Professor Richard Feynman colloquium
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.
Richard Feynman Quarks, Bombs, and Bongos
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
Quantum Man: Richard Feynman's Life in Science
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.
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.).
Richard Feynman a life in science
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.
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 ...
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).
Feynman Lectures on Computation
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,"
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.
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
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)
Drawing theories apart the dispersion of Feynman diagrams in postwar physics
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...
Le cours de physique de Feynman
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.
PROVOCATIVE PERFORMANCE, PROVOCATIVE THEATER: AESTHETIC INTERACTION
Directory of Open Access Journals (Sweden)
ROŞCA ANGELINA
2017-12-01
Full Text Available The author directs her attention to an yet-understudied area of theatre science, namely the aesthetic interaction between the provocative performance and the provocative theatre. The article sheds light on the conceptual coordinates of the performance placed among such artistic trends as Actionism, Conceptualism, Fluxus and Happening. Elements of performing arts infiltrated into the theatre long ago. And it is not just a co-occurrence within an artistic act, but an interference indeed. The provocative performance dispossesses the alternative arts of their distinct codes. First in the USA, then in Europe and eventually in the former Socialist Camp and the territory of the ex-USSR, the performance conquered the theatrical territory. This process has been accelerating since the dramatic theatre began to yield its positions to the post-dramatic one. Some of the overlapping points, which unite the performance with the spectacle in contemporary art, are followed in: the strategy of idiocy in provocative practices; the ready made; the corporeality; the pictorial.
Vous voulez rire, monsieur Feynman !
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.
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.
Introduction to Feynman diagrams
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
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
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
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.
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
Detailed balance of the Feynman micromotor
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.
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.
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.
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.
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
FeynRules - Feynman rules made easy
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...
Analytic Tools for Feynman Integrals
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...
Provocative behavior of a victim and its difference from the provocation of a crime
Directory of Open Access Journals (Sweden)
Valeriy Anatolyevich Cherepakhin
2015-03-01
Full Text Available Objective to define the main elements of provocative behavior of a victim and its difference from the provocation of a crime. Methods dialectic approach to the study of social phenomena and historical and comparativelegal methods for the study of legal reality. Results scientific grounding of theoreticallegal bases of the ldquoprovocationrdquo institution and formulating proposals for improving its legislative regulation and increasing the efficiency of its law enforcement. Scientific novelty the article presents the author39s classification of the types and forms of provocative activity in the norms of both the General and the Specific parts. Practical value summarizing and analysis of the modern empirical data on the practice of implementation of the norms containing the features of provocation and elaboration of organizational and methodological recommendations based on the authorrsquos research. nbsp
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.)
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.)
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
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.
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
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
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.
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.)
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.)
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.)
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.)
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 ...
Distilled water nasal provocation in hyperreactive patients.
Baudoin, T; Anzic, S A; Kalogjera, L
1999-01-01
Nonisotonic aerosol may act as a provocation agent in the upper and lower airways of hyperreactive individuals. The purpose of the study was to compare the results of nasal challenge with distilled water in patients with allergic rhinitis to those with noninfective nonallergic rhinitis (NINAR), with respect to the potential clinical use of the obtained data. A group of 68 ambulatory patients with allergic rhinitis or NINAR (39 perennial allergic, 6 seasonal, 23 NINAR) were challenged with 10 mL of distilled water aerosol after the baseline active anterior rhinomanometry. Patients with nasal polyposis at endoscopy, significant unilateral septal deviation, positive bacteriologic swab, recent nasal surgery, and uncertain anamnestic data about the medication taken 6 weeks before the provocation were excluded from the study. After 10 minutes of nasal provocation, rhinomanometry was repeated to assess the response. In 15 patients of the perennial allergic group, the same measurements were performed after a 2-week oral antihistamine and topical steroid therapy. Nasal resistance was significantly increased on the more patent side of the nose after nasal provocation with distilled water aerosol in allergic patients in comparison to the nasal resistance before provocation. In the patients with NINAR, the provocation resulted in a significant rise on the more patent side, but the total nasal airway resistance (NAR) levels were also significantly increased. The systemic antihistamine and topical steroid 2-week therapy in patients with perennial allergic rhinitis significantly reduced the response to nasal distilled water provocation. Nasal provocation with distilled water aerosol is a cheap, simple, and acceptable method that provides useful clinical data on the level of nonspecific nasal hyperreactivity and the therapy success.
The Importance of Prolonged Provocation in Drug Allergy
DEFF Research Database (Denmark)
Fransson, Sara; Mosbech, Holger; Kappel, Mogens
2017-01-01
BACKGROUND: Drug provocation is the "Gold Standard" in drug allergy investigation. Recent studies suggest that a negative drug provocation on first dose should be followed by a prolonged provocation over several days. OBJECTIVE: To evaluate drug allergy investigations on the basis of drug...
Feynman integrals in QCD made simple
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.
(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.
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)
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.
On Provocation, Education and Entrepreneurship
DEFF Research Database (Denmark)
Hjorth, Daniel
2011-01-01
in processes of learning entrepreneurship, this article responds to previous calls for less economised entrepreneurship education focusing on its creative-relational nature. An affect-based theory of E3 brings together provocation, deterritorialisation (uprooting) and decoding/imagination, which calls for both......This essay develops an affect-based theory of entrepreneurial entrepreneurship education, something we summarise in a model of provocation-based entrepreneurial entrepreneurship education (the E3 model). Taking its starting point in an anecdote that illustrates the importance of provocation...... critique and creativity, and resonates with appreciations of paralogy as driver in learning processes. The implications of this conceptual model of learning entrepreneurship entrepreneurially are discussed, with particular focus on the role of the pedagogue and on the future of learning entrepreneurship....
SPECIFICS AND FUNCTIONS OF THE PROVOCATIVE ACT
Directory of Open Access Journals (Sweden)
ROŞCA ANGELINA
2017-12-01
Full Text Available The author points out that the provocativeness that is at the basis of the creations belonging to different art trends (constructivism, futurism, surrealism, minimalism, conceptualism and so on played a key role in the art of the 20th – 21st centuries. At present, provocation has become the main strategy for the development of the theatrical process, which makes it necessary for theatre science to try to delineate the theoretical outline of what we call provocativity. The author, using worldknown theatrical cases, determines the specificity and functions of provocativity. The latter consists in the fact that the provocation, allows a clearer outline of the boundaries of art, broadening the permissibility framework and increasing the degree of tolerance in society, breaks the taboos, from the sexual to the social ones, contributes to changing the artistic paradigm, destroys stereotypes, radically changes conceptions, artistic means, methods, models of organizing the artistic process, impacts the emergence of radical aesthetics, carries out artistic and social reforms.
; 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
Spin wave Feynman diagram vertex computation package
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.
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.
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
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
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.)
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)
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
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
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
Rigorous time slicing approach to Feynman path integrals
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...
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"...
Counting the number of Feynman graphs in QCD
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.
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
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.)
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)
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
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
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)
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.
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.)
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.
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
J. Richard Hackman (1940-2013)
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...
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
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.
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)
From provocation to aggression: the neural network
Repple, J.; Pawliczek, C.M.; Voss, B.; Siegel, S.; Schneider, F.; Kohn, N.; Habel, U.
2017-01-01
Background In-vivo observations of neural processes during human aggressive behavior are difficult to obtain, limiting the number of studies in this area. To address this gap, the present study implemented a social reactive aggression paradigm in 29 healthy men, employing non-violent provocation in a two-player game to elicit aggressive behavior in fMRI settings. Results Participants responded more aggressively after high provocation reflected in taking more money from their opponents. Compar...
Richard Nixon, 1972-2016 Obituary
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...
Mathematical theory of Feynman path integrals an introduction
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.
Constructive Representation Theory for the Feynman Operator Calculus
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...
Empathy Inhibits Aggression in Competition: The Role of Provocation, Emotion, and Gender.
Stanger, Nicholas; Kavussanu, Maria; McIntyre, David; Ring, Christopher
2016-02-01
Although the empathy-aggression relationship has been well documented, research has yet to establish whether emotions mediate and gender moderates this relationship in athletes, under conditions of low and high provocation. In this experiment, we assigned team-sport athletes to either a high (n = 40) or a low (n = 40) empathy group, and asked them to compete in a reaction-time task against a (fictitious) opponent, under conditions of low and high provocation. Empathy reduced aggression (i.e., intensity of electrical shock administered to the opponent) at low provocation in men, and at both low and high provocation in women. Guilt mediated the effect of empathy on aggression at low provocation in men; anger did not mediate any effects of empathy on aggression. Our findings indicate that the inhibitory effect of empathy on aggression and the mediating role of guilt are moderated by provocation and gender.
Richard's back: death, scoliosis and myth making.
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/
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
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
The Importance of Prolonged Provocation in Drug Allergy - Results From a Danish Allergy Clinic.
Fransson, Sara; Mosbech, Holger; Kappel, Mogens; Hjortlund, Janni; Poulsen, Lars K; Kvisselgaard, Ask D; Garvey, Lene H
Drug provocation is the "Gold Standard" in drug allergy investigation. Recent studies suggest that a negative drug provocation on first dose should be followed by a prolonged provocation over several days. To evaluate drug allergy investigations on the basis of drug provocation, including prolonged provocation. Data from adult patients investigated for drug allergy in a Danish Allergy Clinic during the period 2010 to 2014 were entered into a database. Data included clinical details and results of provocations with suspected culprit drug (for penicillins performed only in specific IgE-negative patients). If provocation was negative on first dose, treatment was continued for 3 to 10 days. A total of 1,913 provocations were done in 1,659 patients, median age 46 years, of whom 1,237 (74.6%) were females. Drugs investigated were antibiotics, 1,776 (92.8%), of which 1,590 (89.5%) were penicillins; analgesics, 59 (3.1%); local anesthetics, 33 (1.7%); and other drugs, 45 (2.4%). In total, 211 of 1,913 (11.0%) provocations were positive. Causes were antibiotics, 198 (93.8%), of which 167 (84.3%) were penicillins; analgesics, 7 (3.3%); local anesthetics, 0; and other drugs, 6 (2.8%). Only 43 (20.4%) provocations were positive on first dose, whereas 95 (45.0%) turned positive more than 3 days later. Only 11.0% of the provocations were positive. Importantly, only 1 of 5 patients tested positive on the first dose, indicating that prolonged exposure should always be considered when drug provocation is included in allergy investigations. Most provocations were with penicillins, reflecting the pattern of antibiotic use in Denmark, which differs from that in other countries, especially outside Northern Europe. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
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....
The Power of the Provocative: Exploring World History Content
Ashkettle, Bryan L.
2013-01-01
This study addresses how my freshman world history students come to understand controversial issues as provocative within the secondary social studies classroom, and in what ways does their engagement with provocative issues influence their understanding of the content and the world around them. In addition, this research study seeks to discover…
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.
arXiv Diagrammatic Hopf algebra of cut Feynman integrals: the one-loop case
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...
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
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
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.
Effect of the nasal cycle on congestive response during bilateral nasal allergen provocation
Directory of Open Access Journals (Sweden)
Tomasz Gotlib
2014-06-01
Full Text Available Background. Bilateral nasal allergen provocation usually produces more pronounced obstruction of one nasal passage. It was found that this could be related to the stage of the nasal cycle before the provocation. objective. To discover whether the stage of the nasal cycle is decisive for asymmetry in congestive response observed during bilateral allergen nasal provocation. methods. Two bilateral nasal allergen provocations were performed in a group of 26 pollen-sensitive volunteers. Acoustic rhinometry measurements were taken during the nasal cycle, and then after the provocation. A cross-sectional area at the level of the inferior turbinate (CSA-2 was measured. Consecutive challenges were performed in the opposite phase of the nasal cycle: the side which had been wide just before the first challenge, was narrow before the second provocation. results. Asymmetry in CSA-2 reduction between the nasal passages was observed in most cases. Significant difference was observed between mean CSA-2 reduction rate (reactivity of the side that responded with greater congestion, and the opposite side. No significant difference was found in mean CSA-2 reduction rate between the side which was narrow, and the side which was wide before provocation. conclusions. Asymmetry of congestive response during bilateral nasal allergen provocation is not dependent on the stage of the nasal cycle preceding the challenge.
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
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
Feynman's operational calculus and beyond noncommutativity and time-ordering
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...
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
Simplifying Differential Equations for Multiscale Feynman Integrals beyond Multiple Polylogarithms.
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.
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
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
Obituary: Richard Joseph Elston, 1960-2004
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
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
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.)
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
Systemic provocation in doxycycline induced fixed drug eruption: a case report
Directory of Open Access Journals (Sweden)
Anik Murwaningsih Rosmarini Estri Sih Hananti Niken Indrastuti
2014-04-01
Full Text Available Fixed drug eruption (FDE is recurrent lesions that upon repeated uptake of causative drug, always appears at the same skin and mucosal site. Determination of causal relationship in drug allergy is very important. In this case report, cases of doxycycline-induced FDE was reported. The subject of the research was a 29-year-old male, referred by dermatologist, with history of reccurent FDE. Physical examination revealed an oval well demarcated patch hyperpigmentation. Patch test was perfomed on previous involved and uninvolved site. The result of the patch test was irrelevant. Retesting patch test gave similar result. Systemic provocation test or drug provocation test (DPT with doxcycline were done with suspected drug under ambulatory survelance and gave positive result. In this case, the DPT succeeded to identify doxycycline as the causal agent of FDE. The work-up of a suspected drug hypersensitivity includes a detailed clinical history, physical examination, skin tests, and provocation tests. The DPT is recommended to confirm drug’s hypersensitivity reactions. Systemic provocation test is considered as the gold standard for diagnosing FDE. Keywords: fixed drug eruption - doxycycline - causal relationship - patch test - systemic provocation test
Analytic properties of Feynman diagrams in quantum field theory
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
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.)
