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Sample records for sarah beth aubrey

  1. Tutorial to SARAH

    CERN Document Server

    Staub, Florian

    2016-01-01

    I give in this brief tutorial a short practical introduction to the Mathematica package SARAH. First, it is shown how an existing model file can be changed to implement a new model in SARAH. In the second part, masses, vertices and renormalisation group equations are calculated with SARAH. Finally, the main commands to generate model files and output for other tools are summarised.

  2. Interview: Sarah Miller

    Directory of Open Access Journals (Sweden)

    Richelle E. Wescott

    2012-01-01

    Full Text Available While still an undergraduate, Sarah Miller served as the Architecture and Design Manager for Purdue’s INHome project, which constructed a self-sufficient solar home for the Department of Energy’s Solar Decathlon. Despite this being Purdue's first time participating in the international contest, the entry earned second place.

  3. Our Friend Sarah

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    EVERY year our magazine Women ofChina(English monthly)engages anEnglish expert to copy edit ourarticles and teach our staff English.Lastautumn, 24-year-old Sarah Yates fromEngland came to our magazine.As an expert,she should be older,yet she is very earnest

  4. Interviews with Infopros: Sarah Warner.

    Science.gov (United States)

    Everett, Melissa

    1997-01-01

    Sarah Warner is manager of content licensing for Amulet, which provides an Internet-based automated research service in information technology (InfoWizard). In this interview, she discusses her work experience as a cataloger and information center manager, carry over skills from past positions, her present responsibilities in content management,…

  5. The Bethe ansatz

    Science.gov (United States)

    Levkovich-Maslyuk, Fedor

    2016-08-01

    We give a pedagogical introduction to the Bethe ansatz techniques in integrable QFTs and spin chains. We first discuss and motivate the general framework of asymptotic Bethe ansatz for the spectrum of integrable QFTs in large volume, based on the exact S-matrix. Then we illustrate this method in several concrete theories. The first case we study is the SU(2) chiral Gross-Neveu model. We derive the Bethe equations via algebraic Bethe ansatz, solving in the process the Heisenberg XXX spin chain. We discuss this famous spin chain model in some detail, covering in particular the coordinate Bethe ansatz, some properties of Bethe states, and the classical scaling limit leading to finite-gap equations. Then we proceed to the more involved SU(3) chiral Gross-Neveu model and derive the Bethe equations using nested algebraic Bethe ansatz to solve the arising SU(3) spin chain. Finally we show how a method similar to the Bethe ansatz works in a completely different setting, namely for the 1D oscillator in quantum mechanics.

  6. Making Sense of Place: Sarah's Story

    Science.gov (United States)

    James, Jennifer H.

    2008-01-01

    Written from the vantage point of both a mother and teacher educator, the author recounts the journey taken by Sarah, her 4-year old daughter, as she is introduced to and explores map making as a means of representing and making sense of familiar and unfamiliar places. Offering Sarah's experience as context, the author offers both a practical and…

  7. Boundary perimeter Bethe ansatz

    Science.gov (United States)

    Frassek, Rouven

    2017-06-01

    We study the partition function of the six-vertex model in the rational limit on arbitrary Baxter lattices with reflecting boundary. Every such lattice is interpreted as an invariant of the twisted Yangian. This identification allows us to relate the partition function of the vertex model to the Bethe wave function of an open spin chain. We obtain the partition function in terms of creation operators on a reference state from the algebraic Bethe ansatz and as a sum of permutations and reflections from the coordinate Bethe ansatz.

  8. The Bethe Wavefunction

    NARCIS (Netherlands)

    Gaudin, M.; Caux, J.-S.

    2014-01-01

    Michel Gaudin's book La fonction d'onde de Bethe is a uniquely influential masterpiece on exactly solvable models of quantum mechanics and statistical physics. Available in English for the first time, this translation brings his classic work to a new generation of graduate students and researchers i

  9. Special issue: Hans Bethe

    CERN Multimedia

    Gottfried, Kurt

    2005-01-01

    "There are a handful of people who soar, whose accompalishments are so off-scale as to nearly defy belief. Hans Bethe (2 July 1906 - 6 March 2005) was of that caliber. As just one measure of his stature, imagine the task of copying his published opus by hand, for that is how he wrote most of it" (2 pages)

  10. The Bethe Wavefunction

    NARCIS (Netherlands)

    Gaudin, M.; Caux, J.-S.

    2014-01-01

    Michel Gaudin's book La fonction d'onde de Bethe is a uniquely influential masterpiece on exactly solvable models of quantum mechanics and statistical physics. Available in English for the first time, this translation brings his classic work to a new generation of graduate students and researchers i

  11. The Bethe wavefunction

    CERN Document Server

    Gaudin, Michel

    2014-01-01

    Michel Gaudin's book La fonction d'onde de Bethe is a uniquely influential masterpiece on exactly solvable models of quantum mechanics and statistical physics. Available in English for the first time, this translation brings his classic work to a new generation of graduate students and researchers in physics. It presents a mixture of mathematics interspersed with powerful physical intuition, retaining the author's unmistakably honest tone. The book begins with the Heisenberg spin chain, starting from the coordinate Bethe Ansatz and culminating in a discussion of its thermodynamic properties. Delta-interacting bosons (the Lieb-Liniger model) are then explored, and extended to exactly solvable models associated to a reflection group. After discussing the continuum limit of spin chains, the book covers six- and eight-vertex models in extensive detail, from their lattice definition to their thermodynamics. Later chapters examine advanced topics such as multi-component delta-interacting systems, Gaudin magnets and...

  12. Hans Bethe's early life

    Science.gov (United States)

    Bernstein, Jeremy

    2012-10-01

    In 1937, two years after he moved to the US to escape Nazi persecution, the physicist Hans Bethe sent a letter to his mother in Germany. In it, he wrote, "I think I am about the leading theoretician in America. [Eugene] Wigner is certainly better and [Robert] Oppenheimer and [Edward] Teller probably just as good. But I do more and talk more and that counts too."

  13. Lectures on the Bethe Ansatz

    CERN Document Server

    Levkovich-Maslyuk, Fedor

    2016-01-01

    We give a pedagogical introduction to the Bethe ansatz techniques in integrable QFTs and spin chains. We first discuss and motivate the general framework of asymptotic Bethe ansatz for the spectrum of integrable QFTs in large volume, based on the exact S-matrix. Then we illustrate this method in several concrete theories. The first case we study is the SU(2) chiral Gross-Neveu model. We derive the Bethe equations via algebraic Bethe ansatz, solving in the process the Heisenberg XXX spin chain. We discuss this famous spin chain model in some detail, covering in particular the coordinate Bethe ansatz, some properties of Bethe states, and the classical scaling limit leading to finite-gap equations. Then we proceed to the more involved SU(3) chiral Gross-Neveu model and derive the Bethe equations using nested algebraic Bethe ansatz to solve the arising SU(3) spin chain. Finally we show how a method similar to the Bethe ansatz works in a completley different setting, namely for the 1d oscillator in quantum mechani...

  14. Introduction to SARAH and related tools

    CERN Document Server

    Staub, Florian

    2015-01-01

    I give in this lecture an overview of the features of the Mathematica package SARAH, and explain how it can be used together with other codes to study all aspects of a BSM model. The focus will be on the description of the analytical calculations which SARAH can perform and how this information is used to generate automatically a spectrum generator based on SPheno. I also summarize the main aspects of the other interfaces to public codes like HiggsBounds/HiggsSignals, FeynArts/FormCalc, CalcHep, MicrOmegas, WHIZARD, Vevacious or MadGraph. The appendix contains a short tutorial about the implementation and usage of a new model.

  15. Sarah Winnemucca. Raintree/Rivilo American Indian Stories Series.

    Science.gov (United States)

    Morrow, Mary Frances

    Sarah Winnemucca was a full-blood Paiute Indian born in 1844 in Nevada. The Paiute hunted and gathered and lived in wigwams constructed of branches, brush, and hides. Sarah's grandfather, Captain Truckee, befriended the explorer John C. Fremont and went with him to California. Captain Truckee admired White people's clothing and houses and,…

  16. HANFORD SAFETY ANALYSIS & RISK ASSESSMENT HANDBOOK (SARAH)

    Energy Technology Data Exchange (ETDEWEB)

    EVANS, C B

    2004-12-21

    The purpose of the Hanford Safety Analysis and Risk Assessment Handbook (SARAH) is to support the development of safety basis documentation for Hazard Category 2 and 3 (HC-2 and 3) U.S. Department of Energy (DOE) nuclear facilities to meet the requirements of 10 CFR 830, ''Nuclear Safety Management''. Subpart B, ''Safety Basis Requirements.'' Consistent with DOE-STD-3009-94, Change Notice 2, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'' (STD-3009), and DOE-STD-3011-2002, ''Guidance for Preparation of Basis for Interim Operation (BIO) Documents'' (STD-3011), the Hanford SARAH describes methodology for performing a safety analysis leading to development of a Documented Safety Analysis (DSA) and derivation of Technical Safety Requirements (TSR), and provides the information necessary to ensure a consistently rigorous approach that meets DOE expectations. The DSA and TSR documents, together with the DOE-issued Safety Evaluation Report (SER), are the basic components of facility safety basis documentation. For HC-2 or 3 nuclear facilities in long-term surveillance and maintenance (S&M), for decommissioning activities, where source term has been eliminated to the point that only low-level, residual fixed contamination is present, or for environmental remediation activities outside of a facility structure, DOE-STD-1120-98, ''Integration of Environment, Safety, and Health into Facility Disposition Activities'' (STD-1120), may serve as the basis for the DSA. HC-2 and 3 environmental remediation sites also are subject to the hazard analysis methodologies of this standard.

  17. Linking SARAH and MadGraph using the UFO format

    CERN Document Server

    Staub, Florian

    2012-01-01

    SARAH is a Mathematica package optimized for the fast, efficient and precise study of supersymmetric models beyond the MSSM: a new model can be defined in a short form and all vertices are derived. This allows SARAH to create model files for FeynArts/FormCalc, CalcHep/CompHep and WHIZARD/OMEGA. The newest version of SARAH now provides the possibility to create model files in the UFO format which is supported by MadGraph 5, MadAnalysis 5, GoSam, and soon by Herwig++. Furthermore, SARAH also calculates the mass matrices, RGEs and 1-loop corrections to the mass spectrum. This information is used to write source code for SPheno in order to create a precision spectrum generator for the given model. This spectrum-generator-generator functionality as well as the output of WHIZARD and CalcHep model files have seen further improvement in this version.

  18. Bethe ansatz and Isomonodromic deformations

    CERN Document Server

    Talalaev, D

    2008-01-01

    We study symmetries of the Bethe equations for the Gaudin model appeared naturally in the framework of the geometric Langlands correspondence under the name of Hecke operators and under the name of Schlesinger transformations in the theory of isomonodromic deformations, and particularly in the theory of Painlev\\'e transcendents.

  19. Erfolgreiche Ambivalenz. Sarah Bernhardts Inszenierungen von Weiblichkeit Successful Ambivalence: Sarah Bernhardt’s Staging of Femininity

    Directory of Open Access Journals (Sweden)

    Doris Kolesch

    2007-03-01

    Full Text Available Claudia Thorun untersucht die Inszenierungen von Weiblichkeit am Beispiel der Schauspielerin Sarah Bernhardt, die im späten 19. und beginnenden 20. Jahrhundert zu den erfolgreichsten Künstlerinnen ihrer Zeit gehörte. Dazu werden die Darstellungen ausgewählter Rollenfiguren ebenso analysiert wie die schauspieltheoretischen Überlegungen Bernhardts und schließlich die Rezeption ihres Schaffens in Theaterkritiken, aber auch Werbebildern und Medieninszenierungen. Das lesenswerte Buch erlaubt Einblicke in konkrete theatrale Verkörperungen von Weiblichkeit im Fin de Siècle, unternimmt jedoch keine ausreichende theatergeschichtliche wie kulturwissenschaftliche Kontextualisierung, obwohl die Verfasserin in der Einleitung ihrer Studie das Ziel formuliert, Gendertheorie, Theatergeschichte und Kulturwissenschaft zu verknüpfen.Claudia Thorun examines the staging of femininity using the example of the actress Sarah Bernhardt, who in the late nineteenth century was among the most successful artists of her time. The study includes analyses of the representation of specific roles, Bernhardt’s theories on acting, and finally the reception of her work in theater critiques, as well as advertisement images and representations in the media. The book, which is a worthwhile read, allows for insight into the concrete theatrical embodiment of femininity at the fin de siècle. It does not provide, however, adequate contextualization within theater history nor cultural studies, even though in her introduction, the author asserts that it is her intention to link together gender theory, theater history, and cultural studies.

  20. Algebraic Bethe ansatz for a singular solution

    CERN Document Server

    Nepomechie, Rafael I

    2013-01-01

    The Bethe equations for the spin-1/2 Heisenberg chain with N sites have a "two-string" solution i/2, -i/2 that is singular: both the corresponding energy and algebraic Bethe ansatz vector are divergent. We show that this solution must be carefully regularized in order to obtain the correct eigenvector. This regularization involves a parameter that can be determined using a generalization of the Bethe equations. It follows that this solution must be excluded for odd N.

  1. Hans Bethe and the Global Energy Problems

    CERN Document Server

    Ioffe, B L

    2005-01-01

    Bethe's view-point on the global energy problems is presented. Bethe claimed that the nuclear power is a necessity in future. Nuclear energetic must be based on breeder reactors. Bethe considered the non-proliferation of nuclear weapons as the main problem of long-range future of nuclear energetics. The solution of this problem he saw in heavy water moderated thermal breeders, using uranium-233, uranium-238 and thorium as a fuel.

  2. 奥博利·比亚兹莱的插画世界%Illustration world of Aubrey Beardsley

    Institute of Scientific and Technical Information of China (English)

    康夫云

    2014-01-01

    插画艺术的发展,拥有着悠久的历史。在插画艺术史上,奥博利·比亚兹莱拥有着超人的艺术天赋和对艺术不断追寻的毅力,成为世界艺术史上一座令人难忘的纪念碑。在他那短暂的生命中,让插画成为了独立的艺术门类,他的插画惊人的艺术表达力为人类插画史留下了宝贵的遗产。充满了奇异的、耐人寻味的黑白插画之美。%The development of the illustration art, has a long history. On the illustration of art history, Aubrey Beardsley has superman's artistic talent and constant perseverance in art, and become the world's history of a memorable monument. In his short life, illustrations became independent art, his amazing art expressive illustration history left a valuable legacy for humans. Full of strange and interesting illustration of the beauty of black and white.

  3. Bethe vectors for XXX-spin chain

    Science.gov (United States)

    Burdík, Čestmír; Fuksa, Jan; Isaev, Alexei

    2014-11-01

    The paper deals with algebraic Bethe ansatz for XXX-spin chain. Generators of Yang-Baxter algebra are expressed in basis of free fermions and used to calculate explicit form of Bethe vectors. Their relation to N-component models is used to prove conjecture about their form in general. Some remarks on inhomogeneous XXX-spin chain are included.

  4. Practitioner Profile: An Interview with Beth Crittenden

    Directory of Open Access Journals (Sweden)

    Martie Gillen

    2016-12-01

    Full Text Available Beth Crittenden offers financial wellness coaching to people who want growth both professionally and personally. Beth has been working with finances as a focus since 2009, after training in somatic psychology, healthy communication in relationship, and mindful meditation practices and theory.

  5. Transcending Domesticity:A Biographic Study on Sarah Orne Jewett

    Institute of Scientific and Technical Information of China (English)

    庄义辉

    2013-01-01

      Following Showalter’s division of the three phases in women’s literary history, namely the“Feminine, Feminist and Fe⁃male”, this essay launches a biographic study on Sarah Orne Jewett, discussing how she transcends domesticity by embracing fe⁃male friendship in life and writing a female culture in literature.

  6. SARAH 3.2: Dirac gauginos, UFO output, and more

    Science.gov (United States)

    Staub, Florian

    2013-07-01

    SARAH is a Mathematica package optimized for the fast, efficient and precise study of supersymmetric models beyond the MSSM: a new model can be defined in a short form and all vertices are derived. This allows SARAH to create model files for FeynArts/FormCalc, CalcHep/CompHep and WHIZARD/O'Mega. The newest version of SARAH now provides the possibility to create model files in the UFO format which is supported by MadGraph 5, MadAnalysis 5, GoSam, and soon by Herwig++. Furthermore, SARAH also calculates the mass matrices, RGEs and 1-loop corrections to the mass spectrum. This information is used to write source code for SPheno in order to create a precision spectrum generator for the given model. This spectrum-generator-generator functionality as well as the output of WHIZARD and CalcHep model files has seen further improvement in this version. Also models including Dirac gauginos are supported with the new version of SARAH, and additional checks for the consistency of the implementation of new models have been created. Program summaryProgram title:SARAH Catalogue identifier: AEIB_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIB_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3 22 411 No. of bytes in distributed program, including test data, etc.: 3 629 206 Distribution format: tar.gz Programming language: Mathematica. Computer: All for which Mathematica is available. Operating system: All for which Mathematica is available. Classification: 11.1, 11.6. Catalogue identifier of previous version: AEIB_v1_0 Journal reference of previous version: Comput. Phys. Comm. 182 (2011) 808 Does the new version supersede the previous version?: Yes, the new version includes all known features of the previous version but also provides the new features mentioned below

  7. Sarah Frances Whiting: A foremother of American women physicists

    Science.gov (United States)

    Stahl, Frieda A.

    2005-11-01

    Sarah Frances Whiting taught physics and astronomy at Wellesley College from 1876 to 1916 and developed the first physics laboratory classes for female students. She was elected a fellow of AAAS in 1883 and received an honorary D. Sc. from Tufts University in 1905. I review her accomplishments and discuss some of the barriers that she had to overcome.

  8. Linnakirjutaja Sarah J. Portner: Tallinn ei jää Pariisile alla / Sarah J. Portner ; intervjueerinud Mari Peegel

    Index Scriptorium Estoniae

    Portner, Sarah Jana, 1983-

    2011-01-01

    Saksa Ida-Euroopa kultuurifoorumi (Deutsches Kulturforum östliches Europa, Potsdam), Tallinna linna ja kirjanike liidu stipendiumiga viibib 5 kuud Tallinnas ja kirjutab linnakrooniku blogi (tallinna-linnakirjutaja-2011.blogspot.com) Passau ülikoolis kultuuriteooriat õppinud Sarah J. Portner. Blogi fookuses on Euroopa rahvaste ühine ajalugu

  9. Linnakirjutaja Sarah J. Portner: Tallinn ei jää Pariisile alla / Sarah J. Portner ; intervjueerinud Mari Peegel

    Index Scriptorium Estoniae

    Portner, Sarah Jana, 1983-

    2011-01-01

    Saksa Ida-Euroopa kultuurifoorumi (Deutsches Kulturforum östliches Europa, Potsdam), Tallinna linna ja kirjanike liidu stipendiumiga viibib 5 kuud Tallinnas ja kirjutab linnakrooniku blogi (tallinna-linnakirjutaja-2011.blogspot.com) Passau ülikoolis kultuuriteooriat õppinud Sarah J. Portner. Blogi fookuses on Euroopa rahvaste ühine ajalugu

  10. Bethe's quantum numbers and rigged configurations

    Directory of Open Access Journals (Sweden)

    Anatol N. Kirillov

    2016-04-01

    Full Text Available We propose a method to determine the quantum numbers, which we call the rigged configurations, for the solutions to the Bethe ansatz equations for the spin-1/2 isotropic Heisenberg model under the periodic boundary condition. Our method is based on the observation that the sums of Bethe's quantum numbers within each string behave particularly nicely. We confirm our procedure for all solutions for length 12 chain (totally 923 solutions.

  11. Tuulegeneraatori sündroom: infraheli mahavaikitud mõju / Sarah Laurie ; intervjueerinud Helen Arusoo

    Index Scriptorium Estoniae

    Laurie, Sarah

    2013-01-01

    Austraalia arst ja tuulegeneraatori sündroomi ohvreid abistava rahvusvahelise organisatsiooni Waubra Foundation tegevtirektor Sarah Laurie loodab saada tuulegeneraatori sündroomile meedikute tunnustuse

  12. Tuulegeneraatori sündroom: infraheli mahavaikitud mõju / Sarah Laurie ; intervjueerinud Helen Arusoo

    Index Scriptorium Estoniae

    Laurie, Sarah

    2013-01-01

    Austraalia arst ja tuulegeneraatori sündroomi ohvreid abistava rahvusvahelise organisatsiooni Waubra Foundation tegevtirektor Sarah Laurie loodab saada tuulegeneraatori sündroomile meedikute tunnustuse

  13. Counting independent sets using the Bethe approximation

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Laboratory; Chandrasekaran, V [MIT; Gamarmik, D [MIT; Shah, D [MIT; Sin, J [MIT

    2009-01-01

    The authors consider the problem of counting the number of independent sets or the partition function of a hard-core model in a graph. The problem in general is computationally hard (P hard). They study the quality of the approximation provided by the Bethe free energy. Belief propagation (BP) is a message-passing algorithm can be used to compute fixed points of the Bethe approximation; however, BP is not always guarantee to converge. As the first result, they propose a simple message-passing algorithm that converges to a BP fixed pont for any grapy. They find that their algorithm converges within a multiplicative error 1 + {var_epsilon} of a fixed point in {Omicron}(n{sup 2}E{sup -4} log{sup 3}(nE{sup -1})) iterations for any bounded degree graph of n nodes. In a nutshell, the algorithm can be thought of as a modification of BP with 'time-varying' message-passing. Next, they analyze the resulting error to the number of independent sets provided by such a fixed point of the Bethe approximation. Using the recently developed loop calculus approach by Vhertkov and Chernyak, they establish that for any bounded graph with large enough girth, the error is {Omicron}(n{sup -{gamma}}) for some {gamma} > 0. As an application, they find that for random 3-regular graph, Bethe approximation of log-partition function (log of the number of independent sets) is within o(1) of corret log-partition - this is quite surprising as previous physics-based predictions were expecting an error of o(n). In sum, their results provide a systematic way to find Bethe fixed points for any graph quickly and allow for estimating error in Bethe approximation using novel combinatorial techniques.

  14. Unitarity and the Bethe-Salpeter equation

    Science.gov (United States)

    Lahiff, A. D.; Afnan, I. R.

    2002-10-01

    We investigate the relation between different three-dimensional reductions of the Bethe-Salpeter equation and the analytic structure of the resultant amplitudes in the energy plane. This correlation is studied for both the φ2σ interaction Lagrangian and the πN system with s-, u-, and t-channel pole diagrams as driving terms. We observe that the equal-time equation, which includes some of the three-body unitarity cuts, gives the best agreement with the Bethe-Salpeter result. This is followed by other three-dimensional approximations that have less of the analytic structure.

  15. Sarah Kane y el espectáculo del dolor

    Directory of Open Access Journals (Sweden)

    Carolina Brnci'c

    2006-11-01

    Full Text Available Este artículo analiza las principales características de la dramaturgia de Sarah Kane en su dimensión textual y escénica. Se establecen los vínculos con la corriente teatral inglesa 'in yer face'de los años 90 y se precisan las influencias de Antonin Artaud en la concepción de Kane del teatro como espectáculo del dolor. El análisis se centra principalmente en la obra Phaedra's love, proyectando los aspectos más relevantes a otras piezas de la autoraThis article analyses the chief characteristics of Sarah Kane' dramaturgy in both its textual and scenic dimensions. Links are established with the English theatrical trend of the 90', known as 'in yer face', and the influences of Antonin Artaud on Kane' conception of theatre as 'a spectacle of pain'comes under consideration. This study basically focuses on Kane' piece, Phaedra' Love, while considering other pieces of the playwight

  16. Iser, Crutcher, and the Reader: Creating the World of Sarah Byrnes.

    Science.gov (United States)

    Daley, Patricia A.

    2002-01-01

    Applies the reader response theory of literary critic Wolfgang Iser to the reading of Chris Crutcher's novel "Staying Fat for Sarah Byrnes." Examines both the reader's engagement with the novel and Eric Calhoune's engagement with the world of Sarah Byrnes. (RS)

  17. Obituary: Hans Albrecht Bethe, 1906-2005

    NARCIS (Netherlands)

    Wijers, R.

    2007-01-01

    One of the unquestioned giants of physics and astrophysics, Hans Bethe, died on 6 March 2005, at the venerable age of 98, in his home town of Ithaca, New York. Seven decades of contributing to research and a Nobel Prize for his work on stellar hydrogen burning make a listing of his honors superfluou

  18. Twisting singular solutions of Bethe's equations

    CERN Document Server

    Nepomechie, Rafael I

    2014-01-01

    The Bethe equations for the periodic XXX and XXZ spin chains admit singular solutions, for which the corresponding eigenvalues and eigenvectors are ill-defined. We use a twist regularization to derive conditions for such singular solutions to be physical, in which case they correspond to genuine eigenvalues and eigenvectors of the Hamiltonian.

  19. Obituary: Hans Albrecht Bethe, 1906-2005

    NARCIS (Netherlands)

    Wijers, R.

    2007-01-01

    One of the unquestioned giants of physics and astrophysics, Hans Bethe, died on 6 March 2005, at the venerable age of 98, in his home town of Ithaca, New York. Seven decades of contributing to research and a Nobel Prize for his work on stellar hydrogen burning make a listing of his honors superfluou

  20. Obituary: Hans Albrecht Bethe, 1906-2005

    Science.gov (United States)

    Wijers, Ralph

    2007-12-01

    One of the unquestioned giants of physics and astrophysics, Hans Bethe, died on 6 March 2005, at the venerable age of 98, in his home town of Ithaca, New York. Seven decades of contributing to research and a Nobel Prize for his work on stellar hydrogen burning make a listing of his honors superfluous (besides being impossible in this space). Bethe was born in Strassburg, in then German Alsass Lothringen, on 2 July 1906. His father, Albrecht Julius Bethe (1872-1954), taught physiology at the University, and his mother, Anna Kuhn (1876-1966), was a musician and writer. Both his grandfathers were physicians. He spent his youth in Strassburg, Kiel, and Frankfurt, and some time in sanatoria due to tuberculosis. Hans's first scientific paper, at age 18, was with his father and a colleague, on dialysis. His education and early career in Germany brought him into contact with many top stars in the quantum revolution. Starting in Frankfurt in chemistry, Bethe soon switched to physics, taught there by Walter Gerlach and Karl Meissner, among others. In 1926, he successfully applied to join Arnold Sommerfeld's group in Munich, where he met one of his later long-term collaborators, Rudolf Peierls. Bethe considered his entry into physics to have come at an ideal time, with the new ideas of wave mechanics being developed and discussed right there; it was certainly also at an ideal place. His doctoral thesis was on the theory of electron diffraction by crystals, following the experimental work by Clinton Davisson and Lester Germer and the work on X-ray diffraction by Max von Laue and Paul Ewald. The newly minted doctor went from there briefly to Frankfurt and then to Ewald in Stuttgart, where he felt at home academically and personally. In 1939, Bethe would marry Ewald's daughter Rose. Not much later, though, Sommerfeld recalled him to Munich, where Sommerfeld created a Privatdozent position for him. There he worked out the solution for a linear chain of coupled spins by what we

  1. Mourir/survivre. Lumières de Sarah Kane

    Directory of Open Access Journals (Sweden)

    Martine Delvaux

    2012-01-01

    Full Text Available L’article propose une lecture de la première et de la dernière œuvres de la dramaturge britannique Sarah Kane, Blasted et 4.48 Psychosis, afin de réfléchir sur son legs théâtral. En s’appuyant sur Survivance des lucioles de Georges Didi-Huberman (2009, le texte met en lumière le rapport à l’espoir qui émane de l’œuvre de Kane et de son pessimisme apparent. Delvaux voit, dans l’écriture fragmentée, sarcastique et provocante, non pas le testament d’une artiste cliniquement dépressive mais plutôt un ultime outil de résistance à la noirceur, un refus radical de cette posture cynique que lui attribuait la critique. This article offers a reading of British dramaturge Sarah Kane’s first and last pieces, Blasted and 4.48 Psychosis, in order to reflect on her dramatic heritage. Drawing upon Georges Didi-Huberman’s Survivance des lucioles (2009, the text sheds light on the question of hope in what has been seen as pessimism in Kane’s work. Rather than understanding Kane’s fragmented, sarcastic and provocative writing as a testament of a clinically depressed author, Delvaux sees it as a work of resistance, a desire to see the light in an all-encompassing cultural darkness, suggesting that Kane, in fact, refuses the cynical posturethat critics have associated with her work.

