (INIS)

    Herrlin, K.; Stroemberg, T.; Lidgren, L.; Walloee, A.; Pettersson, H.; Lund Univ.

    1988-01-01

    Four hundred and thirty trochanteric factures operated upon with McLaughlin, Ender or Richard's osteosynthesis were divided into 6 different types based on their radiographic appearance before and immediately after reposition with special reference to the medial cortical support. A significant correlation was found between the fracture type and subsequent mechanical complications where types 1 and 2 gave less, and types 4 and 5 more complications. A comparison of the various osteosyntheses showed that Richard's had significantly fewer complications than either the Ender or McLaughlin types. For Richard's osteosynthesis alone no correlation to fracture type could be made because of the small number of complications in this group. (orig.)

  5. The effect of the vertical part of the path on the real time Feynman rules in finite temperature field theory 2-point functions and vacuum diagrams

    International Nuclear Information System (INIS)

    Gelis, F.

    1996-01-01

    The effect of the contribution of the vertical part of the real time path is studied completely in the case of two points functions and vacuum diagrams. Indeed, this vertical part generally contributes in the calculation of a given graph. Moreover, this contribution is essential in order to have a consistent equilibrium theory: thanks to this contribution, the Green functions are effectively invariant by time translation, as they should be. As a by product, it is shown that the perturbative calculations give a result which does not depend on the initial time t I and final time t F of the path. The property of independence with respect to t I is closely related to the KMS conditions, i.e. to the fact the system is in thermal equilibrium. In the case of two point functions and vacuum diagrams, the contribution of the vertical part can be taken into account by the n(vertical stroke k 0 vertical stroke) prescription in the usual RTF Feynman rules. The extra Feynman rule needed for vacuum diagrams is shown not to be related directly to the contribution of the vertical part of the path. (orig.). With 4 figs

  6. Path integral formulation and Feynman rules for phylogenetic branching models

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, P D; Bashford, J D; Sumner, J G [School of Mathematics and Physics, University of Tasmania, GPO Box 252C, 7001 Hobart, TAS (Australia)

    2005-11-04

    A dynamical picture of phylogenetic evolution is given in terms of Markov models on a state space, comprising joint probability distributions for character types of taxonomic classes. Phylogenetic branching is a process which augments the number of taxa under consideration, and hence the rank of the underlying joint probability state tensor. We point out the combinatorial necessity for a second-quantized, or Fock space setting, incorporating discrete counting labels for taxa and character types, to allow for a description in the number basis. Rate operators describing both time evolution without branching, and also phylogenetic branching events, are identified. A detailed development of these ideas is given, using standard transcriptions from the microscopic formulation of non-equilibrium reaction-diffusion or birth-death processes. These give the relations between stochastic rate matrices, the matrix elements of the corresponding evolution operators representing them, and the integral kernels needed to implement these as path integrals. The 'free' theory (without branching) is solved, and the correct trilinear 'interaction' terms (representing branching events) are presented. The full model is developed in perturbation theory via the derivation of explicit Feynman rules which establish that the probabilities (pattern frequencies of leaf colourations) arising as matrix elements of the time evolution operator are identical with those computed via the standard analysis. Simple examples (phylogenetic trees with two or three leaves), are discussed in detail. Further implications for the work are briefly considered including the role of time reparametrization covariance.

  7. Path integral formulation and Feynman rules for phylogenetic branching models

    International Nuclear Information System (INIS)

    Jarvis, P D; Bashford, J D; Sumner, J G

    2005-01-01

    A dynamical picture of phylogenetic evolution is given in terms of Markov models on a state space, comprising joint probability distributions for character types of taxonomic classes. Phylogenetic branching is a process which augments the number of taxa under consideration, and hence the rank of the underlying joint probability state tensor. We point out the combinatorial necessity for a second-quantized, or Fock space setting, incorporating discrete counting labels for taxa and character types, to allow for a description in the number basis. Rate operators describing both time evolution without branching, and also phylogenetic branching events, are identified. A detailed development of these ideas is given, using standard transcriptions from the microscopic formulation of non-equilibrium reaction-diffusion or birth-death processes. These give the relations between stochastic rate matrices, the matrix elements of the corresponding evolution operators representing them, and the integral kernels needed to implement these as path integrals. The 'free' theory (without branching) is solved, and the correct trilinear 'interaction' terms (representing branching events) are presented. The full model is developed in perturbation theory via the derivation of explicit Feynman rules which establish that the probabilities (pattern frequencies of leaf colourations) arising as matrix elements of the time evolution operator are identical with those computed via the standard analysis. Simple examples (phylogenetic trees with two or three leaves), are discussed in detail. Further implications for the work are briefly considered including the role of time reparametrization covariance

  8. Dr. Richard J. Whelan: Seeing the Field of Emotional and Behavior Disorders through the Lens of a Pioneer

    Science.gov (United States)

    Kaff, Marilyn S.; Teagarden, Jim; Zabel, Robert H.

    2011-01-01

    Dr. Richard J. Whelan is a distinguished professor emeritus at the University of Kansas. His earliest professional experiences were at the Children's Hospital (Southard School) of the Menninger Clinic, where he served as a recreational therapist, teacher, and director of education. During his career at the University of Kansas and the KU Medical…

  9. Richards growth model and viability indicators for populations subject to interventions

    Directory of Open Access Journals (Sweden)

    Selene Loibel

    2010-12-01

    Full Text Available In this work we study the problem of modeling identification of a population employing a discrete dynamic model based on the Richards growth model. The population is subjected to interventions due to consumption, such as hunting or farming animals. The model identification allows us to estimate the probability or the average time for a population number to reach a certain level. The parameter inference for these models are obtained with the use of the likelihood profile technique as developed in this paper. The identification method here developed can be applied to evaluate the productivity of animal husbandry or to evaluate the risk of extinction of autochthon populations. It is applied to data of the Brazilian beef cattle herd population, and the the population number to reach a certain goal level is investigated.Neste trabalho estudamos o problema de identificação do modelo de uma população utilizando um modelo dinâmico discreto baseado no modelo de crescimento de Richards. A população é submetida a intervenções devido ao consumo, como no caso de caça ou na criação de animais. A identificação do modelo permite-nos estimar a probabilidade ou o tempo médio de ocorrência para que se atinja um certo número populacional. A inferência paramétrica dos modelos é obtida através da técnica de perfil de máxima verossimilhança como desenvolvida neste trabalho. O método de identificação desenvolvido pode ser aplicado para avaliar a produtividade de criação animal ou o risco de extinção de uma população autóctone. Ele foi aplicado aos dados da população global de gado de corte bovino brasileiro, e é utilizado na investigação de a população atingir um certo número desejado de cabeças.