Provocation of symmetry/ordering symptoms in Anorexia nervosa: a functional neuroimaging study.
Suda, Masashi; Brooks, Samantha J; Giampietro, Vincent; Uher, Rudolf; Mataix-Cols, David; Brammer, Michael J; Williams, Steven C R; Treasure, Janet; Campbell, Iain C
2014-01-01
Anorexia nervosa (AN), obsessive-compulsive disorder (OCD), and obsessive-compulsive personality disorder (OCPD) are often co-morbid; however, the aetiology of such co-morbidity has not been well investigated. This study examined brain activation in women with AN and in healthy control (HC) women during the provocation of symmetry/ordering-related anxiety. During provocation, patients with AN showed more anxiety compared to HCs, which was correlated with the severity of symmetry/ordering symptoms. Activation in the right parietal lobe and right prefrontal cortex (rPFC) in response to provocation was reduced in the AN group compared with the HC group. The reduced right parietal activation observed in the AN group is consistent with parietal lobe involvement in visuospatial cognition and with studies of OCD reporting an association between structural abnormalities in this region and the severity of 'ordering' symptoms. Reduced rPFC activation in response to symmetry/ordering provocation has similarities with some, but not all, data collected from patients with AN who were exposed to images of food and bodies. Furthermore, the combination of data from the AN and HC groups showed that rPFC activation during symptom provocation was inversely correlated with the severity of symmetry/ordering symptoms. These data suggest that individuals with AN have a diminished ability to cognitively deal with illness-associated symptoms of provocation. Furthermore, our data also suggest that symptom provocation can progressively overload attempts by the rPFC to exert cognitive control. These findings are discussed in the context of the current neurobiological models of AN.
Provocation of symmetry/ordering symptoms in Anorexia nervosa: a functional neuroimaging study.
Directory of Open Access Journals (Sweden)
Masashi Suda
Full Text Available Anorexia nervosa (AN, obsessive-compulsive disorder (OCD, and obsessive-compulsive personality disorder (OCPD are often co-morbid; however, the aetiology of such co-morbidity has not been well investigated. This study examined brain activation in women with AN and in healthy control (HC women during the provocation of symmetry/ordering-related anxiety. During provocation, patients with AN showed more anxiety compared to HCs, which was correlated with the severity of symmetry/ordering symptoms. Activation in the right parietal lobe and right prefrontal cortex (rPFC in response to provocation was reduced in the AN group compared with the HC group. The reduced right parietal activation observed in the AN group is consistent with parietal lobe involvement in visuospatial cognition and with studies of OCD reporting an association between structural abnormalities in this region and the severity of 'ordering' symptoms. Reduced rPFC activation in response to symmetry/ordering provocation has similarities with some, but not all, data collected from patients with AN who were exposed to images of food and bodies. Furthermore, the combination of data from the AN and HC groups showed that rPFC activation during symptom provocation was inversely correlated with the severity of symmetry/ordering symptoms. These data suggest that individuals with AN have a diminished ability to cognitively deal with illness-associated symptoms of provocation. Furthermore, our data also suggest that symptom provocation can progressively overload attempts by the rPFC to exert cognitive control. These findings are discussed in the context of the current neurobiological models of AN.
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.
Solutions of the Wheeler-Feynman equations with discontinuous velocities.
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.
Richard Florida : loovsektor on majanduskasvu mootor / Richard Florida ; interv. Argo Ideon
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
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 ...
Feynman-Kac equations for reaction and diffusion processes
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.
QED the strange theory of light and matter
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
Systematic approximation of multi-scale Feynman integrals arXiv
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.
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)
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.)
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.)
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)
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.)
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.
DEFF Research Database (Denmark)
Caglio, Agnese
This paper presents the use of ”provocative videos”, as a tool to support and deepen findings from ethnographic investigation on the theme of remote videocommunication. The videos acted as a resource to also investigate potential for novel technologies supporting continuous connection between...... households. They were deployed online as part of a 6 months research project in collaboration with the Danish electronics manifacturer Bang & Olufsen, involving participants from different continents. The intention is to propose the integration of tools that have been always seen as part of the design domain...
Interpretation of growth hormone provocative tests
DEFF Research Database (Denmark)
Andersson, A M; Orskov, H; Ranke, M B
1995-01-01
To compare interpretations of growth hormone (GH) provocative tests in laboratories using six different GH immunoassays (one enzymeimmunometric assay (EIMA, assay 1), one immunoradiometric assay (IRMA, assay 5), one time-resolved fluorimmunometric assay (TRFIA, assay 3) and three radioimmunoassays...
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.
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
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.)
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
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.
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.
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.
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
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
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)
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.
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.)
Feynman Integrals with Absorbing Boundaries
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 ...
Pussy Provocations: Feminist Protest and Anti-Feminist Resurgence in Russia
Directory of Open Access Journals (Sweden)
Jessica Mason
2018-03-01
Full Text Available The Russian feminist punk-art group Pussy Riot sparked a remarkable series of responses with their provocative “punk prayer” in a Moscow cathedral in 2012. This article analyzes the social, political, and cultural dynamics of provocation (provokatsiya by examining everyday conversations, speeches, articles and other linguistic acts through which Russian Orthodox, feminist, and left-leaning and liberal participants in the anti-Putin opposition made sense of Pussy Riot. A provocation violates norms in ways that compel observers to name and defend those norms. This process simultaneously invigorates norms and helps people shore up their own senses of self amid uncertainty. Yet what observers identify as the provocation — what norms are perceived to be violated — shapes what values they reinforce. Responding to Pussy Riot, Russian Orthodox activists asserted themselves as defenders of tradition against the forces of Western cultural imperialism, including feminism and LGBT rights. Yet most responses from the anti-Putin opposition focused on norms related to speech and protest rights, while Russian feminists were often reluctant even to claim Pussy Riot as feminist at all. Due to this asymmetry, Pussy Riot’s feminist protest revitalized anti-feminism in Russia without a concomitant strengthening of feminist values among supporters.
COMMUNICATIVE PROVOCATION AS A STRATEGY OF DESTRUCTIVE BEHAVIOUR IN EVERY-DAY CONFLICT
Directory of Open Access Journals (Sweden)
Volkova Olga Sergeevna
2014-12-01
Full Text Available The article is concentrated on the issue of systematization and classification of strategies and tactics of individual's verbal behavior in a number of typical situations associated with disharmonious communication. Its scientific originality is defined by the necessity to present the provocation phenomenon as a category of communicative linguistics and linguistic pragmatics. The use of discourse analysis and descriptive pragmatic interpretation of real communication forms have enabled the revelation of various patterns of destructive verbal behavior that could provoke a communicative conflict. Communicative provocation is described as a strategy of destructive behavior aimed at dragging a communication partner into a conflict interaction or creating conditions for its occurrence. The provocation strategy is implemented in disharmonious interactions by means of individual or complex communication tactics including not only the aggressive ones: indignation, reproach, deliberate false informing, exaggerated demonstration of emotions, but also such tolerant tactics as praise, advice, apology, assurances, admiration, persuasion, etc. Two forms of communicative provocation are represented in the article. A direct provocation presupposes personal involvement of a provocateur in the conflict interaction while an indirect one allows its initiator stay aside from the open confrontation. In the latter case the provocateur stimulates and demonstrates the parties' conflict of interests, which leads to the communication harmony disruption.
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-.
Probing finite coarse-grained virtual Feynman histories with sequential weak values
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.
Exact Maximum-Entropy Estimation with Feynman Diagrams
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.
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
Reframing Practice through Provocative Co-design
DEFF Research Database (Denmark)
Christiansen, Lotte; Poulsen, Søren Bolvig; Morelli, Nicola
2013-01-01
changes in organisations, as it has the ability to force a shift in face (Goffman 1967) and the potential to motivate and enable stakeholders to reframe practice and initiate change initiatives. This is done by focusing on a service design project in which a provocative assignment in a co-design workshop...
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.)
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
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.)
Lam, Tram Kim; Schully, Sheri D; Rogers, Scott D; Benkeser, Rachel; Reid, Britt; Khoury, Muin J
2013-04-01
In a time of scientific and technological developments and budgetary constraints, the National Cancer Institute's (NCI) Provocative Questions Project offers a novel funding mechanism for cancer epidemiologists. We reviewed the purposes underlying the Provocative Questions Project, present information on the contributions of epidemiologic research to the current Provocative Questions portfolio, and outline opportunities that the cancer epidemiology community might capitalize on to advance a research agenda that spans a translational continuum from scientific discoveries to population health impact.
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.)
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)
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
Exogenous Testosterone Enhances the Reactivity to Social Provocation in Males
Directory of Open Access Journals (Sweden)
Lisa Wagels
2018-03-01
Full Text Available Testosterone affects human social behavior in various ways. While testosterone effects are generally associated with muscular strength and aggressiveness, human studies also point towards enhanced status–seeking motives after testosterone administration. The current study tested the causal influence of exogenous testosterone on male behavior during a competitive provocation paradigm. In this double blind, randomized, placebo (PL-controlled study, 103 males were assigned to a PL or testosterone group receiving a colorless PL or testosterone gel. To induce provocation, males played a rigged reaction time game against an ostensible opponent. When participants lost, the opponent subtracted money from the participant who in return could subtract money from the ostensible opponent. Participants subjectively indicated anger and self-estimated treatment affiliation (testosterone or PL administration. A trial-by-trial analysis demonstrated that provocation and success during the repeated games had a stronger influence on participants’ choice to reduce money from the opponent if they had received testosterone. Participants who believed to be in the testosterone group were angrier after the experiment and increased monetary reductions during the task course. In line with theories about mechanisms of testosterone in humans, provocation is shown to be necessary for the agency of exogenous testosterone. Thus, testosterone reinforces the conditional adjustment of aggressive behavior but not aggressive behavior per se. In contrast undirected frustration is not increased by testosterone but probably interferes with cognitive appraisals about biological mechanisms of testosterone.
Exogenous Testosterone Enhances the Reactivity to Social Provocation in Males.
Wagels, Lisa; Votinov, Mikhail; Kellermann, Thilo; Eisert, Albrecht; Beyer, Cordian; Habel, Ute
2018-01-01
Testosterone affects human social behavior in various ways. While testosterone effects are generally associated with muscular strength and aggressiveness, human studies also point towards enhanced status-seeking motives after testosterone administration. The current study tested the causal influence of exogenous testosterone on male behavior during a competitive provocation paradigm. In this double blind, randomized, placebo (PL)-controlled study, 103 males were assigned to a PL or testosterone group receiving a colorless PL or testosterone gel. To induce provocation, males played a rigged reaction time game against an ostensible opponent. When participants lost, the opponent subtracted money from the participant who in return could subtract money from the ostensible opponent. Participants subjectively indicated anger and self-estimated treatment affiliation (testosterone or PL administration). A trial-by-trial analysis demonstrated that provocation and success during the repeated games had a stronger influence on participants' choice to reduce money from the opponent if they had received testosterone. Participants who believed to be in the testosterone group were angrier after the experiment and increased monetary reductions during the task course. In line with theories about mechanisms of testosterone in humans, provocation is shown to be necessary for the agency of exogenous testosterone. Thus, testosterone reinforces the conditional adjustment of aggressive behavior but not aggressive behavior per se . In contrast undirected frustration is not increased by testosterone but probably interferes with cognitive appraisals about biological mechanisms of testosterone.
Specificity and sensitivity assessment of selected nasal provocation testing techniques
Directory of Open Access Journals (Sweden)
Edyta Krzych-Fałta
2016-12-01
Full Text Available Introduction: Nasal provocation testing involves an allergen-specific local reaction of the nasal mucosa to the administered allergen. Aim: To determine the most objective nasal occlusion assessment technique that could be used in nasal provocation testing. Material and methods : A total of 60 subjects, including 30 patients diagnosed with allergy to common environmental allergens and 30 healthy subjects were enrolled into the study. The method used in the study was a nasal provocation test with an allergen, with a standard dose of a control solution and an allergen (5,000 SBU/ml administered using a calibrated atomizer into both nostrils at room temperature. Early-phase nasal mucosa response in the early phase of the allergic reaction was assessed via acoustic rhinometry, optical rhinometry, nitric oxide in nasal air, and tryptase levels in the nasal lavage fluid. Results : In estimating the homogeneity of the average values, the Levene’s test was used and receiver operating characteristic curves were plotted for all the methods used for assessing the nasal provocation test with an allergen. Statistically significant results were defined for p < 0.05. Of all the objective assessment techniques, the most sensitive and characteristic ones were the optical rhinometry techniques (specificity = 1, sensitivity = 1, AUC = 1, PPV = 1, NPV = 1. Conclusions : The techniques used showed significant differences between the group of patients with allergic rhinitis and the control group. Of all the objective assessment techniques, those most sensitive and characteristic were the optical rhinometry.
Perturbation theory via Feynman diagrams in classical mechanics
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.
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
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.)
The ε-form of the differential equations for Feynman integrals in the elliptic case
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.
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.
Clinical tube weaning supported by hunger provocation in fully-tube-fed children.