  2. Introduction to the thermodynamic Bethe ansatz

    CERN Document Server

    van Tongeren, Stijn J

    2016-01-01

    We give a pedagogical introduction to the thermodynamic Bethe ansatz, a method that allows us to describe the thermodynamics of integrable models whose spectrum is found via the (asymptotic) Bethe ansatz. We set the stage by deriving the Fermi-Dirac distribution and associated free energy of free electrons, and then in a similar though technically more complicated fashion treat the thermodynamics of integrable models, focusing on the one dimensional Bose gas with delta function interaction as a clean pedagogical example, secondly the XXX spin chain as an elementary (lattice) model with prototypical complicating features in the form of bound states, and finally the SU(2) chiral Gross-Neveu model as a field theory example. Throughout this discussion we emphasize the central role of particle and hole densities, whose relations determine the model under consideration. We then discuss tricks that allow us to use the same methods to describe the exact spectra of integrable field theories on a circle, in particular ...

  3. Bethe logarithm and QED shift for lithium.

    Science.gov (United States)

    Yan, Zong-Chao; Drake, G W F

    2003-09-12

    A novel finite basis set method is used to calculate the Bethe logarithm for the ground 2 (2)S(1/2) and excited 3 (2)S(1/2) states of lithium. The basis sets are constructed to span a huge range of distance scales within a single calculation, leading to well-converged values for the Bethe logarithm. The results are used to calculate an accurate value for the complete quantum electrodynamic energy shift up to order alpha(3) Ry. The calculated 3 (2)S(1/2)-2 (2)S(1/2) transition frequency for 7Li is 27 206.092 6(9) cm(-1), and the ionization potential for the 2 (2)S(1/2) state is 43 487.158 3(6) cm(-1). The 7Li-6Li isotope shift is also considered, and all the results compared with experiment.

  4. Bethe Ansatz in Stringy Sigma Models

    OpenAIRE

    Klose, T.; Zarembo, K.

    2006-01-01

    We compute the exact S-matrix and give the Bethe ansatz solution for three sigma-models which arise as subsectors of string theory in AdS(5)xS(5): Landau-Lifshitz model (non-relativistic sigma-model on S(2)), Alday-Arutyunov-Frolov model (fermionic sigma-model with su(1|1) symmetry), and Faddeev-Reshetikhin model (string sigma-model on S(3)xR).

  5. Quantum Computing via The Bethe Ansatz

    OpenAIRE

    Zhang, Yong,

    2011-01-01

    We recognize quantum circuit model of computation as factorisable scattering model and propose that a quantum computer is associated with a quantum many-body system solved by the Bethe ansatz. As an typical example to support our perspectives on quantum computation, we study quantum computing in one-dimensional nonrelativistic system with delta-function interaction, where the two-body scattering matrix satisfies the factorisation equation (the quantum Yang--Baxter equation) and acts as a para...

  6. Nüüdiskunst on maailmas hinnas / Sarah Cosulich Canarutto ; interv. Reet Varblane

    Index Scriptorium Estoniae

    Cosulich Canarutto, Sarah

    2004-01-01

    Põhja-Itaalias Passariano villa Maninis avatud kaasaegse kunsti keskuse kuraator Sarah Cosulich Canarutto uue kunstikeskuse tulevikuplaanidest. Keskust juhatab Francesco Bonami. Alustati näitustega "Love/Hate" ja "Vernice"

  7. Jean Libis, Fabio Ferreira, Catherine Gublin, Sarah Mezaguer (eds.), Les Lectures de Gaston Bachelard. Index bibliographique

    OpenAIRE

    Aurosa Alison

    2012-01-01

    Jean Libis, Fabio Ferreira, Catherine Gublin, Sarah Mezaguer (eds.), Les Lectures de Gaston Bachelard. Index bibliographique (Paris, Presse Universitaire de Franche-Comté, 2011 ISBN: 978-2-84867-392) di     Aurosa Alison

  8. Nüüdiskunst on maailmas hinnas / Sarah Cosulich Canarutto ; interv. Reet Varblane

    Index Scriptorium Estoniae

    Cosulich Canarutto, Sarah

    2004-01-01

    Põhja-Itaalias Passariano villa Maninis avatud kaasaegse kunsti keskuse kuraator Sarah Cosulich Canarutto uue kunstikeskuse tulevikuplaanidest. Keskust juhatab Francesco Bonami. Alustati näitustega "Love/Hate" ja "Vernice"

  9. Jean Libis, Fabio Ferreira, Catherine Gublin, Sarah Mezaguer (eds., Les Lectures de Gaston Bachelard. Index bibliographique

    Directory of Open Access Journals (Sweden)

    Aurosa Alison

    2012-10-01

    Full Text Available Jean Libis, Fabio Ferreira, Catherine Gublin, Sarah Mezaguer (eds., Les Lectures de Gaston Bachelard. Index bibliographique (Paris, Presse Universitaire de Franche-Comté, 2011 ISBN: 978-2-84867-392 di  Aurosa Alison

  10. The Seduction of Sarah: Travel Memoirs and Intercultural Learning

    Directory of Open Access Journals (Sweden)

    Barbara Elizabeth Hanna

    2006-09-01

    Full Text Available The paper explores the nexus between intercultural storytelling and intercultural learning. Noting the wide appeal of the travel memoir set in France, it takes as a case study a book that, while positioned within that genre, attempts to shift some predictable patterns: Sarah Turnbull’s best-selling Almost French. Analysis shows that the book in fact participates in a subtle play of genres, whereby the lure of the travel memoir is used to entice readers towards a position where they read the book as a guide to French culture. The particular form of hybridity attempted is, however, a delicate enterprise, as the reception of the book demonstrates, in that the intercultural lessons on offer risk being overshadowed by the expectations readers bring to the genre of the travel memoir. The paper examines the competing seductions operating throughout the text and relates the conditions for taking up the opportunity for intercultural learning to questions of genre. It offers a pedagogical uptake of the textual analysis, thus bridging disciplines in a way that mirrors Turnbull’s bridging of genres.

  11. SARAH 4: A tool for (not only SUSY) model builders

    CERN Document Server

    Staub, Florian

    2013-01-01

    We present the new version of the Mathematica package SARAH which provides the same features for a non-supersymmetric model as previous versions for supersymmetric models. This includes an easy and straightforward definition of the model, the calculation of all vertices, mass matrices, tadpole equations, and self-energies. Also the two-loop renormalization group equations for a general gauge theory are now included and have been validated with the independent Python code PyR@te. Model files for FeynArts, CalcHep/CompHep, WHIZARD and in the UFO format can be written, and source code for SPheno for the calculation of the mass spectrum, a set of precision observables, and the decay widths and branching ratios of all states can be generated. Furthermore, the new version includes routines to output model files for Vevacious for both, supersymmetric and non-supersymmetric, models. Global symmetries are also supported with this version and by linking Susyno the handling of Lie groups has been improved and extended.

  12. SARAH 4: A tool for (not only SUSY) model builders

    Science.gov (United States)

    Staub, Florian

    2014-06-01

    We present the new version of the Mathematica package SARAH which provides the same features for a non-supersymmetric model as previous versions for supersymmetric models. This includes an easy and straightforward definition of the model, the calculation of all vertices, mass matrices, tadpole equations, and self-energies. Also the two-loop renormalization group equations for a general gauge theory are now included and have been validated with the independent Python code PyR@TE. Model files for FeynArts, CalcHep/CompHep, WHIZARD and in the UFO format can be written, and source code for SPheno for the calculation of the mass spectrum, a set of precision observables, and the decay widths and branching ratios of all states can be generated. Furthermore, the new version includes routines to output model files for Vevacious for both, supersymmetric and non-supersymmetric, models. Global symmetries are also supported with this version and by linking Susyno the handling of Lie groups has been improved and extended.

  13. Introduction to the thermodynamic Bethe ansatz

    Science.gov (United States)

    van Tongeren, Stijn J.

    2016-08-01

    We give a pedagogical introduction to the thermodynamic Bethe ansatz, a method that allows us to describe the thermodynamics of integrable models whose spectrum is found via the (asymptotic) Bethe ansatz. We set the stage by deriving the Fermi-Dirac distribution and associated free energy of free electrons, and then in a similar though technically more complicated fashion treat the thermodynamics of integrable models, focusing first on the one-dimensional Bose gas with delta function interaction as a clean pedagogical example, secondly the XXX spin chain as an elementary (lattice) model with prototypical complicating features in the form of bound states, and finally the {SU}(2) chiral Gross-Neveu model as a field theory example. Throughout this discussion we emphasize the central role of particle and hole densities, whose relations determine the model under consideration. We then discuss tricks that allow us to use the same methods to describe the exact spectra of integrable field theories on a circle, in particular the chiral Gross-Neveu model. We moreover discuss the simplification of TBA equations to Y systems, including the transition back to integral equations given sufficient analyticity data, in simple examples.

  14. Coordinate Bethe ansatz for the string S-matrix

    Energy Technology Data Exchange (ETDEWEB)

    Leeuw, M de [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, 3508 TD Utrecht (Netherlands)

    2007-11-30

    We use the coordinate Bethe ansatz approach to derive the nested Bethe equations corresponding to the recently found S-matrix for strings in AdS{sub 5} x S{sup 5}, compatible with centrally extended su(2 vertical bar 2) symmetry.

  15. Centenary Birth Anniversary of E. W. Beth (1908-1964)

    Science.gov (United States)

    Bagni, Giorgio T.

    2008-01-01

    Evert Willem Beth (1908-1964) was a Dutch logician, mathematician and philosopher, whose work mainly concerned the foundations of mathematics. Beth was among the founders of the Commission Internationale pour l'Etude et l'Amelioration de l'Enseignement des Mathematiques and was a member of the Central Committee of the International Commission on…

  16. Continuous representations of scalar products of Bethe vectors

    CERN Document Server

    Galleas, W

    2016-01-01

    We present families of single determinantal representations of on-shell scalar products of Bethe vectors. Our families of representations are parameterized by a continuous complex variable which can be fixed at convenience. Here we consider Bethe vectors in two versions of the six-vertex model: the case with boundary twists and the case with open boundaries.

  17. Overlaps of Partial Neel States and Bethe States

    CERN Document Server

    Foda, O

    2015-01-01

    Partial Neel states are generalizations of the ordinary Neel (classical anti-ferromagnet) state that can have arbitrary integer spin. We study overlaps of these states with Bethe states. We first identify this overlap with a partial version of reflecting-boundary domain-wall partition function, and then derive various determinant representations for off-shell and on-shell Bethe states.

  18. Obituary: Beth Brown (1969-2008)

    Science.gov (United States)

    Bregman, Joel

    2011-12-01

    The astronomical community lost one of its most buoyant and caring individuals when Beth Brown died, unexpectedly, at the age of 39 from a pulmonary embolism. Beth Brown was born in Roanoke, Virginia where she developed a deep interest in astronomy, science, and science fiction (Star Trek). After graduating as the valedictorian of William Fleming High School's Class of 1987, she attended Howard University, where she graduated summa cum laude in 1991 with a bachelor's degree in astrophysics. Following a year in the graduate physics program at Howard, she entered the graduate program in the Department of Astronomy at the University of Michigan, the first African-American woman in the program. She received her PhD in 1998, working with X-ray observations of elliptical galaxies from the Röntgen Satellite (ROSAT; Joel Bregman was her advisor). She compiled and analyzed the first large complete sample of such galaxies with ROSAT and her papers in this area made an impact in the field. Following her PhD, Beth Brown held a National Academy of Science & National Research Council Postdoctoral Research Fellowship at NASA's Goddard Space Flight Center. Subsequently, she became a civil servant at the National Space Science Data Center at GSFC, where she was involved in data archival activities as well as education and outreach, a continuing passion in her life. In 2006, Brown became an Astrophysics Fellow at GSFC, during which time she worked as a visiting Assistant Professor at Howard University, where she taught and worked with students and faculty to improve the teaching observatory. At the time of her death, she was eagerly looking forward to a new position at GSFC as the Assistant Director for Science Communications and Higher Education. Beth Brown was a joyous individual who loved to work with people, especially in educating them about our remarkable field. Her warmth and openness was a great aid in making accessible explanations of otherwise daunting astrophysical

  19. Fast analytic solver of rational Bethe equations

    Science.gov (United States)

    Marboe, C.; Volin, D.

    2017-05-01

    In this note we propose an approach for a fast analytic determination of all possible sets of Bethe roots corresponding to eigenstates of rational {GL}({N}\\vert {M}) integrable spin chains of given not too large length, in terms of Baxter Q-functions. We observe that all exceptional solutions, if any, are automatically correctly accounted. The key intuition behind the approach is that the equations on the Q-functions are determined solely by the Young diagram, and not by the choice of the rank of the {GL} symmetry. Hence we can choose arbitrary {N} and {M} that accommodate the desired representation. Then we consider all distinguished Q-functions at once, not only those following a certain Kac-Dynkin path.

  20. Cyclotomic Gaudin Models: Construction and Bethe Ansatz

    Science.gov (United States)

    Vicedo, Benoît; Young, Charles

    2016-05-01

    To any finite-dimensional simple Lie algebra g and automorphism {σ: gto g we associate a cyclotomic Gaudin algebra. This is a large commutative subalgebra of {U(g)^{⊗ N}} generated by a hierarchy of cyclotomic Gaudin Hamiltonians. It reduces to the Gaudin algebra in the special case {σ =id}. We go on to construct joint eigenvectors and their eigenvalues for this hierarchy of cyclotomic Gaudin Hamiltonians, in the case of a spin chain consisting of a tensor product of Verma modules. To do so we generalize an approach to the Bethe ansatz due to Feigin, Frenkel and Reshetikhin involving vertex algebras and the Wakimoto construction. As part of this construction, we make use of a theorem concerning cyclotomic coinvariants, which we prove in a companion paper. As a byproduct, we obtain a cyclotomic generalization of the Schechtman-Varchenko formula for the weight function.

  1. Quelques applications de l'Ansatz de Bethe (Some applications of the Bethe Ansatz)

    CERN Document Server

    Zinn-Justin, P

    1998-01-01

    The Bethe Ansatz is a method that is used in quantum integrable models in order to solve them explicitly. This method is explained here in a general framework, which applies to 1D quantum spin chains, 2D statistical lattice models (vertex models) and relativistic field theories with 1 space dimension and 1 time dimension. The connection with quantum groups is expounded. Several applications are then presented. Finite size corrections are calculated via two methods: The Non-Linear Integral Equations, which are applied to the study of the states of the affine Toda model with imaginary coupling, and their interpolation between the high energy (ultra-violet) and low energy (infra-red) regions; and the Thermodynamic Bethe Ansatz Equations, along with the associated Fusion Equations, which are used to determine the thermodynamic properties of the generalized multi-channel Kondo model. The latter is then studied in more detail, still using the Bethe Ansatz and quantum groups, so as to characterize the spectrum of th...

  2. Two-body bound states & the Bethe-Salpeter equation

    Energy Technology Data Exchange (ETDEWEB)

    Pichowsky, M. [Argonne National Lab., IL (United States); Kennedy, M. [Univ. of New Hampshire, Durham, NH (United States). Physics Dept.; Strickland, M. [Duke Univ., Durham, NC (United States)

    1995-01-18

    The Bethe-Salpeter formalism is used to study two-body bound states within a scalar theory: two scalar fields interacting via the exchange of a third massless scalar field. The Schwinger-Dyson equation is derived using functional and diagrammatic techniques, and the Bethe-Salpeter equation is obtained in an analogous way, showing it to be a two-particle generalization of the Schwinger-Dyson equation. The authors also present a numerical method for solving the Bethe-Salpeter equation without three-dimensional reduction. The ground and first excited state masses and wavefunctions are computed within the ladder approximation and space-like form factors are calculated.

  3. Sarah Louise Heath Palin. Siivutu raamatukogutädi tõus päästeingliks / Hendrik Vosman

    Index Scriptorium Estoniae

    Vosman, Hendrik

    2008-01-01

    Ilmunud ka: Postimees : na russkom jazõke 12. sept. lk. 8. Vabariiklaste asepresidendikandidaati Sarah Palini koolitab välispoliitika valdkonnas välja president George W. Bushi endistest nõunikest koosnev meeskond. Sarah Palini poliitilisest karjäärist Alaskas ning valimisest asepresidendikandidaadiks. Lisa: 5 fakti

  4. Sarah Louise Heath Palin. Siivutu raamatukogutädi tõus päästeingliks / Hendrik Vosman

    Index Scriptorium Estoniae

    Vosman, Hendrik

    2008-01-01

    Ilmunud ka: Postimees : na russkom jazõke 12. sept. lk. 8. Vabariiklaste asepresidendikandidaati Sarah Palini koolitab välispoliitika valdkonnas välja president George W. Bushi endistest nõunikest koosnev meeskond. Sarah Palini poliitilisest karjäärist Alaskas ning valimisest asepresidendikandidaadiks. Lisa: 5 fakti

  5. Model of pair aggregation on the Bethe lattice

    DEFF Research Database (Denmark)

    Baillet, M.V.-P.; Pacheco, A.F.; Gómez, J.B.

    1997-01-01

    We extend a recent model of aggregation of pairs of particles, analyzing the case in which the supporting framework is a Bethe lattice. The model exhibits a critical behavior of the percolation theory type....

  6. Norm of Bethe Wave Function as a Determinant

    CERN Document Server

    Korepin, Vladimir E

    2009-01-01

    This is a historical note. Bethe Ansatz solvable models are considered, for example XXZ Heisenberg anti-ferromagnet and Bose gas with delta interaction. Periodic boundary conditions lead to Bethe equation. The square of the norm of Bethe wave function is equal to a determinant of linearized system of Bethe equations (determinant of matrix of second derivatives of Yang action). The proof was first published in Communications in Mathematical Physics, vol 86, page 391 in l982. Also domain wall boundary conditions for 6 vertex model were discovered in the same paper [see Appendix D]. These play an important role for algebraic combinatorics: alternating sign matrices, domino tiling and plane partition. Many publications are devoted to six vertex model with domain wall boundary conditions.

  7. Two-loop Bethe-logarithm correction in hydrogenlike atoms.

    Science.gov (United States)

    Pachucki, Krzysztof; Jentschura, Ulrich D

    2003-09-12

    We calculate the two-loop Bethe logarithm correction to atomic energy levels in hydrogenlike systems. The two-loop Bethe logarithm is a low-energy quantum electrodynamic (QED) effect involving multiple summations over virtual excited atomic states. Although much smaller in absolute magnitude than the well-known one-loop Bethe logarithm, the two-loop analog is quite significant when compared to the current experimental accuracy of the 1S-2S transition: It contributes -8.19 and -0.84 kHz for the 1S and the 2S state, respectively. The two-loop Bethe logarithm has been the largest unknown correction to the hydrogen Lamb shift to date. Together with the ongoing measurement of the proton charge radius at the Paul Scherrer Institute, its calculation will bring theoretical and experimental accuracy for the Lamb shift in atomic hydrogen to the level of 10(-7).

  8. Off-diagonal Bethe ansatz for exactly solvable models

    CERN Document Server

    Wang, Yupeng; Cao, Junpeng; Shi, Kangjie

    2015-01-01

    This book serves as an introduction of the off-diagonal Bethe Ansatz method, an analytic theory for the eigenvalue problem of quantum integrable models. It also presents some fundamental knowledge about quantum integrability and the algebraic Bethe Ansatz method. Based on the intrinsic properties of R-matrix and K-matrices, the book introduces a systematic method to construct operator identities of transfer matrix.  These identities allow one to establish the inhomogeneous T-Q relation formalism to obtain Bethe Ansatz equations and to retrieve corresponding eigenstates. Several longstanding models can thus be solved via this method since the lack of obvious reference states is made up. Both the exact results and the off-diagonal Bethe Ansatz method itself may have important applications in the fields of quantum field theory, low-dimensional condensed matter physics, statistical physics and cold atom systems.

  9. Solving Bethe-Salpeter scattering state equation in Minkowski space

    CERN Document Server

    Carbonell, J

    2014-01-01

    We present a method to directly solving the Bethe-Salpeter equation in Minkowski space, both for bound and scattering states. It is based on a proper treatment of the singularities which appear in the kernel, propagators and Bethe-Salpeter amplitude itself. The off-mass shell scattering amplitude for spinless particles interacting by a one boson exchange is computed for the first time.

  10. Robert Garrett, Tasmanian penal colony surgeon: alcoholism, medical misadventure and the penal colony of Sarah Island.

    Science.gov (United States)

    Stride, P

    2011-09-01

    Robert Garrett emigrated from Scotland to Van Diemen's Land (now Tasmania) in 1822. Within a few months of arrival he was posted to the barbaric penal colony in Macquarie Harbour, known as Sarah Island. His descent into alcoholism, medical misadventure and premature death were related to his largely unsupported professional environment and were, in many respects, typical of those subjected to this experience.

  11. Playing the Indian Princess? Sarah Winnemucca's Newspaper Career and Performance of American Indian Identities

    Science.gov (United States)

    Sorisio, Carolyn

    2011-01-01

    In an age when American newspapers reported on US-Indian Relations in a sporadic and biased manner, Northern Paiute educator, translator, author, and activist Sarah Winnemucca produced sustained, specific, and often sympathetic coverage. She was well aware of newspapers' power, as demonstrated by the more than four hundred newspaper items by or…

  12. Playing the Indian Princess? Sarah Winnemucca's Newspaper Career and Performance of American Indian Identities

    Science.gov (United States)

    Sorisio, Carolyn

    2011-01-01

    In an age when American newspapers reported on US-Indian Relations in a sporadic and biased manner, Northern Paiute educator, translator, author, and activist Sarah Winnemucca produced sustained, specific, and often sympathetic coverage. She was well aware of newspapers' power, as demonstrated by the more than four hundred newspaper items by or…

  13. Sarah J. Hale High School, Project BECOME. O.E.E. Evaluation Report, 1982-1983.

    Science.gov (United States)

    Bulkin, Elly; Sica, Michael

    Project BECOME, a mainstreaming program for Hispanic and Haitian students of limited English proficiency, provided instruction in ESL and native language studies, as well as bilingual instruction in social studies, mathematics, science, and typing. The program, which was implemented at Sarah J. Hale High School (located in downtown Brooklyn, New…

  14. Nuclear forces the making of the physicist Hans Bethe

    CERN Document Server

    Schweber, Silvan S

    2012-01-01

    On the fiftieth anniversary of Hiroshima, Nobel-winning physicist Hans Bethe called on his fellow scientists to stop working on weapons of mass destruction. What drove Bethe, the head of Theoretical Physics at Los Alamos during the Manhattan Project, to renounce the weaponry he had once worked so tirelessly to create? That is one of the questions answered by "Nuclear Forces", a riveting biography of Bethe's early life and development as both a scientist and a man of principle. As Silvan Schweber follows Bethe from his childhood in Germany, to laboratories in Italy and England, and on to Cornell University, he shows how these differing environments were reflected in the kind of physics Bethe produced. Many of the young quantum physicists in the 1930s, including Bethe, had Jewish roots, and Schweber considers how Liberal Judaism in Germany helps explain their remarkable contributions. A portrait emerges of a man whose strategy for staying on top of a deeply hierarchical field was to tackle only those problems h...

  15. On The Ladder Bethe-Salpeter Equation

    CERN Document Server

    Efimov, G V

    2003-01-01

    The Bethe-Salpeter (BS) equation in the ladder approximation is studied within a scalar theory: two scalar fields (constituents) with mass $m$ interacting via an exchange of a scalar field (tieon) with mass $\\mu$. The BS equation is written in the form of an integral equation in the configuration Euclidean $x$-space with the kernel which for stable bound states $M<2m$ is a self-adjoint positive operator. The solution of the BS equation is formulated as a variational problem. The nonrelativistic limit of the BS equation is considered. The role of so-called abnormal states is discussed. The analytical form of test functions for which the accuracy of calculations of bound state masses is better than 1% (the comparison with available numerical calculations is done) is determined. These test functions make it possible to calculate analytically vertex functions describing the interaction of bound states with constituents. As a by-product a simple solution of the Wick-Cutkosky model for the case of massless bound...

  16. On Sarah's Final Freedom-Interpretation of the last ending of The French Lieutenant’s woman

    Institute of Scientific and Technical Information of China (English)

    彭美容

    2013-01-01

    The French Lieutenant’s Woman is the best-known novel written by John Fowles and is also called the post-modern metafiction. In the novel the mysterious woman Sarah is introduced, who rebels against Victorian conventions to pursue indepen-dence and freedom. Undoubtedly, Sarah is an independent woman ahead of her times. This paper is attempted to interpret the last ending of The French Lieutenant’s woman written by John Fowles, thus finding relevant evidence to support this interpreta-tion that Sarah has finally got her freedom which is not allowed against the Victorian background.

  17. Chemostratigraphy of glaciomarine sediments in the Sarah Formation, northwest Saudi Arabia

    Science.gov (United States)

    Craigie, Neil W.; Rees, Andrew J.

    2016-05-01

    The Sarah Formation of northern Saudi Arabia mainly consists of glacial 'outwash' sediments deposited by turbidite channels and fans. Prior to undertaking chemostratigraphy, the results of seismic interpretation revealed the Sarah Formation to be mainly deposited in a NW-SE trending turbidite system in the study area, comprising channels with associated fans. These are succeeded by fluvio marine sediments at the top of the Sarah Formation. In the absence of good biostratigraphic control, chemostratigraphy was found to be one of the few techniques that could be employed to produce a high resolution correlation scheme for four study wells. Geochemical data were acquired for 50 elements in 550 core samples by ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometry) and ICP-MS (Inductively Coupled Plasma - Mass Spectrometry) but only the 'key' ratios Zr/Nb, Nb/Ti, Nb/Cr, Rb/K and Th/Cr were employed for chemostratigraphic purposes as they show significant trends that enable correlative boundaries to be identified and a hierarchical scheme to be proposed. Variations in these parameters are largely related to changes in source/provenance. In order to avoid geochemical variations relating to changes in grain size/lithology, separate schemes were proposed for the sandstone and mudrock samples. The sandstone scheme consists of a hierarchical order of three zones, seven subzones and five divisions, while the mudrock scheme is less detailed, comprising three zones and seven subzones. A 'finalised' scheme, based on a combination of the two aforementioned ones, was found to be more useful than employing the correlation proposed for individual lithologies. One of the main conclusions of the study was that the basal chemozones (general term used to describe any chemostratigraphic zone, subzone or division) were identified in wells B and C but were missing from A and D. It is thought that the areas around the two latter wells represented topographically 'high' areas

  18. Integrable achiral D5-brane reflections and asymptotic Bethe equations

    CERN Document Server

    Correa, Diego H; Young, Charles A S

    2011-01-01

    We study the reflection of magnons from a D5-brane in the framework of the AdS/CFT correspondence. We consider two possible orientations of the D5-brane with respect to the reference vacuum state, namely vacuum states aligned along "vertical" and "horizontal" directions. We show that the reflections are of the achiral type. We also show that the reflection matrices satisfy the boundary Yang-Baxter equations for both orientations. In the horizontal case the reflection matrix can be interpreted in terms of a bulk S-matrix, S(p, -p), and factorizability of boundary scattering therefore follows from that of bulk scattering. Finally, we solve the nested coordinate Bethe ansatz for the system in the vertical case to find the Bethe equations. In the horizontal case, the Bethe equations are of the same form as those for the closed string.

  19. Tea with Mother: Sarah Palin and the Discourse of Motherhood as a Political Ideal

    Directory of Open Access Journals (Sweden)

    Janet McCabe

    2016-02-01

    Full Text Available Seldom has someone emerged so unexpectedly and sensationally on to the American political scene as Sarah Palin. With Palin came what had rarely, if ever, been seen before on a presidential trail: hockey moms, Caribou-hunting, pitbulls in lipstick parcelled as political weaponry. And let’s not forget those five children, including Track 19, set to deploy to Iraq, Bristol, and her unplanned pregnancy at 17, and Trig, a six-month-old infant with Down’s syndrome. Never before had motherhood been so finely balanced with US presidential politics. Biological vigour translated into political energy, motherhood transformed into an intoxicating political ideal. This article focuses on Sarah Palin and how her brand of “rugged Alaskan motherhood” (PunditMom 2008 became central to her media image, as well as what this representation has to tell us about the relationship between mothering as a political ideal, US politics, and the media.