  10. Richard Murphy: Autobiography and the Connemara landscape

    Directory of Open Access Journals (Sweden)

    Elsa Meihuizen

    2015-08-01

    Full Text Available It could be argued that an important feature of Richard Murphy’s work, and of his identity as a poet is the relationship between the creative self and a particular place, where ‘place’ should be understood as referring not just to physical qualities of the natural environment, but in a broader sense to denote an environment in which everything is interrelated and connected, and in which there is no sharp division between the natural and the human. The landscape providing inspiration for Murphy’s poetic imagination is the landscapes and seascapes of Connemara in north-west Ireland. In 1959 he settled in this environment which was to be his base for the next 20 years and from this period and this location emanated the bulk of his poetic oeuvre. For Murphy committing to a life of writing poetry necessarily means being in the Connemara landscape. Returning to this environment in adulthood represents a quest for recovering childhood feelings, of belonging and love, as connected to particular places. Murphy’s Connemara poems could be read as an account of this process of re-placement, as a type of autobiographical text in which the artist creates a ‘double portrait’: in writing about the landscape he also writes about himself, creating a place-portrait which is, at the same time, a self-portrait.

  11. Lucien Cuénot, Richard Goldschmidt y Miquel Crusafont Pairó

    Directory of Open Access Journals (Sweden)

    Casinos, Adrià

    2016-06-01

    Full Text Available An unpublished text, corresponding to a communication done by Crusafont Pairó is analysed. The communication is strongly critical with Cuénot’s necrology published previously by Goldschmidt, where he regrets the teleological ideas on evolution that Cuénot maintained in the last years of his life.Se analiza un texto inédito de Miquel Crusafont Pairó, correspondiente a comunicación que llevó a cabo en la Fundació Bosch i Cardellach, sobre la necrológica de Lucien Cuénot publicada por Richard Goldschmidt. La comunicación es un fuerte ataque a Goldschmidt por sus críticas a la deriva teleológica de Cuénot en los últimos años de su vida.

  12. Why Was General Richard O’Connor’s Command in Northwest Europe Less Effective Than Expected?

    Science.gov (United States)

    2011-03-01

    Commander of 7 Division and Military Governor of Jerusalem , September 1938- August 1939. ______. Papers of General Sir Richard O’Connor KT, GCB, DSO, MC...Montgomery, Brian. A Field Marshall in the Family: A Personal Biography of Montgomery of Alamein. New York: Taplinger, 1973. Montgomery, Field...Commanders: A Composite Biography . Combat Studies Institute publications, Fort Leavenworth, Kansas: U.S. Army Command and General Staff College, 1989

  13. A modern theory of random variation with applications in stochastic calculus, financial mathematics, and Feynman integration

    CERN Document Server

    Muldowney, Patrick

    2012-01-01

    A Modern Theory of Random Variation is a new and radical re-formulation of the mathematical underpinnings of subjects as diverse as investment, communication engineering, and quantum mechanics. Setting aside the classical theory of probability measure spaces, the book utilizes a mathematically rigorous version of the theory of random variation that bases itself exclusively on finitely additive probability distribution functions. In place of twentieth century Lebesgue integration and measure theory, the author uses the simpler concept of Riemann sums, and the non-absolute Riemann-type integration of Henstock. Readers are supplied with an accessible approach to standard elements of probability theory such as the central limmit theorem and Brownian motion as well as remarkable, new results on Feynman diagrams and stochastic integrals. Throughout the book, detailed numerical demonstrations accompany the discussions of abstract mathematical theory, from the simplest elements of the subject to the most complex. I...

  14. Símbolo y forma: los hermanos Grimm en Richard Wagner

    Directory of Open Access Journals (Sweden)

    Miguel Salmerón Infante

    2015-05-01

    Full Text Available Este escrito estudia el cómo y el porqué de la presencia de los Cuentos de los Hermanos Grimm en la obra de Richard Wagner. Para dar un enfoque más concreto a esta reflexión el análisis se centra en Sigfrido, el drama musical de Wagner con más atmósfera de cuento, y las influencias y préstamos temáticos, formales y lingüísticos que le aportan los KHM. El artículo entiende que hay dos elementos que aprovecha Wagner de los Grimm para sus dramas musicales. El símbolo para su proyecto de tejido de la identidad alemana. Y la forma del cuento con sus temas y fórmulas recurrentes que el aplicó a su música y muy concretamente al Leitmotiv. Todo ello sin olvidar la muy frecuente presencia de la figura del huérfano tanto en Wagner como en los Grimm.  

  15. Kinetic parameters of the GUINEVERE reference configuration in VENUS-F reactor obtained from a pile noise experiment using Rossi and Feynman methods

    Energy Technology Data Exchange (ETDEWEB)

    Geslot, Benoit; Pepino, Alexandra; Blaise, Patrick; Mellier, Frederic [CEA, DEN, DER/SPEx, Cadarache, F-13108 St Paul Lez Durance (France); Lecouey, Jean-Luc [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, 6 Bd. Marechal Juin 14050 Caen cedex (France); Carta, Mario [ENEA, UTFISST-REANUC, C.R. Casaccia, S.P.040 via Anguillarese 301, 00123 S. Maria Di Galeria, Roma (Italy); Kochetkov, Anatoly; Vittiglio, Guido [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, BE-2400, Mol (Belgium); Billebaud, Annick [LPSC, CNRS, IN2P3/UJF/INPG, 53 Avenue des Martyrs, 38026 Grenoble cedex (France)

    2015-07-01

    A pile noise measurement campaign has been conducted by the CEA in the VENUS-F reactor (SCK-CEN, Mol Belgium) in April 2011 in the reference critical configuration of the GUINEVERE experimental program. The experimental setup made it possible to estimate the core kinetic parameters: the prompt neutron decay constant, the delayed neutron fraction and the generation time. A precise assessment of these constants is of prime importance. In particular, the effective delayed neutron fraction is used to normalize and compare calculated reactivities of different subcritical configurations, obtained by modifying either the core layout or the control rods position, with experimental ones deduced from the analysis of measurements. This paper presents results obtained with a CEA-developed time stamping acquisition system. Data were analyzed using Rossi-α and Feynman-α methods. Results were normalized to reactor power using a calibrated fission chamber with a deposit of Np-237. Calculated factors were necessary to the analysis: the Diven factor was computed by the ENEA (Italy) and the power calibration factor by the CNRS/IN2P3/LPC Caen. Results deduced with both methods are consistent with respect to calculated quantities. Recommended values are given by the Rossi-α estimator, that was found to be the most robust. The neutron generation time was found equal to 0.438 ± 0.009 μs and the effective delayed neutron fraction is 765 ± 8 pcm. Discrepancies with the calculated value (722 pcm, calculation from ENEA) are satisfactory: -5.6% for the Rossi-α estimate and -2.7% for the Feynman-α estimate. (authors)

  16. Leachate flow around a well in MSW landfill: Analysis of field tests using Richards model.

    Science.gov (United States)