Hartdorff, Caroline M; Kneepkens, C M Frank; Stok-Akerboom, Anita M; van Dijk-Lokkart, Elisabeth M; Engels, Michelle A H; Kindermann, Angelika
2015-04-01
Children with congenital malformations, mental retardation, and complex early medical history frequently have feeding problems. Although tube feeding is effective in providing the necessary energy and nutrients, it decreases the child's motivation to eat and may lead to oral aversion. In this study, we sought to confirm our previous results, showing that a multidisciplinary clinical hunger provocation program may lead to quick resumption of oral feeding. In a crossover study, 22 children of 9 to 24 months of age who were fully dependent on tube feeding were randomly assigned to one of two groups: group A, intervention group (2-week multidisciplinary clinical hunger provocation program); and group B, control group (4-week outpatient treatment by the same multidisciplinary team). Patients failing one treatment were reassigned to the other treatment group. Primary outcome measures were at least 75% orally fed at the conclusion of the intervention and fully orally fed and gaining weight 6 months after the intervention. In group A, 9/11 patients were successfully weaned from tube feeding (2 failures: 1 developed ulcerative colitis, 1 drop-out). In group B, only 1 patient was weaned successfully; 10/11 were reassigned to the clinical hunger provocation program, all being weaned successfully. Six months after the intervention, 1 patient had to resume tube feeding. In total, in the control group, 1/11 (9%) was weaned successfully as compared with 18/21 (86%) in the hunger provocation group (P hunger provocation is an effective short-term intervention for weaning young children from tube feeding.
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.
International Nuclear Information System (INIS)
Kang, Chang Ho; Kim, Yun Hwan; Kim, Jung Hyuk; Chung, Kyoo Byung; Sung, Deuk Jae; Lee, Sang-Heon; Derby, Richard
2009-01-01
To correlate magnetic resonance (MR) image findings with pain response by provocation discography in patients with discogenic low back pain, with an emphasis on the combination analysis of a high intensity zone (HIZ) and disc contour abnormalities. Sixty-two patients (aged 17-68 years) with axial low back pain that was likely to be disc related underwent lumbar discography (178 discs tested). The MR images were evaluated for disc degeneration, disc contour abnormalities, HIZ, and endplate abnormalities. Based on the combination of an HIZ and disc contour abnormalities, four classes were determined: (1) normal or bulging disc without HIZ; (2) normal or bulging disc with HIZ; (3) disc protrusion without HIZ; (4) disc protrusion with HIZ. These MR image findings and a new combined MR classification were analyzed in the base of concordant pain determined by discography. Disc protrusion with HIZ [sensitivity 45.5%; specificity 97.8%; positive predictive value (PPV), 87.0%] correlated significantly with concordant pain provocation (P < 0.01). A normal or bulging disc with HIZ was not associated with reproduction of pain. Disc degeneration (sensitivity 95.4%; specificity 38.8%; PPV 33.9%), disc protrusion (sensitivity 68.2%; specificity 80.6%; PPV 53.6%), and HIZ (sensitivity 56.8%; specificity 83.6%; PPV 53.2%) were not helpful in the identification of a disc with concordant pain. The proposed MR classification is useful to predict a disc with concordant pain. Disc protrusion with HIZ on MR imaging predicted positive discography in patients with discogenic low back pain. (orig.)
Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers
DEFF Research Database (Denmark)
Boelke, Georg; Berger, Uwe; Bergmann, Karl-Christian
2017-01-01
: In a randomized controlled blinded setting subjects suffering from allergic rhinitis were exposed to grass pollen, birch pollen, house dust mite and/or placebo in the GA(2)LEN chamber. Different allergen concentrations were used to evaluate symptom severities. Patients had to perform PNIF before and every 30 min...... during a challenge using a portable PNIF meter. RESULTS: 86 subjects participated in 203 challenges, altogether. House dust mite provocations caused the greatest reduction in PNIF values, followed by grass pollen and birch pollen. Provocations with every allergen or pollen concentration led...... symptoms. CONCLUSION: PNIF is a helpful and feasible tool for conducting provocation trials with allergens, especially grass pollen and house dust mite, in an AEC....
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
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
The algebraic locus of Feynman integrals
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...
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
Violent offenders respond to provocations with high amygdala and striatal reactivity
DEFF Research Database (Denmark)
da Cunha-Bang, Sofi; Fisher, Patrick M.; Hjordt, Liv Vadskjær
2017-01-01
magnetic resonance imaging point-subtraction aggression paradigm in 44 men, of whom 18 were incarcerated violent offenders and 26 were control non-offenders. We measured brain activation following provocations (monetary subtractions), while the subjects had the possibility to behave aggressively or pursue...... monetary rewards. The violent offenders behaved more aggressively than controls (aggression frequency 150 us 84, P = 0.03) and showed significantly higher brain reactivity to provocations within the amygdala and striatum, as well as reduced amygdala-prefrontal and striato-prefrontal connectivity. Amygdala...
Assessment of bronchial provocation by sup(81m)Kr ventilation image in asthmatic children
International Nuclear Information System (INIS)
Sugimoto, Kazuo; Toba, Tsuyoshi; Uchiyama, Guio; Arimizu, Noboru.
1982-01-01
Allergen- or mediator-induced bronchospasm was studied by sup(81m)Kr ventilation image to determine it's sensitivity and safety as an assessment method. Twelve children with house dust sensitive asthma were subjected to inhalation of house dust, prostaglandin F sub(2α), or methacholine by ultrasonic nebulizer with sup(81m)Kr gas. During the examination dynamic ventilation images of both lungs were monitored on oscilloscope to see the changes in the ventilation images. This kind of provocation test has the following advantages compared to the conventional provocation tests. 1) There is no induction of severe attack by provocation when inhalation of antigen of mediator is stopped at the initiation of change on the ventilation image. 2) There is no overload to the patient as compared to the conventional provocation tests. 3) Analysis of the ventilation images stored in the computer can reveal the area of ventilation disturbance in the lung and the changes can be expressed quantitatively. (author)
Richard Avedon ja Annie Leibovitz laulsid kaanonit / Marika Alver
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
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.)
JaxoDraw: A graphical user interface for drawing Feynman diagrams
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
Fixed drug eruption: topical provocation and subsequent phenomena
Energy Technology Data Exchange (ETDEWEB)
Mahboob, A; Haroon, T S [Shaikh Zayed FPGMI, Lahore (Pakistan). Dept. of Dermatology; Haroon, T S [King Edward Medical Univ., Lahore (Pakistan). Dept. of Dematology; Iqbal, Z; Iqbal, F [Shaikh Zayed FPGMI, Lahore (Pakistan). Dept. of Medicine
2006-12-15
To determine the usefulness of topical provocation in detecting the incriminated drug causing fixed eruption. Three hundred and five, clinically diagnosed cases of Fixed Drug Eruption (FDE) of either gender and of any age were subjected to topical provocation with different drugs by using concentration of 1% (n=203), 2% (n=210) and 5% (n=235) in white soft paraffin. Drug ointment of one strength was applied one at a time on normal skin of flexor surface of right or left forearm. The effects of tests on involved and uninvolved skin were observed for 48 hours. The changes in lesions like erythema, hyperpigmentation, itching, burning or appearance of new lesion were considered a positive response. In case of no change, the patients (n=5) were subjected to oral provocation test, by giving half to full therapeutic dose of the suspected drug depending upon the severity of the initial attack. A patient who exhibited see-sawing phenomenon with 5% metamizole TPT was given oral challenge with same drug. Control topical tests were repeated in equal number of normal persons with various drug ointments and in patients of FDE with white soft paraffin on normal and affected skin. One hundred and thirty-seven patients were males and one hundred and sixty-eight patients were females. Maximum number of patients belonged to third decade. With 1% drug preparations 12 out of 316, with 2% drug preparations 28 out of 422 and with 5% drug preparations, 312 out of 523 TPTs were positive. The comparison revealed a highly significant association (Chi-square 448.1 and p<0.000) among various strengths of preparations and positive response. Sulphamethoxazole was found to be the most commonly incriminated cause of FDE applied in 5% concentration yielded sensitivity rate of 91% compared to 4% with lower concentrations. Positive patch test was also observed with oxytetracycline. Five patients who were given oral provocation with different drugs were found to be positive to tinidazole, dapsone
Fixed drug eruption: topical provocation and subsequent phenomena
International Nuclear Information System (INIS)
Mahboob, A.; Haroon, T.S.; Haroon, T.S.; Iqbal, Z.; Iqbal, F.
2006-01-01
To determine the usefulness of topical provocation in detecting the incriminated drug causing fixed eruption. Three hundred and five, clinically diagnosed cases of Fixed Drug Eruption (FDE) of either gender and of any age were subjected to topical provocation with different drugs by using concentration of 1% (n=203), 2% (n=210) and 5% (n=235) in white soft paraffin. Drug ointment of one strength was applied one at a time on normal skin of flexor surface of right or left forearm. The effects of tests on involved and uninvolved skin were observed for 48 hours. The changes in lesions like erythema, hyperpigmentation, itching, burning or appearance of new lesion were considered a positive response. In case of no change, the patients (n=5) were subjected to oral provocation test, by giving half to full therapeutic dose of the suspected drug depending upon the severity of the initial attack. A patient who exhibited see-sawing phenomenon with 5% metamizole TPT was given oral challenge with same drug. Control topical tests were repeated in equal number of normal persons with various drug ointments and in patients of FDE with white soft paraffin on normal and affected skin. One hundred and thirty-seven patients were males and one hundred and sixty-eight patients were females. Maximum number of patients belonged to third decade. With 1% drug preparations 12 out of 316, with 2% drug preparations 28 out of 422 and with 5% drug preparations, 312 out of 523 TPTs were positive. The comparison revealed a highly significant association (Chi-square 448.1 and p<0.000) among various strengths of preparations and positive response. Sulphamethoxazole was found to be the most commonly incriminated cause of FDE applied in 5% concentration yielded sensitivity rate of 91% compared to 4% with lower concentrations. Positive patch test was also observed with oxytetracycline. Five patients who were given oral provocation with different drugs were found to be positive to tinidazole, dapsone
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.)
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)
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
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.
Assaultive behavior. Does provocation begin in the front office?
Blair, D T
1991-05-01
1. Provocation is an important risk predictor because these issues can be recognized, assessed, and appropriate interventions can be implemented to reduce the associated risks. It is only by the reduction of such "non-fixed" risk factors that any reduction of assaults can be accomplished. 2. Involuntary admission, patients with dementia or organic brain disorder, physical or verbal limits, staff attitude, denial of the possibility of assaults, and the educational level and clinical experience of the staff may help provoke an assaultive episode. 3. An important step is assessing the assault to identify provocation due to certain medical causes, and to document the extent of degeneration in patients with dementia or organic brain disorder. Medical intervention would be indicated and would appropriately address the causes of some violent episodes.
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.)
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)
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
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
77 FR 21555 - Manning, Richard W.; Notice of Filing
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...
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''
Impulsivity and suicidality: the mediating role of painful and provocative experiences.
Bender, Theodore W; Gordon, Kathryn H; Bresin, Konrad; Joiner, Thomas E
2011-03-01
Multiple studies have reported a link between high levels of impulsivity and suicidal behavior. Joiner's (2005) explanation for this link is that impulsive individuals have a greater tendency to experience painful and provocative events that habituate them to fear and pain, which leads to an acquired capability for engaging in suicidal behavior. Study 1 tested Joiner's (2005) hypothesis in a sample of 182 undergraduate students who completed self-report questionnaires on impulsivity, frequency of painful and provocative events, and acquired capability for suicide. In addition to self-report, pain tolerance (an aspect of acquired capability for suicide) was measured with a pressure algometer. Study 2 sought to replicate our findings from Study 1 in a sample of 516 clinical outpatients using a multi-faceted measure of impulsivity. Consistent with prediction, product of coefficients tests for mediation (MacKinnon et al., 2002) revealed that impulsivity has an indirect relationship with acquired capability for suicidal behavior, and that this relationship is mediated by painful and provocative events. Data from our studies are cross-sectional in nature, which does not allow for conclusions about the temporal ordering of our variables. In addition, self-report was used to measure most variables. Future research may benefit from a longitudinal design and the inclusion of other modes of assessment (e.g., behavioral measures of impulsivity). Our findings suggest that the link between impulsivity and suicidal behavior occurs because impulsive people tend to have a greater capability for suicidal behavior, which they have acquired through experiencing painful and provocative events. Copyright © 2010 Elsevier B.V. All rights reserved.
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
Destructive interferences results in bosons anti bunching: refining Feynman's argument
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.
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
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
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.
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.
Soleimanifar, Manijeh; Karimi, Noureddin; Arab, Amir Massoud
2017-04-01
The sacroiliac joint (SIJ) has been implicated as a potential source of low back and buttock pain. Several types of motion palpation and pain provocation tests are used to evaluate SIJ dysfunction. The purpose of this study was to investigate the relationship between motion palpation and pain provocation tests in assessment of SIJ problems. This study is Descriptive Correlation. 50 patients between the ages of 20 and 65 participated. Four motion palpation tests (Sitting flexion, Standing flexion, Prone knee flexion, Gillet test) and three pain provocation tests (FABER, Posterior shear, Resisted abduction test) were examined. Chi-square analysis was used to assess the relationship between results of the individuals and composites of these two groups of tests. No significant relationship was found between these two groups of tests. It seems that motion palpation tests assess SIJ dysfunction and provocative tests assessed SIJ pain which do not appear to be related. Copyright © 2016 Elsevier Ltd. All rights reserved.
Solving differential equations for Feynman integrals by expansions near singular points
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.
Richard Halliburton's Bearded Tales
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),…
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
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.
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...
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.
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.
Huygens-Feynman-Fresnel principle as the basis of applied optics.
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.
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.