  20. Sarah Abrevaya Stein, Saharan Jews and the fate of French Algeria

    OpenAIRE

    Everett, Sami

    2015-01-01

    The local is the global; the personal is the political. This simple maxim crudely encapsulates the intellectual approach taken over a prolific decade of writing about Mediterranean Jewries by the Professor of History and Maurice Amado Chair in sephardic studies, at the University of California, Sarah Abrevaya Stein. Her project renders transnational and local nuance to Jewish diasporic lives and puts that polyphony into conversation with the processes of classifying, segregating, and differen...

  1. Sarah L. Higley, Hildegard of Bingen’s Unknown Language: An Edition, Translation, and Discussion

    OpenAIRE

    Láng, Benedek

    2008-01-01

    Few books can so convincingly demonstrate that there is a real continuity between the Middle Ages and our times, and that a diachronic examination of a medieval work can prove to be fruitful. Sarah Higley’s monograph contains a contextualization, edition and translation of the famous Lingua ignota of Hildegard of Bingen (1098-1179). It is a genuinely medievalist study and text edition, however, when explaining the motivation behind the construction of such invented languages, the author persu...

  2. Sarah Daynes, Time and Memory in Reggae Music. The Politics of Hope

    OpenAIRE

    Aarons, David

    2017-01-01

    In Time and Memory in Reggae Music: The Politics of Hope, sociologist Sarah Daynes offers thoughtful reflections on the dynamic relationship between time and memory as articulated in reggae music and Rastafari ideology. She uses music as a case study in collective memory, demonstrating how reggae artists draw on biblical and more recent events (e.g. the Trans-Atlantic slave trade) to construct and transmit memories that impact and are impacted by present and future events. This book also high...

  3. Walking in London: The fiction of Neil Bartlett, Sarah Waters and Alan Hollinghurst

    OpenAIRE

    Cleminson, Julie

    2010-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. This thesis examines the fiction of Neil Bartlett, Sarah Waters and Alan Hollinghurst, considering how they write missing voices of sexuality, gender and class back into history through re-imagining the city space. It examines the ways in which traditional, linear narratives and the notion of objectivity in historical discourse are challenged when history is presented through fiction.Waters, ...

  4. Evaluations of energy coefficients of Bethe-Weizsacker mass formula

    CERN Document Server

    Basu, D N

    2004-01-01

    A mass fit to the liquid drop model is presented. Coefficients of the volume, surface, coulomb, asymmetry and pairing energy terms of the semiemirical Bethe-Weizsacker mass formula have been determined by furnishing best fit to the observed mass excesses. Different sets of the weighting parameters for liquid drop model Bethe-Weizsacker mass formula have been obtained from minimizations of chisquare and mean square deviation. The recent exerimental and estimated mass excesses from Audi-Wapstra-Thibault atomic mass table have been used for the least square fitting procedure. Some implications of the modifications of parameters have been discussed.

  5. Improved Numerical Generalization of Bethe- Weizsacker Mass Formula

    CERN Document Server

    Mavrodiev, Strachimir

    2016-01-01

    In this paper is presented explicit improved numerical generalization of Bethe-Weizsacker mass formulae which describes the values of measured 2654 nuclear mass in AME2012 nuclear database with accuracy less than 2.2 MeV, starting from the number of protons Z=1 and number of neutrons N=1. In the obtained generazation of the Bethe-Weizsacker formula the influence of magic numbers and boundaries of their influence between them is defined for nine proton (2, 8, 14, 20, 28, 50, 82, 108, 124) and ten neutron (2, 8, 14, 20, 28, 50, 82, 124, 152, 202) magic numbers.

  6. Quantum Waveguide Properties of Bethe Lattices with a Ring

    Institute of Scientific and Technical Information of China (English)

    LIN Zhi-Ping; HOU Zhi-Lin; LIU You-Yan

    2008-01-01

    Based on waveguide theory we investigate electronic transport properties of Bethe lattices with a mesoscopic ring threaded by a magnetic flux. The generalized eigen-function method (GEM) is used to calculate the transmission and reflection coefficients up to the fifth generation of Bethe lattices. The relationships among the transmission coefficient T, magnetic flux φ and wave vector kl axe investigated in detail. The numerical results are shown by the three-dimensional plots and contour maps. Some resonant-transmission features and the symmetry of the transmission coefficient T to flux φ are observed and discussed.

  7. Algebraic Bethe Ansatz for O(2N) sigma models with integrable diagonal boundaries

    CERN Document Server

    Gombor, Tamas

    2015-01-01

    The finite volume problem of O(2N) sigma models with integrable diagonal boundaries on a finite interval is investigated. The double row transfer matrix is diagonalized by Algebraic Bethe Ansatz. The boundary Bethe Yang equations for the particle rapidities and the accompanying Bethe Ansatz equations are derived.

  8. Algebraic Bethe Ansatz for O(2N) sigma models with integrable diagonal boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Gombor, Tamás [MTA Lendület Holographic QFT Group, Wigner Research Centre,H-1525 Budapest 114, P.O.B. 49 (Hungary); Institute for Theoretical Physics, Roland Eötvös University,1117 Budapest, Pázmány s. 1/A (Hungary); Palla, László [Institute for Theoretical Physics, Roland Eötvös University,1117 Budapest, Pázmány s. 1/A (Hungary)

    2016-02-24

    The finite volume problem of O(2N) sigma models with integrable diagonal boundaries on a finite interval is investigated. The double row transfer matrix is diagonalized by Algebraic Bethe Ansatz. The boundary Bethe Yang equations for the particle rapidities and the accompanying Bethe Ansatz equations are derived.

  9. The Bethe ansatz for AdS5 × S5 bound states

    NARCIS (Netherlands)

    de Leeuw, M.

    2009-01-01

    We reformulate the nested coordinate Bethe ansatz in terms of coproducts of Yangian symmetry generators. This allows us to derive the nested Bethe equations for arbitrary bound state string S-matrices. The bound state number dependence in the Bethe equations appears through the parameters x± and the

  10. Algebraic Bethe Ansatz for Open XXX Model with Triangular Boundary Matrices

    Science.gov (United States)

    Belliard, Samuel; Crampé, Nicolas; Ragoucy, Eric

    2013-05-01

    We consider an open XXX spin chain with two general boundary matrices whose entries obey a relation, which is equivalent to the possibility to put simultaneously the two matrices in a upper-triangular form. We construct Bethe vectors by means of a generalized algebraic Bethe ansatz. As usual, the method uses Bethe equations and provides transfer matrix eigenvalues.

  11. Twisting singular solutions of Betheʼs equations

    Science.gov (United States)

    Nepomechie, Rafael I.; Wang, Chunguang

    2014-12-01

    The Bethe equations for the periodic XXX and XXZ spin chains admit singular solutions, for which the corresponding eigenvalues and eigenvectors are ill-defined. We use a twist regularization to derive conditions for such singular solutions to be physical, in which case they correspond to genuine eigenvalues and eigenvectors of the Hamiltonian.

  12. Bethe ansatz solution of triangular trimers on the triangular lattice

    NARCIS (Netherlands)

    Verberkmoes, A.; Nienhuis, B.

    2001-01-01

    Recently, a model consisting of triangular trimers covering the triangular lattice was introduced and its exact free energy given. In this paper we present the complete calculation leading to this exact result. The solution involves a coordinate Bethe ansatz with two kinds of particles. It is simila

  13. Pionierin der Religionspsychologie: Marianne Beth (1890-1984)

    NARCIS (Netherlands)

    Belzen, J.A.

    2010-01-01

    This article deals with the contributions to the psychology of religion made by Dr. Marianne Beth (1890-1984), an almost totally forgotten pioneer of the psychology of religion. The article especially contextualizes her initiative to turn "unbelief" into a topic for research in psychology of religio

  14. Mean values of local operators in highly excited Bethe states

    NARCIS (Netherlands)

    Pozsgay, B.

    2011-01-01

    We consider expectation values of local operators in (continuum) integrable models in a situation when the mean value is calculated in a single Bethe state with a large number of particles. We develop a form factor expansion for the thermodynamic limit of the mean value, which applies whenever the d

  15. Scalar product of Bethe vectors from functional equations

    OpenAIRE

    Galleas, W.

    2012-01-01

    In this work the scalar product of Bethe vectors for the six-vertex model is studied by means of functional equations. The scalar products are shown to obey a system of functional equations originated from the Yang-Baxter algebra and its solution is given as a multiple contour integral.

  16. Boundary Quantum Knizhnik-Zamolodchikov Equations and Bethe Vectors

    NARCIS (Netherlands)

    Reshetikhin, N.; Stokman, J.; Vlaar, B.

    2015-01-01

    Solutions to boundary quantum Knizhnik-Zamolodchikov equations are constructed as bilateral sums involving "off-shell" Bethe vectors in case the reflection matrix is diagonal and only the 2-dimensional representation of Uq(slˆ2) is involved. We also consider their rational and classical degeneration

  17. Coordinate Bethe Ansatz for Spin s XXX Model

    Science.gov (United States)

    Crampé, Nicolas; Ragoucy, Eric; Alonzi, Ludovic

    2011-01-01

    We compute the eigenfunctions and eigenvalues of the periodic integrable spin s XXX model using the coordinate Bethe ansatz. To do so, we compute explicitly the Hamiltonian of the model. These results generalize what has been obtained for spin 1/2 and spin 1 chains.

  18. Generalized coordinate Bethe ansatz for non diagonal boundaries

    CERN Document Server

    Crampe, N

    2011-01-01

    We compute the spectrum and the eigenstates of the open XXX model with non-diagonal (triangular) boundary matrices. Since the boundary matrices are not diagonal, the usual coordinate Bethe ansatz does not work anymore, and we use a generalization of it to solve the problem.

  19. Algebraic Bethe ansatz for the XXX chain with triangular boundaries and Gaudin model

    Energy Technology Data Exchange (ETDEWEB)

    Cirilo António, N., E-mail: nantonio@math.ist.utl.pt [Centro de Análise Funcional e Aplicações, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Manojlović, N., E-mail: nmanoj@ualg.pt [Grupo de Física Matemática da Universidade de Lisboa, Av. Prof. Gama Pinto 2, PT-1649-003 Lisboa (Portugal); Departamento de Matemática, F.C.T., Universidade do Algarve, Campus de Gambelas, PT-8005-139 Faro (Portugal); Salom, I., E-mail: isalom@ipb.ac.rs [Institute of Physics, University of Belgrade, P.O. Box 57, 11080 Belgrade (Serbia)

    2014-12-15

    We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model.

  20. Algebraic Bethe ansatz for the XXX chain with triangular boundaries and Gaudin model

    Science.gov (United States)

    Cirilo António, N.; Manojlović, N.; Salom, I.

    2014-12-01

    We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model.

  1. Tea with Mother: Sarah Palin and the Discourse of Motherhood as a Political Ideal

    OpenAIRE

    Janet McCabe

    2016-01-01

    Seldom has someone emerged so unexpectedly and sensationally on to the American political scene as Sarah Palin. With Palin came what had rarely, if ever, been seen before on a presidential trail: hockey moms, Caribou-hunting, pitbulls in lipstick parcelled as political weaponry. And let’s not forget those five children, including Track 19, set to deploy to Iraq, Bristol, and her unplanned pregnancy at 17, and Trig, a six-month-old infant with Down’s syndrome. Never before had motherhood bee...

  2. Scalar products of Bethe vectors in models with \\mathfrak{g}\\mathfrak{l}(2|1) symmetry 2. Determinant representation

    Science.gov (United States)

    Hutsalyuk, A.; Liashyk, A.; Pakuliak, S. Z.; Ragoucy, E.; Slavnov, N. A.

    2017-01-01

    We study integrable models with gl(2|1) symmetry and solvable by nested algebraic Bethe ansatz. We obtain a determinant representation for scalar products of Bethe vectors, when the Bethe parameters obey some relations weaker than the Bethe equations. This representation allows us to find the norms of on-shell Bethe vectors and obtain determinant formulas for form factors of the diagonal entries of the monodromy matrix. Dedicated to the memory of Petr Petrovich Kulish.

  3. Scalar products of Bethe vectors in models with $\\mathfrak{gl}(2|1)$ symmetry 2. Determinant representation

    CERN Document Server

    Hutsalyuk, A; Pakuliak, S Z; Ragoucy, E; Slavnov, N A

    2016-01-01

    We study integrable models with $\\mathfrak{gl}(2|1)$ symmetry and solvable by nested algebraic Bethe ansatz. We obtain a determinant representation for scalar products of Bethe vectors, when the Bethe parameters obey some relations weaker than the Bethe equations. This representation allows us to find the norms of on-shell Bethe vectors and obtain determinant formulas for form factors of the diagonal entries of the monodromy matrix.

  4. Bethe-Salpeter bound-state structure in Minkowski space

    CERN Document Server

    Gutierrez, C; Frederico, T; Salmè, G; Viviani, M; Tomio, Lauro

    2016-01-01

    The quantitative investigation of the scalar Bethe-Salpeter equation in Minkowski space, within the ladder-approximation framework, is extended to include the excited states. This study has been carried out for an interacting system composed by two massive bosons exchanging a massive scalar, by adopting (i) the Nakanishi integral representation of the Bethe-Salpeter amplitude, and (ii) the formally exact projection onto the null plane. Our analysis, on one hand, confirms the reliability of the method already applied to the ground state and, on the other one, extends the investigation from the valence distribution in momentum space to the corresponding quantity in the impact-parameter space, pointing out some relevant features, like (i) the equivalence between Minkowski and Euclidean transverse-momentum amplitudes, and (ii) the leading exponential fall-off of the valence wave function in the impact-parameter space.

  5. Euclidean to Minkowski Bethe-Salpeter amplitude and observables

    Energy Technology Data Exchange (ETDEWEB)

    Carbonell, J. [Universite Paris-Sud, IN2P3-CNRS, Institut de Physique Nucleaire, Orsay Cedex (France); Frederico, T. [Instituto Tecnologico de Aeronautica, DCTA, Sao Jose dos Campos (Brazil); Karmanov, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)

    2017-01-15

    We propose a method to reconstruct the Bethe-Salpeter amplitude in Minkowski space given the Euclidean Bethe-Salpeter amplitude - or alternatively the light-front wave function - as input. The method is based on the numerical inversion of the Nakanishi integral representation and computing the corresponding weight function. This inversion procedure is, in general, rather unstable, and we propose several ways to considerably reduce the instabilities. In terms of the Nakanishi weight function, one can easily compute the BS amplitude, the LF wave function and the electromagnetic form factor. The latter ones are very stable in spite of residual instabilities in the weight function. This procedure allows both, to continue the Euclidean BS solution in the Minkowski space and to obtain a BS amplitude from a LF wave function. (orig.)

  6. Instantaneous Bethe-Salpeter Kernel for the Lightest Pseudoscalar Mesons

    CERN Document Server

    Lucha, Wolfgang

    2016-01-01

    Starting from a phenomenologically successful, numerical solution of the Dyson-Schwinger equation that governs the quark propagator, we reconstruct in detail the interaction kernel that has to enter the instantaneous approximation to the Bethe-Salpeter equation to allow us to describe the lightest pseudoscalar mesons as quark-antiquark bound states exhibiting the (almost) masslessness necessary for them to be interpretable as the (pseudo) Goldstone bosons related to the spontaneous chiral symmetry breaking of quantum chromodynamics.

  7. How algebraic Bethe ansatz works for integrable model

    CERN Document Server

    Fadeev, L

    1996-01-01

    I study the technique of Algebraic Bethe Ansatz for solving integrable models and show how it works in detail on the simplest example of spin 1/2 XXX magnetic chain. Several other models are treated more superficially, only the specific details are given. Several parameters, appearing in these generalizations: spin s, anisotropy parameter \\ga, shift \\om in the alternating chain, allow to include in our treatment most known examples of soliton theory, including relativistic model of Quantum Field Theory.

  8. Application of the Bethe-Salpeter Equation to Mesonic Atoms

    CERN Document Server

    Owen, David

    2015-01-01

    We use quantum electrodynamics and the Bethe-Salpeter equation to calculate the bound state energies for a two-particle system comprised of a spin-0 and spin-1/2 particle. We generalize our treatment to include the finite size of the nucleus and of the meson and our results can be applied to kaonic and pionic atoms. Our treatment includes quantum electrodynamics and recoils corrections to all orders.

  9. The Potts model on a Bethe lattice with nonmagnetic impurities

    Energy Technology Data Exchange (ETDEWEB)

    Semkin, S. V., E-mail: li15@rambler.ru; Smagin, V. P. [Vladivistok State University of Economics and Service (VSUES) (Russian Federation)

    2015-10-15

    We have obtained a solution for the Potts model on a Bethe lattice with mobile nonmagnetic impurities. A method is proposed for constructing a “pseudochaotic” impurity distribution by a vanishing correlation in the arrangement of impurity atoms for the nearest sites. For a pseudochaotic impurity distribution, we obtained the phase-transition temperature, magnetization, and spontaneous magnetization jumps at the phase-transition temperature.

  10. Reflection Amplitudes of ADE Toda Theories and Thermodynamic Bethe Ansatz

    CERN Document Server

    Ahn, C; Kim, C; Rim, C; Yang, B; Ahn, Changrim; Kim, Chanju; Rim, Chaiho; Yang, Bedl

    2000-01-01

    We study the ultraviolet asymptotics in affine Toda theories. These models are considered as perturbed non-affine Toda theories. We calculate the reflection amplitudes, which relate different exponential fields with the same quantum numbers. Using these amplitudes we derive the quantization condition for the vacuum wave function, describing zero-mode dynamics, and calculate the UV asymptotics of the effective central charge. These asymptotics are in a good agreement with thermodynamic Bethe ansatz results.

  11. Linking Chains Together: String Bits And The Bethe Ansatz

    CERN Document Server

    Lübcke, M

    2004-01-01

    This thesis is divided into two parts. In the first part we focus mainly on certain aspects of the AdS/CFT correspondence. The AdS/CFT correspondence is a proposed duality between Type IIB superstring theory on AdS5 × S5 and N = 4 supersymmetric Yang-Mills theory. In the BMN limit string states located in the center of AdS5 rotate quickly around the equator of the S5 and correspond, in the dual theory, to operators constructed as long chains of sub-operators. This structure of the operators can be formulated as a spin chain and by using the Bethe ansatz their properties can be obtained by solving a set of Bethe equations. Having infinitely many sub-operators, there are methods for solving the Bethe equations in certain sectors. In paper III finite size corrections to the anomalous dimensions in the SU(2) sector are calculated to leading order. Inspired by the chain structure of the corresponding operators, the theory of string bits treats the strings as a discrete sets of points. This theory suffers...

  12. GW and Bethe-Salpeter study of small water clusters

    Science.gov (United States)

    Blase, Xavier; Boulanger, Paul; Bruneval, Fabien; Fernandez-Serra, Marivi; Duchemin, Ivan

    2016-01-01

    We study within the GW and Bethe-Salpeter many-body perturbation theories the electronic and optical properties of small (H2O)n water clusters (n = 1-6). Comparison with high-level CCSD(T) Coupled-Cluster at the Single Double (Triple) levels and ADC(3) Green's function third order algebraic diagrammatic construction calculations indicates that the standard non-self-consistent G0W0@PBE or G0W0@PBE0 approaches significantly underestimate the ionization energy by about 1.1 eV and 0.5 eV, respectively. Consequently, the related Bethe-Salpeter lowest optical excitations are found to be located much too low in energy when building transitions from a non-self-consistent G0W0 description of the quasiparticle spectrum. Simple self-consistent schemes, with update of the eigenvalues only, are shown to provide a weak dependence on the Kohn-Sham starting point and a much better agreement with reference calculations. The present findings rationalize the theory to experiment possible discrepancies observed in previous G0W0 and Bethe-Salpeter studies of bulk water. The increase of the optical gap with increasing cluster size is consistent with the evolution from gas to dense ice or water phases and results from an enhanced screening of the electron-hole interaction.

  13. GW and Bethe-Salpeter study of small water clusters

    Energy Technology Data Exchange (ETDEWEB)

    Blase, Xavier, E-mail: xavier.blase@neel.cnrs.fr; Boulanger, Paul [CNRS, Institut NEEL, F-38042 Grenoble (France); Bruneval, Fabien [CEA, DEN, Service de Recherches de Métallurgie Physique, F-91191 Gif-sur-Yvette (France); Fernandez-Serra, Marivi [Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800 (United States); Institute for Advanced Computational Sciences, Stony Brook University, Stony Brook, New York 11794-3800 (United States); Duchemin, Ivan [INAC, SP2M/L-Sim, CEA/UJF Cedex 09, 38054 Grenoble (France)

    2016-01-21

    We study within the GW and Bethe-Salpeter many-body perturbation theories the electronic and optical properties of small (H{sub 2}O){sub n} water clusters (n = 1-6). Comparison with high-level CCSD(T) Coupled-Cluster at the Single Double (Triple) levels and ADC(3) Green’s function third order algebraic diagrammatic construction calculations indicates that the standard non-self-consistent G{sub 0}W{sub 0}@PBE or G{sub 0}W{sub 0}@PBE0 approaches significantly underestimate the ionization energy by about 1.1 eV and 0.5 eV, respectively. Consequently, the related Bethe-Salpeter lowest optical excitations are found to be located much too low in energy when building transitions from a non-self-consistent G{sub 0}W{sub 0} description of the quasiparticle spectrum. Simple self-consistent schemes, with update of the eigenvalues only, are shown to provide a weak dependence on the Kohn-Sham starting point and a much better agreement with reference calculations. The present findings rationalize the theory to experiment possible discrepancies observed in previous G{sub 0}W{sub 0} and Bethe-Salpeter studies of bulk water. The increase of the optical gap with increasing cluster size is consistent with the evolution from gas to dense ice or water phases and results from an enhanced screening of the electron-hole interaction.

  14. Algebraic Bethe ansatz for Q-operators: The Heisenberg spin chain

    CERN Document Server

    Frassek, Rouven

    2015-01-01

    We diagonalize Q-operators for rational homogeneous sl(2)-invariant Heisenberg spin chains using the algebraic Bethe ansatz. After deriving the fundamental commutation relations relevant for this case from the Yang-Baxter equation we demonstrate that the Q-operators act diagonally on the Bethe vectors if the Bethe equations are satisfied. In this way we provide a direct proof that the eigenvalues of the Q-operators studied here are given by Baxter's Q-functions.

  15. Modified algebraic Bethe ansatz for XXZ chain on the segment – II – general cases

    Directory of Open Access Journals (Sweden)

    S. Belliard

    2015-05-01

    Full Text Available The spectral problem of the Heisenberg XXZ spin-12 chain on the segment is investigated within a modified algebraic Bethe ansatz framework. We consider in this work the most general boundaries allowed by integrability. The eigenvalues and the eigenvectors are obtained. They are characterised by a set of Bethe roots with cardinality equal to N, the length of the chain, and which satisfies a set of Bethe equations with an additional term.

  16. Bethe states for the two-site Bose–Hubbard model: A binomial approach

    Directory of Open Access Journals (Sweden)

    Gilberto Santos

    2015-06-01

    Full Text Available We calculate explicitly the Bethe vectors states by the algebraic Bethe ansatz method with the gl(2-invariant R-matrix for the two-site Bose–Hubbard model. Using a binomial expansion of the n-th power of a sum of two operators we get and solve a recursion equation. We calculate the scalar product and the norm of the Bethe vectors states. The form factors of the imbalance current operator are also computed.

  17. Electromagnetic form factor via Minkowski and Euclidean Bethe-Salpeter amplitudes

    CERN Document Server

    Karmanov, V A; Mangin-Brinet, M

    2007-01-01

    The electromagnetic form factors calculated through Euclidean Bethe-Salpeter amplitude and through the light-front wave function are compared with the one found using the Bethe-Salpeter amplitude in Minkowski space. The form factor expressed through the Euclidean Bethe-Salpeter amplitude (both within and without static approximation) considerably differs from the Minkowski one, whereas form factor found in the light-front approach is almost indistinguishable from it.

  18. Bethe-Salpeter equation in Minkowski space with cross-ladder kernel

    CERN Document Server

    Karmanov, V A

    2006-01-01

    A new method for solving the Bethe-Salpeter equation is developed. It allows to find the Bethe-Salpeter amplitudes both in Minkowski and in Euclidean spaces and, as a by product, the light-front wave function. The method is valid for any kernel given by irreducible Feynman graphs. Bethe-Salpeter and Light-Front equations for scalar particles with ladder + cross-ladder kernel are solved.

  19. Algebraic Bethe ansatz for the XXX chain with triangular boundaries and Gaudin model

    CERN Document Server

    António, N Cirilo; Salom, I

    2014-01-01

    We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the corresponding Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the Bethe vectors through the so-called quasi-classical limit.

  20. Modified algebraic Bethe ansatz for XXZ chain on the segment – I: Triangular cases

    Directory of Open Access Journals (Sweden)

    Samuel Belliard

    2015-03-01

    Full Text Available The modified algebraic Bethe ansatz, introduced by Crampé and the author [8], is used to characterize the spectral problem of the Heisenberg XXZ spin-12 chain on the segment with lower and upper triangular boundaries. The eigenvalues and the eigenvectors are conjectured. They are characterized by a set of Bethe roots with cardinality equal to N the length of the chain and which satisfies a set of Bethe equations with an additional term. The conjecture follows from exact results for small chains. We also present a factorized formula for the Bethe vectors of the Heisenberg XXZ spin-12 chain on the segment with two upper triangular boundaries.

  1. [And Sarah Félix created "L 'Eau des Fées" and "La Parfumerie des Fées"].

    Science.gov (United States)

    Raynal, Cécile

    2015-12-01

    century, the parisian perfumery of Sarah Felix was famous especially for her cosmetic "L'Eau des Fées" ("Water of the Fairies"), a dyeing supposed to give back to the old hair the color of their youth. Sarah Felix, sister of the famous actress Rachel, exercised several jobs before becoming perfumer. At first, she was actress, then she tried ... oyster culture in Normandy ! Abandoning these activities, Sarah Felix became really a businesswoman in Paris. She dedicated herself to perfumery, in particular to "L'Eau des Fées", from 1866. To launch its product, she was associated to competency characters (engineer, pharmacist, physician) and benefited from the protection of the imperial family. A lawsuit between the associates and the 1870 war hindered the company's early days, but "L'Eau des Fées" provided with quality pledges, imposed itself definitely. The "Parfumerie des Fées" completed the range of its cosmetics with creams, powders, etc. Sarah Félix paid attention to present "L'Eau des Fées" as a dye devoid of toxicity. Was it really the case and could il be sold nowadays? These two issues are discussed in the last part.

  2. 自我反省 SARAH BRAMAN的深秋暖日展

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    这是一个严肃的命题。作为艺术界的"饱学之士",龚福尔现代艺术中心(Confort Moderne)将通过SarahBraman的雕塑传达一种"针对近期某些愤世嫉俗的知识分子言论以及带有自我反省色彩的玄妙语言而作出的救赎性反应"。我可以向你保证,有许多理由足以促使你去普瓦捷(Poitiers)参观这位美国艺术家的展览!

  3. Bethe Ansatz Solutions of the Bose-Hubbard Dimer

    Directory of Open Access Journals (Sweden)

    Jon Links

    2006-12-01

    Full Text Available The Bose-Hubbard dimer Hamiltonian is a simple yet effective model for describing tunneling phenomena of Bose-Einstein condensates. One of the significant mathematical properties of the model is that it can be exactly solved by Bethe ansatz methods. Here we review the known exact solutions, highlighting the contributions of V.B. Kuznetsov to this field. Two of the exact solutions arise in the context of the Quantum Inverse Scattering Method, while the third solution uses a differential operator realisation of the su(2 Lie algebra.