    Slimani, R; Oxarango, L; Sbartai, B; Tinet, A-J; Olivier, F; Dias, D

    2017-05-01

    During the lifespan of a Municipal Solid Waste landfill, its leachate drainage system may get clogged. Then, as a consequence of rainfall, leachate generation and possibly leachate injection, the moisture content in the landfill increases to the point that a leachate mound could be created. Therefore, pumping the leachate becomes a necessary solution. This paper presents an original analysis of leachate pumping and injection in an instrumented well. The water table level around the well is monitored by nine piezometers which allow the leachate flow behaviour to be captured. A numerical model based on Richards equation and an exponential relationship between saturated hydraulic conductivity and depth is used to analyze the landfill response to pumping and injection. Decreasing permeability with depth appears to have a major influence on the behaviour of the leachate flow. It could have a drastic negative impact on the pumping efficiency with a maximum quasi-stationary pumping rate limited to approximately 1m 3 /h for the tested well and the radius of influence is less than 20m. The numerical model provides a reasonable description of both pumping and injection tests. However, an anomalous behaviour observed at the transition between pumping and recovery phases is observed. This could be due to a limitation of the Richards model in that it neglects the gas phase behaviour and other double porosity heterogeneous effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. An experimental ‘Life’ for an experimental life : Richard Waller's biography of Robert Hooke (1705)

    OpenAIRE

    Moxham, Noah

    2016-01-01

    Richard Waller's ‘Life of Dr Robert Hooke’, prefixed to his edition of Hooke's Posthumous Works (1705), is an important source for the life of one of the most eminent members of the early Royal Society. It also has the distinction of being one of the earliest biographies of a man of science to be published in English. I argue that it is in fact the first biography to embrace the subject's natural-philosophical work as the centre of his life, and I investigate Waller's reasons for adopting thi...

  18. Exact and grid-free solutions to the Lighthill-Whitham-Richards traffic flow model with bounded acceleration for a class of fundamental diagrams

    KAUST Repository

    Qiu, Shanwen; Abdelaziz, Mohamed Ewis; Abdel Latif, Fadl Hicham Fadl; Claudel, Christian G.

    2013-01-01

    In this article, we propose a new exact and grid-free numerical scheme for computing solutions associated with an hybrid traffic flow model based on the Lighthill-Whitham-Richards (LWR) partial differential equation, for a class of fundamental

  19. Harmonic analysis, partial differential equations and applications in honor of Richard L. Wheeden

    CERN Document Server

    Franchi, Bruno; Lu, Guozhen; Perez, Carlos; Sawyer, Eric

    2017-01-01

    This is a collection of contributed papers by many eminent Harmonic Analysts and specialists of Partial Differential equations. The papers focus on weighted norm equalities for singular integrals, focusing wave equations, degenerate elliptic equations, Navier-Stokes flow in two dimensions and Poincare-Sobolev inequalities in the setting of metric spaces equipped with measures among others. Many topics considered in this volume stem from the interests of Richard L. Wheeden whose contributions to Potential Theory, singular integral theory and degenerate elliptic PDE theory this volume honors. Luis Caffarelli, Sagun Chanillo, Bruno Franchi, Cristian Guttierez, Xiaojun Huang, Carlos Kenig, Ermanno Lanconelli, Eric Sawyer and Alexander Volberg, are some of the many contributors to this volume. .

  20. Building logical qubits in a superconducting quantum computing system

    Science.gov (United States)

    Gambetta, Jay M.; Chow, Jerry M.; Steffen, Matthias

    2017-01-01

    The technological world is in the midst of a quantum computing and quantum information revolution. Since Richard Feynman's famous `plenty of room at the bottom' lecture (Feynman, Engineering and Science23, 22 (1960)), hinting at the notion of novel devices employing quantum mechanics, the quantum information community has taken gigantic strides in understanding the potential applications of a quantum computer and laid the foundational requirements for building one. We believe that the next significant step will be to demonstrate a quantum memory, in which a system of interacting qubits stores an encoded logical qubit state longer than the incorporated parts. Here, we describe the important route towards a logical memory with superconducting qubits, employing a rotated version of the surface code. The current status of technology with regards to interconnected superconducting-qubit networks will be described and near-term areas of focus to improve devices will be identified. Overall, the progress in this exciting field has been astounding, but we are at an important turning point, where it will be critical to incorporate engineering solutions with quantum architectural considerations, laying the foundation towards scalable fault-tolerant quantum computers in the near future.

  1. Book review: Unholy trinity: The IMF, World Bank and WTO Richard Peet

    Directory of Open Access Journals (Sweden)

    M Breitenbach

    2014-05-01

    Full Text Available In this timely book Richard Peet and his team lay the foundation with an excellent analysis of the process of globalisation and the resultant emergence of the global economy. The authors are especially critical of the increasing influence of institutions like the International Monetary Fund (IMF, World Bank and World Trade Organisation (WTO on the economy and the consequences experienced by peoples, cultures and the environment. The single ideology of neo-liberalism is blamed for the undesirable outcomes. This book considers concepts of power, political interest, hegemony, discourse, responsibility and the power of practicality, in critically examining the IMF, World Bank and WTO. The conclusion is reached that “all three institutions play roles greatly different from those originally agreed to under the charters that set them up”.

  2. The charged Higgs boson mass of the MSSM in the Feynman-diagrammatic approach

    Energy Technology Data Exchange (ETDEWEB)

    Frank, M. [Karlsruhe Univ. (Germany). Inst. fuer Theoretische Physik; Galeta, L.; Heinemeyer, S. [Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain); Hahn, T.; Hollik, W. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany); Rzehak, H. [CERN, Geneva (Switzerland); Weiglein, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-06-15

    The interpretation of the Higgs signal at {proportional_to}126 GeV within the Minimal Supersymmetric Standard Model (MSSM) depends crucially on the predicted properties of the other Higgs states of the model, as the mass of the charged Higgs boson, M{sub H}{sup {sub {+-}}}. This mass is calculated in the Feynman-diagrammatic approach within the MSSM with real parameters. The result includes the complete one-loop contributions and the two-loop contributions of O({alpha}{sub t}{alpha}{sub s}). The one-loop contributions lead to sizable shifts in the M{sub H}{sup {sub {+-}}} prediction, reaching up to {proportional_to}8 GeV for relatively small values of M{sub A}. Even larger effects can occur depending on the sign and size of the {mu} parameter that enters the corrections affecting the relation between the bottom-quark mass and the bottom Yukawa coupling. The two-loop O({alpha}{sub t}{alpha}{sub s}) terms can shift M{sub H}{sup {sub {+-}}} by more than 2 GeV. The two-loop contributions amount to typically about 30% of the one-loop corrections for the examples that we have studied. These effects can be relevant for precision analyses of the charged MSSM Higgs boson.

  3. Richard Wrangham. Catching fire. How cooking made us Human. Basic Books (Perseus Books Group

    Directory of Open Access Journals (Sweden)

    Claude-Marcel Hladik

    2009-11-01

    Full Text Available L’histoire de l’émergence de l’homme est remise en cause par cet ouvrage puisque jusqu’à présent la plupart des anthropologues et des paléontologues s’accordaient pour faire remonter à environ 500.000 ans les premières utilisations du feu pour la cuisson des aliments par le genre Homo. Les arguments présentés par Richard Wrangham dans son dernier ouvrage nous font remonter aux deux derniers millions d’années. Wrangham et ses collègues avaient publié, dès 1999, les résultats de fouilles au cou...