Bancroftian filariasis: long-term effect of the DEC provocative day test on microfilaraemia
DEFF Research Database (Denmark)
Simonsen, Poul Erik; Meyrowitsch, Dan Wolf; Makunde, W.H.
1997-01-01
The diethylcarbamazine (DEC) provocative day test has been widely used for daytime diagnosis of Wuchereria bancrofti infections in areas where microfilariae exhibit nocturnal periodicity. Since DEC is also the primary drug for treatment of bancroftian filariasis, we examined the long term effect...... amicrofilaraemic. No significant reduction of microfilaraemia was observed in the placebo group. The results imply that the DEC provocative day test should not be used as a diagnostic tool in follow-up studies on microfilaraemias....
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)
Swearing Used in Richard Wright’s Black Boy
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...
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
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
Academic Training Lecture | Beyond Feynman Diagrams (1/3) | 24 April
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 ...
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
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.
Neurofunctional correlates of posttraumatic stress disorder: a PET symptom provocation study.
Pissiota, Anna; Frans, Orjan; Fernandez, Manuel; von Knorring, Lars; Fischer, Håkan; Fredrikson, Mats
2002-04-01
Patients with combat-related posttraumatic stress disorder (PTSD) show altered cognitive and affective processing and symptomatic responding following exposure to trauma reminders. Previous symptom provocation studies using brain imaging have involved Vietnam veterans. In this study neural correlates were investigated in patients with PTSD resulting from trauma in more recent war zones. (15)Oxygen water and positron emission tomography were used to measure regional cerebral blood flow (rCBF) in patients with war- and combat-related chronic PTSD during exposure to combat and neutral sounds. Self-reports and heart rate confirmed symptomatic responding during traumatic stimulation. The war-related condition, as compared to the neutral, increased rCBF in the right sensorimotor areas (Brodmann areas 4/6), extending into the primary sensory cortex (areas 1/2/3), and the cerebellar vermis. RCBF also increased in the right amygdala and in the periaqueductal gray matter adjacent to the pons. During provocation rCBF was lowered in the right retrosplenial cortex (areas 26/29/30 extending into area 23). Symptom provocation in PTSD promote sensorimotor, amygdaloid and midbrain activation. We conclude that perceptually induced symptom activation in PTSD is associated with an emotionally determined motor preparation and propose that subcortically initiated rather than cortically controlled memory mechanisms determine this pattern.
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
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
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
Potshemu medved rõtshit / Richard Pipes
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
A guide to Feynman diagrams in the many-body problem
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.
Richard Peters and Valuing Authenticity
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.…
Provocative Pedagogies in e-Learning: Making the Invisible Visible
Sinclair, Anne
2009-01-01
The purpose of this case study was to explore the experiences of participants (practicing teachers) involved in an online course entitled: "Reflective Practice for Teachers." Using a provocative pedagogy in the course, the teachers were challenged to confront beliefs and assumptions about teaching and learning and become active participants in the…
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.)
Provocative design for unprovocative designers : Strategies for triggering personal dilemmas
Ozkaramanli, D.; Desmet, P.M.A.; Lloyd, Peter; Bohemia, Erik
2016-01-01
Traditional design approaches stimulate the creation of products that make daily interactions more efficient, comfortable, and pleasant. In contrast, provocative design approaches, such as critical design, have a different focus: they aim to challenge the status quo through products that expose
In Conversation with Paul Richards
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.
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.
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
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
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
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
Staudenmayer, H; Kramer, R E
1999-08-01
A middle-aged woman with a 10-year history of disability attributed to chemical sensitivities complained that exposure to specific fragrances immediately elicited seizures. Video-EEG monitoring was performed in a hospital neurodiagnostic laboratory during provocative challenge studies employing fragrances identified by the patient as reliably inducing symptoms. The baseline clinical EEG was normal. Immediately after each provocation with air deodorant and perfume, she consistently showed both generalized tonic/clonic and multifocal myoclonic jerking, at times was nonresponsive, spoke with slurred speech, and complained of right-sided paralysis and lethargy. None of these events were associated with any EEG abnormalities. Psychological assessment (MMPI-2, MCMI-II) revealed personality traits that predisposed her to somatization and beliefs about environmental sensitivities. The convulsions were a manifestation of psychogenic pseudoseizures that had been iatrogenically reinforced.
Teaching Electron--Positron--Photon Interactions with Hands-on Feynman Diagrams
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…
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.
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...
ALOHA: Automatic libraries of helicity amplitudes for Feynman diagram computations
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
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
Recensie "The Great Reset" : Richard Florida
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
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
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.
Theodore William Richards and the Periodic Table
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)
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.
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
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
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.)
Helseth, Sarah A; Waschbusch, Daniel A; King, Sara; Willoughby, Michael T
2015-11-01
Callous/unemotional traits (CU) moderate children's conduct problems (CP) in numerous domains, including social functioning. The present study examined whether CU traits also moderate the aggressiveness of children's social information processing (SIP) and responses to varying intensities of peer provocation. Sixty elementary school-age children (46 males) were grouped into those without CP or CU (controls, n = 32), those with CP but not CU (CP-only; n = 14), and those with both CP and CU (CPCU, n = 14). Participants completed a task that measured two aspects of SIP (response generation and hostile attribution bias) and a computerized reaction time task (CRTT) that measured behavior, affect, and communication before and after provocation under instrumental and hostile aggressive conditions. Children with CPCU generated more aggressive responses than controls on measures of SIP. On the CRTT, all children exhibited reactive aggression following high provocation, but only children with CPCU exhibited proactive aggression, and reactive aggression following low provocation; no differences in affect were found. In a series of exploratory analyses, CPCU children communicated antisocially, while CP-only communicated prosocially. Finally, children with CPCU did not seem to hold a grudge following the final instance of provocation, instead gradually returning to baseline like their non-CU peers. These distinct social cognitive and behavioral profiles hint at different etiologies of CP and CPCU, underscoring the variability of aggression in these populations.
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.)
Directory of Open Access Journals (Sweden)
Hannah L. Pincham
2015-10-01
Full Text Available Increasingly, research is turning to the ways in which social context impacts decision making and feedback processing in adolescents. The current study recorded electroencephalography to examine the trajectory of development across adolescence, with a focus on how social context impacts cognition and behaviour. To that end, younger (10–12 years and older (14–16 years adolescents played a modified Taylor Aggression Paradigm against two virtual opponents: a low-provoker and a high-provoker. During the task's decision phase (where participants select punishment for their opponent, we examined two event-related potentials: the N2 and the late positive potential (LPP. During the outcome phase (where participants experience win or loss feedback, we measured the feedback related negativity (FRN. Although N2 amplitudes did not vary with provocation, LPP amplitudes were enhanced under high provocation for the younger group, suggesting that emotional reactivity during the decision phase was heightened for early adolescents. During the outcome phase, the FRN was reduced following win outcomes under high provocation for both groups, suggesting that a highly provocative social opponent may influence the reward response. Collectively, the data argue that social context is an important factor modulating neural responses in adolescent behavioural and brain development.
Laryngeal effects of nasal allergen provocation in singers with allergic rhinitis
Verguts, Monique M. L.; Eggermont, Anita; Decoster, Wivine; de Jong, Felix I. C. R. S.; Hellings, Peter W.
2011-01-01
In spite of our recent insight into nasobronchial interaction mechanisms in allergic airway disease, the association between allergic rhinitis and voice complaints remains obscure. To evaluate the effects of nasal allergen provocation and seasonal grass pollen exposure on subjective and objective
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
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.
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
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.
Extended Hellmann-Feynman theorem for degenerate eigenstates
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.
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.)
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)
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....
Advances in the use of inhalation provocation tests in clinical evaluation
Hargreave, F. E.; Ramsdale, E. H.; Sterk, P. J.; Juniper, E. F.
1985-01-01
Recent advances in the use of inhalation provocation tests in the clinical evaluation of asthma have been made with methacholine and histamine tests. The tests can be better standardized and the results more accurately interpreted. The ease of stimulation of bronchoconstriction by methacholine and
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
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
Kuues väljasuremine / Richard Leakey, Roger Lewin
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
Lubis, Azwin; Barlianto, Wisnu; Endaryanto, Anang; Harsono, Ariyanto
2017-01-01
Background: Subjective diagnostic test of food allergy is hugely biased, resulting in irrational diet avoidance. Additional objective tools by skin prick test following food provocation test resulting more accurate cause and prevalence on population. Purpose: To evaluate the compatibility of clinical symptoms with skin prick test and provocation test for imunoglobulin E (IgE) mediated food allergy in Dr. Soetomo Hospital Surabaya. Methods: Cross sectional observational analytic study. Patient...
Bridging the Knowledge Gaps between Richards' Equation and Budyko Equation
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.
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...
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.
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
Hostile attribution biases for relationally provocative situations and event-related potentials.
Godleski, Stephanie A; Ostrov, Jamie M; Houston, Rebecca J; Schlienz, Nicolas J
2010-04-01
This exploratory study investigates how hostile attribution biases for relationally provocative situations may be related to neurocognitive processing using the P300 event-related potential. Participants were 112 (45 women) emerging adults enrolled in a large, public university in upstate New York. Participants completed self-report measures on relational aggression and hostile attribution biases and performed an auditory perseveration task to elicit the P300. It was found that hostile attribution biases for relational provocation situations was associated with a larger P300 amplitude above and beyond the role of hostile attribution biases for instrumental situations, relational aggression, and gender. Larger P300 amplitude is interpreted to reflect greater allocation of cognitive resources or enhanced "attending" to salient stimuli. Implications for methodological approaches to studying aggression and hostile attribution biases and for theory are discussed, as well as implications for the fields of developmental psychology and psychopathology. Copyright 2010 Elsevier B.V. All rights reserved.
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.
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
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.)
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)
Schaubschläger, W; Ruschmeyer, J; Zabel, P; Schlaak, M
1988-06-01
Adverse reactions to tartrazine have been known since 1958. The mechanism of this reaction, a not IgE-mediated, anaphylactoid reaction, is not fully understood. The demonstration of this adverse reaction by provocative challenge feeding may be problematic by a score of subjective symptoms because of the placebo effect. This report deals with the intragastral provocation under endoscopic control with tartrazine and tartrazine-induced histamine release in vitro from gastric mucosa and from blood. Two patients with anamnestically suspected adverse reactions to tartrazine were studied. Correspondence of in vivo and in vitro testing with tartrazine could be demonstrated.
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
Making Choices: Simultaneous Report and Provocative Statements, Tools for Appreciative Inquiry
Nelson, Eric M.; Wright, Christine M.
2011-01-01
Many educators find that students do not participate actively in class, and are constantly seeking a variety of techniques to encourage student participation. The focus of this paper is to show how simultaneous report and provocative statements can be combined to foster appreciative inquiry, thereby, creating a learning environment with greater…
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:
Tremblay, Paul F; Mihic, Ljiljana; Graham, Kathryn; Jelley, Jennifer
2007-01-01
Little attention has been paid to the motivation to respond to provocation and to the interaction between this motivation, alcohol, the drinking environment, and individual characteristics. Undergraduates at six Canadian universities (N = 1,232) read three vignettes describing conflict situations with social environmental manipulations while imagining themselves as either sober or intoxicated. Self-ratings assessed likelihood of assertive and aggressive responses and motivational indices of anger, offensiveness of the instigator's actions, and importance to respond to the provocation. Respondents also completed a measure of trait aggression. Multi-group structural equation models supported the hypothesis that perceived likelihood of reactive aggression is influenced by perceived alcohol intoxication, gender, trait aggression, social environmental factors, and motivation to respond to the provocation. In addition, a number of interactions were found among the predictors. These results provide insight into the types of factors that may influence aggression in drinking situations. Copyright 2007 Wiley-Liss, Inc.
Global Estimates of Errors in Quantum Computation by the Feynman-Vernon Formalism
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.
Global Estimates of Errors in Quantum Computation by the Feynman-Vernon Formalism
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.
Expressing Solutions of the Dirac Equation in Terms of Feynman Path Integral
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...
Richard Mattessich: vida y obra
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.
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.
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
Richard Weaver's Untraditional Case for Federalism
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...
Designing to bring the field to the showroom through open-ended provocation.
Kelly, J.; Wensveen, S.A.G.
2014-01-01
Engaging formats are required to communicate designerly understandings of field studies to a broader audience within organisations. Here we present a case where the format of an exhibition, consisting of a collection of open-ended provocative design concepts, has been used to disseminate knowledge
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.))
Feynman propagator for spin foam quantum gravity.
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".
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 ...
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
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.
A Hundred Years of Physics on Show
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?
Teaching Basic Quantum Mechanics in Secondary School Using Concepts of Feynman Path Integrals Method
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.)
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)
Richard Wollheim 1923-2003 / Marek Volt
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
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...
Richard von Volkmann: surgeon and Renaissance man.
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.
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.
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...
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 ...