  4. Physics over easy Breakfasts with Beth and physics

    CERN Document Server

    Azaroff, L V

    2010-01-01

    During a sequence of meals, the author relates the principal features of physics in easy-to-understand conversations with his wife Beth. Beginning with the studies of motion by Galileo and Newton through to the revolutionary theories of relativity and quantum mechanics in the 20th century, all important aspects of electricity, energy, magnetism, gravity and the structure of matter and atoms are explained and illustrated. The second edition similarly recounts the more recent application of these theories to nanoparticles, Bose-Einstein condensates, quantum entanglement and quantum computers. By

  5. Spectra of Free Diquark in the Bethe-Salpeter Approach

    Institute of Scientific and Technical Information of China (English)

    YU Yan-Ming; KE Hong-Wei; DING Yi-Bing; GUO Xin-Heng; JIN Hong-Ying; LI Xue-Qian; SHEN Peng-Nian; WANG Guo-Li

    2006-01-01

    In this work, we employ the Bethe-Salpeter (B-S) equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks with two heavy quarks or one heavy and one light quarks, but for two light-quark systems, the results are not reliable. There are a few free parameters in the whole scenario which can only be fixed phenomenologically. Thus, to determine them, one has to study baryons which are composed of quarks and diquarks.

  6. Bethe-Salpeter equation in non-commutative space

    Directory of Open Access Journals (Sweden)

    M. Haghighat

    2005-06-01

    Full Text Available  We consider Bethe-Salpeter (BS equation for the bound state of two point particles in the non-commutative space-time. We subsequently explore the BS equation for spin0-spin0, spin1/2-spin1/2 and spin0-spin1/2 bound states. we show that the lowest order spin independent correction to energy spectrum in each case is of the order θ a 4 while the spin dependent one in NC space, is started at the order θ a 6.

  7. Solving Bethe-Salpeter equation in Minkowski space

    CERN Document Server

    Karmanov, V A

    2005-01-01

    We develop a new method of solving Bethe-Salpeter (BS) equation for spinless particles. It is based on projecting the BS equation on the light-front plane and on the Nakanishi integral representation of the BS amplitude. The method is valid for any kernel given by the irreducible Feynman graphs and does not assume a transformation to the Euclidean space. For massless ladder exchange our approach reproduces analytically the Wick-Cutkosky equation. For massive ladder exchange the numerical results coincide with ones obtained by Wick rotation.

  8. Direct Bethe-Salpeter solutions in Minkowski space

    CERN Document Server

    Carbonell, J

    2016-01-01

    We review a method to directly solve the Bethe-Salpeter equation in Minkowski space, both for bound and scattering states. It is based on a proper treatment of the many singularities which appear in the kernel and propagators. The off-mass shell scattering amplitude for spinless particles interacting by a one boson exchange was computed for the first time. Using our Minkowski space solutions for the initial (bound) and final (scattering) states, we calculate elastic and transition (bound to scattering state) electromagnetic form factors. The conservation of the transition electromagnetic current J.q=0, verified numerically, confirms the validity of our solutions.

  9. Integrability in three dimensions: Algebraic Bethe ansatz for anyonic models

    Directory of Open Access Journals (Sweden)

    Sh. Khachatryan

    2015-10-01

    Full Text Available We extend basic properties of two dimensional integrable models within the Algebraic Bethe Ansatz approach to 2+1 dimensions and formulate the sufficient conditions for the commutativity of transfer matrices of different spectral parameters, in analogy with Yang–Baxter or tetrahedron equations. The basic ingredient of our models is the R-matrix, which describes the scattering of a pair of particles over another pair of particles, the quark-anti-quark (meson scattering on another quark-anti-quark state. We show that the Kitaev model belongs to this class of models and its R-matrix fulfills well-defined equations for integrability.

  10. Functional Bethe ansatz methods for the open XXX chain

    Energy Technology Data Exchange (ETDEWEB)

    Frahm, Holger; Grelik, Jan H; Seel, Alexander; Wirth, Tobias, E-mail: Holger.Frahm@itp.uni-hannover.d, E-mail: Jan.Grelik@itp.uni-hannover.d, E-mail: Alexander.Seel@itp.uni-hannover.d [Institut fuer Theoretische Physik, Leibniz Universitaet Hannover, Appelstr. 2, 30167 Hannover (Germany)

    2011-01-07

    We study the spectrum of the integrable open XXX Heisenberg spin chain subject to non-diagonal boundary magnetic fields. The spectral problem for this model can be formulated in terms of functional equations obtained by separation of variables or, equivalently, from the fusion of transfer matrices. For generic boundary conditions the eigenvalues cannot be obtained from the solution of finitely many algebraic Bethe equations. Based on careful finite size studies of the analytic properties of the underlying hierarchy of transfer matrices we devise two approaches to analyze the functional equations. First we introduce a truncation method leading to Bethe-type equations determining the energy spectrum of the spin chain. In a second approach, the hierarchy of functional equations is mapped to an infinite system of nonlinear integral equations of TBA type. The two schemes have complementary ranges of applicability and facilitate an efficient numerical analysis for a wide range of boundary parameters. Some data are presented on the finite-size corrections to the energy of the state which evolves into the antiferromagnetic ground state in the limit of parallel boundary fields.

  11. Functional Bethe ansatz methods for the open XXX chain

    Science.gov (United States)

    Frahm, Holger; Grelik, Jan H.; Seel, Alexander; Wirth, Tobias

    2011-01-01

    We study the spectrum of the integrable open XXX Heisenberg spin chain subject to non-diagonal boundary magnetic fields. The spectral problem for this model can be formulated in terms of functional equations obtained by separation of variables or, equivalently, from the fusion of transfer matrices. For generic boundary conditions the eigenvalues cannot be obtained from the solution of finitely many algebraic Bethe equations. Based on careful finite size studies of the analytic properties of the underlying hierarchy of transfer matrices we devise two approaches to analyze the functional equations. First we introduce a truncation method leading to Bethe-type equations determining the energy spectrum of the spin chain. In a second approach, the hierarchy of functional equations is mapped to an infinite system of nonlinear integral equations of TBA type. The two schemes have complementary ranges of applicability and facilitate an efficient numerical analysis for a wide range of boundary parameters. Some data are presented on the finite-size corrections to the energy of the state which evolves into the antiferromagnetic ground state in the limit of parallel boundary fields.

  12. Off-diagonal Bethe ansatz solution of the XXX spin chain with arbitrary boundary conditions

    Science.gov (United States)

    Cao, Junpeng; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

    2013-10-01

    Employing the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the XXX spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated T-Q relation and the Bethe ansatz equations are derived.

  13. The Bethe Sum Rule and Basis Set Selection in the Calculation of Generalized Oscillator Strengths

    DEFF Research Database (Denmark)

    Cabrera-Trujillo, Remigio; Sabin, John R.; Oddershede, Jens;

    1999-01-01

    Fulfillment of the Bethe sum rule may be construed as a measure of basis set quality for atomic and molecular properties involving the generalized oscillator strength distribution. It is first shown that, in the case of a complete basis, the Bethe sum rule is fulfilled exactly in the random phase...

  14. Off-diagonal Bethe ansatz solution of the XXX spin-chain with arbitrary boundary conditions

    CERN Document Server

    Cao, Junpeng; Shi, Kangjie; Wang, Yupeng

    2013-01-01

    With the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the $XXX$ spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated $T-Q$ relation and the Bethe ansatz equations are derived.

  15. Yangian symmetry, S-Matrices and Bethe Ansats for the Ads5 x S5 superstring

    NARCIS (Netherlands)

    de Leeuw, M.

    2009-01-01

    We discuss the relation between the recently derived bound state S-matrices for the AdS5× S5 superstring and Yangian symmetry. We will study the relation between this Yangian symmetry and the Bethe ansatz. In particular we can use it to derive the Bethe equations for bound states.

  16. Algebraic Bethe Ansatz Solution to CN Vertex Model with Open Boundary Conditions

    Institute of Scientific and Technical Information of China (English)

    LI Guang-Liang; SHI Kang-Jie; YUE Rui-Hong

    2005-01-01

    We present three diagonal reflecting matrices for the CN vertex model with open boundary conditions and exactly solve the model by using the algebraic Bethe ansatz. The eigenvector is constructed and the eigenvalue and the associated Bethe equations are achieved. All the unwanted terms are cancelled out by three kinds of identities.

  17. Bethe ansatz matrix elements as non-relativistic limits of form factors of quantum field theory

    NARCIS (Netherlands)

    Kormos, M.; Mussardo, G.; Pozsgay, B.

    2010-01-01

    We show that the matrix elements of integrable models computed by the algebraic Bethe ansatz (BA) can be put in direct correspondence with the form factors of integrable relativistic field theories. This happens when the S-matrix of a Bethe ansatz model can be regarded as a suitable non-relativistic

  18. Algebraic Bethe ansatz for the Temperley–Lieb spin-1 chain

    Energy Technology Data Exchange (ETDEWEB)

    Nepomechie, Rafael I., E-mail: nepomechie@physics.miami.edu [Physics Department, P.O. Box 248046, University of Miami, Coral Gables, FL 33124 (United States); Pimenta, Rodrigo A., E-mail: pimenta@df.ufscar.br [Physics Department, P.O. Box 248046, University of Miami, Coral Gables, FL 33124 (United States); Departamento de Física, Universidade Federal de São Carlos, Caixa Postal 676, CEP 13565-905, São Carlos (Brazil)

    2016-09-15

    We use the algebraic Bethe ansatz to obtain the eigenvalues and eigenvectors of the spin-1 Temperley–Lieb open quantum chain with “free” boundary conditions. We exploit the associated reflection algebra in order to prove the off-shell equation satisfied by the Bethe vectors.

  19. In Defense of Today's Struggling Reader: What Policymakers Can Learn from Beth

    Science.gov (United States)

    Spencer, Tamara

    2012-01-01

    Beth attends a New York City K-8, dual-language (Spanish/English) public school where 96% of the students qualify as low-income, based on participation in the federally funded lunch program. Early in Beth's 1st-grade year, she was classified as a struggling reader, based on district-wide assessments that identified academic deficits in such skill…

  20. Algebraic Bethe ansatz for the Temperley–Lieb spin-1 chain

    Directory of Open Access Journals (Sweden)

    Rafael I. Nepomechie

    2016-09-01

    Full Text Available We use the algebraic Bethe ansatz to obtain the eigenvalues and eigenvectors of the spin-1 Temperley–Lieb open quantum chain with “free” boundary conditions. We exploit the associated reflection algebra in order to prove the off-shell equation satisfied by the Bethe vectors.

  1. Algebraic Bethe ansatz for the Temperley-Lieb spin-1 chain

    CERN Document Server

    Nepomechie, Rafael I

    2016-01-01

    We use the algebraic Bethe ansatz to obtain the eigenvalues and eigenvectors of the spin-1 Temperley-Lieb open quantum chain with "free" boundary conditions. We exploit the associated reflection algebra in order to prove the off-shell equation satisfied by the Bethe vectors.

  2. Algebraic Bethe ansatz for the Temperley-Lieb spin-1 chain

    Science.gov (United States)

    Nepomechie, Rafael I.; Pimenta, Rodrigo A.

    2016-09-01

    We use the algebraic Bethe ansatz to obtain the eigenvalues and eigenvectors of the spin-1 Temperley-Lieb open quantum chain with "free" boundary conditions. We exploit the associated reflection algebra in order to prove the off-shell equation satisfied by the Bethe vectors.

  3. Bethe-Salpeter equation with cross-ladder kernel in Minkowski and Euclidean spaces

    CERN Document Server

    Karmanov, V A; Mangin-Brinet, M

    2007-01-01

    Some results obtained by a new method for solving the Bethe-Salpeter equation are presented. The method is valid for any kernel given by irreducible Feynman graphs. The Bethe-Salpeter amplitude, both in Minkowski and in Euclidean spaces, and the binding energy for ladder + cross-ladder kernel are found. We calculate also the corresponding electromagnetic form factor.

  4. Roy Ellen, Stephen J. Lycett, Sarah E. Johns, eds., 2013, Understanding Cultural Transmission in Anthropology: A Critical Synthesis New York and Oxford: Berghahn Books

    Directory of Open Access Journals (Sweden)

    Clelia Viecelli

    2015-10-01

    Full Text Available recensione: Roy Ellen, Stephen J. Lycett, Sarah E. Johns, eds., 2013, Understanding Cultural Transmission in Anthropology: A Critical Synthesis New York and Oxford: Berghahn Books di Clelia Viecelli

  5. Women peers in the scientific realm: Sarah Bowdich (Lee)'s expert collaborations with Georges Cuvier, 1825–33

    Science.gov (United States)

    Orr, Mary

    2015-01-01

    The accepted rule for women contributing to nineteenth-century science before 1851 was that they could play only secondary roles in its production and authorship—as translators, illustrators, popularizers—and these by virtue of kinship or marriage to eminent scientists in the field or the laboratory. Sarah Bowdich (Lee) (1791–1856) presents an important amendment to this rule. As an explorer of West Africa on an equal scientific footing with her husband, and then a writer of science independently after his early death, she had other key roles as Georges Cuvier's cross-Channel scientific collaborator and as his first biographer. This article investigates and reframes Sarah's many individual achievements in science and its writing, to examine the larger questions of her case. How were her publications and ‘uneasy career’ in science possible? Can research on women in science today find inspiration in her example? PMID:26489182

  6. Just emotions: Reading the Sarah and Hagar narrative (Genesis 16, 21 through the lens of human dignity

    Directory of Open Access Journals (Sweden)

    Juliana Claassens

    2013-09-01

    Full Text Available This article seeked to read the interconnected narratives of Sarah and Hagar (Genesis 16, 21 in terms of the hermeneutical lens of human dignity. For the purpose of this article, recent studies on the performative nature of emotions, which considered the central role of emotions such as pain, disgust and hatred in shaping the lives of individuals as well as the ways in which people relate to one another, were helpful in contemplating the situations of dehumanisation faced by both Sarah and Hagar as well as the broader question regarding upholding human worth in a context of indignity. This article furthermore considered the role of emotions in a conversation on ethics and particularly the way in which the narrative offered a fruitful avenue for considering Israel�s relationship to their neighbours � a line of interpretation that holds potential for reflecting on complex interracial and interethnic relationships in today�s global context.

  7. Bethe-salpeter equation from many-body perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Sander, Tobias; Starke, Ronald; Kresse, Georg [Computational Materials Physics, University of Vienna, Sensengasse 8/12, 1090 Vienna (Austria)

    2013-07-01

    The Green function formalism is a powerful tool to calculate not only electronic structure within the quasi-particle (QP) picture, but it also gives access to optical absorption spectra. Starting from QP energies within the GW method, the polarizability, as central quantity, is calculated from the solution of a Bethe-Salpeter-like equation (BSE). It is usually solved within the Tamm-Dancoff Approximation (TDA) which neglects the coupling of resonant (positive frequency branch) and anti-resonant (negative frequency branch) excitations. In this work we solve the full BSE (beyond TDA) based on self-consistently calculated QP orbitals and energies for typical systems. The dielectric function is averaged over many low dimensional shifted k-meshes to obtain k-point converged results. We compare the results to recently introduced approximation to the BSE kernel. Additionally, the time-evolution ansatz is employed to calculate the polarizability, which avoids the direct solution of the BSE.

  8. Critical phenomena in one dimension from a Bethe ansatz perspective

    Science.gov (United States)

    Guan, Xiwen

    2014-08-01

    This article briefly reviews recent theoretical developments in quantum critical phenomena in one-dimensional (1D) integrable quantum gases of cold atoms. We present a discussion on quantum phase transitions, universal thermodynamics, scaling functions and correlations for a few prototypical exactly solved models, such as the Lieb-Liniger Bose gas, the spin-1 Bose gas with antiferromagnetic spin-spin interaction, the two-component interacting Fermi gas as well as spin-3/2 Fermi gases. We demonstrate that their corresponding Bethe ansatz solutions provide a precise way to understand quantum many-body physics, such as quantum criticality, Luttinger liquids (LLs), the Wilson ratio, Tan's Contact, etc. These theoretical developments give rise to a physical perspective using integrability for uncovering experimentally testable phenomena in systems of interacting bosonic and fermonic ultracold atoms confined to 1D.

  9. Modified binary encounter Bethe model for electron-impact ionization

    CERN Document Server

    Guerra, M; Indelicato, P; Santos, J P

    2013-01-01

    Theoretical expressions for ionization cross sections by electron impact based on the binary encounter Bethe (BEB) model, valid from ionization threshold up to relativistic energies, are proposed. The new modified BEB (MBEB) and its relativistic counterpart (MRBEB) expressions are simpler than the BEB (nonrelativistic and relativistic) expressions because they require only one atomic parameter, namely the binding energy of the electrons to be ionized, and use only one scaling term for the ionization of all sub-shells. The new models are used to calculate the K-, L- and M-shell ionization cross sections by electron impact for several atoms with Z from 6 to 83. Comparisons with all, to the best of our knowledge, available experimental data show that this model is as good or better than other models, with less complexity.

  10. Twist-three at five loops, Bethe Ansatz and wrapping

    CERN Document Server

    Beccaria, M; Lukowski, T; Zieme, S

    2009-01-01

    We present a formula for the five-loop anomalous dimension of N=4 SYM twist-three operators in the sl(2) sector. We obtain its asymptotic part from the Bethe Ansatz and finite volume corrections from the generalized Luescher formalism, considering scattering processes of spin chain magnons with virtual particles that travel along the cylinder. The complete result respects the expected large spin scaling properties and passes non-trivial tests including reciprocity constraints. We analyze the pole structure and find agreement with a conjectured resummation formula. In analogy with the twist-two anomalous dimension at four-loops, wrapping effects are of order log^2 M/M^2 for large values of the spin.

  11. Solving the Bethe-Salpeter Equation in Euclidean Space

    CERN Document Server

    Dorkin, S M; Atti, C Ciofi degli; Kämpfer, B

    2010-01-01

    Different approaches to solve the spinor-spinor Bethe-Salpeter (BS) equation in Euclidean space are considered. It is argued that the complete set of Dirac matrices is the most appropriate basis to define the partial amplitudes and to solve numerically the resulting system of equations with realistic interaction kernels. Other representations can be obtained by performing proper unitary transformations. A generalization of the iteration method for finding the energy spectrum of the BS equation is discussed and examples of concrete calculations are presented. Comparison of relativistic calculations with available experimental data and with corresponding non relativistic results together with an analysis of the role of Lorentz boost effects and relativistic corrections are presented. A novel method related to the use of hyperspherical harmonics is considered for a representation of the vertex functions suitable for numerical calculations.

  12. Solving the Bethe-Salpeter Equation in Euclidean Space

    Science.gov (United States)

    Dorkin, S. M.; Kaptari, L. P.; Ciofi degli Atti, C.; Kämpfer, B.

    2011-03-01

    Different approaches to solve the spinor-spinor Bethe-Salpeter (BS) equation in Euclidean space are considered. It is argued that the complete set of Dirac matrices is the most appropriate basis to define the partial amplitudes and to solve numerically the resulting system of equations with realistic interaction kernels. Other representations can be obtained by performing proper unitary transformations. A generalization of the iteration method for finding the energy spectrum of the BS equation is discussed and examples of concrete calculations are presented. Comparison of relativistic calculations with available experimental data and with corresponding non relativistic results together with an analysis of the role of Lorentz boost effects and relativistic corrections are presented. A novel method related to the use of hyperspherical harmonics is considered for a representation of the vertex functions suitable for numerical calculations.

  13. Phase Diagram for Ashkin-Teller Model on Bethe Lattice

    Institute of Scientific and Technical Information of China (English)

    LE Jian-Xin; YANG Zhan-Ru

    2005-01-01

    Using the recursion method, we study the phase transitions of the Ashkin-Teller model on the Bethe lattice,restricting ourselves to the case of ferromagnetic interactions. The isotropic Ashkin-Teller model and the anisotropic one are respectively investigated, and exact expressions for the free energy and the magnetization are obtained. It can be found that each of the three varieties of phase diagrams, for the anisotropic Ashkin-Teller model, consists of four phases, I.e., the fully disordered paramagnetic phase Para, the fully ordered ferromagnetic phase Ferro, and two partially ordered ferromagnetic phases and , while the phase diagram, for the isotropic Ashkin-Teller model,contains three phases, I.e., the fully disordered paramagnetic phase Para, the fully ordered ferromagnetic phase Baxter Phase, and the partially ordered ferromagnetic phase .

  14. Universal Bethe ansatz solution for the Temperley-Lieb spin chain

    Science.gov (United States)

    Nepomechie, Rafael I.; Pimenta, Rodrigo A.

    2016-09-01

    We consider the Temperley-Lieb (TL) open quantum spin chain with "free" boundary conditions associated with the spin-s representation of quantum-deformed sl (2). We construct the transfer matrix, and determine its eigenvalues and the corresponding Bethe equations using analytical Bethe ansatz. We show that the transfer matrix has quantum group symmetry, and we propose explicit formulas for the number of solutions of the Bethe equations and the degeneracies of the transfer-matrix eigenvalues. We propose an algebraic Bethe ansatz construction of the off-shell Bethe states, and we conjecture that the on-shell Bethe states are highest-weight states of the quantum group. We also propose a determinant formula for the scalar product between an off-shell Bethe state and its on-shell dual, as well as for the square of the norm. We find that all of these results, except for the degeneracies and a constant factor in the scalar product, are universal in the sense that they do not depend on the value of the spin. In an appendix, we briefly consider the closed TL spin chain with periodic boundary conditions, and show how a previously-proposed solution can be improved so as to obtain the complete (albeit non-universal) spectrum.

  15. Universal Bethe ansatz solution for the Temperley-Lieb spin chain

    CERN Document Server

    Nepomechie, Rafael I

    2016-01-01

    We consider the Temperley-Lieb (TL) open quantum spin chain with "free" boundary conditions associated with the spin-$s$ representation of quantum-deformed $sl(2)$. We construct the transfer matrix, and determine its eigenvalues and the corresponding Bethe equations using analytical Bethe ansatz. We show that the transfer matrix has quantum group symmetry, and we propose explicit formulas for the number of solutions of the Bethe equations and the degeneracies of the transfer-matrix eigenvalues. We propose an algebraic Bethe ansatz construction of the off-shell Bethe states, and we conjecture that the on-shell Bethe states are highest-weight states of the quantum group. We also propose a determinant formula for the scalar product between an off-shell Bethe state and its on-shell dual, as well as for the square of the norm. We find that all of these results, except for the degeneracies and a constant factor in the scalar product, are universal in the sense that they do not depend on the value of the spin. In an...

  16. Off-diagonal Bethe Ansatz solution of the $\\tau_2$-model

    CERN Document Server

    Xu, Xiaotian; Cui, Shuai; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

    2015-01-01

    The generic quantum $\\tau_2$-model (also known as Baxter-Bazhanov-Stroganov (BBS) model) with periodic boundary condition is studied via the off-diagonal Bethe Ansatz method. The eigenvalues of the corresponding transfer matrix (solutions of the recursive functional relations in $\\tau_j$-hierarchy) with generic site-dependent inhomogeneity parameters are given in terms of an inhomogeneous T-Q relation with polynomial Q-functions. The associated Bethe Ansatz equations are obtained. Numerical solutions of the Bethe Ansatz equations for small number of sites indicate that the inhomogeneous T-Q relation does indeed give the complete spectrum.

  17. Heisenberg XXX Model with General Boundaries: Eigenvectors from Algebraic Bethe Ansatz

    Science.gov (United States)

    Belliard, Samuel; Crampé, Nicolas

    2013-11-01

    We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations) formally similar to the ones obtained in the periodic case or with diagonal boundaries.

  18. Heisenberg XXX Model with General Boundaries: Eigenvectors from Algebraic Bethe Ansatz

    Directory of Open Access Journals (Sweden)

    Samuel Belliard

    2013-11-01

    Full Text Available We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations formally similar to the ones obtained in the periodic case or with diagonal boundaries.

  19. Algebraic Bethe ansatz for the sl(2) Gaudin model with boundary

    CERN Document Server

    António, N Cirilo; Ragoucy, E; Salom, I

    2015-01-01

    Following Sklyanin's proposal in the periodic case, we derive the generating function of the Gaudin Hamiltonians with boundary terms. Our derivation is based on the quasi-classical expansion of the linear combination of the transfer matrix of the XXX Heisenberg spin chain and the central element, the so-called Sklyanin determinant. The corresponding Gaudin Hamiltonians with boundary terms are obtained as the residues of the generating function. By defining the appropriate Bethe vectors which yield strikingly simple off shell action of the generating function, we fully implement the algebraic Bethe ansatz, obtaining the spectrum of the generating function and the corresponding Bethe equations.

  20. Heisenberg XXX model with general boundaries: Eigenvectors from Algebraic Bethe ansatz

    CERN Document Server

    Belliard, S

    2013-01-01

    We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations) formally similar to the ones obtained in the periodic case or with diagonal boundaries.

  1. Solutions of the Bethe-Salpeter Equation in Minkowski space: a comparative study

    CERN Document Server

    Salme`, Giovanni; Viviani, Michele

    2014-01-01

    The Bethe-Salpeter Equation for a two-scalar, S-wave bound system, interacting through a massive scalar, is investigated within the ladder approximation. By assuming a Nakanishi integral representation of the Bethe-Salpeter amplitude, one can deduce new integral equations that can be solved and quantitatively studied, overcoming the analytic difficulties of the Minkowski space. Finally, it is shown that the Light-front distributions of the valence state, directly obtained from the Bethe-Salpeter amplitude, open an effective window for studying the two-body dynamics.

  2. Graph Zeta Function in the Bethe Free Energy and Loopy Belief Propagation

    CERN Document Server

    Watanabe, Yusuke

    2010-01-01

    We propose a new approach to the analysis of Loopy Belief Propagation (LBP) by establishing a formula that connects the Hessian of the Bethe free energy with the edge zeta function. The formula has a number of theoretical implications on LBP. It is applied to give a sufficient condition that the Hessian of the Bethe free energy is positive definite, which shows non-convexity for graphs with multiple cycles. The formula clarifies the relation between the local stability of a fixed point of LBP and local minima of the Bethe free energy. We also propose a new approach to the uniqueness of LBP fixed point, and show various conditions of uniqueness.

  3. Off-diagonal Bethe Ansatz solution of the τ{sub 2}-model

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaotian [Institute of Modern Physics, Northwest University,Xian 710069 (China); Cao, Junpeng [Beijing National Laboratory for Condensed Matter Physics,Institute of Physics, Chinese Academy of Sciences,Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter,Beijing (China); Cui, Shuai [Beijing National Laboratory for Condensed Matter Physics,Institute of Physics, Chinese Academy of Sciences,Beijing 100190 (China); Yang, Wen-Li [Institute of Modern Physics, Northwest University,Xian 710069 (China); Beijing Center for Mathematics and Information Interdisciplinary Sciences,Beijing 100048 (China); Shi, Kangjie [Institute of Modern Physics, Northwest University,Xian 710069 (China); Wang, Yupeng [Beijing National Laboratory for Condensed Matter Physics,Institute of Physics, Chinese Academy of Sciences,Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter,Beijing (China)

    2015-09-30

    The generic quantum τ{sub 2}-model (also known as Baxter-Bazhanov-Stroganov (BBS) model) with periodic boundary condition is studied via the off-diagonal Bethe Ansatz method. The eigenvalues of the corresponding transfer matrix (solutions of the recursive functional relations in τ{sub j}-hierarchy) with generic site-dependent inhomogeneity parameters are given in terms of an inhomogeneous T−Q relation with polynomial Q-functions. The associated Bethe Ansatz equations are obtained. Numerical solutions of the Bethe Ansatz equations for small number of sites indicate that the inhomogeneous T−Q relation does indeed give the complete spectrum.

  4. Solutions of the Bethe-Salpeter equation in Minkowski space and applications to electromagnetic form factors

    CERN Document Server

    Carbonell, J

    2010-01-01

    We present a new method for solving the two-body Bethe-Salpeter equation in Minkowski space. It is based on the Nakanishi integral representation of the Bethe-Salpeter amplitude and on subsequent projection of the equation on the light-front plane. The method is valid for any kernel given by the irreducible Feynman graphs and for systems of spinless particles or fermions. The Bethe-Salpeter amplitudes in Minkowski space are obtained. The electromagnetic form factors are computed and compared to the Euclidean results.

  5. BETHE ANSATZ FOR SUPERSYMMETRIC MODEL WITH?Uq[osp( 1|2 ) ] SYMMETRY

    Institute of Scientific and Technical Information of China (English)

    杨文力

    2001-01-01

    Using the algebraic Bethe ansatz method, we obtain the eigenvalues of the transfer matrix of the supersymmetric model with Uq[osp(1|2)] symmetry under periodic boundary and twisted boundary conditions.