  4. A new look at the Feynman ‘hodograph’ approach to the Kepler first law

    Science.gov (United States)

    Cariñena, José F.; Rañada, Manuel F.; Santander, Mariano

    2016-03-01

    Hodographs for the Kepler problem are circles. This fact, known for almost two centuries, still provides the simplest path to derive the Kepler first law. Through Feynman’s ‘lost lecture’, this derivation has now reached a wider audience. Here we look again at Feynman’s approach to this problem, as well as the recently suggested modification by van Haandel and Heckman (vHH), with two aims in mind, both of which extend the scope of the approach. First we review the geometric constructions of the Feynman and vHH approaches (that prove the existence of elliptic orbits without making use of integral calculus or differential equations) and then extend the geometric approach to also cover the hyperbolic orbits (corresponding to E\\gt 0). In the second part we analyse the properties of the director circles of the conics, which are used to simplify the approach, and we relate with the properties of the hodographs and Laplace-Runge-Lenz vector the constant of motion specific to the Kepler problem. Finally, we briefly discuss the generalisation of the geometric method to the Kepler problem in configuration spaces of constant curvature, i.e. in the sphere and the hyperbolic plane.

  5. A Conditional Fourier-Feynman Transform and Conditional Convolution Product with Change of Scales on a Function Space II

    Directory of Open Access Journals (Sweden)

    Dong Hyun Cho

    2017-01-01

    Full Text Available Using a simple formula for conditional expectations over continuous paths, we will evaluate conditional expectations which are types of analytic conditional Fourier-Feynman transforms and conditional convolution products of generalized cylinder functions and the functions in a Banach algebra which is the space of generalized Fourier transforms of the measures on the Borel class of L2[0,T]. We will then investigate their relationships. Particularly, we prove that the conditional transform of the conditional convolution product can be expressed by the product of the conditional transforms of each function. Finally we will establish change of scale formulas for the conditional transforms and the conditional convolution products. In these evaluation formulas and change of scale formulas, we use multivariate normal distributions so that the conditioning function does not contain present positions of the paths.

  6. A sense of the mysterious science and the human spirit

    CERN Document Server

    Lightman, Alan

    2006-01-01

    From the bestselling author of Einstein's Dreams comes this lyrical and insightful collection of science writing that delves into the mysteries of the scientific process and exposes its beauty and intrigue.In these brilliant essays, Lightman explores the emotional life of science, the power of imagination, the creative moment, and the alternate ways in which scientists and humanists think about the world. Along the way, he provides in-depth portraits of some of the great geniuses of our time, including Albert Einstein, Richard Feynman, Edward Teller, and astronomer Vera Rubin. Thoughtful, beautifully written, and wonderfully original, A Sense of the Mysterious confirms Alan Lightman's unique position at the crossroads of science and art.

  7. Scanning probe microscopy

    International Nuclear Information System (INIS)

    Mainsbridge, B.

    1994-01-01

    In late 1959, Richard Feynman observed that manoeuvring atoms was something that could be done in principle but has not been done, 'because we are too big'. In 1982, the scanning tunnelling microscope (STM) was invented and is now a central tool for the construction of nanoscale devices in what was known as molecular engineering, and now, nanotechnology. The principles of the microscope are outlined and references are made to other scanning devices which have evolved from the original invention. The method of employment of the STM as a machine tool is described and references are made to current speculations on applications of the instrument in nanotechnology. A short bibliography on this topic is included. 27 refs., 7 figs

  8. Scanning probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mainsbridge, B [Murdoch Univ., WA (Australia). School of Mathematical and Physical Sciences

    1994-12-31

    In late 1959, Richard Feynman observed that manoeuvring atoms was something that could be done in principle but has not been done, `because we are too big`. In 1982, the scanning tunnelling microscope (STM) was invented and is now a central tool for the construction of nanoscale devices in what was known as molecular engineering, and now, nanotechnology. The principles of the microscope are outlined and references are made to other scanning devices which have evolved from the original invention. The method of employment of the STM as a machine tool is described and references are made to current speculations on applications of the instrument in nanotechnology. A short bibliography on this topic is included. 27 refs., 7 figs.

  9. Fred Hoyle, Le Nuage noir ; James Lequeux, « Et si c’était possible »

    OpenAIRE

    Chabot, Hugues

    2014-01-01

    Fred Hoyle (1915-2001), un des plus brillants astronomes du vingtième siècle, est resté célèbre pour ses contributions à l’astrophysique nucléaire et pour avoir défendu toute sa vie une cosmologie alternative à la théorie du Grand Boum (Big Bang), théorie qu’il avait d’ailleurs lui-même baptisée ainsi par dérision. Son nom figure aux côtés de ceux de Francis Crick (1916-2004) ou de Richard Feynman (1918-1988) dans le très sélectif New Dictionary of Scientific Biography publié par Noretta Koer...

  10. Meeting to honor F. Richard Stephenson on his 70th birthday

    CERN Document Server

    Green, David; Strom, Richard

    2015-01-01

    This book contains papers from a conference held to celebrate the 70th birthday of one of the world’s foremost astronomical historians, Professor F. Richard Stephenson, the latest recipient of the American Astronomical Society’s highest award for research in astronomical history, the LeRoy Doggett Prize. Reflecting Professor Stephenson’s extensive research portfolio, this book brings together under one cover papers on four different areas of scholarship: applied historical astronomy (which Stephenson founded); Islamic astronomy; Oriental astronomy; and amateur astronomy.  These papers are penned by astronomers from Canada, China, England, France, Georgia, Iran, Japan, Lebanon, the Netherlands, Portugal, Thailand and the USA. Its diverse coverage represents a wide cross-section of the history of astronomy community.  Under discussion are ways in which recent research using historical data has provided new insights into auroral and solar activity, supernovae and changes in the rotation rate of the E...

  11. A critical review of Richard Lynn's reports on reaction time and race.

    Science.gov (United States)

    Thomas, Drew M

    2011-01-01

    In the early 1990s, psychologist Richard Lynn published papers documenting average reaction times and decision times in samples of nine-year-olds taken from across the world. After summarizing these data, Lynn interpreted his results as evidence of national and racial differences in decision time and general intelligence. Others have also interpreted Lynn's data as evidence of racial differences in decision time and intelligence. However, comparing Lynn's summaries with his original reports shows that Lynn misreported and omitted some of his own data. Once these errors are fixed the rankings of nations in Lynn's datasets are unstable across different decision time measures. This instability, as well as within-race heterogeneity and between-race overlap in decision times, implies that Lynn's reaction time data do not permit generalizations about the decision times and intelligence of people of different races.