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
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
Anzic, Srdjan Ante; Dzepina, Davor; Kalogjera, Livije
2007-11-01
Patients with allergic rhinitis demonstrate hyperreactive response in distilled water nasal provocation, shown by significant increase in nasal airway resistance (NAR). Antihistamines, including topical antihistamine, levocabastine, reduce response in non-specific nasal provocation tests. Furosemide is a diuretic which reduces hyperreactivity in lower airways, but the mode of its action is not yet fully understood. In this study, we hypothesized that either levocabastine or furosemide pre-treatment in allergic rhinitis patients reduced response to nasal challenge with non-isotonic aerosol. To test the hypothesis, we measured the effect of pre-treatment with levocabastine and furosemide in topical application on suppression of hyperreactive response to distilled water nasal inhalation. Nasal resistance was measured, prior to and after the provocation, by active anterior rhinomanometry in two randomized groups of patients, according to pre-treatment, either by levocabastine or furosemide, 20 patients in each group, respectively. Nasal airflow resistance and level of hyperreactive response considering nasal eosinophilia were tested. Significant increase in nasal resistance following provocation was found at baseline conditions (without pre-medication); pre-treatment with levocabastine and furosemide has suppressed such response. Patients with positive nasal eosinophilia showed a significantly higher increase in nasal resistance compared to those with negative smears. Furosemide has shown significantly better protective effect on nasal resistance increase in patients with positive eosinophils nasal smears. Levocabastine and furosemide pre-treatment suppress hyperreactive response to distilled water nasal provocation. Comparison of resistances (pre-treatment vs. without) showed more protective effect of furosemide, measured on both better and worse patent side of nose, in contrast to levocabastine group for which it was shown only on better patent side prior to
Scopolamine provocation-based pharmacological MRI model for testing procognitive agents.
Hegedűs, Nikolett; Laszy, Judit; Gyertyán, István; Kocsis, Pál; Gajári, Dávid; Dávid, Szabolcs; Deli, Levente; Pozsgay, Zsófia; Tihanyi, Károly
2015-04-01
There is a huge unmet need to understand and treat pathological cognitive impairment. The development of disease modifying cognitive enhancers is hindered by the lack of correct pathomechanism and suitable animal models. Most animal models to study cognition and pathology do not fulfil either the predictive validity, face validity or construct validity criteria, and also outcome measures greatly differ from those of human trials. Fortunately, some pharmacological agents such as scopolamine evoke similar effects on cognition and cerebral circulation in rodents and humans and functional MRI enables us to compare cognitive agents directly in different species. In this paper we report the validation of a scopolamine based rodent pharmacological MRI provocation model. The effects of deemed procognitive agents (donepezil, vinpocetine, piracetam, alpha 7 selective cholinergic compounds EVP-6124, PNU-120596) were compared on the blood-oxygen-level dependent responses and also linked to rodent cognitive models. These drugs revealed significant effect on scopolamine induced blood-oxygen-level dependent change except for piracetam. In the water labyrinth test only PNU-120596 did not show a significant effect. This provocational model is suitable for testing procognitive compounds. These functional MR imaging experiments can be paralleled with human studies, which may help reduce the number of false cognitive clinical trials. © The Author(s) 2015.
Bronchial provocation testing does not detect exercise-induced laryngeal obstruction.
Walsted, Emil Schwarz; Hull, James H; Sverrild, Asger; Porsbjerg, Celeste; Backer, Vibeke
2017-01-02
Exercise-induced laryngeal obstruction (EILO) is a key differential diagnosis for asthma in the presence of exertional respiratory symptoms. Continuous laryngoscopy during exercise (CLE), the current gold standard diagnostic test for EILO, has practical limitations. We aimed to establish if inspiratory flow data obtained during standard bronchoprovocation testing, to establish the presence of extra-thoracic hyper-responsiveness, may prove diagnostic for EILO and thus preclude requirement for CLE testing. We consecutively evaluated 37 adult subjects with exertional dyspnea and possible asthma referred over 6 months. All subjects received comprehensive assessment including a detailed clinical evaluation; pulmonary function testing, indirect and direct bronchial provocation testing, and CLE testing. Out of 37 subjects, moderate or severe EILO was diagnosed in 8 subjects (22%, all female) while 5 (14%) had both asthma and EILO. There was no correlation between degree of EILO during CLE and mean decrease in forced inspiratory flow (%FIF 50 ) obtained during neither the Methacholine (r = -0.15; p = 0.38) nor Mannitol (r = 0.04; p = 0.84) provocation tests. Inspiratory flow parameters obtained during bronchoprovocation tests did not reliably detect EILO. It remains that CLE is an important and key investigation modality in establishing a secure diagnosis of EILO.
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...
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.
Fluid flow in porous media using image-based modelling to parametrize Richards' equation.
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.
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.)
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.)
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.
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.
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...
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
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
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.
78 FR 43093 - Richard C. Theuer; Filing of Food Additive Petition and Citizen Petition
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...
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
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.
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.)
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.
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 ...
H.E. Mr Richard J. Fredericks, Ambassador of the United States of America to Switzerland
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
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.)
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.)
Nanotechnology: The Incredible Invisible World
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…
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.
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.
A Staged Reading of the Play: Moving Bodies
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.
Arnerlöv, Conny; Söderström, Minette; Öhberg, Lars
2016-01-01
The aim of this study was to evaluate whether mobile kidney pain provocation ultrasonography together with intravenous pyelography in supine and standing positions and a full medical history can confirm the diagnosis of the clinical condition of symptomatic mobile kidney and aid the selection of patients for surgical treatment. In a consecutive study, 43 patients with the clinical picture of symptomatic mobile kidney, a positive mobile kidney pain provocation ultrasonography and a renal descent of at least 2 lumbar vertebral heights on intravenous pyelography in the standing position, were operated on with nephropexy. Patients' pain relief after nephropexy was evaluated by clinical follow-up, a questionnaire and visual analogue scale (VAS) scoring. Reduction of pain after nephropexy was associated with a significant decrease in VAS scoring from a median of 8 (range 4-10) preoperatively to a median of 0 (range 0-7) postoperatively (p mobile kidney pain provocation ultrasonography and intravenous pyelography in supine and standing positions can verify the diagnosis of symptomatic mobile kidney and aid the selection of patients who will benefit from nephropexy.
Success: Richard Dyer on Diana Ross [and Beyond
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
Feynman rules for the Standard Model Effective Field Theory in R ξ -gauges
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.
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.)
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
Advanced Thin Layer Deposition of Materials for Li-ion Batteries via Electrospray
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
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)
An appreciation of Richard Threlkeld Cox
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.
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
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
Tawk, Rabih G; Tummala, Ramachandra P; Memon, Muhammad Z; Siddiqui, Adnan H; Hopkins, L Nelson; Levy, Elad I
2011-01-01
Endovascular treatment is an established option for treatment of cerebral arteriovenous malformations (AVMs). However, embolization has been associated with postprocedural neurological complications. We sought to evaluate the usefulness of intra-arterial pharmacologic provocative (superselective Wada) testing before embolization of occipital lobe AVMs. We performed a retrospective review of cases of occipital AVMs that were embolized at our institution (Millard Fillmore Gates Hospital) while the patient was under conscious sedation. Visual field testing was performed before and after superselective Wada testing and again after embolization. After microcatheterization of the target feeding pedicle, amobarbital (or, occasionally, methohexital) was administered, followed immediately by neurological testing. If the provocative test results were negative, the evaluated feeder was embolized with a liquid agent. Complications were categorized as transient or permanent neurological deficit, visual field loss, ischemic or hemorrhagic stroke, and death. Thirteen patients with occipital AVMs underwent 39 Wada tests of 34 pedicles before embolization during 26 endovascular treatment sessions. Patients were treated under conscious sedation with local anesthesia. The mean age of these patients was 43.5 years (range 16-62 years); 6 were women. Testing induced a neurological deficit in six patients. A positive test result led us to abort embolization attempts in four pedicles. In the two remaining cases, advancement of the catheter tip distally within the feeding pedicle allowed us to proceed with embolization after initial test failure. Neither patient developed a visual field deficit after embolization. Despite passing the Wada test before embolization, one other patient had a visual deficit that was detected a few hours after the procedure; this deficit lessened but was permanent. No further ischemic complications and no hemorrhagic complications occurred. Pharmacologic
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.)
Planck's Constant as a Natural Unit of Measurement
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…
Die grossen Physiker und ihre Entdeckungen von den fallenden Körpern zu den Quarks
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.
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.
DEFF Research Database (Denmark)
da Cunha-Bang, Sofi; Fisher, Patrick M; Hjordt, Liv V
2018-01-01
Serotonin signalling influences amygdala reactivity to threat-related emotional facial expressions in healthy adults, but in vivo serotonin signalling has never been investigated in the context of provocative stimuli in aggressive individuals. The aim of this study was to evaluate associations...
Richard H. Thaler: Wirtschaftsnobelpreisträger 2017
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...
Children's Moral Reasoning about Family and Peer Violence: The Role of Provocation and Retribution.
Astor, Ron A.
1994-01-01
Examined violent and nonviolent inner-city children's moral reasoning about violence in family and peer situations. All of the children condemned unprovoked violence. With provoked situations, the violent group focused more on the immorality of the provocation and perceived force akin to reciprocal justice, whereas the nonviolent group perceived…
International Nuclear Information System (INIS)
Kai, Yutaka; Morioka, Motohiro; Yano, Shigetoshi; Nakamura, Hideo; Makino, Keishi; Mizuno, Takamasa; Takeshima, Hideo; Kuratsu, Jun-ichi; Hamada, Jun-ichiro
2007-01-01
Cellulose porous beads (CPBs) are exceptionally uniform in size and nonabsorbable and they provide highly effective tumor devascularization. The risk of cranial nerve palsy must not be overlooked when embolization with CPBs is considered in meningioma patients. We attempted to identify patients at risk of cranial nerve palsy after meningioma embolization. Prior to preoperative superselective embolization with 200 μm diameter CPBs, 141 patients with meningioma underwent provocation test with lidocaine and amytal. They were divided into two groups on the basis of whether they were or were not considered eligible for embolization. We evaluated the differences between the two groups with respect to tumor anatomy, angiographic findings, and clinical presentation and recorded complications associated with the embolization of the meningioma. Of the 141 patients, 128 underwent CPB embolization (group 2); 13 were not embolized because their provocation test results were positive (group 1, n = 11) or because they showed vasospasm (n = 2). Group 1 patients had meningioma in the cavernous sinus or petroclival region. Characteristically, the feeders were of middle meningeal artery origin and exhibited a posteromedial course toward the petrous apex or cavernous sinus. In group 2 patients the middle meningeal artery was the feeder, but it lacked branches coursing posteromedially. Three of these patients experienced complications which included intratumoral hemorrhage (n 2) and post-embolization hearing disturbance (n = 1). Patients with meningioma whose tumor-feeding arteries run posteromedially toward the petrous apex or cavernous sinus are at increased risk of post-embolization cranial nerve palsy. Appropriate protocols, including lidocaine and amytal provocation tests, may reduce the risk of complications after CPB embolization of the external carotid territory in this group of patients. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Kai, Yutaka; Morioka, Motohiro; Yano, Shigetoshi; Nakamura, Hideo; Makino, Keishi; Mizuno, Takamasa; Takeshima, Hideo; Kuratsu, Jun-ichi [Kumamoto University, Department of Neurosurgery, Graduate School of Medical Sciences, Kumamoto (Japan); Hamada, Jun-ichiro [Kanazawa University, Department of Neurosurgery, Graduate School of Medical Sciences, Kanazawa (Japan)
2007-05-15
Cellulose porous beads (CPBs) are exceptionally uniform in size and nonabsorbable and they provide highly effective tumor devascularization. The risk of cranial nerve palsy must not be overlooked when embolization with CPBs is considered in meningioma patients. We attempted to identify patients at risk of cranial nerve palsy after meningioma embolization. Prior to preoperative superselective embolization with 200 {mu}m diameter CPBs, 141 patients with meningioma underwent provocation test with lidocaine and amytal. They were divided into two groups on the basis of whether they were or were not considered eligible for embolization. We evaluated the differences between the two groups with respect to tumor anatomy, angiographic findings, and clinical presentation and recorded complications associated with the embolization of the meningioma. Of the 141 patients, 128 underwent CPB embolization (group 2); 13 were not embolized because their provocation test results were positive (group 1, n = 11) or because they showed vasospasm (n = 2). Group 1 patients had meningioma in the cavernous sinus or petroclival region. Characteristically, the feeders were of middle meningeal artery origin and exhibited a posteromedial course toward the petrous apex or cavernous sinus. In group 2 patients the middle meningeal artery was the feeder, but it lacked branches coursing posteromedially. Three of these patients experienced complications which included intratumoral hemorrhage (n = 2) and post-embolization hearing disturbance (n = 1). Patients with meningioma whose tumor-feeding arteries run posteromedially toward the petrous apex or cavernous sinus are at increased risk of post-embolization cranial nerve palsy. Appropriate protocols, including lidocaine and amytal provocation tests, may reduce the risk of complications after CPB embolization of the external carotid territory in this group of patients. (orig.)
Directory of Open Access Journals (Sweden)
Dominiak-Kochanek Monika
2015-12-01
Full Text Available This study examined the effect of history of harsh parenting on readiness for aggression in young adults testing the mediating effect of emotional reaction to frustration and provocation that is assumed to arise in the context of a history of physical punishment and psychological aggression. Data were collected from 402 participants including 187 Poles (Mage = 9.5; SD = 1.2 and 215 Americans (Mage = 19.16, SD = 1.15. Participants reported retrospectively on corporal punishment and psychological aggression experienced during childhood. Based on self-report instruments, sensitivity to provocation and frustration and three patterns of readiness for aggression in adulthood were assessed. Contrary to the US sample, sensitivity to provocation and frustration were mediators in the Polish sample alone. The important role of contextual factors that define harsh parenting circumstances, such as cultural context and sex of the parent, are discussed.
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
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)
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.
Illustrated & Dissected: Professor Richard Sawdon Smith.
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.
Richard Bright and his neurological studies.
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.