  6. Transition electromagnetic form factor in the Minkowski space Bethe-Salpeter approach

    CERN Document Server

    Carbonell, J

    2013-01-01

    Using the solutions of the Bethe-Salpeter equation in Minkowski space for bound and scattering states found in previous works, we calculate the transition electromagnetic form factor describing the electro-disintegration of a bound system.

  7. Scattering solutions of Bethe-Salpeter equation in Minkowski and Euclidean spaces

    CERN Document Server

    Carbonell, J

    2016-01-01

    We shortly review different methods to obtain the scattering solutions of the Bethe-Salpeter equation in Minkowski space. We emphasize the possibility to obtain the zero energy observables in terms of the Euclidean scattering amplitude.

  8. The calcineurin inhibitor Sarah (Nebula exacerbates Aβ42 phenotypes in a Drosophila model of Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Soojin Lee

    2016-03-01

    Full Text Available Expression of the Down syndrome critical region 1 (DSCR1 protein, an inhibitor of the Ca2+-dependent phosphatase calcineurin, is elevated in the brains of individuals with Down syndrome (DS or Alzheimer's disease (AD. Although increased levels of DSCR1 were often observed to be deleterious to neuronal health, its beneficial effects against AD neuropathology have also been reported, and the roles of DSCR1 on the pathogenesis of AD remain controversial. Here, we investigated the role of sarah (sra; also known as nebula, a Drosophila DSCR1 ortholog, in amyloid-β42 (Aβ42-induced neurological phenotypes in Drosophila. We detected sra expression in the mushroom bodies of the fly brain, which are a center for learning and memory in flies. Moreover, similar to humans with AD, Aβ42-expressing flies showed increased Sra levels in the brain, demonstrating that the expression pattern of DSCR1 with regard to AD pathogenesis is conserved in Drosophila. Interestingly, overexpression of sra using the UAS-GAL4 system exacerbated the rough-eye phenotype, decreased survival rates and increased neuronal cell death in Aβ42-expressing flies, without modulating Aβ42 expression. Moreover, neuronal overexpression of sra in combination with Aβ42 dramatically reduced both locomotor activity and the adult lifespan of flies, whereas flies with overexpression of sra alone showed normal climbing ability, albeit with a slightly reduced lifespan. Similarly, treatment with chemical inhibitors of calcineurin, such as FK506 and cyclosporin A, or knockdown of calcineurin expression by RNA interference (RNAi, exacerbated the Aβ42-induced rough-eye phenotype. Furthermore, sra-overexpressing flies displayed significantly decreased mitochondrial DNA and ATP levels, as well as increased susceptibility to oxidative stress compared to that of control flies. Taken together, our results demonstrating that sra overexpression augments Aβ42 cytotoxicity in Drosophila suggest that DSCR1

  9. Spin-12 XYZ model revisit: General solutions via off-diagonal Bethe ansatz

    Directory of Open Access Journals (Sweden)

    Junpeng Cao

    2014-09-01

    Full Text Available The spin-12 XYZ model with both periodic and anti-periodic boundary conditions is studied via the off-diagonal Bethe ansatz method. The exact spectra of the Hamiltonians and the Bethe ansatz equations are derived by constructing the inhomogeneous T–Q relations, which allow us to treat both the even N (the number of lattice sites and odd N cases simultaneously in a unified approach.

  10. Small polaron with generic open boundary conditions: Exact solution via the off-diagonal Bethe ansatz

    Directory of Open Access Journals (Sweden)

    Xiaotian Xu

    2015-09-01

    Full Text Available The small polaron, a one-dimensional lattice model of interacting spinless fermions, with generic non-diagonal boundary terms is studied by the off-diagonal Bethe ansatz method. The presence of the Grassmann valued non-diagonal boundary fields gives rise to a typical U(1-symmetry-broken fermionic model. The exact spectra of the Hamiltonian and the associated Bethe ansatz equations are derived by constructing an inhomogeneous T–Q relation.

  11. Bethe ansatz solution of the $\\tau_2$-model with arbitrary boundary fields

    CERN Document Server

    Xu, Xiaotian; Yang, Tao; Cao, Junpeng; Yang, Wen-Li; Shi, Kangjie

    2016-01-01

    The quantum $\\tau_2$-model with generic site-dependent inhomogeneity and arbitrary boundary fields is studied via the off-diagonal Bethe Ansatz method. The eigenvalues of the corresponding transfer matrix are given in terms of an inhomogeneous T-Q relation, which is based on the operator product identities among the fused transfer matrices and the asymptotic behavior of the transfer matrices. Moreover, the associated Bethe Ansatz equations are also obtained.

  12. A systematic approach to sketch Bethe-Salpeter equation

    CERN Document Server

    Qin, Si-xue

    2016-01-01

    To study meson properties, one needs to solve the gap equation for the quark propagator and the Bethe-Salpeter (BS) equation for the meson wavefunction, self-consistently. The gluon propagator, the quark-gluon vertex, and the quark--anti-quark scattering kernel are key pieces to solve those equations. Predicted by lattice-QCD and Dyson-Schwinger analyses of QCD's gauge sector, gluons are non-perturbatively massive. In the matter sector, the modeled gluon propagator which can produce a veracious description of meson properties needs to possess a mass scale, accordingly. Solving the well-known longitudinal Ward-Green-Takahashi identities (WGTIs) and the less-known transverse counterparts together, one obtains a nontrivial solution which can shed light on the structure of the quark-gluon vertex. It is highlighted that the phenomenologically proposed anomalous chromomagnetic moment (ACM) vertex originates from the QCD Lagrangian symmetries and its strength is proportional to the magnitude of dynamical chiral symm...

  13. Instantaneous Bethe-Salpeter Equation and Its Exact Solution

    Institute of Scientific and Technical Information of China (English)

    CHANG Chao-Hsi; CHEN Jiao-Kai; LI Xue-Qian; WANG Guo-Li

    2005-01-01

    We present an approach to solve Bethe-Salpeter (BS) equations exactly without any approximation if the kernel of the BS equations exactly is instantaneous, and take positronium as an example to illustrate the general features of the exact solutions. The key step for the approach is from the BS equations to derive a set of coupled and welldetermined integration equations in linear eigenvalue for the components of the BS wave functions equivalently, which may be solvable numerically under a controlled accuracy, even though there is no analytic solution. For positronium,the exact solutions precisely present corrections to those of the corresponding Schrodinger equation in order v1 (v is the relative velocity) for eigenfunctions, in order v2 for eigenvalues, and the mixing between S and D components in JPC = 1- states etc., quantitatively. Moreover, we also point out that there is a questionable step in some existent derivations for the instantaneous BS equations if one is pursuing the exact solutions. Finally, we emphasize that one should take the O(v) corrections emerging in the exact solutions into account accordingly if one is interested in the relativistic corrections for relevant problems to the bound states.

  14. A systematic approach to sketch Bethe-Salpeter equation

    Directory of Open Access Journals (Sweden)

    Qin Si-xue

    2016-01-01

    Full Text Available To study meson properties, one needs to solve the gap equation for the quark propagator and the Bethe-Salpeter (BS equation for the meson wavefunction, self-consistently. The gluon propagator, the quark-gluon vertex, and the quark–anti-quark scattering kernel are key pieces to solve those equations. Predicted by lattice-QCD and Dyson-Schwinger analyses of QCD’s gauge sector, gluons are non-perturbatively massive. In the matter sector, the modeled gluon propagator which can produce a veracious description of meson properties needs to possess a mass scale, accordingly. Solving the well-known longitudinal Ward-Green-Takahashi identities (WGTIs and the less-known transverse counterparts together, one obtains a nontrivial solution which can shed light on the structure of the quark-gluon vertex. It is highlighted that the phenomenologically proposed anomalous chromomagnetic moment (ACM vertex originates from the QCD Lagrangian symmetries and its strength is proportional to the magnitude of dynamical chiral symmetry breaking (DCSB. The color-singlet vector and axial-vector WGTIs can relate the BS kernel and the dressed quark-gluon vertex to each other. Using the relation, one can truncate the gap equation and the BS equation, systematically, without violating crucial symmetries, e.g., gauge symmetry and chiral symmetry.

  15. Belief Propagation and Bethe approximation for Traffic Prediction

    CERN Document Server

    Furtlehner, C; Lasgouttes, J M; Fortelle, Arnaud De La; Furtlehner, Cyril; Lasgouttes, Jean-Marc

    2007-01-01

    We define and study an inference algorithm based on "belief propagation" (BP) and the Bethe approximation. The idea is to encode into a graph an a priori information composed of correlations or marginal probabilities of variables, and to use a message passing procedure to estimate the actual state from some extra real-time information. This method is originally designed for traffic prediction and is particularly suitable in settings where the only information available is floating car data. We propose a discretized traffic description, based on the Ising model of statistical physics, in order to both reconstruct and predict the traffic in real time. General properties of BP are addressed in this context. In particular, a detailed study of stability is proposed with respect to the a priori data and the graph topology. The behavior of the algorithm is illustrated by numerical studies on a simple traffic toy model. How this approach can be generalized to encode superposition of many traffic patterns is discussed...

  16. Efficient implementation of core-excitation Bethe Salpeter equation calculations

    CERN Document Server

    Gilmore, K; Shirley, E L; Prendergast, D; Pemmaraju, C D; Kas, J J; Vila, F D; Rehr, J J

    2016-01-01

    We present an efficient implementation of the Bethe-Salpeter equation (BSE) method for obtaining core-level spectra including x-ray absorption (XAS), x-ray emission (XES), and both resonant and non-resonant inelastic x-ray scattering spectra (N/RIXS). Calculations are based on density functional theory (DFT) electronic structures generated either by abinit or Quantumespresso, both plane-wave basis, pseudopotential codes. This electronic structure is improved through the inclusion of a GW self energy. The projector augmented wave technique is used to evaluate transition matrix elements between core-level and band states. Final two-particle scattering states are obtained with the NIST core-level BSE solver (NBSE). We have previously reported this implementation, which we refer to as ocean (Obtaining Core Excitations from Ab initio electronic structure and NBSE) [Phys. Rev. B 83, 115106 (2011)]. Here, we present additional efficiencies that enable us to evaluate spectra for systems ten times larger than previous...

  17. Bethe, Oppenheimer, Teller and the Fermi Award: Norris Bradbury Speaks

    Energy Technology Data Exchange (ETDEWEB)

    Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-04-28

    In 1956 the Enrico Fermi Presidential Award was established to recognize scientists, engineers, and science policymakers who gave unstintingly over their careers to advance energy science and technology. The first recipient was John von Neumann. .1 Among those scientists who were thought eligible for the award were Hans Bethe, J. Robert Oppenheimer, and Edward Teller. In 1959 Norris Bradbury was asked to comment on the relative merits of each these three men, whom he knew well from their affiliation with Los Alamos. Below is a reproduction of the letter Bradbury sent to Dr. Warren C. Johnson of the AEC’s General Advisory Committee(GAC) containing his evaluation of each man. The letter might surprise those not accustomed to Bradbury’s modus operandi of providing very detailed and forthright answers to the AEC. The letter, itself, was found in cache of old microfilm. Whether because of the age of the microfilm or the quality of the filming process, portions of the letter are not legible. Where empty brackets appear, the word or words could not be read or deduced. Words appearing in brackets are guesses that appear, from the image, to be what was written. These guesses, of course, are just that – guesses.

  18. Hyperon stars in the Brueckner-Bethe-Goldstone theory

    CERN Document Server

    Baldo, Marcello; Schulze, H J

    2000-01-01

    In the framework of the Brueckner-Bethe-Goldstone theory, we determine a fully microscopic equation of state for asymmetric and $\\beta$-stable nuclear matter containing $\\sim$ and $\\la$ hyperons. We use the Paris and the new Argonne $Av_{18}$ two-body nucleon interaction, whereas the nucleon-hyperon interaction is described by the Njimegen soft-core model. We stress the role played by the three-body nucleon interaction, which produces a strong repulsion at high densities. This enhances enormously the hyperon population, and produces a strong softening of the equation of state, which turns out almost independent on the nucleon-nucleon interaction. We use the new equation of state in order to calculate the structure of static neutron stars. We obtain a maximum mass configuration with $M_{\\rm max}$ = 1.26 (1.22) when the Paris ($Av_{18}$) nucleon potential is adopted. Central densities are about 10 times normal nuclear matter density. Stellar rotations, treated within a perturbative approach, increase the value ...

  19. A systematic approach to sketch Bethe-Salpeter equation

    Science.gov (United States)

    Qin, Si-xue

    2016-03-01

    To study meson properties, one needs to solve the gap equation for the quark propagator and the Bethe-Salpeter (BS) equation for the meson wavefunction, self-consistently. The gluon propagator, the quark-gluon vertex, and the quark-anti-quark scattering kernel are key pieces to solve those equations. Predicted by lattice-QCD and Dyson-Schwinger analyses of QCD's gauge sector, gluons are non-perturbatively massive. In the matter sector, the modeled gluon propagator which can produce a veracious description of meson properties needs to possess a mass scale, accordingly. Solving the well-known longitudinal Ward-Green-Takahashi identities (WGTIs) and the less-known transverse counterparts together, one obtains a nontrivial solution which can shed light on the structure of the quark-gluon vertex. It is highlighted that the phenomenologically proposed anomalous chromomagnetic moment (ACM) vertex originates from the QCD Lagrangian symmetries and its strength is proportional to the magnitude of dynamical chiral symmetry breaking (DCSB). The color-singlet vector and axial-vector WGTIs can relate the BS kernel and the dressed quark-gluon vertex to each other. Using the relation, one can truncate the gap equation and the BS equation, systematically, without violating crucial symmetries, e.g., gauge symmetry and chiral symmetry.

  20. Agglomerative percolation on the Bethe lattice and the triangular cactus

    Science.gov (United States)

    Chae, Huiseung; Yook, Soon-Hyung; Kim, Yup

    2013-08-01

    Agglomerative percolation (AP) on the Bethe lattice and the triangular cactus is studied to establish the exact mean-field theory for AP. Using the self-consistent simulation method based on the exact self-consistent equations, the order parameter P∞ and the average cluster size S are measured. From the measured P∞ and S, the critical exponents βk and γk for k = 2 and 3 are evaluated. Here, βk and γk are the critical exponents for P∞ and S when the growth of clusters spontaneously breaks the Zk symmetry of the k-partite graph. The obtained values are β2 = 1.79(3), γ2 = 0.88(1), β3 = 1.35(5) and γ3 = 0.94(2). By comparing these exponents with those for ordinary percolation (β∞ = 1 and γ∞ = 1), we also find β∞ γ3 > γ2. These results quantitatively verify the conjecture that the AP model belongs to a new universality class if the Zk symmetry is broken spontaneously, and the new universality class depends on k.

  1. Hidden Relation between Reflection Amplitudes and Thermodynamic Bethe Ansatz

    CERN Document Server

    Ahn, C; Rim, C; Ahn, Changrim; Kim, Chanju; Rim, Chaiho

    1999-01-01

    In this paper we compute the scaling functions of the effective central charges for various quantum integrable models in a deep ultraviolet region $R\\to 0$ using two independent methods. One is based on the ``reflection amplitudes'' of the (super-)Liouville field theory where the scaling functions are given by the conjugate momentum to the zero-modes. The conjugate momentum is quantized for the sinh-Gordon, the Bullough-Dodd, and the super sinh-Gordon models where the quantization conditions depend on the size $R$ of the system and the reflection amplitudes. The other method is to solve the standard thermodynamic Bethe ansatz (TBA) equations for the integrable models in a perturbative series of $1/(const. - \\ln R)$. The constant factor which is not fixed in the lowest order computations can be identified {\\it only when} we compare the higher order corrections with the quantization conditions. Numerical TBA analysis shows a perfect match for the scaling functions obtained by the first method. Our results show ...

  2. The Visual Metaphor of Disability in Sarah Leavitt's Graphic Memoir Tangles: A story about alzheimer's, my mother, and me

    Directory of Open Access Journals (Sweden)

    Renata Lucena Dalmaso

    2016-01-01

    Borrowing George Lakoff and Mark Johnson’s Conceptual Metaphor theory, and its implications for the study of visual metaphors, this article seeks to investigate the representation of the disabled body in the graphic memoir Tangles: A Story about Alzheimer’s, My Mother, and Me (2012, by Sarah Leavitt. The genre of comics, as a cross-discursive medium, is prolific in the use of visual metaphor as a narrative technique and Leavitt’s graphic memoir, in particular, employs visual metaphor in the depiction of her mother’s experience of Alzheimer’s, as someone slowly distancing herself from her family.

  3. N=6 super Chern-Simons theory S-matrix and all-loop Bethe ansatz equations

    CERN Document Server

    Ahn, Changrim

    2008-01-01

    We propose the exact S-matrix for the planar limit of the N=6 super Chern-Simons theory recently proposed by Aharony, Bergman, Jafferis, and Maldacena for the AdS_4/CFT_3 correspondence. Assuming SU(2|2) symmetry, factorizability and certain crossing-unitarity relations, we find the S-matrix including the dressing phase. We use this S-matrix to formulate the asymptotic Bethe ansatz. Our result for the Bethe-Yang equations and corresponding Bethe ansatz equations confirms the all-loop Bethe ansatz equations recently conjectured by Gromov and Vieira.

  4. Scalar products of Bethe vectors in models with $\\mathfrak{gl}(2|1)$ symmetry 1. Super-analog of Reshetikhin formula

    CERN Document Server

    Hutsalyuk, A; Pakuliak, S Z; Ragoucy, E; Slavnov, N A

    2016-01-01

    We study scalar products of Bethe vectors in integrable models solvable by nested algebraic Bethe ansatz and possessing $\\mathfrak{gl}(2|1)$ symmetry. Using explicit formulas of the monodromy matrix entries multiple actions onto Bethe vectors we obtain a representation for the scalar product in the most general case. This explicit representation appears to be a sum over partitions of the Bethe parameters. It can be used for the analysis of scalar products involving on-shell Bethe vectors. As a by-product, we obtain a determinant representation for the scalar products of generic Bethe vectors in integrable models with $\\mathfrak{gl}(1|1)$ symmetry.

  5. Topologically Twisted SUSY Gauge Theory, Gauge-Bethe Correspondence and Quantum Cohomology

    CERN Document Server

    Chung, Hee-Joong

    2016-01-01

    We calculate partition function and correlation functions in A-twisted 2d $\\mathcal{N}=(2,2)$ theories and topologically twisted 3d $\\mathcal{N}=2$ theories containing adjoint chiral multiplet with particular choices of $R$-charges and the magnetic fluxes for flavor symmetries. According to Gauge-Bethe correspondence, they correspond to Heisenberg XXX and XXZ spin chain models. We identify the partition function as the inverse of the norm of the Bethe eigenstates. Correlation functions are identified as the coefficients of the expectation value of Baxter $Q$-operators. In addition, we consider correlation functions of 2d $\\mathcal{N}=(2,2)^*$ theory and their relation to equivariant quantum cohomology and equivariant integration of cotangent bundle of Grassmann manifolds. Also, we study the ring relations of supersymmetric Wilson loops in 3d $\\mathcal{N}=2^*$ theory and Bethe subalgebra of XXZ spin chain model.

  6. Three-body bound states with zero-range interaction in the Bethe-Salpeter approach

    Science.gov (United States)

    Ydrefors, E.; Alvarenga Nogueira, J. H.; Gigante, V.; Frederico, T.; Karmanov, V. A.

    2017-07-01

    The Bethe-Salpeter equation for three bosons with zero-range interaction is solved for the first time. For comparison the light-front equation is also solved. The input is the two-body scattering length and the outputs are the three-body binding energies, Bethe-Salpeter amplitudes and light-front wave functions. Three different regimes are analyzed: (i) For weak enough two-body interaction the three-body system is unbound. (ii) For stronger two-body interaction a three-body bound state appears. It provides an interesting example of a deeply bound Borromean system. (iii) For even stronger two-body interaction this state becomes unphysical with a negative mass squared. However, another physical (excited) state appears, found previously in light-front calculations. The Bethe-Salpeter approach implicitly incorporates three-body forces of relativistic origin, which are attractive and increase the binding energy.

  7. Correlation functions and the algebraic Bethe ansatz in the AdS/CFT correspondence

    CERN Document Server

    Hernandez, Rafael

    2014-01-01

    Inverse scattering and the algebraic Bethe ansatz can be used to reduce the evaluation of form factors and correlation functions to the calculation of a product of Bethe states. In this article we develop a method to compute correlation functions of spin operators located at arbitrary sites of the spin chain. We will focus our analysis on the SU(2) sector of N=4 supersymmetric Yang-Mills at weak-coupling. At one-loop we provide a systematic treatment of the apparent divergences arising from the algebra of the elements of the monodromy matrix of an homogeneous spin chain. Beyond one-loop the analysis can be extended through the map of the long-range Bethe ansatz to an inhomogeneous spin chain. We also show that a careful normalization of states in the spin chain requires choosing them as Zamolodchikov-Faddeev states.

  8. Solution of the Bethe-Salpeter equation for pion-nucleon scattering

    Science.gov (United States)

    Lahiff, A. D.; Afnan, I. R.

    1999-08-01

    A relativistic description of pion-nucleon scattering based on the four-dimensional Bethe-Salpeter equation is presented. The kernel of the equation consists of s- and u-channel nucleon and Δ(1232) pole diagrams, as well as ρ and σ exchange in the t channel. The Bethe-Salpeter equation is solved by means of a Wick rotation, and good fits are obtained to the s- and p-wave πN phase shifts up to 360 MeV pion laboratory energy. The coupling constants determined by the fits are consistent with the commonly accepted values in the literature.

  9. Modified Bethe formula for low-energy electron stopping power without fitting parameters.

    Science.gov (United States)

    Nguyen-Truong, Hieu T

    2015-02-01

    We propose a modified Bethe formula for low-energy electron stopping power without fitting parameters for a wide range of elements and compounds. This formula maintains the generality of the Bethe formula and gives reasonable agreement in comparing the predicted stopping powers for 15 elements and 6 compounds with the experimental data and those calculated within dielectric theory including the exchange effect. Use of the stopping power obtained from this formula for hydrogen silsesquioxane in Monte Carlo simulation gives the energy deposition distribution in consistent with the experimental data.

  10. A Novel Approach in Solving the Spinor-Spinor Bethe-Salpeter Equation

    CERN Document Server

    Dorkin, S M; Semikh, S S; Kaptari, L P

    2008-01-01

    To solve the spinor-spinor Bethe-Salpeter equation in Euclidean space we propose a novel method related to the use of hyperspherical harmonics. We suggest an appropriate extension to form a new basis of spin-angular harmonics that is suitable for a representation of the vertex functions. We present a numerical algorithm to solve the Bethe-Salpeter equation and investigate in detail the properties of the solution for the scalar, pseudoscalar and vector meson exchange kernels including the stability of bound states. We also compare our results to the non relativistic ones and to the results given by light front dynamics.

  11. Non-equilibrium transport in the Anderson model of a biased quantum dot: Scattering Bethe Ansatz phenomenology

    NARCIS (Netherlands)

    Chao, S.-P.; Palacios, G.

    2010-01-01

    We derive the transport properties of a quantum dot subject to a source-drain bias voltage at zero temperature and magnetic field. Using the Scattering Bethe Anstaz, a generalization of the traditional Thermodynamic Bethe Ansatz to open systems out of equilibrium, we derive exact results for the

  12. The Dynamics of The Potts-Bethe Mapping over ℚ p : The Case p ≡ 2 (mod 3)

    Science.gov (United States)

    Saburov, Mansoor; Khameini Ahmad, Mohd Ali

    2017-03-01

    In this paper, we study the dynamics of the Potts-Bethe mapping associated with the p-adic q-state Potts model over the Cayley tree of order three. Namely, we establish the regularity of the Potts-Bethe mapping for the case p ≡ 2 (mod 3) with p ≥ 5.

  13. Outcasts Searching for a Place To Fit: A Study of "Frankenstein" by Mary Shelley and "Staying Fat for Sarah Byrnes" by Chris Crutcher.

    Science.gov (United States)

    Martin, Amy

    All people have to deal with feelings of loneliness, isolation, fear, and lack of acceptance, especially in the teenage years. Both of the novels "Staying Fat for Sarah Byrnes" and "Frankenstein" deal with these issues. By 10th grade, students are really searching for who they are and what they want out of life. It is especially important to these…

  14. Lesson Development for English Learners in Content Area Settings: Key Considerations. Q&A with Sarah Catherine K. Moore, Ph.D. 2016 Educator Effectiveness Webinar Series

    Science.gov (United States)

    Moore, Sarah Catherine K.

    2016-01-01

    In this webinar, Dr. Sarah Catherine K. Moore, Program Director at the Center for Applied Linguistics, outlined factors for content area teachers to consider as they design and deliver lessons for mainstream classrooms that include English learner (EL) students. This Q&A addressed the questions participants had for Dr. Moore following the…

  15. Normalization and perturbation theory for tightly bound states of the spinor Bethe-Salpeter equation

    NARCIS (Netherlands)

    L.G. Suttorp

    1976-01-01

    The normalisation integrals for the tightly-bound-state solutions of the spinor Bethe-Salpeter equation that have been derived recently are evaluated. Ghost states are found to appear when the continuous parameters characterising the type of fermion-boson interaction reach a critical value. Perturba

  16. The Bethe-Salpeter equation and the Low Energy Theorems for {pi}N scattering

    Energy Technology Data Exchange (ETDEWEB)

    Afnan, I.R. [School of Chemistry, Physics and Earth Sciences, Flinders University, GPO Box 2100, 5001, Adelaide (Australia); Lahiff, A.D. [TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, BC (Canada)

    2003-11-01

    The Bethe-Salpeter (BS) amplitude for {pi}N scattering is evaluated at the off-mass-shell points corresponding to the Low Energy Theorems (LET) based on PCAC and current algebra. The results suggest a way of maintaining constructing between BS equation and LET. (orig.)

  17. The Bethe-Salpeter equation and the Low Energy Theorems for π N scattering

    Science.gov (United States)

    Afnan, I. R.; Lahiff, A. D.

    The Bethe-Salpeter (BS) amplitude for $\\pi N$ scattering is evaluated at the off mass shell points corresponding to the Low Energy Theorems (LET) based on PCAC and current algebra. The results suggest a way of maintaining consistency between BS equation and LET.

  18. Numerical solution of the spinor Bethe-Salpeter equation and the Goldstein problem

    NARCIS (Netherlands)

    L.G. Suttorp

    1978-01-01

    The spinor Bethe-Salpeter equation describing bound states of a fermion-antifermion pair with massless-boson exchange reduces to a single (uncoupled) partial differential equation for special combinations of the fermion-boson couplings. For spinless bound states with positive or negative parity this

  19. Normalization and perturbation theory for tightly bound states of the spinor Bethe-Salpeter equation

    NARCIS (Netherlands)

    Suttorp, L.G.

    1976-01-01

    The normalisation integrals for the tightly-bound-state solutions of the spinor Bethe-Salpeter equation that have been derived recently are evaluated. Ghost states are found to appear when the continuous parameters characterising the type of fermion-boson interaction reach a critical value. Perturba

  20. Exact solutions of the spinor Bethe-Salpeter equation for tightly bound states

    NARCIS (Netherlands)

    Suttorp, L.G.

    1975-01-01

    Exact solutions are obtained for the spinor Bethe-Salpeter equation that describes tightly bound states of spin-/sup 1///sub 2/ fermions with massless-boson exchange. The corresponding coupling constants form a discrete spectrum that depends continuously on the parameters characterizing the type of

  1. Bethe ansatz for an AdS/CFT open spin chain with non-diagonal boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xin [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics,Chinese Academy of Sciences,Beijing, 100190 (China); Cao, Junpeng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics,Chinese Academy of Sciences,Beijing, 100190 (China); Collaborative Innovation Center of Quantum Matter,Beijing (China); Cui, Shuai [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics,Chinese Academy of Sciences,Beijing, 100190 (China); Nepomechie, Rafael I. [Physics Department, University of Miami,P.O. Box 248046, Coral Gables, FL 33124 (United States); Yang, Wen-Li [Institute of Modern Physics, Northwest University,Xian, 710069 (China); Beijing Center for Mathematics and Information Interdisciplinary Sciences,Beijing, 100048 (China); Shi, Kangjie [Institute of Modern Physics, Northwest University,Xian, 710069 (China); Wang, Yupeng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics,Chinese Academy of Sciences,Beijing, 100190 (China); Collaborative Innovation Center of Quantum Matter,Beijing (China)

    2015-10-21

    We consider the integrable open-chain transfer matrix corresponding to a Y=0 brane at one boundary, and a Y{sub θ}=0 brane (rotated with the respect to the former by an angle θ) at the other boundary. We determine the exact eigenvalues of this transfer matrix in terms of solutions of a corresponding set of Bethe equations.