  12. AD-1 with research pilot Richard E. Gray

    Science.gov (United States)

    1982-01-01

    Standing in front of the AD-1 Oblique Wing research aircraft is research pilot Richard E. Gray. Richard E. Gray joined National Aeronautics and Space Administration's Johnson Space Center, Houston, Texas, in November 1978, as an aerospace research pilot. In November 1981, Dick joined the NASA's Ames-Dryden Flight Research Facility, Edwards, California, as a research pilot. Dick was a former Co-op at the NASA Flight Research Center (a previous name of the Ames-Dryden Flight Research Facility), serving as an Operations Engineer. At Ames-Dryden, Dick was a pilot for the F-14 Aileron Rudder Interconnect Program, AD-1 Oblique Wing Research Aircraft, F-8 Digital Fly-By-Wire and Pilot Induced Oscillations investigations. He also flew the F-104, T-37, and the F-15. On November 8, 1982, Gray was fatally injured in a T-37 jet aircraft while making a pilot proficiency flight. Dick graduated with a Bachelors degree in Aeronautical Engineering from San Jose State University in 1969. He joined the U.S. Navy in July 1969, becoming a Naval Aviator in January 1971, when he was assigned to F-4 Phantoms at Naval Air Station (NAS) Miramar, California. In 1972, he flew 48 combat missions in Vietnam in F-4s with VF-111 aboard the USS Coral Sea. After making a second cruise in 1973, Dick was assigned to Air Test and Evaluation Squadron Four (VX-4) at NAS Point Mugu, California, as a project pilot on various operational test and evaluation programs. In November 1978, Dick retired from the Navy and joined NASA's Johnson Space Center. At JSC Gray served as chief project pilot on the WB-57F high-altitude research projects and as the prime television chase pilot in a T-38 for the landing portion of the Space Shuttle orbital flight tests. Dick had over 3,000 hours in more than 30 types of aircraft, an airline transport rating, and 252 carrier arrested landings. He was a member of the Society of Experimental Test Pilots serving on the Board of Directors as Southwest Section Technical Adviser in

  13. Forjando nuestras democracias: entre Richard Rorty y Vladimiro Montesinos

    Directory of Open Access Journals (Sweden)

    Miguel Giusti

    2001-07-01

    Full Text Available This article aims at explaining the recent history of Peru, in an exercise in which it is possible to extract lessons about the way Latin American democracies have been(or have not been forged. The text draws a parallel between the ideas developed by Richard Rorty in his recently published book, Forjar nuestro país. El pensamiento de izquierdas en los Estados Unidos del siglo XX, and the events in Fugimori's and Montesinos' Peru. If, according to what Rorty believes, "national pride is for the countries what self esteem is for individuals ... " how would it be possible to narrate a history in which there are few motives to be proud of? Trying to escape fatalism and sarcasm, the text tries to show that Montesino's political course is, symbolically, a summary of the decomposition process of Peruvian democracy. Secondly, the text analyses the movements of the political left wing and deals with the support the regimen received from inside and outside the country, a support that was largely based on the illusion of political stability. Finally, it states, as Rorty does, that in order to forge democracies it is necessary for us to be deeply committed to the defense of the State of Right.

  14. Richard Arwed Pfeifer - a pioneer of 'medical pedagogy' and an opponent of Paul Schroder.

    Science.gov (United States)

    Steinberg, Holger; Carius, Dirk; Himmerich, Hubertus

    2013-12-01

    Richard Arwed Pfeifer (1877-1957) was one of the initiators and foster fathers of the renowned child-psychiatric and special needs education workgroup at Leipzig University under Paul Schröder (1873-1941) in the 1920s and 1930s. This paper is an account of their dispute concerning the interrelations between child and adolescent psychiatry and special needs education, as well as their disagreement about whether adolescent psychopaths should be admitted to specialized child psychiatric wards or elsewhere. Moreover, Pfeifer questioned the practical relevance of the separation of constitutional and environmentally-based psychopathy and fought eugenic research, which he found incompatible with the ethics of his profession as a remedial teacher and child psychiatrist.

  15. PolyRES: A polygon-based Richards equation solver

    International Nuclear Information System (INIS)

    Hills, R.G.

    1995-12-01

    This document describes the theory, implementation, and use of a software package designed to solve the transient, two-dimensional, Richards equation for water flow in unsaturated-saturated soils. This package was specifically designed to model complex geometries with minimal input from the user and to simulate groundwater flow related to assessment of low-level radioactive waste disposal sites and engineered facilities. The spatial variation of the hydraulic properties can be defined across individual polygon-shaped subdomains, called objects. These objects combine to form a polygon-shaped model domain. Each object can have its own distribution of hydraulic parameters. The resulting model domain and polygon-shaped internal objects are mapped onto a rectangular, finite-volume, computational grid by a preprocessor. This allows the user to specify model geometry independently of the underlying grid and greatly simplifies user input for complex geometries. In addition, this approach significantly reduces the computational requirements since complex geometries are actually modeled on a rectangular grid. This results in well-structured, finite difference-like systems of equations that require minimal storage and are very efficient to solve. The documentation for this software package includes a user's manual, a detailed description of the underlying theory, and a detailed discussion of program flow. Several example problems are presented that show the use and features of the software package. The water flow predictions for several of these example problems are compared to those of another algorithm to test for prediction equivalency

  16. O ateísmo de Richard Dawkins nas fronteiras da ciência evolucionista e do senso comum

    OpenAIRE

    Franco, Clarissa de

    2014-01-01

    O objeto de estudo consiste nas principais ideias ateístas de Richard Dawkins e na recepção destas por parte dos ateus inseridos na cultura brasileira. Dawkins é um dos principais divulgadores e militantes do movimento ateísta da atualidade, e a despeito de sua faceta pública divulgada em sites mundiais e em livros de reconhecido sucesso existem debates do autor, concernentes aos espaços acadêmicos e restritos a cientistas, que nem sempre se apresentam congruentes às suas e...

  17. Path probability distribution of stochastic motion of non dissipative systems: a classical analog of Feynman factor of path integral

    International Nuclear Information System (INIS)

    Lin, T.L.; Wang, R.; Bi, W.P.; El Kaabouchi, A.; Pujos, C.; Calvayrac, F.; Wang, Q.A.

    2013-01-01

    We investigate, by numerical simulation, the path probability of non dissipative mechanical systems undergoing stochastic motion. The aim is to search for the relationship between this probability and the usual mechanical action. The model of simulation is a one-dimensional particle subject to conservative force and Gaussian random displacement. The probability that a sample path between two fixed points is taken is computed from the number of particles moving along this path, an output of the simulation, divided by the total number of particles arriving at the final point. It is found that the path probability decays exponentially with increasing action of the sample paths. The decay rate increases with decreasing randomness. This result supports the existence of a classical analog of the Feynman factor in the path integral formulation of quantum mechanics for Hamiltonian systems

  18. Feynman variance for neutrons emitted from photo-fission initiated fission chains - a systematic simulation for selected speacal nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Soltz, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Danagoulian, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sheets, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Korbly, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hartouni, E. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-05-22

    Theoretical calculations indicate that the value of the Feynman variance, Y2F for the emitted distribution of neutrons from ssionable exhibits a strong monotonic de- pendence on a the multiplication, M, of a quantity of special nuclear material. In 2012 we performed a series of measurements at the Passport Inc. facility using a 9- MeV bremsstrahlung CW beam of photons incident on small quantities of uranium with liquid scintillator detectors. For the set of objects studies we observed deviations in the expected monotonic dependence, and these deviations were later con rmed by MCNP simulations. In this report, we modify the theory to account for the contri- bution from the initial photo- ssion and benchmark the new theory with a series of MCNP simulations on DU, LEU, and HEU objects spanning a wide range of masses and multiplication values.