Losing one’s Cool: Social Competence as a Novel Inverse Predictor of Provocation-Related Aggression
Fetterman, Adam K.; Hopkins, Kay; Krishnakumar, Sukumarakurup
2013-01-01
Provocations and frustrating events can trigger an urge to act aggressively. Such behaviors can be controlled, but perhaps more so for people who can better distinguish effective from ineffective courses of action. The present three studies (total N = 285) introduce a scenario-based measure of this form of social competence. In Study 1, higher levels of social competence predicted lower levels of trait anger. Study 2 presented provocation scenarios and asked people whether they would engage in direct, indirect, and symbolic forms of aggression when provoked. Social competence was inversely predictive of all forms of aggressive responding. Study 3 focused on reactions to frustrating events in daily life. Such events were predictive of hostile behavior and cognitive failures particularly at low levels of social competence. The research establishes that social competence can be assessed in an objective manner and that variations in it are systematically predictive of reactive aggression. PMID:23754040
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
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
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
Allaire, C; Siou-Mermet, R; Bassols, A
2012-09-01
To evaluate the safety and efficacy of preservative-free levocabastine 0.05 % ophthalmic solution compared to placebo (vehicle) and to preserved levocabastine 0.05 % ophthalmic suspension in the prevention of allergic conjunctivitis induced by a conjunctival provocation test. Ninety-two subjects (18-50 years) with a previous history of allergic conjunctivitis to pollen were randomised to receive either preservative-free levocabastine solution in one eye and preserved levocabastine suspension in the fellow eye (n=69), or preservative-free levocabastine in one eye and placebo in the fellow eye (n=23). One drop of each product was administered 10 minutes (visit 3) and 4 hours (visit 4) prior to the provocation test. The primary efficacy criterion was the sum of the itching and conjunctival hyperemia scores assessed at 3, 5 and 10 minutes after the provocation test. The safety evaluation included adverse events, visual acuity, intra-ocular pressure and study drug drop sensation. The efficacy of the preservative-free solution was significantly higher than that of placebo at all time points (P≤0.01) with one exception at visit 4 (3 minutes after the provocation test). It was significantly higher than that of the preserved suspension at visit 3, and equivalent at visit 4. The incidence of adverse events was lower with the preservative-free solution than with the preserved suspension. 94.2 % and 95.7 % subjects rated preservative-free levocabastine drop sensation as "good" or "very good" at visits 3 and 4 respectively, whereas these rates were 68.1 % and 63.8 % with preserved levocabastine. This difference between the two formulations was highly statistically significant (Ppreservative-free levocabastine was superior to that of the placebo and of the preserved suspension at visit 3, at least as effective as the preserved suspension at visit 4, and better tolerated at each visit. Copyright © 2012 Elsevier Masson SAS. All rights reserved.
Fuchsia : A tool for reducing differential equations for Feynman master integrals to epsilon form
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
One of the many visiting theoreticians, R P Feynman, who gave lectures at CERN during the year
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.
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.)
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.
International Nuclear Information System (INIS)
Chung, Hye Won; Cheon, Jung Eun; Hong, Sung Hwan; Kang, Heung Sik; Lee, Ji Ho; Oh, Joo Han; Jeon, Pyoung
2004-01-01
The aim of this study was to correlate the MR imaging abnormalities of the lumbar intervertebral discs, with emphasis being placed on the high intensity zone (HIZ) with the use of discography for pain provocation and disc morphologic evaluation of the disc. Consecutive patients with low back pain unresponsive to conservative treatment, and who were being considered for spinal fusion had MRI performed, and this was followed by lumbar discography. The MR imaging, discography and CT discography (CTD) were evaluated for all of the 19 patients. Forty-three lumbar discs in 19 patients were included in this study. The findings of MR and CTD images were evaluated retrospectively with the professional opinion and agreement of two radiologists. MR images were assessed for the presence or absence of decreased T2-wighted signal intensity, decreased disc height, annular bulging, HIZ on T2-weighted images and disc herniation. The results of pain provocation were graded as 0, nonconcordant pain; 1, definite pain, but only as part of the symptom complex; 2, concordant pain. The morphology of CTD was analyzed for presence or absence of disc degeneration, radial tearing and extravasation of the contrast agent. The presence of radial tearing was defined as contrast extension to the outer third of the annulus. The prevalence of all MR abnormalities was calculated, and the data were compared with disc morphologic characteristics and the pain response on provocative discography. We used the chi-square test to analyze the results. Grade 1 and 2 discogenic pain was observed in 8 (19%) and 12 disc levels (28%), respectively. All of the seven non-degenerated discs on MR had no pain response. The decreased SI on T2-weighted image, annular bulging and HIZ were significantly correlated with discogenic pain. Extravasation of contrast media had good correlation with annular bulging and disc herniation on MRI. Radial tearing on CT discography correlated significantly with HIZ. The HIZ was
Quasi-constitutional change without intent : A response to Richard Albert
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
Koht, kust tagasi ei tulda / Mark Jenkins ; fotod Cory Richards
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
Wooing-Scenes in “Richard III”: A Parody of Courtliness?
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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’.
Yrjämä, M; Tervonen, O; Vanharanta, H
1996-03-01
The diagnostic information achieved by a combination of ultrasonographic imaging of discs and local bony vibration of lumbar vertebrae was compared to that obtained by discographic imaging and pain provocation. The purpose of this study was to find a noninvasive method for spine diagnostics to replace expensive and invasive methods such as discography. Internal anular fissures of the lumbar discs have been shown to be a source of back pain. Intradiscal changes associated with disc degeneration can be imaged by ultrasonography. The bony vibration test of spinal processes has shown to correlate well with discographic pain provocation tests in cases of internal anular ruptures. Discographic examination of the spine is the only widely accepted diagnostic method that combines pathoanatomic changes and patients' pain. Patients with back pain in this study were examined by means of ultrasonography, bony vibration stimulation, and discography. The three lowest lumbar discs were examined. In the cases of intradiscal ultrasound findings, the vibration provocation test showed a sensitivity of 0.90 and a specificity of 0.75 compared to the discographic pain provocation test. In cases of total anular ruptures seen in ultrasound examination, the sensitivity and the specificity of the vibration pain provocation test were much lower, being 0.50 and 0.50, respectively. The combination of the two noninvasive methods provides a useful screening test for the evaluation of low back pain. The combination test can accurately depict painful disc degeneration with internal disc rupture and the use of discography can be limited to the cases suggesting total anular rupture in ultrasound examination.
Richard Kelly: Pioneirismo na iluminação da arquitetura moderna
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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
Richard Rorty's Conception of Philosophy of Education Revisited
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…
Experimental provocation of 'ice-cream headache' by ice cubes and ice water.
Mages, Stephan; Hensel, Ole; Zierz, Antonia Maria; Kraya, Torsten; Zierz, Stephan
2017-04-01
Background There are various studies on experimentally provoked 'ice-cream headache' or 'headache attributed to ingestion or inhalation of a cold stimulus' (HICS) using different provocation protocols. The aim of this study was to compare two provocation protocols. Methods Ice cubes pressed to the palate and fast ingestion of ice water were used to provoke HICS and clinical features were compared. Results The ice-water stimulus provoked HICS significantly more often than the ice-cube stimulus (9/77 vs. 39/77). Ice-water-provoked HICS had a significantly shorter latency (median 15 s, range 4-97 s vs. median 68 s, range 27-96 s). There was no difference in pain localisation. Character after ice-cube stimulation was predominantly described as pressing and after ice-water stimulation as stabbing. A second HICS followed in 10/39 (26%) of the headaches provoked by ice water. Lacrimation occurred significantly more often in volunteers with than in those without HICS. Discussion HICS provoked by ice water was more frequent, had a shorter latency, different pain character and higher pain intensity than HICS provoked by ice cubes. The finding of two subsequent HICS attacks in the same volunteers supports the notion that two types of HICS exist. Lacrimation during HICS indicates involvement of the trigeminal-autonomic reflex.
The Paradox of the Public Realm in Richard Rorty
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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.
Has Richard Rorty a moral philosophy?
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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?
Whatever Happened to Richard Reid's List of First Programming Languages?
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…
Richard Wright, Toni Morrison, and United States book clubs
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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.
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)
Argument from Design in Richard Baxter's Natural Theology
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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.
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
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
Properties of the Feynman-alpha method applied to accelerator-driven subcritical systems.
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.
Response to Richard Widdess: Music, Meaning and Culture
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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.
Review: Lyn Richards (2005. Handling Qualitative Data: A Practical Guide
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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
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
Drawings of fossils by Robert Hooke and Richard Waller
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’.
DEFF Research Database (Denmark)
Arnbak, B; Jurik, A G; Jensen, R K
2017-01-01
OBJECTIVES: The aim of the current study was to investigate the diagnostic value of three sacroiliac (SI) joint pain provocation tests for sacroiliitis identified by magnetic resonance imaging (MRI) and stratified by gender. METHOD: Patients without clinical signs of nerve root compression were...
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.
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)
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
Justiça e sociedade liberal em Richard Rorty: justiça como lealdade e o projeto social de uma utopia
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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.
Strauss, Richard. Ariane a Naxos: opera seulement, integrale. Miliza Korjus / Michel Parouty
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"
Rubinstein, S.M.; Pool, J.J.; van Tulder, M.W.; Riphagen, II; de Vet, H.C.W.
2007-01-01
Clinical provocative tests of the neck, which position the neck and arm inorder to aggravate or relieve arm symptoms, are commonly used in clinical practice in patients with a suspected cervical radiculopathy. Their diagnostic accuracy, however, has never been examined in a systematic review. A
Making the Road While Walking It: A Conversation with Richard Simpson
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…
Lendab nagu kotkas üle maailmas kogutud tarkuse / Richard Aroksaar ; intervjueerinud Ene Riet
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
Prof. Richard Mattessich at 95. His Research Methodology
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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.
Swearing Used in Richard Wright’s Black Boy
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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.
Historical Investigations of the Richard B. Russell Multiple Resource Area.
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
Esophageal Manometry with Provocative Testing in Patients with Noncardiac Angina-Like Chest Pain
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William G Paterson
1991-01-01
Full Text Available In a five year period 238 of 594 esophageal manometric studies performed in the authors’ laboratory were done on patients whose major reason for referral was noncardiac angina-like chest pain. Standard eophageal manometry was performed followed by an acid-antacid perfusion period (Bernstein test and then subcutaneous bethanechol (80 μg/kg to a maximum of 5 mg was adminstered. Baseline manometry was normal in 38% of patients and was diagnostic of ‘nutcracker’ esophagus, nonspecific esophageal motility disorder, diffuse esophageal spasm and isolated hypertensive lower esophageal sphincter in 24%, 19%, 16% and 3% of patients, respectively. Ninety-six of 238 patients (40% experienced reproduction of their presenting angina-like chest pain during acid perfusion. In 80% of these patients there were associated esophageal motor abnormal ilies induced by the acid perfusion. Thirty-six of 212 (17% experienced pain reproduction following the injection of bethanechol; however, 16 of these had already had their presenting chest pain reproduced during the acid perfusion study. In two-thirds of the patients with pain reproduction following bechanechol there was an associated bethanechol-induced esophageal motility disorder. Overall 49% of patients had their pain reproduced during provocative testing. The acid perfusion test reproduced the pain much more frequently than bethanechol simulation. This study reaffirms the value of esophageal manometry and provocative testing in this group of patients.
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…
Review of Richard Bausch, Hello to the Cannibals
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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,...
Responses of dogs with food allergies to single-ingredient dietary provocation.
Jeffers, J G; Meyer, E K; Sosis, E J
1996-08-01
To characterize specific food ingredients causing allergic reactions in dogs and to assess cross-reactivity between proteins derived from a single animal source or from different plant products. Prospective study. 25 dogs with histories and cutaneous signs consistent with food-allergic dermatitis. Dogs were fed a food-elimination diet until resolution of clinical signs and then challenged with their original diet. A diagnosis of food allergy was made if there was complete return of pruritus within 14 days of challenge exposure. After diagnosis, dogs were fed the food-elimination diet until signs related to dietary challenge abated. The dogs then were fed beef, chicken, chicken eggs, cows' milk, wheat, soy, and corn in single-ingredient provocation trials for 1 week. Any cutaneous reactions to these food ingredients were recorded by their owners. Beef and soy most often caused adverse cutaneous reactions, although all ingredients induced clinical signs in at least 1 dog. Mean number of allergens per dog was 2.4, with 80% reacting to 1 or 2 proteins and 64% reacting to 2 or more of the proteins tested. A significant difference was found between dogs reacting to beef versus cows' milk and between dogs reacting to soy versus wheat; thus, the hypothesis of cross-reactivity to ingredients derived from a single animal source or to different plant products was not supported. Similar differences between chicken meat and eggs were not identified. Long-term management of dogs with food allergies is facilitated by identification of the most commonly encountered food allergens. Because cross-reactivity cannot be verified, each protein source should be included separately in food-provocation trials.
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Daniela Simon
2014-01-01
Full Text Available Anxiety disorders have been linked to a hyperactivated cortico-amygdalar circuitry. Recent findings highlight the amygdala's role in mediating elevated anxiety in obsessive–compulsive disorder (OCD. However, modulation of amygdala hyperactivation by attentional distraction – an effective emotion regulation strategy in healthy individuals – has not yet been examined. While undergoing functional magnetic resonance imaging twenty-one unmedicated OCD patients and 21 controls performed an evaluation and a distraction task during symptom provocation with individually tailored OCD-relevant pictures. To test the specificity of responses, additional aversive and neutral stimuli were included. Significant group-by-picture type interactions were observed within fronto–striato–limbic circuits including the amygdala. In these regions patients showed increased BOLD responses during processing of OCD triggers relative to healthy controls. Amygdala hyperactivation was present across OCD symptom dimensions indicating that it represents a common neural correlate. During distraction, we observed dampening of patients' amygdala hyperactivity to OCD-relevant stimuli. Augmented amygdala involvement in patients during symptom provocation, present across OCD symptom dimensions, might constitute a correlate of fear expression in OCD linking it to other anxiety disorders. Attentional distraction seemed to dampen emotional processing of disorder-relevant stimuli via amygdala downregulation. The clinical impact of this strategy to manage anxiety in OCD should be further elucidated.