  2. Distinct solutions of infinite U Hubbard model through nested Bethe ansatz and Gutzwiller projection operator approach

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A.K., E-mail: mishra@imsc.res.i [Insitituto Nacional de Pesquidas Espaciais - INPE, P.O. Box 103, CP 515, S. J. Campos, SP 12245-970 (Brazil); Kishore, R., E-mail: kishore@las.inpe.b [Insitituto Nacional de Pesquidas Espaciais - INPE, P.O. Box 103, CP 515, S. J. Campos, SP 12245-970 (Brazil)

    2009-10-15

    The exact nested Bethe ansatz solution for the one dimensional (1-D) U infinity Hubbard model show that the state vectors are a product of spin-less fermion and spin wavefunctions, or an appropriate superposition of such factorized wavefunctions. The spin-less fermion component of the wavefunctions ensures no double occupancy at any site. It had been demonstrated that the nested Bethe ansatz wavefunctions in the U infinity limit obey orthofermi statistics. Gutzwiller projection operator formalism is the another well known technique employed to handle U infinity Hubbard model. In general, this approach does not lead to spin-less fermion wavefunctions. Therefore, the nested Bethe ansatz and Gutzwiller projection operator approach give rise to different kinds of the wavefunctions for the U infinity limit of 1-D Hubbard Hamiltonian. To compare the consequences of this dissimilarity in the wavefunctions, we have obtained the ground state energy of a finite system consisting of three particles on a four site closed chain. It is shown that in the nested Bethe ansatz implemented through orthofermion algebra, all the permissible 2{sup 3} spin configurations are degenerate in the ground state. This eight fold degeneracy of the ground state is absent in the Gutzwiller projection operator approach. This finding becomes relevant in the context of known exact U infinity results, which require that all the energy levels are 2{sup N}-fold degenerate for an N particle system.

  3. Exact solutions of the spinor Bethe-Salpeter equation for tightly bound states

    NARCIS (Netherlands)

    Suttorp, L.G.

    1975-01-01

    Exact solutions are obtained for the spinor Bethe-Salpeter equation that describes tightly bound states of spin-/sup 1///sub 2/ fermions with massless-boson exchange. The corresponding coupling constants form a discrete spectrum that depends continuously on the parameters characterizing the type of

  4. Siloxanes: A new class of candidate Bethe-Zel’dovich-Thompson fluids

    NARCIS (Netherlands)

    Colonna, P.; Guardone, A.; Nannan, N.R.

    2007-01-01

    This paper presents a new class of Bethe-Zel’dovich-Thompson fluids, which are expected to exhibit nonclassical gasdynamic behavior in the single-phase vapor region. These are the linear and cyclic siloxanes, light silicon oils currently employed as working fluids in organic Rankine cycle turbines.

  5. The Spin Symmetry of Heavy Baryons in the Framework of the Bethe-Salpeter Equation

    Institute of Scientific and Technical Information of China (English)

    CUI Jian-Ying; JIN Hong-Ying; WU Ji-Min

    2001-01-01

    We study the baryons containing a heavy quark in the framework of Bethe-Salpeter (BS) equation. The most general forms of the BS wavefunctions are given. In the heavy-quark limit we simplify the BS equations and we show clearly that the spin symmetry exists in heavy baryon states.``

  6. Anisotropic generalization of Stinchcombe's solution for the conductivity of random resistor networks on a Bethe lattice

    Energy Technology Data Exchange (ETDEWEB)

    Semeriyanov, F; Saphiannikova, M; Heinrich, G [Leibniz Institute of Polymer Research Dresden, Hohe str. 6, 01069 Dresden (Germany)], E-mail: fsemeriyanov@yahoo.de

    2009-11-20

    Our study is based on the work of Stinchcombe (1974 J. Phys. C: Solid State Phys. 7 179) and is devoted to the calculations of average conductivity of random resistor networks placed on an anisotropic Bethe lattice. The structure of the Bethe lattice is assumed to represent the normal directions of the regular lattice. We calculate the anisotropic conductivity as an expansion in powers of the inverse coordination number of the Bethe lattice. The expansion terms retained deliver an accurate approximation of the conductivity at resistor concentrations above the percolation threshold. We make a comparison of our analytical results with those of Bernasconi (1974 Phys. Rev. B 9 4575) for the regular lattice.

  7. NRDA-processed CTD data from the Sarah Bordelon in the Gulf of Mexico, Cruise 7 Leg 1, collected from 2010-12-04 to 2010-12-19, associated with the Deepwater Horizon Oil Spill event (NCEI Accession 0130702)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Conductivity Temperature and Depth (CTD) measurements were collected aboard the M/V Sarah Bordelon, Cruise 07 to determine physical oceanographic parameters of the...

  8. A new integral representation for the scalar products of Bethe states for the XXX spin chain

    Science.gov (United States)

    Kazama, Yoichi; Komatsu, Shota; Nishimura, Takuya

    2013-09-01

    Based on the method of separation of variables due to Sklyanin, we construct a new integral representation for the scalar products of the Bethe states for the SU(2) XXX spin 1/2 chain obeying the periodic boundary condition. Due to the compactness of the symmetry group, a twist matrix must be introduced at the boundary in order to extract the separated variables properly. Then by deriving the integration measure and the spectrum of the separated variables, we express the inner product of an on-shell and an off-shell Bethe states in terms of a multiple contour integral involving a product of Baxter wave functions. Its form is reminiscent of the integral over the eigenvalues of a matrix model and is expected to be useful in studying the semi-classical limit of the product.

  9. Zero-Temperature Limit of a Convergent Algorithm to Minimize the Bethe Free Energy

    CERN Document Server

    Werner, Tomas

    2011-01-01

    After the discovery that fixed points of loopy belief propagation coincide with stationary points of the Bethe free energy, several researchers proposed provably convergent algorithms to directly minimize the Bethe free energy. These algorithms were formulated only for non-zero temperature (thus finding fixed points of the sum-product algorithm) and their possible extension to zero temperature is not obvious. We present the zero-temperature limit of the double-loop algorithm by Heskes, which converges a max-product fixed point. The inner loop of this algorithm is max-sum diffusion. Under certain conditions, the algorithm combines the complementary advantages of the max-product belief propagation and max-sum diffusion (LP relaxation): it yields good approximation of both ground states and max-marginals.

  10. Quantitative studies of the homogeneous Bethe-Salpeter Equation in Minkowski space

    CERN Document Server

    Frederico, Tobias; Viviani, Michele

    2013-01-01

    The Bethe-Salpeter Equation for a bound system, composed by two massive scalars exchanging a massive scalar, is quantitatively investigated in ladder approximation, within the Nakanishi integral representation approach. For the S-wave case, numerical solutions with a form inspired by the Nakanishi integral representation, have been calculated. The needed Nakanishi weight functions have been evaluated by solving two different eigenequations, obtained directly from the Bethe-Salpeter equation applying the Light-Front projection technique. A remarkable agreement, in particular for the eigenvalues, has been achieved, numerically confirming that the Nakanishi uniqueness theorem for the weight functions, demonstrated in the context of the perturbative analysis of the multi-leg transition amplitudes and playing a basic role in suggesting one of the two adopted eigenequations, can be extended to a non perturbative realm. The detailed, quantitative studies are completed by presenting both probabilities and Light-Front...

  11. Solving the inhomogeneous Bethe-Salpeter Equation in Minkowski space: the zero-energy limit

    CERN Document Server

    Frederico, T; Viviani, M

    2015-01-01

    For the first time, the inhomogeneous Bethe-Salpeter Equation for an interacting system, composed by two massive scalars exchanging a massive scalar, is numerically investigated in ladder approximation, directly in Minkowski space, by using an approach based on the Nakanishi integral representation. In this paper, the limiting case of zero-energy states is considered, extending the approach successfully applied to bound states presented in Phys. Rev. D 89, (2014) 016010, where the Nakanishi integral representation has been exploited for solving the homogeneous Bethe-Salpeter Equation. The numerical values of scattering lengths, evaluated by using two different integral equations that stem within the Nakanishi framework, are compared with the analogous quantities recently obtained, within a totally different framework. Moreover, relevant functions, like the Nakanishi weight functions and the distorted part of the zero-energy Light-front wave functions are also presented. Interestingly, a highly non trivial iss...

  12. Spectrum and Bethe-Salpeter amplitudes of $\\Omega$ baryons from lattice QCD

    CERN Document Server

    Liang, Jian; Chen, Ying; Chiu, Wei-Feng; Gong, Ming; Liu, Chuan; Liu, Yu-Bin; Liu, Zhaofeng; Ma, Jian-Ping; Zhang, Jian-Bo

    2015-01-01

    The $\\Omega$ baryons with $J^P=3/2^\\pm, 1/2^\\pm$ are studied on the lattice in the quenched approximation. Their mass levels are ordered as $M_{3/2^+}Bethe-Salpeter amplitudes of $\\Omega(3/2^+)$ and $\\Omega(1/2^+)$ and find there is a radial node for the $\\Omega(1/2^+)$ Bethe-Salpeter amplitude, which may imply that $\\Omega(1/2^+)$ is an orbital excitation of $\\Omega$ baryons as a member of the $(D,L_N^P)=(70,0_2^+)$ supermultiplet in the $SU(6)\\bigotimes O(3)$ quark model description. Our results are helpful for identifying the quantum number of experimentally observed $\\Omega$ states.

  13. Algebraic Bethe ansatz for the quantum group invariant open XXZ chain at roots of unity

    Science.gov (United States)

    Gainutdinov, Azat M.; Nepomechie, Rafael I.

    2016-08-01

    For generic values of q, all the eigenvectors of the transfer matrix of the Uq sl (2)-invariant open spin-1/2 XXZ chain with finite length N can be constructed using the algebraic Bethe ansatz (ABA) formalism of Sklyanin. However, when q is a root of unity (q =e iπ / p with integer p ≥ 2), the Bethe equations acquire continuous solutions, and the transfer matrix develops Jordan cells. Hence, there appear eigenvectors of two new types: eigenvectors corresponding to continuous solutions (exact complete p-strings), and generalized eigenvectors. We propose general ABA constructions for these two new types of eigenvectors. We present many explicit examples, and we construct complete sets of (generalized) eigenvectors for various values of p and N.

  14. Calculation of the relativistic Bethe logarithm in the two-center problem

    CERN Document Server

    Korobov, Vladimir I; Karr, Jean-Philippe

    2013-01-01

    We present a variational approach to evaluate relativistic corrections of order \\alpha^2 to the Bethe logarithm for the ground electronic state of the Coulomb two center problem. That allows to estimate the radiative contribution at m\\alpha^7 order in molecular-like three-body systems such as hydrogen molecular ions H_2^+ and HD^+, or antiprotonic helium atoms. While we get 10 significant digits for the nonrelativistic Bethe logarithm, calculation of the relativistic corrections is much more involved especially for small values of bond length R. We were able to achieve a level of 3-4 significant digits starting from R=0.2 bohr, that will allow to reach 10^{-10} relative uncertainty on transition frequencies.

  15. Calculation of the relativistic Bethe logarithm in the two-center problem

    Science.gov (United States)

    Korobov, Vladimir I.; Hilico, L.; Karr, J.-Ph.

    2013-06-01

    We present a variational approach to evaluate relativistic corrections of order α2 to the Bethe logarithm for the ground electronic state of the Coulomb two-center problem. That allows us to estimate the radiative contribution at mα7 order in molecular-like three-body systems such as hydrogen molecular ions H2+ and HD+ or antiprotonic helium atoms. While we get ten significant digits for the nonrelativistic Bethe logarithm, calculation of the relativistic corrections is much more involved, especially for small values of bond length R. We were able to achieve a level of three to four significant digits starting from R=0.2 bohr, which will allow us to reach 10-10 relative uncertainty on transition frequencies.

  16. ODE/IM correspondence and Bethe ansatz for affine Toda field equations

    CERN Document Server

    Ito, Katsushi

    2015-01-01

    We study the linear problem associated with modified affine Toda field equation for the Langlands dual $\\hat{\\mathfrak{g}}^\\vee$, where $\\hat{\\mathfrak{g}}$ is an untwisted affine Lie algebra. The connection coefficients for the asymptotic solutions of the linear problem correspond to the Q-functions for $\\mathfrak{g}$-type quantum integrable models. The $\\psi$-system for the solutions associated with the fundamental representations of $\\mathfrak{g}$ leads to Bethe ansatz equations associated with the affine Lie algebra $\\hat{\\mathfrak{g}}$. We also study the $A^{(2)}_{2r}$ affine Toda field equation in massless limit in detail and find its Bethe ansatz equations as well as T-Q relations.

  17. A new integral representation for the scalar products of Bethe states for the XXX spin chain

    CERN Document Server

    Kazama, Yoichi; Nishimura, Takuya

    2013-01-01

    Based on the method of separation of variables due to Sklyanin, we construct a new integral representation for the scalar products of the Bethe states for the SU(2) XXX spin 1/2 chain obeying the periodic boundary condition. Due to the compactness of the symmetry group, a twist matrix must be introduced at the boundary in order to extract the separated variables properly. Then by deriving the integration measure and the spectrum of the separated variables, we express the inner product of an on-shell and an off-shell Bethe states in terms of a multiple contour integral involving a product of Baxter wave functions. Its form is reminiscent of the integral over the eigenvalues of a matrix model and is expected to be useful in studying the semi-classical limit of the product.

  18. The Beer/Bethe/Uexküll paper (1899) and misinterpretations surrounding 'vitalistic behaviorism'.

    Science.gov (United States)

    Mildenberger, Florian

    2006-01-01

    In the history of behaviorism the paper of the three physiologists Theodor Beer, Albrecht Bethe and Jakob von Uexküll from 1899 plays an important role. Many researchers were influenced by this paper and identified it as fundamental for objective psychological research. But during the period of its adoption (1900-1925) psychologists did not notice that Beer, Bethe and Uexküll had distanced themselves from their own paper, because it had been ignored in physiological and biological discussions. Moreover, one of the three (Beer) had to resign from the scientific community because of private scandal and another one (Uexküll) changed all of his views and left the base of objective science for subjective vitalism. However, this did not change his adoption of behaviorism.

  19. Transition electromagnetic form factor and current conservation in the Bethe-Salpeter approach

    CERN Document Server

    Carbonell, J

    2015-01-01

    The transition form factor for electrodisintegration of a two-body bound system is calculated in the Bethe-Salpeter framework. For the initial (bound) and the final (scattering) states, we use our solutions of the Bethe-Salpeter equation in Minkowski space which were first obtained recently. The gauge invariance, which manifests itself in the conservation of the transition electromagnetic current Jq = 0, is studied numerically. It results from a cancellation between the plane wave and the final state interaction contributions. This cancellation takes place only if the initial bound state BS amplitude, the final scattering state and the operator of electromagnetic current are strictly consistent with each other, that is if they are found in the same dynamical framework. A reliable result for the transition form factor can be obtained in this case only.

  20. Solving Bethe-Salpeter equation for two fermions in Minkowski space

    CERN Document Server

    Carbonell, J

    2010-01-01

    The method of solving the Bethe-Salpeter equation in Minkowski space, which we developed previously for spinless particles, is extended to a system of two fermions. The method is based on the Nakanishi integral representation of the amplitude and on projecting the equation on the light-front plane. The singularities in the projected two-fermion kernel are regularized without modifying the original Bethe-Salpeter amplitudes. The numerical solutions for the J=0 bound state with the scalar, pseudoscalar and massless vector exchange kernels are found. The stability of the scalar and positronium states without vertex form factor is discussed. Binding energies are in close agreement with the Euclidean results. Corresponding amplitudes in Minkowski space are obtained.

  1. Current conservation in electrodisintegration of a bound system in the Bethe-Salpeter approach

    CERN Document Server

    Karmanov, V A

    2014-01-01

    Using our solutions of the Bethe-Salpeter equation with OBE kernel in Minkowski space both for the bound and scattering states, we calculate the transition form factors for electrodisintegration of the bound system which determine the electromagnetic current J of this process. Special emphasis is put on verifying the gauge invariance which should manifest itself in the current conservation. We find that for any value of the momentum transfer q the contributions of the plane wave and the final state interaction to the quantity J.q cancel each other thus providing J.q=0. However, this cancellation is obtained only if the initial Bethe-Salpeter amplitude (bound state), the final one (scattering state) and the current operator are strictly consistent with each other. A reliable result for the transition form factor can be found only in this case.

  2. ODE/IM correspondence and Bethe ansatz for affine Toda field equations

    Directory of Open Access Journals (Sweden)

    Katsushi Ito

    2015-07-01

    Full Text Available We study the linear problem associated with modified affine Toda field equation for the Langlands dual gˆ∨, where gˆ is an untwisted affine Lie algebra. The connection coefficients for the asymptotic solutions of the linear problem are found to correspond to the Q-functions for g-type quantum integrable models. The ψ-system for the solutions associated with the fundamental representations of g leads to Bethe ansatz equations associated with the affine Lie algebra gˆ. We also study the A2r(2 affine Toda field equation in massless limit in detail and find its Bethe ansatz equations as well as T–Q relations.

  3. Algebraic Bethe ansatz for the quantum group invariant open XXZ chain at roots of unity

    CERN Document Server

    Gainutdinov, Azat M

    2016-01-01

    For generic values of q, all the eigenvectors of the transfer matrix of the U_q sl(2)-invariant open spin-1/2 XXZ chain with finite length N can be constructed using the algebraic Bethe ansatz (ABA) formalism of Sklyanin. However, when q is a root of unity (q=exp(i pi/p) with integer p>1), the Bethe equations acquire continuous solutions, and the transfer matrix develops Jordan cells. Hence, there appear eigenvectors of two new types: eigenvectors corresponding to continuous solutions (exact complete p-strings), and generalized eigenvectors. We propose general ABA constructions for these two new types of eigenvectors. We present many explicit examples, and we construct complete sets of (generalized) eigenvectors for various values of p and N.

  4. Correlation functions of the spin chains. Algebraic Bethe Ansatz approach; Fonctions de correlation des chaines de spin. Approche de l'ansatz de Bethe algebrique

    Energy Technology Data Exchange (ETDEWEB)

    Kitanine, N

    2007-09-15

    Spin chains are the basic elements of integrable quantum models. These models have direct applications in condense matter theory, in statistical physics, in quantum optics, in field theory and even in string theory but they are also important because they enable us to solve, in an exact manner, non-perturbative phenomena that otherwise would stay unresolved. The method described in this work is based on the algebraic Bethe Ansatz. It is shown how this method can be used for the computation of null temperature correlation functions of the Heisenberg 1/2 spin chain. The important point of this approach is the solution of the inverse quantum problem given by the XXZ spin chain. This solution as well as a simple formulae for the scalar product of the Bethe states, have enabled us to get the most basic correlation functions under the form of multiple integrals. The formalism of multiple integrals open the way for asymptotic analysis for a few physical quantities like the probability of vacuum formation. It is worth noticing that this formalism can give exact results for two-point functions that are the most important correlation functions for applications. A relationship has been discovered between these multiple integrals and the sum of the form factors. The results have been extended to dynamical correlation functions. (A.C.)

  5. Numerical Studies of the Zero-Energy Bethe-Salpeter Equation in Minkowski Space

    Science.gov (United States)

    Viviani, Michele; Frederico, Tobias; Salmè, Giovanni

    2015-09-01

    The inhomogeneous Bethe-Salpeter equation describing the zero-energy scattering of a system composed by two massive scalars exchanging a massive scalar is numerically investigated in ladder approximation, directly in Minkowski space. The solution is obtained by using the Nakanishi integral representation, as performed in Frederico et al. (Phys Rev D 89:016010, 2014) where the method was successfully applied to bound states. The scattering lengths are quantitatively investigated and the results compared with the corresponding ones present in literature.

  6. An exact solution on the ferromagnetic Face-Cubic spin model on a Bethe lattice

    OpenAIRE

    Ohanyan, V. R.; Ananikyan, L. N.; Ananikian, N. S.

    2006-01-01

    The lattice spin model with $Q$--component discrete spin variables restricted to have orientations orthogonal to the faces of $Q$-dimensional hypercube is considered on the Bethe lattice, the recursive graph which contains no cycles. The partition function of the model with dipole--dipole and quadrupole--quadrupole interaction for arbitrary planar graph is presented in terms of double graph expansions. The latter is calculated exactly in case of trees. The system of two recurrent relations wh...

  7. Generalized Coordinate Bethe Ansatz for open spin chains with non-diagonal boundaries

    CERN Document Server

    Ragoucy, E

    2011-01-01

    We introduce a generalization of the original Coordinate Bethe Ansatz that allows to treat the case of open spin chains with non-diagonal boundary matrices. We illustrate it on two cases: the XXX and XXZ chains. Short review on a joint work with N. Crampe (L2C) and D. Simon (LPMA), see arXiv:1009.4119, arXiv:1105.4119 and arXiv:1106.3264.

  8. Solutions of Bethe-Salpeter and Light-Front equations with cross-ladder kernel

    CERN Document Server

    Carbonell, J

    2005-01-01

    By method developed in our previous paper we solve the Bethe-Salpeter (BS) equation for the kernel given by sum of ladder and cross-ladder exchanges. We solve also corresponding equation in light-front dynamics (LFD), where we add the time-ordered stretched boxes. Cross-ladder contribution is large and attractive, whereas the influence of stretched boxes is negligible. Both approaches -- BS and LFD -- give very close results.

  9. The Potts Model on a Bethe Lattice in an External Field

    Science.gov (United States)

    Semkin, S. V.; Smagin, V. P.

    2017-02-01

    A solution for the Potts model with arbitrary number of states on a Bethe lattice in a nonzero external field has been obtained. A line of first-order phase transitions has been constructed in the temperature - external-field plane, terminating at the point of the second-order phase transition. The magnitude of the magnetization jump on the phase-transition lines has been found, as well as some of the critical exponents characterizing this phase transition.

  10. Calculation of Spin Observables for Proton-Proton Elastic Scattering in the Bethe-Salpeter Equation

    CERN Document Server

    Kinpara, Susumu

    2015-01-01

    Bethe-Salpeter equation is applied to $p$-$p$ elastic scattering. The observables of spin are calculated in the framework of the M matrix using the two-body interaction potential. The parameter of the pseudovector coupling constant is adjusted so as to reproduce the spin singlet part. It is shown that the spin rotation $R(\\theta)$ and $A(\\theta)$ are improved by the resonance effect for ${}^{\\rm 1}S_{\\rm 0}$.

  11. The gendered embodiment of shame: Intersections of acquaintance rape, trauma and self-blame in Pompidou posse by Sarah Lotz

    Directory of Open Access Journals (Sweden)

    Jessica Murray

    2014-08-01

    Full Text Available This article offers a feminist literary analysis of the gendered embodiment of shame in Pompidou posse by Sarah Lotz. In this novel, Lotz depicts female characters who are sexually assaulted by acquaintances and the resultant shame and trauma reside in their bodies. I will demonstrate that the embodied shame of these characters is distinctly gendered and that this shapes their attempts to cope with the aftermath of the sexual assaults. A close reading of the text reveals that the characters are exposed to overwhelming social messages of female culpability in a larger context that is rife with misogyny. As a result, they anticipate blame to such an extent that they blame themselves and internalise this blame as shame. By focusing on the bodies of the survivors, Lotz demonstrates the embodiment of shame, but she also suggests a corporeal challenge to silencing. The bodies of these characters speak loudly, albeit sometimes in the halting language of trauma, and they function to alert them to danger, to help them excavate memories that are made inaccessible and to testify to traumatic sexual assault.

  12. Ludwik Gross, Sarah Stewart, and the 1950s discoveries of Gross murine leukemia virus and polyoma virus.

    Science.gov (United States)

    Morgan, Gregory J

    2014-12-01

    The Polish-American scientist Ludwik Gross made two important discoveries in the early 1950s. He showed that two viruses - murine leukemia virus and parotid tumor virus - could cause cancer when they were injected into susceptible animals. At first, Gross's discoveries were greeted with skepticism: it seemed implausible that viruses could cause a disease as complex as cancer. Inspired by Gross's initial experiments, similar results were obtained by Sarah Stewart and Bernice Eddy who later renamed the parotid tumor virus SE polyoma virus after finding it could cause many different types of tumors in mice, hamsters, and rats. Eventually the "SE" was dropped and virologists adopted the name "polyoma virus." After Gross's work was published, additional viruses capable of causing solid tumors or blood-borne tumors in mice were described by Arnold Graffi, Charlotte Friend, John Moloney and others. By 1961, sufficient data had been accumulated for Gross to confidently publish an extensive monograph--Oncogenic Viruses--the first history of tumor virology, which became a standard reference work and marked the emergence of tumor virology as a distinct, legitimate field of study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Symmetry preserving truncations of the gap and Bethe-Salpeter equations

    Energy Technology Data Exchange (ETDEWEB)

    Binosi, Daniele; Chang, Lei; Papavassiliou, Joannis; Qin, Si-Xue; Roberts, Craig D.

    2016-05-01

    Ward-Green-Takahashi (WGT) identities play a crucial role in hadron physics, e.g. imposing stringent relationships between the kernels of the one-and two-body problems, which must be preserved in any veracious treatment of mesons as bound states. In this connection, one may view the dressed gluon-quark vertex, Gamma(alpha)(mu), as fundamental. We use a novel representation of Gamma(alpha)(mu), in terms of the gluon-quark scattering matrix, to develop a method capable of elucidating the unique quark-antiquark Bethe-Salpeter kernel, K, that is symmetry consistent with a given quark gap equation. A strength of the scheme is its ability to expose and capitalize on graphic symmetries within the kernels. This is displayed in an analysis that reveals the origin of H-diagrams in K, which are two-particle-irreducible contributions, generated as two-loop diagrams involving the three-gluon vertex, that cannot be absorbed as a dressing of Gamma(alpha)(mu) in a Bethe-Salpeter kernel nor expressed as a member of the class of crossed-box diagrams. Thus, there are no general circumstances under which the WGT identities essential for a valid description of mesons can be preserved by a Bethe-Salpeter kernel obtained simply by dressing both gluon-quark vertices in a ladderlike truncation; and, moreover, adding any number of similarly dressed crossed-box diagrams cannot improve the situation.

  14. A Generalized Uhlenbeck and Beth Formula for the Third Cluster Coefficient

    CERN Document Server

    Larsen, Sigurd Yves; Amaya-Tapia, Alejandro

    2016-01-01

    Relatively recently (A. Amaya-Tapia, S. Y. Larsen and M. Lassaut. Ann. Phys., vol. 306 (2011) 406), we presented a formula for the evaluation of the third Bose fugacity coefficient - leading to the third virial coefficient - in terms of three-body eigenphase shifts, for particles subject to repulsive forces. An analytical calculation for a 1-dim. model, for which the result is known, confirmed the validity of this approach. We now extend the formalism to particles with attractive forces, and therefore must allow for the possibility that the particles have bound states. We thus obtain a true generalization of the famous formula of Uhlenbeck and Beth (G.E. Uhlenbeck and E. Beth. Physica, vol. 3 (1936) 729; E. Beth and G.E. Uhlenbeck. ibid, vol.4 (1937) 915) (and of Gropper (L. Gropper. Phys. Rev. vol. 50 (1936) 963; ibid vol. 51 (1937) 1108)) for the second virial. We illustrate our formalism by a calculation, in an adiabatic approximation, of the third cluster in one dimension, using McGuire's model as in our ...