  19. The Mysterious Fall of Soeharto: A Genre Analysis of Richard Mann’s Plots and Schemes that Brought Down Soeharto (PSBDS

    Directory of Open Access Journals (Sweden)

    Sugeng Purwanto

    2012-12-01

    Full Text Available The real cause of Soeharto’s fall from the Indonesian presidency remains a mystery. Richard Mann (1998 launched three significant rhetorical questions: (a Was President Soeharto toppled by student demonstrators and people’s power? (b Was he brought down by the withdrawal of support from the United States? (c Or, was his sudden fall brought about by all of the two plus large doses of Oriental plotting and scheming? This article attempts to analyze Richard Mann’s PSBDS in terms of its macrostructure in order to find out the real cause of Soeharto’s fall. The analysis is substantiated by different resources as linguistic evidences, to justify the validity of the findings. The study revealed a proposition that critical reading is the key to successful comprehension of a text which may include a crosschecking with other resources, a careful identification of the generic structure of a text, and paying attention to how an author positions his or her readers. The article concludes, that in fact, Soeharto resigned from presidency on his own wisdom in order to avoid more bloodshed in Indonesian dreamland.

  20. Mentoring in nursing: a historical approach.

    Science.gov (United States)

    Fields, W L

    1991-01-01

    Most nurses today have or have had mentors. Several historical nurse leaders also had mentors. Florence Nightingale's mentor gave her the opportunity to work as a nurse during the Crimean War. Linda Richards, Mary Adelaide Nutting, and Annie Goodrich were all encouraged by their respective mentors to develop professionally.

  1. Femineidad y ficción en la obra operística de Richard Strauss

    Directory of Open Access Journals (Sweden)

    María José Sánchez Usón

    2014-01-01

    Full Text Available Tras la muerte de Wagner y Brahms, Richard Straussemergió como uno de los compositores más importantesy populares de la música del siglo XX. Su trayectoria vitaly profesional, azarosa y turbulenta, al igual que las décadasque vivió, estuvo marcada por la realidad femenina.Es innegable que las mujeres de la vida de Strauss, todasde fuerte y distintiva personalidad, dejaron en él huellastan hondas que fue necesario llevarlas a escena, no sólocomo una aportación valiosa a la tipología caracterológicafemenina, sino también como un ejercicio terapéuticopersonal. Así, mujeres reales y mujeres ficticias se confundenen sus obras en un proceso creativo único: el delhombre-artista.

  2. Arte y política: un estudio comparativo de Jacques Rancière y Nelly Richard para el arte latinoamericano

    Directory of Open Access Journals (Sweden)

    Verónica Capasso

    2016-01-01

    Full Text Available En este artículo se indagan y comparan las teorías de Jacques Rancière y Nelly Richard sobre la relación entre arte y política desde el pensamiento posfundacional, y se producen reflexiones y análisis de manifestaciones artísticas latinoamericanas vanguardistas o críticas en diálogo con ambas. Para ello, se parte de una presentación de las teorías de Rancière y Richard en términos generales, se focaliza en las ideas que dichos autores tienen de la política y, específicamente, en la conceptualización que hacen del arte y su relación con la política. Al mismo tiempo, se desarrolla una interpretación de producciones artísticas desde una mirada centrada en sus diversas conexiones con lo político, más allá del contenido temático de estas. Se utiliza la perspectiva metodológica cualitativa transdisciplinaria, que articula distintas áreas de conocimiento (filosofía política, sociología, historia del arte. En el caso de los desarrollos de Jacques Rancière, se recurre a herramientas teóricas metropolitanas para resituarlas y repensarlas en función del arte de Latinoamérica. En este sentido, se trata de potenciar sus ideas en el análisis de casos locales. En cuanto a la teoría de Nelly Richard, sus conceptos de arte crítico y vanguardista se ponen en relación con el arte latinoamericano. Finalmente, se propone una comparación en la cual se destacan similitudes y diferencias conceptuales entre ambos en combinación con análisis de casos para abrir el panorama analítico e interpretativo que vincule teorías actuales con estudios de manifestaciones artísticas locales.

  3. Two-slit experiment: quantum and classical probabilities

    International Nuclear Information System (INIS)

    Khrennikov, Andrei

    2015-01-01

    Inter-relation between quantum and classical probability models is one of the most fundamental problems of quantum foundations. Nowadays this problem also plays an important role in quantum technologies, in quantum cryptography and the theory of quantum random generators. In this letter, we compare the viewpoint of Richard Feynman that the behavior of quantum particles cannot be described by classical probability theory with the viewpoint that quantum–classical inter-relation is more complicated (cf, in particular, with the tomographic model of quantum mechanics developed in detail by Vladimir Man'ko). As a basic example, we consider the two-slit experiment, which played a crucial role in quantum foundational debates at the beginning of quantum mechanics (QM). In particular, its analysis led Niels Bohr to the formulation of the principle of complementarity. First, we demonstrate that in complete accordance with Feynman's viewpoint, the probabilities for the two-slit experiment have the non-Kolmogorovian structure, since they violate one of basic laws of classical probability theory, the law of total probability (the heart of the Bayesian analysis). However, then we show that these probabilities can be embedded in a natural way into the classical (Kolmogorov, 1933) probability model. To do this, one has to take into account the randomness of selection of different experimental contexts, the joint consideration of which led Feynman to a conclusion about the non-classicality of quantum probability. We compare this embedding of non-Kolmogorovian quantum probabilities into the Kolmogorov model with well-known embeddings of non-Euclidean geometries into Euclidean space (e.g., the Poincaré disk model for the Lobachvesky plane). (paper)

  4. Perception of Leitmotives in Richard Wagner's Der Ring des Nibelungen

    Directory of Open Access Journals (Sweden)

    David J. Baker

    2017-05-01

    Full Text Available The music of Richard Wagner tends to generate very diverse judgments indicative of the complex relationship between listeners and the sophisticated musical structures in Wagner's music. This paper presents findings from two listening experiments using the music from Wagner's Der Ring des Nibelungen that explores musical as well as individual listener parameters to better understand how listeners are able to hear leitmotives, a compositional device closely associated with Wagner's music. Results confirm findings from a previous experiment showing that specific expertise with Wagner's music can account for a greater portion of the variance in an individual's ability to recognize and remember musical material compared to measures of generic musical training. Results also explore how acoustical distance of the leitmotives affects memory recognition using a chroma similarity measure. In addition, we show how characteristics of the compositional structure of the leitmotives contributes to their salience and memorability. A final model is then presented that accounts for the aforementioned individual differences factors, as well as parameters of musical surface and structure. Our results suggest that that future work in music perception may consider both individual differences variables beyond musical training, as well as symbolic features and audio commonly used in music information retrieval in order to build robust models of musical perception and cognition.

  5. The ISS flight of Richard Garriott: a template for medicine and science investigation on future spaceflight participant missions.