El vocabulario sechurano de Richard Spruce
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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.
Transforming Faith: H. Richard Niebuhr and Paulo Freire on Moral Education
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…
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.)
Richard Carwardine and Jay Sexton, eds., The Global Lincoln.
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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...
Provocative Containment and the Drift of Social-Scientific Realism
DEFF Research Database (Denmark)
Lezaun, Javier; Muniesa, Fabian; Vikkelsø, Signe
2013-01-01
The post-World War II period gave rise to a large number of social-scientific techniques for investigating and intervening in social reality. A particular group of these, exemplified here by the experiments of Moreno, Lewin, Bion, Milgram and Zimbardo, worked by establishing suggestive micro......-realities in which participants were exposed to, or experimented with, selected ‘social problems’. We investigate the nature of these techniques – being simultaneously highly artificial and disturbingly realistic – and propose the notion of ‘provocative containment’ to understand their operation and effects. We...... point to five ingredients of their characteristic mode of operation – expressionism, incitement, trauma, distillation and technology – and argue that they do not serve to represent a simplified version of social reality, but rather to ‘realize’ particular forms of social life intrinsic to the medium...
DEFF Research Database (Denmark)
Lindblad, Marianne; Hougaard, Anders; Amin, Faisal Mohammad
2017-01-01
, physical activity, calcitonin gene-related peptide infusion, chocolate ingestion, and the intravenous injection of insulin. In addition, carotid artery puncture has consistently been reported as a trigger of aura. Conclusions No safe and efficient method for aura provocation exists at present, but several...
Generalized internal multiple imaging (GIMI) using Feynman-like diagrams
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.
Generalized internal multiple imaging (GIMI) using Feynman-like diagrams
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.
Gravitational lensing of the CMB: A Feynman diagram approach
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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.
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.)
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.)
Transgression médiatique et provocations décadentes: La décadence comme comportement médiatique.
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Yoan Vérilhac
2012-03-01
Full Text Available The decadent and symbolist movements are deeply connected to the creation of media: newspapers, small reviews which make the promotion of the young poets and their original works. In the 1880’s, the decadent reviews use in a provocative way the codes and the media potentialities. However this provocative press is based on a double language (especially about the relationship with the public, and this contradiction generates a negative image in the popular press: the new generation of poets and writers appears to be a noisy group of « hoaxers ». Therefore, around 1890, when the new reviews grouped around the « symbolist » label define themselves a media identity, it is important for them to distance from decadent behaviours. The decadent moment of the mediatization of literature is thus indispensable to understand the history of connections between press and poetic avant-gardes.
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Yahav Yaacov
2005-06-01
Full Text Available Abstract Background Determination of PC20-FEV1 during Methacholine bronchial provocation test (MCT is considered to be impossible in preschool children, as it requires repetitive spirometry sets. The aim of this study was to assess the feasibility of determining PC20-FEV1 in preschool age children and compares the results to the wheeze detection (PCW method. Methods 55 preschool children (ages 2.8–6.4 years with recurrent respiratory symptoms were recruited. Baseline spirometry and MCT were performed according to ATS/ERS guidelines and the following parameters were determined at baseline and after each inhalation: spirometry-indices, lung auscultation at tidal breathing, oxygen saturation, respiratory and heart rate. Comparison between PCW and PC20-FEV1 and clinical parameters at these end-points was done by paired Student's t-tests. Results and discussion Thirty-six of 55 children (65.4% successfully performed spirometry-sets up to the point of PCW. PC20-FEV1 occurred at a mean concentration of 1.70+/-2.01 while PCW occurred at a mean concentration of 4.37+/-3.40 mg/ml (p 1 by 44.7+/-14.5%; PEFR by 40.5+/-14.5 and FEF25–75 by 54.7+/-14.4% (P Conclusion Determination of PC20-FEV1 by spirometry is feasible in many preschool children. PC20-FEV1 often appears at lower provocation dose than PCW. The lower dose may shorten the test and encourage participation. Significant decrease in spirometry indices at PCW suggests that PC20-FEV1 determination may be safer.
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
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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)
Ripples from a Passing Ship: Memories; and a Legacy of Richard Peters
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.)
Tokodi, Margaréta; Csábi, Eszter; Kiricsi, Ágnes; Schultz, Rebeka; Molnár H, Andor; Rovó, László; Bella, Zsolt
2018-01-30
Allergy is an endemic disease and has a considerable impact on the quality of life. This study aimed to measure the effect of active allergic rhinitis on memory functions of physically active and inactive patients with ragweed allergy. Memory functions were assessed before and after allergen exposure. Participants in both groups were provoked nasally with 30 IR/mL ragweed allergen in each nostril. Explicit memory was measured with story-recalling and implicit memory was investigated with reaction time task. In neuropsychological assessments athletes performed significantly better, compared with the control group after allergen provocation in short-term and long-term memory functions. There was no difference between the groups in the implicit tasks. Athletes have achieved better results after provocation, comparing to the baseline test and the tests that measured short-term and long-term memory functions. Short-term disturbing factors, e.g. swollen nasal mucosa, sneezing, and watery eyes after provocation did have not caused deterioration in cognitive functions. A single-shot allergen in high doses have caused an increase of mental concentration, which was more pronounced in athletes.
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.
Süütuse kaotamine / Richard Branson ; intervjueerinud Peter Fisk ; tõlkinud Endrik Randoja
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
Obituary: Richard D. Schwartz (1941-2011)
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
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
Richard Wollheim über die Metapher in der Malerei
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...
Kodama, Hiroyuki; Fujita, Kazumasa; Moriyama, Shouhei; Irie, Kei; Noda, Hirotaka; Yokoyama, Taku; Fukata, Mitsuhiro; Arita, Takeshi; Odashiro, Keita; Maruyama, Toru; Akashi, Koichi
2017-06-01
A 51-year-old man with a resuscitation episode was referred to our hospital. Coronary angiography revealed a focal spasm overlapped with organic stenosis where a bare metal stent was implanted. Acetylcholine (ACh) provocation test did not induce chest pain. It revealed no discernible ST-T changes but unmasked a J wave at the end of the QRS complex, which was associated with short-coupled repetitive premature ventricular beats. A J wave reportedly appears immediately before the onset of ventricular fibrillation caused by vasospastic angina. However, a J wave observed newly after a coronary spasm provocation test using ACh without ST-T changes is informative when considering the mechanisms of the J wave.
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)
DEFF Research Database (Denmark)
Kvisselgaard, Ask D; Mosbech, Holger F; Fransson, Sara
2017-01-01
BACKGROUND: Local anesthetics (LAs) are used in many health care settings and exposure during a lifetime is almost inevitable. Immediate-type allergy to LAs is considered rare among allergy experts but is commonly suspected by health care workers from other specialties, and by patients. OBJECTIVE...... of 164 patients (123 women/41 men; median age, 56 years; range, 7-89 years) who had 189 provocations with LAs were included over the 5-year period 2010 to 2014. All 164 patients had negative subcutaneous provocations to all 189 tests with LAs (95% CI, 0%-1.83%). Another allergen was identified in 10% (n...
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.
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.
Resisting Biopolitics through “Diaphanous Wonder”: Richard Flanagan's Gould's Book of Fish
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
"Symposium" by Richard Dawkins, Gerard 't Hooft, Alain Connes
Maximilien Brice
2004-01-01
Richard Dawkins will speak on biology, Gerard ât 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?
Quantum leap from Dirac and Feynman, across the universe, to human body and mind
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
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.)
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
Don't panic. A guide to tryptophan depletion with disorder-specific anxiety provocation.
Hood, S D; Bell, C J; Argyropoulos, S V; Nutt, D J
2016-11-01
The 2002 paper "Does 5-HT restrain panic? A tryptophan depletion study in panic disorder patients recovered on paroxetine" by Bell and colleagues - reprinted in this issue of the Journal - reports on a study undertaken in the halcyon days of David Nutt's Psychopharmacology Unit at the University of Bristol, England. In this invited commentary authors of the original work discuss the impact of this paper on the field of acute tryptophan depletion research (especially in the field of clinical anxiety disorders) and the development of disorder-specific anxiogenic provocations over the past decade. © The Author(s) 2016.
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.
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.
Editorial, Forum and Book Reviews
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.
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.)
Sesé, L; Gaouar, H; Autegarden, J-E; Alari, A; Amsler, E; Vial-Dupuy, A; Pecquet, C; Francès, C; Soria, A
2016-03-01
The diagnosis of HSR to iodinated contrast media (ICM) is challenging based on clinical history and skin tests. This study evaluates the negative predictive value (NPV) of skin tests and intravenous provocation test (IPT) with low-dose ICM in patients with suspected immediate hypersensitivity reaction (HSR) to ICM. Thirty-seven patients with suspected immediate hypersensitivity reaction to ICM were included retrospectively. Skin tests and a single-blind placebo-controlled intravenous provocation test (IPT) with low-dose iodinated contrast media (ICM) were performed. Skin tests with ICM were positive in five cases (one skin prick test and five intradermal test). Thirty-six patients were challenged successfully by IPT, and only one patient had a positive challenge result, with a grade I reaction by the Ring and Messmer classification. Ten of 23 patients followed up by telephone were re-exposed to a negative tested ICM during radiologic examination; two experienced a grade I immediate reaction. For immediate hypersensitivity reaction to ICM, the NPV for skin tests and IPT with low dose was 80% (95% CI 44-97%). © 2016 John Wiley & Sons Ltd.
Astronomical fire: Richard Carrington and the solar flare of 1859.
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.
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…
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.
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
Salecker-Wigner-Peres clock, Feynman paths, and a tunneling time that should not exist
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.
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
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.
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
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...
Maternal risk factors in fetal alcohol syndrome: provocative and permissive influences.
Abel, E L; Hannigan, J H
1995-01-01
We present an hypothesis integrating epidemiological, clinical case, and basic biomedical research to explain why only relatively few women who drink alcohol during pregnancy give birth to children with alcohol-related birth defects (ARBDs), in particular, Fetal Alcohol Syndrome (FAS). We argue that specific sociobehavioral risk factors, e.g., low socioeconomic status, are permissive for FAS in that they provide the context for increased vulnerability. We illustrate how these permissive factors are related to biological factors, e.g., decreased antioxidant status, which in conjunction with alcohol, provoke FAS/ARBDs in vulnerable fetuses. We propose an integrative heuristic model hypothesizing that these permissive and provocative factors increase the likelihood of FAS/ARBDs because they potentiate two related mechanisms of alcohol-induced teratogenesis, specifically, maternal/fetal hypoxia and free radical formation.
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.
Transforming differential equations of multi-loop Feynman integrals into canonical form
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.
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.
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
Rotenberg, Ken J.; Betts, Lucy R.; Moore, Jolene
2013-01-01
The authors examined the relation between early adolescents' trust beliefs in peers and both their attributions for, and retaliatory aggression to, peer provocation. One hundred and eight-five early adolescents (102 male) from the United Kingdom (M age = 12 years, 2 months, SD = 3 months) completed the Children's Generalized Trust Beliefs in peer…
JaxoDraw: A graphical user interface for drawing Feynman diagrams. Version 2.0 release notes
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
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)
Vaden, S L; Hammerberg, B; Davenport, D J; Orton, S M; Trogdon, M M; Melgarejo, L T; VanCamp, S D; Williams, D A
2000-01-01
The purpose of this study was to evaluate Soft Coated Wheaten Terriers (SCWTs) affected with protein-losing enteropathy (PLE) or protein-losing nephropathy (PLN) or both for allergy to food. We performed gastroscopic food-sensitivity testing, a provocative dietary trial, and measurement of fecal immunoglobulin E (IgE) in 6 SCWTs affected with PLE or PLN or both. Positive gastroscopic food-sensitivity test reactions were noted in 5 of 6 dogs. Positive reactions were found to milk in 4 dogs, to lamb in 2 dogs, and to wheat and chicken each in 1 dog. Adverse reactions to food (diarrhea, vomiting, or pruritus) were detected in all 6 dogs during the provocative dietary trial. Adverse reactions were found to corn in 5 dogs, to tofu in 3 dogs, to cottage cheese in 2 dogs, to milk in 2 dogs, to farina cream of wheat in 2 dogs, and to lamb in 2 dogs. Serum albumin concentrations significantly decreased and fecal alpha1-protease inhibitor concentration significantly increased 4 days after the provocative trial when compared with baseline values. Antigen-specific fecal IgE varied throughout the provocative trial, with peak levels following ingestion of test meals. We conclude that food hypersensitivities are present in SCWTs affected with the syndrome of PLE/PLN. Mild inflammatory bowel disease was already established in the 6 SCWTs of this report at the time of study, making it impossible to determine if food allergies were the cause or result of the enteric disease.