  15. Advances in solving the two-fermion homogeneous Bethe-Salpeter equation in Minkowski space

    CERN Document Server

    de Paula, W; Salmè, G; Viviani, M

    2016-01-01

    Actual solutions of the Bethe-Salpeter equation for a two-fermion bound system are becoming available directly in Minkowski space, by virtue of a novel technique, based on the so-called Nakanishi integral representation of the Bethe-Salpeter amplitude and improved by expressing the relevant momenta through light-front components, i.e. $k^\\pm=k^0 \\pm k^3$. We solve a crucial problem that widens the applicability of the method to real situations by providing an analytically exact treatment of the singularities plaguing the two-fermion problem in Minkowski space, irrespective of the complexity of the irreducible Bethe-Salpeter kernel. This paves the way for feasible numerical investigations of relativistic composite systems, with any spin degrees of freedom. We present a thorough comparison with existing numerical results, evaluated in both Minkowski and Euclidean space, fully corroborating our analytical treatment, as well as fresh light-front amplitudes illustrating the potentiality of non perturbative calcula...

  16. A generalized Uhlenbeck and Beth formula for the third cluster coefficient

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Sigurd Yves [Department of Physics, Temple University, Philadelphia, PA 19122 (United States); Lassaut, Monique [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, F-91406 Orsay Cedex (France); Amaya-Tapia, Alejandro, E-mail: jano@icf.unam.mx [Instituto de Ciencias Fi ´sicas, Universidad Nacional Autónoma de México, AP 48-3, Cuernavaca, Mor. 62251 (Mexico)

    2016-11-15

    Relatively recently (Amaya-Tapia et al., 2011), we presented a formula for the evaluation of the third Bose fugacity coefficient–leading to the third virial coefficient–in terms of three-body eigenphase shifts, for particles subject to repulsive forces. An analytical calculation for a 1-dim. model, for which the result is known, confirmed the validity of this approach. We now extend the formalism to particles with attractive forces, and therefore must allow for the possibility that the particles have bound states. We thus obtain a true generalization of the famous formula of Uhlenbeck and Beth (Uhlenbeck and Beth, 1936; Beth and Uhlenbeck, 1937) and of Gropper (Gropper, 1936, 1937) for the second virial. We illustrate our formalism by a calculation, in an adiabatic approximation, of the third cluster in one dimension, using McGuire’s model as in our previous paper, but with attractive forces. The inclusion of three-body bound states is trivial; taking into account states having asymptotically two particles bound, and one free, is not.

  17. Symmetry preserving truncations of the gap and Bethe-Salpeter equations

    Science.gov (United States)

    Binosi, Daniele; Chang, Lei; Papavassiliou, Joannis; Qin, Si-Xue; Roberts, Craig D.

    2016-05-01

    Ward-Green-Takahashi (WGT) identities play a crucial role in hadron physics, e.g. imposing stringent relationships between the kernels of the one- and two-body problems, which must be preserved in any veracious treatment of mesons as bound states. In this connection, one may view the dressed gluon-quark vertex, Γμa , as fundamental. We use a novel representation of Γμa , in terms of the gluon-quark scattering matrix, to develop a method capable of elucidating the unique quark-antiquark Bethe-Salpeter kernel, K , that is symmetry consistent with a given quark gap equation. A strength of the scheme is its ability to expose and capitalize on graphic symmetries within the kernels. This is displayed in an analysis that reveals the origin of H -diagrams in K , which are two-particle-irreducible contributions, generated as two-loop diagrams involving the three-gluon vertex, that cannot be absorbed as a dressing of Γμa in a Bethe-Salpeter kernel nor expressed as a member of the class of crossed-box diagrams. Thus, there are no general circumstances under which the WGT identities essential for a valid description of mesons can be preserved by a Bethe-Salpeter kernel obtained simply by dressing both gluon-quark vertices in a ladderlike truncation; and, moreover, adding any number of similarly dressed crossed-box diagrams cannot improve the situation.

  18. Gluon bound state and asymptotic freedom derived from the Bethe--Salpeter equation

    CERN Document Server

    Fukamachi, Hitoshi; Nishino, Shogo; Shinohara, Toru

    2016-01-01

    In this paper we study the two-body bound states for gluons and ghosts in a massive Yang-Mills theory which is obtained by generalizing the ordinary massless Yang-Mills theory in a manifestly Lorentz covariant gauge. First, we give a systematic derivation of the coupled Bethe-Salpeter equations for gluons and ghosts by using the Cornwall-Jackiw-Tomboulis effective action of the composite operators within the framework of the path integral quantization. Then, we obtain the numerical solutions for the Bethe-Salpeter amplitude representing the simultaneous bound states of gluons and ghosts by solving the homogeneous Bethe-Salpeter equation in the ladder approximation. We study how the inclusion of ghosts affects the two-gluon bound states in the cases of the standing and running gauge coupling constant. Moreover, we show explicitly that the approximate solutions obtained for the gluon-gluon amplitude are consistent with the ultraviolet asymptotic freedom signaled by the negative $\\beta$ function.

  19. Scalar products of Bethe vectors in models with {\\mathfrak{gl}}(2| 1) symmetry 1. Super-analog of Reshetikhin formula

    Science.gov (United States)

    Hutsalyuk, A.; Liashyk, A.; Pakuliak, S. Z.; Ragoucy, E.; Slavnov, N. A.

    2016-11-01

    We study the scalar products of Bethe vectors in integrable models solvable by the nested algebraic Bethe ansatz and possessing {gl}(2| 1) symmetry. Using explicit formulas of the monodromy matrix entries’ multiple actions onto Bethe vectors we obtain a representation for the scalar product in the most general case. This explicit representation appears to be a sum over partitions of the Bethe parameters. It can be used for the analysis of scalar products involving on-shell Bethe vectors. As a by-product, we obtain a determinant representation for the scalar products of generic Bethe vectors in integrable models with {gl}(1| 1) symmetry. Dedicated to the memory of Petr Petrovich Kulish.

  20. The election of Sarah McNutt as the first woman member of the American Neurological Association.

    Science.gov (United States)

    Horn, Stacy S; Goetz, Christopher G

    2002-07-09

    The authors investigated the early women physicians of the New York Infirmary for Women and Children and their role in shaping the career and accomplishments of their student and later colleague, Dr. Sarah J. McNutt. These influences eventually led McNutt to be inducted into the American Neurologic Association (ANA). McNutt was educated at the New York Infirmary for Women and Children by early women physicians including Drs. Elizabeth and Emily Blackwell and Mary Putnam Jacobi. McNutt worked to improve the educational opportunities for practicing physicians and nurses by developing postgraduate lectures and organizations. With her early colleagues she developed the New York Infirmary for Women and Children into a reputable hospital and woman's medical college. One of the consultants to the New York Infirmary for Women and Children was Royal W. Amidon, secretary of the ANA in 1883. McNutt's close association with the Clinical Society of the New York Post Graduate Medical School and Hospital brought her into direct contact with other prominent ANA members including C.L. Dana and W.A. Hammond. In 1884, McNutt was nominated by Amidon and Hammond as the first woman member to the ANA and was elected. Her ANA thesis was Double Infantile Spastic Hemiplegia. McNutt was elected into the ANA at a time when women physicians were first being recognized and included into mainstream medicine. Her historic election acknowledged her accomplishments and highlighted the proactive role of the early ANA in forging new medical policies in the United States.

  1. Bethe Ansatz solution of the small polaron with nondiagonal boundary terms

    CERN Document Server

    Karaiskos, Nikos; Frahm, Holger

    2013-01-01

    The small polaron with generic, nondiagonal boundary terms is investigated within the framework of quantum integrability. The eigenvalues of the model are extracted by using the fusion hierarchy of the transfer matrices and the corresponding Bethe Ansatz equations are presented. For particular values of the anisotropy parameter the fusion hierarchy truncates, giving rise to a set of functional relations for the transfer matrix. Exploiting the latter ones, the same set of eigenvalues is rederived, confirming our results. Finally, we comment on the eigenvectors of the model and explicitly compute the state with all sites unoccupied for arbitrary chain lengths.

  2. Delta and Omega electromagnetic form factors in a Dyson-Schwinger/Bethe-Salpeter approach

    Energy Technology Data Exchange (ETDEWEB)

    Diana Nicmorus, Gernot Eichmann, Reinhard Alkofer

    2010-12-01

    We investigate the electromagnetic form factors of the Delta and the Omega baryons within the Poincare-covariant framework of Dyson-Schwinger and Bethe-Salpeter equations. The three-quark core contributions of the form factors are evaluated by employing a quark-diquark approximation. We use a consistent setup for the quark-gluon dressing, the quark-quark bound-state kernel and the quark-photon interaction. Our predictions for the multipole form factors are compatible with available experimental data and quark-model estimates. The current-quark mass evolution of the static electromagnetic properties agrees with results provided by lattice calculations.

  3. Nested Bethe Ansatz for Spin Ladder Model with Open Boundary Conditions

    Institute of Scientific and Technical Information of China (English)

    WU Jun-Fang; ZHANG Chun-Min; YUE Rui-Hong; LI Run-Ling

    2005-01-01

    The nested Bethe ansatz (BA) method is applied to find the eigenvalues and the eigenvectors of the transfer matrix for spin-ladder model with open boundary conditions. Based on the reflection equation, we find the general diagonal solution, which determines the generalboundary interaction in the Hamiltonian. We introduce the spin-ladder model with open boundary conditions. By finding the solution K± of the reflection equation which determines the nontrivial boundary terms in the Hamiltonian, we diagonalize the transfer matrix of the spin-ladder model with open boundary conditions in the framework of nested BA.

  4. Instantaneous Bethe-Salpeter Equation and Its Analog: Breit-like Equation

    Institute of Scientific and Technical Information of China (English)

    CHANG Chao-Hsi; CHEN Jiao-Kai

    2005-01-01

    We take the (μ士e干) system as an example, but restrict ourselves to highlight the states with quantum number JP = 0-, to explore the different contents of the instantaneous Bethe-Salpeter (BS) equation and its analog,the relativistic version of Breit equation, by solving them exactly. The results show that the two equations are not equivalent, although they are analogous. Furthermore, since the Breit equation contains extra un-physical solutions,so we point out that it should be abandoned if one wishes to have an accurate description of the bound states for the instantaneous interacting binding systems.

  5. Inner products of Bethe states as partial domain wall partition functions

    CERN Document Server

    Kostov, Ivan

    2012-01-01

    We study the inner product of Bethe states in the inhomogeneous periodic XXX spin-1/2 chain of length L, which is given by the Slavnov determinant formula. We show that the inner product of an on-shell M-magnon state with a generic M-magnon state is given by the same expression as the inner product of a 2M-magnon state with a vacuum descendent. The second inner product is proportional to the partition function of the six-vertex model on a rectangular Lx2M grid, with partial domain-wall boundary conditions.

  6. Electromagnetic form factor via Bethe-Salpeter amplitude in Minkowski space

    CERN Document Server

    Carbonell, J; Mangin-Brinet, M

    2008-01-01

    For a relativistic system of two scalar particles, we find the Bethe-Salpeter amplitude in Minkowski space and use it to compute the electromagnetic form factor. The comparison with Euclidean space calculation shows that the Wick rotation in the form factor integral induces errors which increase with the momentum transfer Q^2. At JLab domain (Q^2=10 GeV^2/c^2), they are about 30%. Static approximation results in an additional and more significant error. On the contrary, the form factor calculated in light-front dynamics is almost indistinguishable from the Minkowski space one.

  7. Solution of the Bethe-Salpeter equation in Minkowski space for a two fermion system

    CERN Document Server

    Carbonell, J

    2010-01-01

    The method of solving the Bethe-Salpeter equation in Minkowski space, developed previously for spinless particles, is extended to a system of two fermions. The method is based on the Nakanishi integral representation of the amplitude and on projecting the equation on the light-front plane. The singularities in the projected two-fermion kernel are regularized without modifying the original BS amplitudes. The numerical solutions for the J=0 bound state with the scalar, pseudoscalar and massless vector exchange kernels are found. Binding energies are in close agreement with the Euclidean results. Corresponding amplitudes in Minkowski space are obtained.

  8. Isothermal vs. isentropic description of protoneutron stars in the Brueckner-Bethe-Goldstone theory

    CERN Document Server

    Burgio, G F

    2009-01-01

    We study the structure of hadronic protoneutron stars within the finite temperature Brueckner-Bethe-Goldstone theoretical approach. Assuming beta-equilibrated nuclear matter with nucleons and leptons in the stellar core, with isothermal or isentropic profile, we show that particle populations and equation of state are very similar. As far as the maximum mass is concerned, we find that its value turns out to be almost independent on T, while a slight decrease is observed in the isentropic case, due to the enhanced proton fraction in the high density range.

  9. Study of BB ¯*/DD ¯* bound states in a Bethe-Salpeter approach

    Science.gov (United States)

    He, Jun

    2014-10-01

    In this work the BB ¯*/DD ¯* system is studied in the Bethe-Salpeter approach with quasipotential approximation. In our calculation both direct and cross diagrams are included in the one-boson-exchange potential. The numerical results indicate the existence of an isoscalar bound state DD ¯* with JPC=1++, which may be related to the X(3872). In the isovector sector, no bound state is produced from the interactions of DD ¯* and BB ¯*, which suggests the molecular state explanations for Zb(10610) and Zc(3900) are excluded.

  10. Speeding up the solution of the Bethe-Salpeter equation by a double-grid method and Wannier interpolation

    Science.gov (United States)

    Kammerlander, David; Botti, Silvana; Marques, Miguel A. L.; Marini, Andrea; Attaccalite, Claudio

    2012-09-01

    The Bethe-Salpeter equation is a widely used approach to describe optical excitations in bulk semiconductors. It leads to spectra that are in very good agreement with experiment, but the price to pay for such accuracy is a very high computational burden. One of the main bottlenecks is the large number of k points required to obtain converged spectra. In order to circumvent this problem we propose a strategy to solve the Bethe-Salpeter equation based on a double-grid technique coupled to a Wannier interpolation of the Kohn-Sham band structure. This strategy is then benchmarked for a particularly difficult case, the calculation of the absorption spectrum of GaAs, and for the well-studied case of Si. The considerable gains observed in these cases fully validate our approach, and open the way for the application of the Bethe-Salpeter equation to large and complex systems.

  11. Exact satisfiability threshold for k -satisfiability problems on a Bethe lattice

    Science.gov (United States)

    Krishnamurthy, Supriya; Sumedha

    2015-10-01

    The satisfiability threshold for constraint satisfaction problems is that value of the ratio of constraints (or clauses) to variables, above which the probability that a random instance of the problem has a solution is zero in the large system limit. Two different approaches to obtaining this threshold have been discussed in the literature: using first or second moment methods which give rigorous bounds or using the nonrigorous but powerful replica-symmetry-breaking (RSB) approach, which gives very accurate predictions on random graphs. In this paper, we lay out a different route to obtaining this threshold on a Bethe lattice. We need make no assumptions about the solution-space structure, a key assumption in the RSB approach. Despite this, our expressions and threshold values exactly match the best predictions of the cavity method under the one-step RSB hypothesis. In addition we can use the same procedure to obtain other useful quantities on the Bethe lattice such as the second moment of the number of solutions. Our method hence provides alternate interpretations as well as motivations for the key equations in the RSB approach.

  12. Semi-classical analysis of the inner product of Bethe states

    CERN Document Server

    Bettelheim, Eldad

    2014-01-01

    We study the inner product of two Bethe states, one of which is taken on-shell, in an inhomogeneous XXX chain in the Sutherland limit, where the number of magnons is comparable with the length L of the chain and the magnon rapidities arrange in a small number of macroscopically large Bethe strings. The leading order in the large L limit is known to be expressed through a contour integral of a dilogarithm. Here we derive the subleading term. Our analysis is based on a new contour-integral representation of the inner product in terms of a Fredholm determinant. We give two derivations of the sub-leading term. Besides a direct derivation by solving a Riemann-Hilbert problem, we give a less rigorous, but more intuitive derivation by field-theoretical methods. For that we represent the Fredholm determinant as an expectation value in a Fock space of chiral fermions and then bosonize. We construct a collective field for the bosonized theory, the short wave-length part of which may be evaluated exactly, while the long...

  13. Solution to Bethe-Salpeter equation via Mellin-Barnes transform

    CERN Document Server

    Allendes, Pedro; Kondrashuk, Igor; Cuello, Eduardo A Notte; Medar, Marko Rojas

    2012-01-01

    We consider Mellin-Barnes transform of triangle ladder-like scalar diagram in d=4 dimensions. It is shown how multi-fold MB transform of the momentum integral corresponding to any number of rungs is reduced to two-fold MB transform. For this purpose we use Belokurov-Usyukina reduction method for four-dimensional scalar integrals in the position space. The result is represented in terms of Euler psi-function and its derivatives. We derive new formulas for MB two-fold integration in the complex planes of two complex variables. We demonstrate that these formulas solve Bethe-Salpeter equation. We comment on further applications of solution to Bethe-Salpeter equation for vertices in N=4 supersymmetric Yang-Mills theory. We show that the recursive property of MB transforms observed in the present work for that kind of diagrams has nothing to do with quantum field theory, theory of integral transforms, or with theory of polylogarithms in general, but has an origin in a simple recursive property for smooth functions ...

  14. Ground State Mass Spectrum for Scalar Diquarks with Bethe-Salpeter Equation

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-Gang; WAN Shao-Long; YANG Wei-Min

    2007-01-01

    In this article,we study the structures of the pseudoscalar mesons π,K and the scalar diquarks Ua,Da,Sa in the framework of the coupled rainbow Schwinger-Dyson equation and ladder Bethe-Salpeter equation with the confining effective potential.The u,d,s quarks have small current masses,and the renormalization is very large,the mass poles in the timelike region are absent which implements confinement naturally.The Bethe-Salpeter wavefunctions of the pseudoscalar mesons π,K,and the scalar diquarks Ua,Da,Sa have the same type (Gaussian type) momentum dependence,center around zero momentum and extend to the energy scale about q2 = 1 GeV2,which happens to be the energy scale for the chiral symmetry breaking,the strong interactions in the infrared region result in bound (or quasi-bound) states.The numerical results for the masses and decay constants of the π and K mesons can reproduce the experimental values,and the ground state masses of the scalar diquarks Ua,Da,Sa are consistent with the existing theoretical calculations.We suggest a new Lagrangian which may explain the uncertainty of the masses of the scalar diquarks.

  15. "Generalized" algebraic Bethe ansatz, Gaudin-type models and Zp-graded classical r-matrices

    Science.gov (United States)

    Skrypnyk, T.

    2016-12-01

    We consider quantum integrable systems associated with reductive Lie algebra gl (n) and Cartan-invariant non-skew-symmetric classical r-matrices. We show that under certain restrictions on the form of classical r-matrices "nested" or "hierarchical" Bethe ansatz usually based on a chain of subalgebras gl (n) ⊃ gl (n - 1) ⊃ . . . ⊃ gl (1) is generalized onto the other chains or "hierarchies" of subalgebras. We show that among the r-matrices satisfying such the restrictions there are "twisted" or Zp-graded non-skew-symmetric classical r-matrices. We consider in detail example of the generalized Gaudin models with and without external magnetic field associated with Zp-graded non-skew-symmetric classical r-matrices and find the spectrum of the corresponding Gaudin-type hamiltonians using nested Bethe ansatz scheme and a chain of subalgebras gl (n) ⊃ gl (n -n1) ⊃ gl (n -n1 -n2) ⊃ gl (n - (n1 + . . . +np-1)), where n1 +n2 + . . . +np = n.

  16. The single-particle density matrix of a quantum bright soliton from the coordinate Bethe ansatz

    Science.gov (United States)

    Ayet, Alex; Brand, Joachim

    2017-02-01

    We present a novel approach for computing reduced density matrices for superpositions of eigenstates of a Bethe-ansatz solvable model by direct integration of the wave function in coordinate representation. A diagrammatic approach is developed to keep track of relevant terms and identify symmetries, which helps to reduce the number of terms that have to be evaluated numerically. As a first application we compute with modest numerical resources the single-particle density matrix and its eigenvalues including the condensate fraction for a quantum bright soliton with up to N  =  10 bosons. The latter are constructed as superpositions of string-type Bethe-ansatz eigenstates of nonrelativistic bosons in one spatial dimension with attractive contact interaction. Upon delocalising the superposition in momentum space we find that the condensate fraction reaches maximum values larger than 97% with weak particle-number dependence in the range of particles studied. The presented approach is suitable for studying time-dependent problems and generalises to higher-order correlation functions.

  17. Symmetry preserving truncations of the gap and Bethe-Salpeter equations

    CERN Document Server

    Binosi, Daniele; Papavassiliou, Joannis; Qin, Si-Xue; Roberts, Craig D

    2016-01-01

    Ward-Green-Takahashi (WGT) identities play a crucial role in hadron physics, e.g. imposing stringent relationships between the kernels of the one- and two-body problems, which must be preserved in any veracious treatment of mesons as bound-states. In this connection, one may view the dressed gluon-quark vertex, $\\Gamma_\\mu^a$, as fundamental. We use a novel representation of $\\Gamma_\\mu^a$, in terms of the gluon-quark scattering matrix, to develop a method capable of elucidating the unique quark-antiquark Bethe-Salpeter kernel, $K$, that is symmetry-consistent with a given quark gap equation. A strength of the scheme is its ability to expose and capitalise on graphic symmetries within the kernels. This is displayed in an analysis that reveals the origin of $H$-diagrams in $K$, which are two-particle-irreducible contributions, generated as two-loop diagrams involving the three-gluon vertex, that cannot be absorbed as a dressing of $\\Gamma_\\mu^a$ in a Bethe-Salpeter kernel nor expressed as a member of the class...

  18. Counting in Graph Covers: A Combinatorial Characterization of the Bethe Entropy Function

    CERN Document Server

    Vontobel, Pascal O

    2010-01-01

    We present a \\emph{combinatorial} characterization of the Bethe entropy function of a factor graph, such a characterization being in contrast to the original, \\emph{analytical}, definition of this function. We achieve this combinatorial characterization by counting valid configurations in finite graph covers of the factor graph. Analogously, we give a \\emph{combinatorial} characterization of the Bethe partition function, whose original definition was also of an \\emph{analytical} nature. As we point out, our approach has similarities to the replica method, but also stark differences. The above findings are a natural backdrop for introducing a decoder for graph-based codes that we will call the symbolwise graph-cover decoder, a decoder that extends our earlier work on blockwise graph-cover decoding. Both graph-cover decoders are theoretical tools that help towards a better understanding of message-passing iterative decoding, namely blockwise graph-cover decoding links max-product (min-sum) algorithm decoding wi...

  19. Solution to Bethe-Salpeter equation via Mellin-Barnes transform

    Energy Technology Data Exchange (ETDEWEB)

    Allendes, Pedro [Concepcion Univ. (Chile). Dept. de Fisica; Kniehl, Bernd [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Kondrashuk, Igor; Rojas Medar, Marko [Univ. del Bio-Bio, Chillan (Chile). Dept. de Ciencias Basicas; Notte Cuello, Eduardo A. [Univ. de La Serena (Chile). Facultad de Ciencias

    2012-06-15

    We consider Mellin-Barnes transform of triangle ladder-like scalar diagram in d=4 dimensions. It is shown how multi-fold MB transform of the momentum integral corresponding to any number of rungs is reduced to two-fold MB transform. For this purpose we use Belokurov-Usyukina reduction method for four-dimensional scalar integrals in the position space. The result is represented in terms of Euler {psi}-function and its derivatives. We derive new formulas for MB two-fold integration in the complex planes of two complex variables. We demonstrate that these formulas solve Bethe-Salpeter equation. We comment on further applications of solution to Bethe-Salpeter equation for vertices in N=4 supersymmetric Yang-Mills theory. We show that the recursive property of MB transforms observed in the present work for that kind of diagrams has nothing to do with quantum field theory, theory of integral transforms, or with theory of polylogarithms in general, but has an origin in a simple recursive property for smooth functions which can be shown by using basic methods of mathematical analysis.

  20. A Novel Algorithm for Extracting the Parton Distribution Amplitude from the Euclidean Bethe-Salpeter Wave Function

    CERN Document Server

    Gao, Fei; Liu, Yu-xin

    2016-01-01

    We propose a new numerical method to compute parton distribution amplitude(PDA) from the Euclidean Bethe-Salpeter wave function. The essential step is to extract the weight function in the Nakanishi representation of the Bethe-Salpeter wave function in Euclidean space, which is an ill-posed inversion problem, via the maximum entropy method(MEM). The Nakanishi weight function as well as the corresponding light-front PDA can be well determined. We confirm the previous works on PDA computation therein the different method has been performed.

  1. Review of AdS/CFT Integrability, Chapter III.1: Bethe Ans\\"atze and the R-Matrix Formalism

    CERN Document Server

    Staudacher, Matthias

    2012-01-01

    The one-dimensional Heisenberg XXX spin chain appears in a special limit of the AdS/CFT integrable system. We review various ways of proving its integrability, and discuss the associated methods of solution. In particular, we outline the coordinate and the algebraic Bethe ansatz, giving reference to literature suitable for learning these techniques. Finally we speculate which of the methods might lift to the exact solution of the AdS/CFT system, and sketch a promising method for constructing the Baxter Q-operator of the XXX chain. It allows to find the spectrum of the model using certain algebraic techniques, while entirely avoiding Bethe's ansatz.

  2. Yangian symmetry, S-matrices and Bethe Ansatz for the AdS{sub 5} x S{sup 5} superstring

    Energy Technology Data Exchange (ETDEWEB)

    Leeuw, M. de [Institute for Theoretical Physics and Spinoza Institute, Utrecht University (Netherlands)

    2009-05-15

    We discuss the relation between the recently derived bound state S-matrices for the AdS{sub 5} x S{sup 5} superstring and Yangian symmetry. We will study the relation between this Yangian symmetry and the Bethe ansatz. In particular we can use it to derive the Bethe equations for bound states. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  3. Environmental Impact Statement, Aubrey Lake, Elm Fork, Trinity River, Texas.

    Science.gov (United States)

    1973-01-01

    Freshwater fish production has made a substantial contri- bution to human nutrition and to comerce over the years. Although commercial fishing in...of phylum Brachiopoda , characterized by acorn-like shape and looped valves. LACUSTRINE - Of, relating to, or formed in lakes. LIGNITIC - Containing

  4. An Electromagnetic Form Factor of a Charged Scalar Meson with Schwinger-Dyson and Bethe-Salpeter Equations

    Institute of Scientific and Technical Information of China (English)

    XIE Chuan-Mei; LI Heng-Mei; WAN Shao-Long

    2009-01-01

    The wave functions and electromagnetic form factor of charged scalar mesons are studied with a modified vector-vector flat-bottom potential model under the framework of the Schwinger-Dyeon and Bethe-Salpeter equations.The obtained results agree well with other theories.

  5. Bethe Ansatz for Supersymmetric Model Constructed from Uq[osp(2|2)(2)] R-Matrix

    Institute of Scientific and Technical Information of China (English)

    YANG Wen-Li; ZHEN Yi

    2001-01-01

    Using the algebraic Bethe ansatz method, we obtain the eigenvalues of transfer matrix of the supersymmetric model constructed from the R-matrix of the twisted affine superalgebra Uq[osp(2|2)(2)] in periodic boundary condition and twisted boundary condition.``

  6. Coordinate Bethe ansatz computation for low temperature behavior of a triangular lattice of a spin-1 Heisenberg antiferromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Shuaibu, A. [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia and Physics Department, Faculty of Science, Nigerian Defence Academy, P.M.B 2109, Kaduna (Nigeria); Rahman, M. M. [Physics Department, Faculty of Science, Nigerian Defence Academy, P.M.B 2109, Kaduna (Nigeria)

    2014-03-05

    We study the low temperature behavior of a triangular lattice quantum spin-1 Heisenberg antiferromagnet with single-site anisotropy by using coordinate Bethe ansatz method. We compute the standard two-particle Hermitian Hamiltonian, and obtain the eigenfunctions and eigenvalue of the system. The obtained results show a number of advantages in comparison with many results.

  7. Eigenvalues of Ruijsenaars-Schneider models associated with $A_{n-1}$ root system in Bethe ansatz formalism

    CERN Document Server

    Hou, B; Yang, W L; Hou, Boyu; Sasaki, Ryu; Yang, Wen-Li

    2004-01-01

    Ruijsenaars-Schneider models associated with $A_{n-1}$ root system with a discrete coupling constant are studied. The eigenvalues of the Hamiltonian are givein in terms of the Bethe ansatz formulas. Taking the "non-relativistic" limit, we obtain the spectrum of the corresponding Calogero-Moser systems in the third formulas of Felder et al [20].