    Science.gov (United States)

    Jennings, Richard T; Garriott, Owen K; Bogomolov, Valery V; Pochuev, Vladimir I; Morgun, Valery V; Garriott, Richard A

    2010-02-01

    A total of eight commercial spaceflight participants have launched to the International Space Station (ISS) on Soyuz vehicles. Based on an older mean age compared to career astronauts and an increased prevalence of medical conditions, spaceflight participants have provided the opportunity to learn about the effect of space travel on crewmembers with medical problems. The 12-d Soyuz TMA-13/12 ISS flight of spaceflight participant Richard Garriott included medical factors that required preflight intervention, risk mitigation strategies, and provided the opportunity for medical study on-orbit. Equally important, Mr. Garriott conducted extensive medical, scientific, and educational payload operations during the flight. These included 7 medical experiments and a total of 15 scientific projects such as protein crystal growth, Earth observations/photography, educational projects with schools, and amateur radio. The medical studies included the effect of microgravity on immune function, sleep, bone loss, corneal refractive surgery, low back pain, motion perception, and intraocular pressure. The overall mission success resulted from non-bureaucratic agility in mission planning, cooperation with investigators from NASA, ISS, International Partners, and the Korean Aerospace Research Institute, in-flight support and leadership from a team with spaceflight and Capcom experience, and overall mission support from the ISS program. This article focuses on science opportunities that suborbital and orbital spaceflight participant flights offer and suggests that the science program on Richard Garriott's flight be considered a model for future orbital and suborbital missions. The medical challenges are presented in a companion article.

  6. Genetics and the origin of species: the continuing synthesis a symposium in honor of Richard G. Harrison

    Science.gov (United States)

    Grosberg, Richard K.; Rand, David M.; Normark, Benjamin B.

    2013-01-01

    This is a special issue of Genetica that has its origins in a symposium held in honor of Richard G. Harrison at Ithaca, New York on July 22–23. Former students of Rick Harrison organized the symposium and most of the speakers were former students, as well. The quality and breadth of the talks were a testament to Rick’s influence as a thinker, synthesizer, and mentor and it is only appropriate to reflect on Rick’s contributions to the fields of evolutionary ecology, systematics, and genetics in this preface to the symposium articles. PMID:21152955

  7. Book Review: The future of spacetime. Stephen William Hawking (ed.); Kip S. Thorne, Igor Novikov, Timothy Ferris, Alan Lightman, and Richard Price, W.W. Norton & Company, 2002, 224 pp., US 25.95, ISBN 0393020223

    Science.gov (United States)

    Smeenk, Chris

    2003-12-01

    The study of Einstein's theory of general relativity experienced a renaissance beginning in the early 1960s. Prior to this resurgence of interest, general relativity was isolated from mainstream physics-admired for its elegance, perhaps, but only from a distance. The generation of students who risked their careers by entering this neglected field has now reached the age of festschrifts. In June of 2000, Caltech hosted ;Kipfest,; a conference in honor of Kip Thorne's 60th birthday. Thorne started graduate school at Princeton in 1962 and began research in general relativity under John Wheeler's guidance in the heady early days of the renaissance. Since then, he has played a prominent role in general relativity: as co-author of the influential textbook Gravitation, as a leader in research regarding astrophysical applications of Einstein's theory, and as a co-founder and chief advocate for the Laser Interferometer Gravitational Wave Observatory (LIGO), to mention a few aspects of his far-reaching work. ;Kipfest; included 14 speakers discussing fields to which Thorne has contributed. But the conference also reflected Thorne's long-standing commitment to communicating science to a general audience: Igor Novikov, Stephen Hawking, Timothy Ferris, and Alan Lightman gave popular talks at ;Kipfest,; with Thorne himself tricked into delivering a fifth. The Future of Spacetime gathers adaptations of these five lectures, along with a lengthy introductory essay by Richard Price.

  8. Hamilton on surnud, tema mõju mitte : in memoriam Richard Hamilton (24. II 1922 - 13. IX 2011) / Kadri Karro ; kommenteerinud Eha Komissarov, Sirje Helme, Jaak Kangilaski

    Index Scriptorium Estoniae

    Karro,Kadri

    2011-01-01

    Briti kunstniku Richard Hamiltoni (1922 - 2011) loomingust eesti kunstiteadlaste Eha Komissarovi, Sirje Helme ja Jaak Kangilaski pilgu läbi. Lähemalt 1956. aastal valminud kollaažist "Mis teeb tänapäeva kodud nii eriliseks, nii meeldivaks?"

  9. Destruction of the Phoenix/Hibiscus and Barringtonia racemosa Communities at Richards Bay, Natal, South Africa

    Directory of Open Access Journals (Sweden)

    P. J. Weisser

    1982-10-01

    Full Text Available The destruction of the Phoenix!Hibiscus and Barringtonia racemosa Communities described by Venter in 1972 on the southern shores of Richards Bay is reported. The cause was the artificial openingof a new mouth about 5,5 km south of the original mouth, which increased tidal range and salinity. These swamp communities occupied a narrow band about 6 ha in area behind the Bruguiera gymnorrhiza Community. An estimated 95 % of the communities was affected and only on the landward border were some isolated remnants of species such as Acrostichum aureum, Hibiscus tiliaceus and Phoenix reclinata detected .Young stands of  Phragmites australis, seedlings of  Bruguiera gymnorrhiza and Avicennia marina and epipelic algae are recoIonizing the affected area.

  10. BACK TO THE ORIGINS OF THE REPUDIATION OF WUNDT: OSWALD KÜLPE AND RICHARD AVENARIUS.

    Science.gov (United States)

    Russo Krauss, Chiara

    2017-01-01

    This essay provides a fresh account of the break between Oswald Külpe and his master Wilhelm Wundt. Kurt Danziger's reconstruction of the "repudiation" of Wundt, which has become the canon for this significant episode of history of psychology, focused on the supposed influence of Ernst Mach on this set of events, overshadowing the other exponent of Empiriocriticism: Richard Avenarius. Analyzing archival documents and examining anew the primary sources, the paper shows that Avenarius was himself a member of Wundt's circle, and that his "repudiation" of the master paved the way for Külpe. The essay points out the original anti-Wundtian aspects of Avenarius' notion of psychology, thus showing how they were then adopted by Külpe. © 2016 Wiley Periodicals, Inc.

  11. HealthSouth's most wanted. Founder and former chairman and CEO Richard Scrushy is indicted for 85 counts of conspiracy, fraud and money laundering.

    Science.gov (United States)

    Piotrowski, Julie

    2003-11-10

    Wake-up call for the industry or an isolated case of corporate chicanery? Healthcare experts are divided on the import of Richard Scrushy's indictment on 85 counts last week in connection with the financial scandal at HealthSouth Corp. The indictment alleges the company founder relied on electronic and telephone surveillance, threats and intimidation to control his accomplices.

  12. Measurement of Feynman-x spectra of photons and neutrons in the very forward direction in deep-inelastic scattering at HERA

    International Nuclear Information System (INIS)

    Andreev, V.; Baghdasaryan, A.; Begzsuren, K.

    2014-03-01

    Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic ep scattering at HERA are presented as a function of the Feynman variable x F and of the centre-of-mass energy of the virtual photon-proton system W. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 131 pb -1 . The measurement is restricted to photons and neutrons in the pseudorapidity range η > 7.9 and covers the range of negative four momentum transfer squared at the positron vertex 6 2 2 , of inelasticity 0.05 F dependent cross sections is investigated. Predictions of deep-inelastic scattering models and of models for hadronic interactions of high energy cosmic rays are compared to the measured cross sections.