Guaranha, Mirian Salvadori Bittar; da Silva Sousa, Patrícia; de Araújo-Filho, Gerardo Maria; Lin, Katia; Guilhoto, Laura Maria Figueiredo Ferreira; Caboclo, Luís Otávio Sales Ferreira; Yacubian, Elza Márcia Targas
2009-11-01
Studies suggest that higher cognitive functions could precipitate seizures in juvenile myoclonic epilepsy (JME). The present study aimed to analyze the effects of higher mental activity on epileptiform discharges and seizures in patients with JME and compare them to those of habitual methods of activation. Seventy-six patients with JME (41 female) underwent a video-EEG (electroencephalography) neuropsychologic protocol (VNPP) and habitual methods of activation for 4-6 h. Twenty-nine of the 76 (38.2%) presented provocative effect, and inhibition was seen in 28 of 31 (90.3%). A mixed effect was observed in 11 (35.5%), and 30 patients (39.5%) suffered no effect of VNPP. Action-programming tasks were more effective than thinking in provoking epileptiform discharges (23.7% and 11.0% of patients, respectively, p = 0.03). Inhibitory effect was observed equally in the various categories of tasks, except in mental calculation, which had a higher inhibitory rate. Habitual methods of activation were more effective than VNPP in provoking discharges. Anxiety disorders were diagnosed in 24 of 58 patients (41.4%); anxious patients had greater discharge indexes and no significant inhibitory effect on VNPP. Praxis exerted the most remarkable provocative effect, in accordance with the motor circuitry hyperexcitability hypothesis in JME. Inhibitory effect, which had no such task specificity, might be mediated by a widespread cortical-thalamic pathway, possibly involving the parietal cortex. The frequent inhibitory effect found under cortical activation conditions, influenced by the presence of anxiety, supports nonpharmacologic therapeutic interventions in JME.
[Sir William Richard Gowers: author of the "bible of neurology"].
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.
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.
Kamo, Minobu; Fuwa, Sokun; Fukuda, Katsuyuki; Fujita, Yoshiyuki; Kurihara, Yasuyuki
2016-07-01
This report describes a novel approach to endoscopically induce bleeding by removing a clot from the bleeding site during angiography for upper gastrointestinal (UGI) hemorrhage. This procedure enabled accurate identification of the bleeding site, allowing for successful targeted embolization despite a negative initial angiogram. Provocative endoscopy may be a feasible and useful option for angiography of obscure bleeding sites in patients with UGI arterial hemorrhage. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.
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,…
Il concetto di medium artistico: Richard Wollheim interprete di Ludwig Wittgenstein
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...
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.)
Papain-induced asthma: diagnosis by skin test, RAST and bronchial provocation test
International Nuclear Information System (INIS)
Baur, X.; Fruhmann, G.
1979-01-01
Seven out of eleven workers occupationally exposed to airborne papain developed immediate hypersensitive reactions, predominantly asthma and rhinitis. Skin tests and RAST with papain were positive in all symptomatic workers, but not in the four asymptomatic workers. Furthermore, out of forty non-exposed asthmatics, thirty-eight had negative RAST results and all had negative skin test results. Bronchial provocation tests with 0.15-0.5 mg papain performed in five patients with a positive case history showed in each case an immediate asthmatic reaction; in addition to that, one patient developed signs of a dual asthmatic reaction. These results suggest that airborne papain is a highly immunogenic agent in humans, which induces type I allergic reactions in a large percentage of the exposed subjects. (author)
Krämer, Ulrike M.
2017-01-01
When intentionally pushed or insulted, one can either flee from the provoker or retaliate. The implementation of such fight-or-flight decisions is a central aspect in the genesis and evolution of aggression episodes, yet it is usually investigated only indirectly or in nonsocial situations. In the present fMRI study, we aimed to distinguish brain regions associated with aggressive and avoidant responses to interpersonal provocation in humans. Participants (thirty-six healthy young women) could either avoid or face a highly (HP) and a lowly (LP) provoking opponent in a competitive reaction time task: the fight-or-escape (FOE) paradigm. Subjects avoided the HP more often, but retaliated when facing her. Moreover, they chose to fight the HP more quickly, and showed increased heart rate (HR) right before confronting her. Orbitofrontal cortex (OFC) and sensorimotor cortex were more active when participants decided to fight, whereas the mentalizing network was engaged when deciding to avoid. Importantly, avoiding the HP relative to the LP was associated with both higher activation in the right basolateral amygdala and lower relative activity in several mentalizing regions [e.g., medial and inferior frontal gyrus (IFG), temporal-parietal junction (TPJ)]. These results suggest that avoidant responses to provocation might result from heightened threat anticipation and are associated with reduced perspective taking. Furthermore, our study helps to reconcile conflicting findings on the role of the mentalizing network, the amygdala, and the OFC in aggression. PMID:28660251
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…
Richard III in Russian Theatre at the Twilight of the "Thaw"
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...
Metaforos populiarojo mokslo literatūroje: Richard Dawkins knygos analizė
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...
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
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.
Cognitive reactivity to sad mood provocation and the prediction of depressive relapse.
Segal, Zindel V; Kennedy, Sidney; Gemar, Michael; Hood, Karyn; Pedersen, Rebecca; Buis, Tom
2006-07-01
Episode remission in unipolar major depression, while distinguished by minimal symptom burden, can also be a period of marked sensitivity to emotional stress as well as an increased risk of relapse. To examine whether mood-linked changes in dysfunctional thinking predict relapse in recovered patients who were depressed. In phase 1 of this study, patients with major depressive disorder were randomly assigned to receive either antidepressant medication or cognitive behavior therapy. In phase 2, patients who achieved clinical remission underwent sad mood provocation and were then observed with regular clinical assessments for 18 months. Outpatient psychiatric clinics at the Centre for Addiction and Mental Health, Toronto, Ontario. A total of 301 outpatients with major depressive disorder, aged 18 to 65 years, participated in phase 1 of this study and 99 outpatients with major depressive disorder in remission, aged 18 to 65 years, participated in phase 2. Occurrence of a relapse meeting DSM-IV criteria for a major depressive episode as assessed by the longitudinal interval follow-up evaluation and a Hamilton Depression Rating Scale score of 16 or greater. Patients who recovered through antidepressant medication showed greater cognitive reactivity following the mood provocation than those who received cognitive behavior therapy. Regardless of type of prior treatment, the magnitude of mood-linked cognitive reactivity was a significant predictor of relapse over the subsequent 18 months. Patients whose mood-linked endorsement of dysfunctional attitudes increased by a minimum of 8 points had a significantly shorter time to relapse than those whose scores were not as elevated. The vulnerability of remitted depressed patients for illness relapse may be related to the (re)activation of depressive thinking styles triggered by temporary dysphoric states. This is the first study to link such differences to prognosis following successful treatment for depression. Further
Free as in Freedom Richard Stallman's Crusade for Free Software
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'
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.
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...
Missing Kettles and Too Few Toasters: The Forecasting Methodology at Morphy Richards
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...
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)
The 1D Richards' equation in two layered soils: a Filippov approach to treat discontinuities
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.
Directory of Open Access Journals (Sweden)
Strąkowska Maria
2016-09-01
Full Text Available Measurement of the perfusion coefficient and thermal parameters of skin tissue using dynamic thermography is presented in this paper. A novel approach based on cold provocation and thermal modelling of skin tissue is presented. The measurement was performed on a person’s forearm using a special cooling device equipped with the Peltier module. The proposed method first cools the skin, and then measures the changes of its temperature matching the measurement results with a heat transfer model to estimate the skin perfusion and other thermal parameters. In order to assess correctness of the proposed approach, the uncertainty analysis was performed.
Richard Murphy: a life in writing
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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.
Kuepper, Yvonne; Grant, Phillip; Wielpuetz, Catrin; Hennig, Juergen
2013-06-15
The MAOA-uVNTR has been suggested to play a role regarding aggression, however, results are inconsistent. We aimed at further elucidating potential effects of the MAOA-uVNTR on aggressiveness with respect to potential modulators: sex, experimental vs. trait aggressiveness and type of aggressiveness (proactive vs. reactive aggressiveness). We tested 239 healthy young adults (88 men/151 women). Participants were genotyped for the MAOA-uVNTR and performed a modified version of a competitive reaction time task - a commonly used and well established tool to elicit and measure aggressiveness. Furthermore, they completed a self-report scale measuring trait aggressiveness. We found a main effect of MAOA-uVNTR on a measure of reactive aggressiveness for both men and women, whereby the low-activity alleles of the MAOA-uVNTR were associated with substantially increased aggressive reactions (pimpulsive experimental aggressiveness in healthy men and women. Furthermore the association between the MAOA-uVNTR genotype and aggressive responses increases in a fashion linear to the degree of provocation. This indicates that the low-functional alleles of the MAOA-uVNTR are not associated with increased aggressive behavior per se, but rather with an increased aggressive reactivity to provocation. Copyright © 2013 Elsevier B.V. All rights reserved.
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
Astronaut Richard H. Truly in training session RMS for STS-2 bldg 9A
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).
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.
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.
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
Prologue to super quantum mechanics something is rotten in the state of quantum mechanics
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.
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.
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
An elementary treatise on electricity
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
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
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.
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.
Directory of Open Access Journals (Sweden)
Ping Hu
2017-04-01
Full Text Available The current study investigated the interactive effects of individual differences in automatic emotion regulation (AER and primed emotion regulation strategy on skin conductance level (SCL and heart rate during provoked anger. The study was a 2 × 2 [AER tendency (expression vs. control × priming (expression vs. control] between subject design. Participants were assigned to two groups according to their performance on an emotion regulation-IAT (differentiating automatic emotion control tendency and automatic emotion expression tendency. Then participants of the two groups were randomly assigned to two emotion regulation priming conditions (emotion control priming or emotion expression priming. Anger was provoked by blaming participants for slow performance during a subsequent backward subtraction task. In anger provocation, SCL of individuals with automatic emotion control tendencies in the control priming condition was lower than of those with automatic emotion control tendencies in the expression priming condition. However, SCL of individuals with automatic emotion expression tendencies did no differ in the automatic emotion control priming or the automatic emotion expression priming condition. Heart rate during anger provocation was higher in individuals with automatic emotion expression tendencies than in individuals with automatic emotion control tendencies regardless of priming condition. This pattern indicates an interactive effect of individual differences in AER and emotion regulation priming on SCL, which is an index of emotional arousal. Heart rate was only sensitive to the individual differences in AER, and did not reflect this interaction. This finding has implications for clinical studies of the use of emotion regulation strategy training suggesting that different practices are optimal for individuals who differ in AER tendencies.
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
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)
Newtonian nudging for a Richards equation-based distributed hydrological model
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
Richard Rufus's theory of mixture: a medieval explanation of chemical combination.
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.
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.
Süüme sundis vabrikujuhti palgatööliseks jääma / Richard Mutso ; interv. Jüri Saar
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
Iwata, Eiichiro; Shigematsu, Hideki; Inoue, Kazuya; Egawa, Takuya; Sakamoto, Yoshihiro; Tanaka, Yasuhito
2017-01-01
Rotator cuff tears and cervical spondylotic amyotrophy (CSA) are often confused as the main symptom in those with difficulty in shoulder elevation. Empty and full can tests are frequently used for the clinical diagnosis of rotator cuff tears. The aim of the present study was to investigate whether the empty and full can test results can help differentiate rotator cuff tears from CSA. Twenty-seven consecutive patients with rotator cuff tears and 25 with CSA were enrolled. We prospectively performed empty and full can tests in patients with rotator cuff tears and CSA. The following signs were considered positive: (a) muscle weakness during the empty can test, (b) muscle weakness during the full can test, (c) pain provocation during the empty can test, and (d) pain provocation during the full can test. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of rotator cuff tears for each positive finding. The sensitivity and specificity of each index were as follows (sensitivity, specificity, PPV, NPV): (a) 77.8%, 0%, 45.7%, 0%; (b) 66.7%, 4.0%, 42.9%, 10.0%; (c) 88.9%, 96.0%, 96.0%, 88.9%; and (d) 74.1%, 96.0%, 95.2%, 77.4%. There were significant differences for each index. Muscle weakness during the empty and full can tests was not useful in differentiating rotator cuff tears from CSA because of low specificity and PPV. However, pain provocation was useful in differentiating these two conditions because of high specificity and PPV.
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…
Finding new relationships between hypergeometric functions by evaluating Feynman integrals
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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.)
Regularizing Feynman path integrals using the generalized Kontsevich-Vishik trace
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.
Pimping climate change: Richard Branson, global warming, and the performance of green capitalism
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...
Psychobiological characteristics of dissociative identity disorder: a symptom provocation study.
Reinders, A A T Simone; Nijenhuis, Ellert R S; Quak, Jacqueline; Korf, Jakob; Haaksma, Jaap; Paans, Anne M J; Willemsen, Antoon T M; den Boer, Johan A
2006-10-01
Dissociative identity disorder (DID) patients function as two or more identities or dissociative identity states (DIS), categorized as 'neutral identity states' (NIS) and 'traumatic identity states' (TIS). NIS inhibit access to traumatic memories thereby enabling daily life functioning. TIS have access and responses to these memories. We tested whether these DIS show different psychobiological reactions to trauma-related memory. A symptom provocation paradigm with 11 DID patients was used in a two-by-two factorial design setting. Both NIS and TIS were exposed to a neutral and a trauma-related memory script. Three psychobiological parameters were tested: subjective ratings (emotional and sensori-motor), cardiovascular responses (heart rate, blood pressure, heart rate variability) and regional cerebral blood flow as determined with H(2)(15)O positron emission tomography. Psychobiological differences were found for the different DIS. Subjective and cardiovascular reactions revealed significant main and interactions effects. Regional cerebral blood flow data revealed different neural networks to be associated with different processing of the neutral and trauma-related memory script by NIS and TIS. Patients with DID encompass at least two different DIS. These identities involve different subjective reactions, cardiovascular responses and cerebral activation patterns to a trauma-related memory script.