  13. Going Beyond the Point Nucleus Approximation to Satisfy the Hellmann–Feynman Theorem: Born–Oppenheimer H2+ in the Ground State

    International Nuclear Information System (INIS)

    Gutlé, Claudine

    2017-01-01

    Incomplete spaces are investigated for solving the Schrödinger equation under the Born–Oppenheimer approximation. It is shown that the Hellmann–Feynman theorem cannot be used for computing the electronic force exerted on a nucleus, when a variational wavefunction with floating centers is used, if multicenter polynomial components are added in order to describe the polarization effects through the chemical bond. This is because the minimum of the potential energy surface is not a stationary point in the direction of the float parameter. Such a failure can be fixed by considering a molecular model with finite size nuclei, as defined herein. The classical electronic force is computed for that model, as compared with the standard point charge approximation, and it is applied to the H 2 + molecular ion. As a result, the former model is found more accurate by several orders of magnitude. (author)

  14. “This World Is Not My Home”: Richard Mouw and Christian Nationalism

    Directory of Open Access Journals (Sweden)

    Aaron Pattillo-Lunt

    2016-12-01

    Full Text Available American evangelicalism has often been punctuated by dual commitments to the United States and to God. Those commitments were strongest within politically conservative evangelicalism. Though representing a solid majority among professing evangelicals, conservatives could not speak for the movement as a whole. Politically progressive evangelicals, beginning in the 1960s, formed a dissenting opinion of the post-World War II revival of Christian nationalism. They dared to challenge American action abroad, noticeably during the Vietnam War. Their critique of Christian nationalism and conservative evangelicals’ close ties to the Republican Party led them to seek refuge in either progressive policies or the Democratic Party. A third, underexplored subgroup of evangelicalism rooted in reformed theology becomes important to consider in this regard. These reformed evangelicals sought to contextualize nationalism in biblical rather than partisan or political terms. This goal is championed well by Richard Mouw, resulting in a nuanced look at evangelical Christians’ difficult dual role as both citizens of the Kingdom of God and the United States.

  15. Analytical and grid-free solutions to the Lighthill-Whitham-Richards traffic flow model

    KAUST Repository

    Mazaré , Pierre Emmanuel; Dehwah, Ahmad H.; Claudel, Christian G.; Bayen, Alexandre M.

    2011-01-01

    In this article, we propose a computational method for solving the Lighthill-Whitham-Richards (LWR) partial differential equation (PDE) semi-analytically for arbitrary piecewise-constant initial and boundary conditions, and for arbitrary concave fundamental diagrams. With these assumptions, we show that the solution to the LWR PDE at any location and time can be computed exactly and semi-analytically for a very low computational cost using the cumulative number of vehicles formulation of the problem. We implement the proposed computational method on a representative traffic flow scenario to illustrate the exactness of the analytical solution. We also show that the proposed scheme can handle more complex scenarios including traffic lights or moving bottlenecks. The computational cost of the method is very favorable, and is compared with existing algorithms. A toolbox implementation available for public download is briefly described, and posted at http://traffic.berkeley.edu/project/downloads/lwrsolver. © 2011 Elsevier Ltd.

  16. Analytical and grid-free solutions to the Lighthill-Whitham-Richards traffic flow model

    KAUST Repository

    Mazaré, Pierre Emmanuel

    2011-12-01

    In this article, we propose a computational method for solving the Lighthill-Whitham-Richards (LWR) partial differential equation (PDE) semi-analytically for arbitrary piecewise-constant initial and boundary conditions, and for arbitrary concave fundamental diagrams. With these assumptions, we show that the solution to the LWR PDE at any location and time can be computed exactly and semi-analytically for a very low computational cost using the cumulative number of vehicles formulation of the problem. We implement the proposed computational method on a representative traffic flow scenario to illustrate the exactness of the analytical solution. We also show that the proposed scheme can handle more complex scenarios including traffic lights or moving bottlenecks. The computational cost of the method is very favorable, and is compared with existing algorithms. A toolbox implementation available for public download is briefly described, and posted at http://traffic.berkeley.edu/project/downloads/lwrsolver. © 2011 Elsevier Ltd.

  17. Je suis un zombie : Études récentes sur Richard Matheson et le mort-vivant

    OpenAIRE

    Ransom, Amy J.; Trudel, Jean-Louis

    2013-01-01

    Dans ce texte nous résumons quatre essais récents sur le phénomène actuel du zombie ainsi qu’un collectif sur l’œuvre de Richard Matheson dont la première version filmique du roman Je suis une légende a servi d’inspiration à l’ur-film de zombies, La nuit des morts vivants de George A. Romero. Tandis que Pierre Cassou-Noguès et Maxime Coulombe signent des traitements plus philosophiques du zombie, leurs ouvrages diffèrent beaucoup dans leur forme et leur fonction. Pour leur part, Amélie Pépin ...

  18. [Richard Koch's life in national socialism and in Soviet emigration].

    Science.gov (United States)

    Boltres, Daniela; Töpfer, Frank; Wiesing, Urban

    2006-01-01

    The Jewish historian and theorist of medicine, Richard Koch, teaching in Frankfurt/Main, fled in 1936 from National Socialist Germany to the USSR where he lived in the Caucasian spa Essentuki until his death in 1949. Here he worked as a doctor and continued his scientific work, especially on the foundations of medicine in natural philosophy. None of his works of this time were published. Koch was a scientific outsider in the USSR, and he was aware of this. However, he tried to make his views compatible with official doctrines. In 1947 he lost his employment at the medical clinic of Essentuki, and his material situation grew worse. It is still an open question whether this development was related to an increasingly anti-Jewish atmosphere in the USSR that was linked with the Stalinist "purges", as Koch himself appeared to believe. Before his flight from Germany Koch did not show any tendency towards communism or the political left at all. His attitude towards Soviet society and Stalin was mixed: cautious criticism was accompanied by strong expressions of commitment to Stalin and Koch's new Socialist home. The question to what extent Koch's comments showed his true convictions must remain without a definite answer. At least in part they can be understood as precautions in threatening circumstances. The opportunity of a remigration to Germany after 1945, however, was turned down by Koch.

  19. Untitled

    Indian Academy of Sciences (India)

    r Xmax - - calculations of Bonner and Fisher and gave a good fit with but one parameter,. 86 Richard L. Carlin and Ruud Block discussion of the exchange paths in Cs2CoCl4 and a rationalization of the linear chain character has been presented (McElearney et al 1977). The copper analog is found to behave somewhat ...

  20. Chinese Function Manager of 2006 Partenariat Comments on the Selection Principle for Chinese Enterprises

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Fang Lei, EU-China Partenariat 2006Function Manager for Chinese Host Companies, worked together with Mr. Richard Morgan, EU Project Expert,Mr. Han Meiqing, Chinese Project Expert in the primary selection of Chinese enterprises.In reply to the strong request of the relevant governmental institutions, CCPIT and enterprises, he gave the following introductions about the details of selection.