  8. Self-consistent approximation to the solution of the Bethe-Salpeter equation

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, G.A. (Department of Physics and Astronomy, University of Massachusetts, Amherst, MA (USA)); Thaler, R.M. (Department of Physics, Case Western Reserve University, Cleveland, OH (USA) Los Alamos National Laboratory, Mail Stop B243, Los Alamos, NM (USA))

    1990-07-01

    A technique for the approximate solution of the Bethe-Salpeter equation is examined. The technique requires the solution of a pair of coupled equations for the relative-momentum and relative-energy dependence of the relativistic {ital T} matrix. The solutions obey a self-consistency requirement as well as the usual elastic-unitarity constraint. It is also shown that the approximate {ital T} matrix is stable under a single iteration in the exact four-dimensional equation at certain kinematic points, including the fully on-shell point. A model problem with an exactly solvable separable interaction is examined and exact, approximate, as well as three-dimensional reduction results are compared. The phase shifts calculated in this self-consistent approximation scheme are found to be in excellent agreement with the exact phase shifts.

  9. Self-consistent approximation to the solution of the Bethe-Salpeter equation

    Science.gov (United States)

    Crawford, G. A.; Thaler, R. M.

    1990-07-01

    A technique for the approximate solution of the Bethe-Salpeter equation is examined. The technique requires the solution of a pair of coupled equations for the relative-momentum and relative-energy dependence of the relativistic T matrix. The solutions obey a self-consistency requirement as well as the usual elastic-unitarity constraint. It is also shown that the approximate T matrix is stable under a single iteration in the exact four-dimensional equation at certain kinematic points, including the fully on-shell point. A model problem with an exactly solvable separable interaction is examined and exact, approximate, as well as three-dimensional reduction results are compared. The phase shifts calculated in this self-consistent approximation scheme are found to be in excellent agreement with the exact phase shifts.

  10. Topics in dual models and extended solutions. [Bethe-Salpeter equation

    Energy Technology Data Exchange (ETDEWEB)

    Roth, R.S.

    1977-06-01

    Two main topics are explored. The first deals with the infinities arising from the one loop planar string diagram of the standard dual model. It is shown that for the number of dimensions d = 25 or 26, these infinities lead to a renormalization of the slope of the Regge trajectories, in addition to a renormalization of the coupling constant. The second topic deals with the propagator for a confined particle (monopole) in a field theory. When summed to all orders, this propagator is altogether free of singularities in the finite momentum plane, and an attempt is made to illustrate this. One examines the Bethe-Salpeter equation and shows that ladder diagrams are not sufficient to obtain this result. However, in a nonrelativistic approximation confinement is obtained and all poles disappear.

  11. Helium atom excitations by the GW and Bethe-Salpeter many-body formalism

    CERN Document Server

    Li, Jing; Duchemin, Ivan; Blase, Xavier; Olevano, Valerio

    2016-01-01

    Helium atom is the simplest many-body electronic system provided by nature. The exact solution to the Schr\\"odinger equation is known for helium ground and excited states, and represents a workbench for any many-body methodology. Here we check ab initio many-body GW approximation and Bethe-Salpeter equation (BSE) against helium exact solution. Starting from Hartree-Fock, we show that GW and BSE yield impressingly accurate results on excitation energies and oscillator strength. These findings suggest that the accuracy of BSE and GW approximations is not significantly limited by self-interaction and self-screening problems even in this few electron limit. We further discuss our results in comparison to those obtained by time-dependent density-functional theory.

  12. Comultiplication in ABCD algebra and scalar products of bethe wave functions

    Science.gov (United States)

    Mikhailov, A.

    1994-07-01

    The representation of scalar products of Bethe wave functions in terms of dual fields, proved by A. G. Izergin and V. E. Korepin in 1987, plays an important role in the theory of completely integrable models. The proof in [A. G. Izergin, Dokl. Akad. Nauk SSSR, 297, No. 2, 331 (1987)] and [V. E. Korepin, Commun. Math. Phys., 113, 177 190 (1978)] is based on the explicit expression for the “senior” coefficient, which was guessed in the Izergin paper and then proved to satisfy some recurrent relations, which determine it unambiguously. In this paper we present an alternative proof based on direct computation. It uses the operation of comultiplication in the ABCD-algebra.

  13. Open spin chains with generic integrable boundaries: Baxter equation and Bethe ansatz completeness from SOV

    CERN Document Server

    Kitanine, N; Niccoli, G

    2014-01-01

    We solve the longstanding problem to define a functional characterization of the spectrum of the transfer matrix associated to the most general spin-1/2 representations of the 6-vertex reflection algebra for general inhomogeneous chains. The corresponding homogeneous limit reproduces the spectrum of the Hamiltonian of the spin-1/2 open XXZ and XXX quantum chains with the most general integrable boundaries. The spectrum is characterized by a second order finite difference functional equation of Baxter type with an inhomogeneous term which vanishes only for some special but yet interesting non-diagonal boundary conditions. This functional equation is shown to be equivalent to the known separation of variable (SOV) representation hence proving that it defines a complete characterization of the transfer matrix spectrum. The polynomial character of the Q-function allows us then to show that a finite system of equations of generalized Bethe type can be similarly used to describe the complete transfer matrix spectru...

  14. Sandwiched trilayer of Bethe lattices in the form of spin-(1/2,1,1/2)

    Energy Technology Data Exchange (ETDEWEB)

    Albayrak, Erhan, E-mail: albayrak@erciyes.edu.t [Erciyes University, Department of Physics, 38039 Kayseri (Turkey); Aker, Aynur [Erciyes University, Department of Physics, 38039 Kayseri (Turkey)

    2010-11-15

    The sandwiched trilayer of Bethe lattices in the form of the spins with spin-(1/2,1,1/2) Ising model is studied in terms of the recursion relations with either ferromagnetic or antiferromagnetic type bilinear interactions between the nearest-neighbor (NN) spins. The ground-state (GS) phase diagrams are obtained and it was found that the model presents six different GS phase configurations. In order to obtain the phase diagrams, the thermal variations of the order-parameter, spin-spin correlation functions and free energy are analyzed and different topological phase diagrams are obtained. It was found that the system exhibits different critical behaviors such as, second- and first-order phase transitions, tricritical and bicritical points for the values of the coordination numbers q=3,4 and 6.

  15. Bethe ansatz solution of the small polaron with nondiagonal boundary terms

    Science.gov (United States)

    Karaiskos, Nikos; Grabinski, André M.; Frahm, Holger

    2013-07-01

    The small polaron with generic, nondiagonal boundary terms is investigated within the framework of quantum integrability. The fusion hierarchy of the transfer matrices and its truncation for particular values of the anisotropy parameter are both employed, so that the spectral problem is formulated in terms of a TQ equation. The solution of this equation for generic boundary conditions is based on a deformation of the diagonal case. The eigenvalues of the model are extracted and the corresponding Bethe ansatz equations are presented. Finally, we comment on the eigenvectors of the model and explicitly compute the eigenstate of the model which evolves into the Fock vacuum when the off-diagonal boundary terms are switched off.

  16. Analysis of quantum spin models on hyperbolic lattices and Bethe lattice

    Science.gov (United States)

    Daniška, Michal; Gendiar, Andrej

    2016-04-01

    The quantum XY, Heisenberg, and transverse field Ising models on hyperbolic lattices are studied by means of the tensor product variational formulation algorithm. The lattices are constructed by tessellation of congruent polygons with coordination number equal to four. The calculated ground-state energies of the XY and Heisenberg models and the phase transition magnetic field of the Ising model on the series of lattices are used to estimate the corresponding quantities of the respective models on the Bethe lattice. The hyperbolic lattice geometry induces mean-field-like behavior of the models. The ambition to obtain results on the non-Euclidean lattice geometries has been motivated by theoretical studies of the anti-de Sitter/conformal field theory correspondence.

  17. Nuclear magnetic polarizability and the slope of the Thomas-Reiche-Kuhn-Levinger-Bethe sum rule

    CERN Document Server

    Gorchtein, Mikhail

    2015-01-01

    Thomas-Reiche-Kuhn-Levinger-Bethe sum rule that relates the strength of the photoexcitation of the giant dipole resonance in a nucleus to the number of elementary scatterers-protons within that nucleus by means of a subtracted forward dispersion relation. I extend this dispersion relation consideration to the case of virtual photons and show that the size of the magnetic polarizability of a nucleus, under the assumption of a separation between the nuclear and hadronic scales, may be related to the slope of the transverse virtual photoabsorption cross section integrated over the energy. I check this approximate sum rule for the deuteron where necessary data is available, discuss possible applications and connection with other sum rules postulated in the literature.

  18. All-loop Bethe ansatz equations for AdS3/CFT2

    CERN Document Server

    Borsato, Riccardo; Sfondrini, Alessandro

    2012-01-01

    Using the S-matrix for the d(2,1;alpha)^2 symmetric spin-chain of AdS3/CFT2, we propose a new set of all-loop Bethe equations for the system. These equations differ from the ones previously found in the literature by the choice of relative grading between the two copies of the d(2,1;alpha) superalgebra, and involve four undetermined scalar factors that play the role of dressing phases. Imposing crossing symmetry and comparing with the near-BMN form of the S-matrix found in the literature, we find several novel features. In particular, the scalar factors must differ from the Beisert-Eden-Staudacher phase, and should couple nodes of different masses to each other. In the semiclassical limit the phases are given by a suitable generalization of Arutyunov-Frolov-Staudacher phase.

  19. Particle-hole symmetry in algebraic Bethe Ansatz for the XXX model

    Science.gov (United States)

    Stagraczynski, R.; Lulek, T.

    2010-03-01

    It is well known that the space of all quantum states of the XXX model for a magnetic ring of N nodes, each with the spin 1/2, decomposes into sectors with r spin deviations, r = 0,1, 2,..., N [1, 2, 3, 4]. The sectors r and N - r are related mutually by the particle-hole transformation which exchanges the signs + and - on each node. We discuss here effects of this transformation on the formalism of algebraic Bethe Ansatz, in particular on the form of the monodromy matrix, the main tool of this formalism. We derive explicitly appropriate transformation rules for CN- orbits of magnetic configurations and the corresponding Fourier transformations within the bases of wavelets. In particular, we point out some important phase relations between orbits on both sides of the equator.

  20. All-loop Bethe ansatz equations for AdS3/CFT2

    Science.gov (United States)

    Borsato, Riccardo; Sax, Olof Ohlsson; Sfondrini, Alessandro

    2013-04-01

    Using the S-matrix for the {d}{{( {2, 1; α } )}^2} symmetric spin-chain of AdS3/CFT2, we propose a new set of all-loop Bethe equations for the system. These equations differ from the ones previously found in the literature by the choice of relative grading between the two copies of the {d}( {2, 1; α } ) superalgebra, and involve four undetermined scalar factors that play the role of dressing phases. Imposing crossing symmetry and comparing with the near-BMN form of the S-matrix found in the literature, we find several novel features. In particular, the scalar factors must differ from the Beisert-Eden-Staudacher phase, and should couple nodes of different masses to each other. In the semiclassical limit the phases are given by a suitable generalization of Arutyunov-Frolov-Staudacher phase.

  1. Strange hadronic stellar matter within the Brueckner-Bethe-Goldstone theory

    CERN Document Server

    Baldo, Marcello; Schulze, H J

    2000-01-01

    In the framework of the non-relativistic Brueckner-Bethe-Goldstone theory, we derive a microscopic equation of state for asymmetric and $\\beta$-stable matter containing $\\Sigma^-$ and $\\Lambda$ hyperons. We mainly study the effects of three-body forces (TBFs) among nucleons on the hyperon formation and the equation of state (EoS). We find that, when TBFs are included, the stellar core is almost equally populated by nucleons and hyperons. The resulting EoS, which turns out to be extremely soft, has been used in order to calculate the static structure of neutron stars. We obtain a value of the maximum mass of 1.26 solar masses (1 solar mass $M_o \\simeq 1.99 \\cdot 10^{33} g$). Stellar rotations increase this value by about 12%.

  2. The algebraic Bethe ansatz for rational braid-monoid lattice models

    CERN Document Server

    Martins, M J

    1997-01-01

    In this paper we study isotropic integrable systems based on the braid-monoid algebra. These systems constitute a large family of rational multistate vertex models and are realized in terms of the B_n, C_n and D_n Lie algebra and by the superalgebra Osp(n|2m). We present a unified formulation of the quantum inverse scattering method for many of these lattice models. The appropriate fundamental commutation rules are found, allowing us to construct the eigenvectors and the eigenvalues of the transfer matrix associated to the B_n, C_n, D_n, Osp(2n-1|2), Osp(2|2n-2), Osp(2n-2|2) and Osp(1|2n) models. The corresponding Bethe Ansatz equations can be formulated in terms of the root structure of the underlying algebra.

  3. Reflection Amplitudes in Non-Simply Laced Toda Theories and Thermodynamic Bethe Ansatz

    CERN Document Server

    Ahn, C; Fateev, V A; Kim, C; Rim, C; Ahn, Changrim; Kim, Chanju; Rim, Chaiho

    2000-01-01

    We study the ultraviolet asymptotics in non-simply laced affine Toda theoriesconsidering them as perturbed non-affine Toda theories, which possess theextended conformal symmetry. We calculate the reflection amplitudes, innon-affine Toda theories and use them to derive the quantization condition forthe vacuum wave function, describing zero-mode dynamics. The solution of thisquantization conditions for the ground state energy determines the UVasymptotics of the effective central charge. These asymptotics are in a goodagreement with Thermodynamic Bethe Ansatz(TBA) results. To make the comparisonwith TBA possible, we give the exact relations between parameters of the actionand masses of particles as well as the bulk free energies for non-simply lacedaffine Toda theories.

  4. La cerámica Khirbet Kerak (Beth Yerah, Israel y la etnicidad: un enfoque alternativo

    Directory of Open Access Journals (Sweden)

    Bernardo Gandulla

    2007-07-01

    Full Text Available

    La cerámica Khirbet Kerak, descubierta en el sudoeste del Mar de Galilea en 1930 por W. F. Albright, ha sido desde entonces motivo de muchas controversias. Las razones de las discusiones en torno a este estilo radican  en su carácter aparentemente intrusivo en Palestina, entre el 2800-2400  a.C., puesto que esta cerámica es típica en la Cultura Transcaucásica Temprana o Cultura Kura-Araxes y en Siria Septentrional, durante el Bronce Antiguo, siendo especialmente abundante en la etapa final de este período. Sin embargo los estudios realizados en Beth Shan (Chazan y McGovern, ver n. 17, muestran que los materiales Khirbet Kerak fueron de producción local lo que parece descartar su carácter intrusivo. Por tanto, desde nuestro punto de vista, el “fenómeno Khirbet Kerak” constituye así un hito de singular importancia en la conformación de las tradiciones culturales de Canaan a partir de un sustrato etnocultural común hurrita, en un eje de interacción cultural norte a sur desde la región del Lago Van, que habrá de proyectarse de distintas formas en la macrorregión alcanzando hasta los antiguos hebreos, en cuanto cananeos, como se reflejan en instituciones del derecho privado presentes en las narraciones del Génesis.

    Palabras clave: Canaán - Bronce Antiguo - Beth Yerah - Khirbet Kerak - Hurritas
    - Hebreos

  5. Analyzing the DK molecular state in the Bethe-Salpeter approach%在Bethe-Salpeter方程框架下研究DK分子态

    Institute of Scientific and Technical Information of China (English)

    谢振兴

    2012-01-01

    本文研究了BaBar合作组在分析正负电子湮灭的不变质量时发现的一个很窄的峰结构,该峰结构被命名为D(*s0)+(2317).首先假定它是S波的DK分子束缚态,利用Bethe-Salpeter方程研究了其结构并研究了其同位旋破缺衰变过程D(*s0)+ (2317)→D(s+)+π0,同时在末态考虑了η-π0混合效应对衰变宽度的影响.研究结果表明,D(*s0)+(2317)可以具有DK的分子束缚态结构,而且η-π0混合效应对衰变宽度影响非常明显,D(*s0)+(2317)→D(s+)π0衰变宽度的理论结果与实验结果相符.其它的理论模型也对D(*s0)+(2317)的结构和性质进行了研究,认为D(*s0)+ (2317)可能存在其它形式的结构,并且得到的理论结果和实验结果相符.因此的结构存在多种形式,或者是几种结构的混合.该研究结果对未来的实验进一步确定D(*s0)(2317)的结构有指导意义.%We analyze the state D++s0 (2317) ,which was discovered as a very narrow peak by the Babar collaboration while analyzing the invariant mass distribution of the decay final state D++,0. Assuming D++s0(2317) that is composed of DK, we use the Bethe-Salpeter equation to study the structure of D++s0(2317) and the isospin breaking decay process D++s0 (2317)→Ds+π0. We also consider the η -π0 mixing effect in the decay. It is shown that D++s0 (2317) can be formed as a molecular bound state of DK and the mixing effect has significant influence on the decay. The decay width in our model agrees with the resolution of the detector. Other theoretical models are also used to study the property and the structure of D++s0(2317) .assuming that D++s0(2317) may have other forms, and the results agree with the experimental data too. So the structure of may be other forms or the mixing of them. Our results will give important instructions to the forthcoming experiments.

  6. Tallinna vanalinn on punaseim paik, mida rännates olen näinud! / Sarah Jana Portner ; intervjueerinud Maarja-Liis Arujärv, Oliver Õunmaa

    Index Scriptorium Estoniae

    Portner, Sarah Jana, 1983-

    2011-01-01

    Intervjuu sakslannast ajakirjaniku Sarah Jana Portneriga, kelle Saksa Ida-Euroopa Kultuurifoorum valis Tallinna linnakirjutajaks. Kirjutatu läheb kirja Tallinna-teemalisse blogisse. 26. septembril avab Portner Tallinna Ülikooli Akadeemilise Raamatukogu fuajees fotonäituse "Tallinn - inimeste ja majade lood". Näitus annab ettekujutuse, mis toimub Tallinna vanalinna fassaadide taga ning kes seal elavad

  7. Tallinna vanalinn on punaseim paik, mida rännates olen näinud! / Sarah Jana Portner ; intervjueerinud Maarja-Liis Arujärv, Oliver Õunmaa

    Index Scriptorium Estoniae

    Portner, Sarah Jana, 1983-

    2011-01-01

    Intervjuu sakslannast ajakirjaniku Sarah Jana Portneriga, kelle Saksa Ida-Euroopa Kultuurifoorum valis Tallinna linnakirjutajaks. Kirjutatu läheb kirja Tallinna-teemalisse blogisse. 26. septembril avab Portner Tallinna Ülikooli Akadeemilise Raamatukogu fuajees fotonäituse "Tallinn - inimeste ja majade lood". Näitus annab ettekujutuse, mis toimub Tallinna vanalinna fassaadide taga ning kes seal elavad

  8. Wirklich wie im wirklichen Leben. Sarah Kember untersucht die (Re-Produktion des kleinen Unterschieds und seiner großen Folgen in Theorie und Praxis von Artificial Life Real as in real life. Sarah Kember examines the (reproduction of ‘the small difference and its big consequences’ in the theory and practice of artificial life.

    Directory of Open Access Journals (Sweden)

    Verena Kuni

    2004-03-01

    Full Text Available Wie greifen diese ‚virtuellen Realitäten‘ in unsere Körper- und Identitätskonzepte, unsere Subjekt- und Geschlechtervorstellungen ein? Sarah Kembers Buch verspricht, erhellende Schneisen durch das Dickicht der definitionsmächtigen Diskurse, Konzepte und Konstruktionen zu schlagen und neue Wege für feministische Interventionen in die Auseinandersetzungen um ‚Artificial Life‘ aufzuzeigen.ow a way through the labyrinth of discourse, concepts and constructions, and to open the door for feminist interpretations in debates about artificial life.

  9. Decay of Bethe-Salpeter kernel and bound states for the lattice four Fermi model

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, Petrus Henrique Ribeiro dos [Universidade Federal de Goias (UFG), Goiania, GO (Brazil)

    2012-07-01

    Full text: We consider an imaginary-time functional integral formulation of the the lattice four-Fermi or Gross-Neveu model in d + 1 space-time dimensions (d = 1, 2, 3) and with N-component fermions. Let 0 < {kappa} << 1 be the hopping parameter, {lambda} > 0 the four-fermion coupling, m > 0 the bare fermion mass and take s x s spin matrices (s = 2,4). In a previous work, we derive spectral representations for two- and four- point correlation functions and use this result to show that the low-lying energy-momentum spectrum of this model exhibits isolated dispersion curves which are identified as single particles, multi-particle bands and bound states. In this previous analysis, the one-particle energy-momentum spectrum is obtained rigorously and is manifested by sN/2 isolated and identical dispersion curves, and the mass of particles has asymptotic value order of order 1n {kappa}. The existence of two-particle bound states above or below the two-particle band depends on whether Gaussian domination does hold or does not, respectively. Two-particle bound states emerge from solutions to a lattice Bethe-Salpeter equation that we solve in a ladder approximation. Within this approximation, the bound states have O({kappa}{sup 0}) binding energies at zero system momentum and their masses are all equal, with value {approx} -2 1n {kappa}. In this work, using the hyperplane decoupling method, we provide a detailed analysis of the decay of the Bethe-Salpeter kernel and show how to use this decay to extend the spectral result obtained in the ladder approximation to the full model. In particular, we prove that if the two-point function decays faster than the four-point function (Gaussian subjugation) then the only point in the mass spectrum above the one-particle mass and below the two-particle band is the bound state mass. (author)

  10. Excited states properties of organic molecules: from density functional theory to the GW and Bethe-Salpeter Green's function formalisms.

    Science.gov (United States)

    Faber, C; Boulanger, P; Attaccalite, C; Duchemin, I; Blase, X

    2014-03-13

    Many-body Green's function perturbation theories, such as the GW and Bethe-Salpeter formalisms, are starting to be routinely applied to study charged and neutral electronic excitations in molecular organic systems relevant to applications in photovoltaics, photochemistry or biology. In parallel, density functional theory and its time-dependent extensions significantly progressed along the line of range-separated hybrid functionals within the generalized Kohn-Sham formalism designed to provide correct excitation energies. We give an overview and compare these approaches with examples drawn from the study of gas phase organic systems such as fullerenes, porphyrins, bacteriochlorophylls or nucleobases molecules. The perspectives and challenges that many-body perturbation theory is facing, such as the role of self-consistency, the calculation of forces and potential energy surfaces in the excited states, or the development of embedding techniques specific to the GW and Bethe-Salpeter equation formalisms, are outlined.

  11. Bethe/Gauge correspondence in odd dimension: modular double, non-perturbative corrections and open topological strings

    Science.gov (United States)

    Sciarappa, Antonio

    2016-10-01

    Bethe/Gauge correspondence as it is usually stated is ill-defined in five dimensions and needs a "non-perturbative" completion; a related problem also appears in three dimensions. It has been suggested that this problem, probably due to incompleteness of Omega background regularization in odd dimension, may be solved if we consider gauge theory on compact S 5 and S 3 geometries. We will develop this idea further by giving a full Bethe/Gauge correspondence dictionary on S 5 and S 3 focussing mainly on the eigenfunctions of (open and closed) relativistic 2-particle Toda chain and its quantized spectral curve: these are most properly written in terms of non-perturbatively completed NS open topological strings. A key ingredient is Faddeev's modular double structure which is naturally implemented by the S 5 and S 3 geometries.

  12. New Closed Expression of Interaction Kernel in Bethe-Salpeter Equation for Quark-Antiquark Bound States

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The interaction kernel in the Bethe-Salpeter equation for quark-antiquark bound states is derived newly from QCD in the case where the quark and the antiquark are of different flavors. The technique of the derivation is the usage of the irreducible decomposition of the Green's functions involved in the Bethe-Salpeter equation satisfied by the quark-antiquark four-point Green's function. The interaction kernel derived is given a closed and explicit expression which shows a specific structure of the kernel since the kernel is represented in terms of the quark, antiquark and gluon propagators and some kinds of quark, antiquark and/or gluon three, four, five and six-point vertices. Therefore,the expression of the kernel is not only convenient for perturbative calculations, but also suitable for nonperturbative investigations.

  13. Bethe Ansatz and the Spectral Theory of affine Lie algebra--valued connections. The non simply--laced case

    CERN Document Server

    Masoero, Davide; Valeri, Daniele

    2015-01-01

    We assess the ODE/IM correspondence for the quantum $\\mathfrak{g}$-KdV model, for a non-simply laced Lie algebra $\\mathfrak{g}$. This is done by studying a meromorphic connection with values in the Langlands dual algebra of the affine Lie algebra ${\\mathfrak{g}}^{(1)}$, and constructing the relevant $\\Psi$-system among subdominant solutions. We then use the $\\Psi$-system to prove that the generalized spectral determinants satisfy the Bethe Ansatz equations of the quantum $\\mathfrak{g}$-KdV model. We also consider generalized Airy functions for twisted Kac--Moody algebras and we construct new explicit solutions to the Bethe Ansatz equations. The paper is a continuation of our previous work on the ODE/IM correspondence for simply-laced Lie algebras.

  14. Bethe Ansatz and the Spectral Theory of Affine Lie algebra-Valued Connections II: The Non Simply-Laced Case

    Science.gov (United States)

    Masoero, Davide; Raimondo, Andrea; Valeri, Daniele

    2016-09-01

    We assess the ODE/IM correspondence for the quantum g -KdV model, for a non-simply laced Lie algebra g. This is done by studying a meromorphic connection with values in the Langlands dual algebra of the affine Lie algebra g^{(1)} , and constructing the relevant {Ψ} -system among subdominant solutions. We then use the {Ψ} -system to prove that the generalized spectral determinants satisfy the Bethe Ansatz equations of the quantum g -KdV model. We also consider generalized Airy functions for twisted Kac-Moody algebras and we construct new explicit solutions to the Bethe Ansatz equations. The paper is a continuation of our previous work on the ODE/IM correspondence for simply-laced Lie algebras.

  15. The mixed-spin ternary-alloy in the form of ABpC1- p on the Bethe lattice

    Science.gov (United States)

    Albayrak, Erhan

    2011-04-01

    The ABpC1-p type of mixed ferromagnetic-ferrimagnetic ternary-alloy with A (spin-3/2), B (spin-1) and C (spin-5/2) ions was studied on the Bethe lattice with the odd numbered shells containing only A ions, while the even numbered shells either containing B or C ions randomly. The phase diagrams were obtained on the (R=|JAC|/JAB,kTc/JAB) and (p, kTc/JAB) planes for given values of p and R, respectively, with the coordination numbers z=3, 4, 5 and 6. The explicit dependence of the phase diagrams on z and each shell of the Bethe lattice having only one type of ion lead to some differences when compared with the previous works. The model presents one or two compensation temperatures for appropriate values of the system parameters.

  16. Massless L\\"uscher Terms and the Limitations of the AdS3 Asymptotic Bethe Ansatz

    CERN Document Server

    Abbott, Michael C

    2015-01-01

    In AdS5/CFT4 integrability the Bethe ansatz gives the spectrum of long strings, accurate up to exponentially small corrections. This is no longer true in AdS3, as we demonstrate here by studying L\\"uscher F-terms with a massless particle running in the loop. We apply this to the classic test of Hern\\'andez & L\\'opez, in which the su(2) sector Bethe equations (including one-loop dressing phase) should match the semiclassical string theory result for a circular spinning string. These calculations did not agree in AdS3xS3xT4, and we show that the sum of all massless L\\"uscher F-terms can reproduce the difference.

  17. Bethe/Gauge correspondence in odd dimension: modular double, non-perturbative corrections and open topological strings

    CERN Document Server

    Sciarappa, Antonio

    2016-01-01

    Bethe/Gauge correspondence as it is usually stated is ill-defined in five dimensions and needs a "non-perturbative" completion; a related problem also appears in three dimensions. It has been suggested that this problem, probably due to incompleteness of Omega background regularization in odd dimension, may be solved if we consider gauge theory on compact $S^5$ and $S^3$ geometries. We will develop this idea further by giving a full Bethe/Gauge correspondence dictionary on $S^5$ and $S^3$ focussing mainly on the eigenfunctions of (open and closed) relativistic 2-particle Toda chain and its quantized spectral curve: these are most properly written in terms of non-perturbatively completed NS open topological strings. A key ingredient is Faddeev's modular double structure which is naturally implemented by the $S^5$ and $S^3$ geometries.

  18. Calculation of Kaon Electromagnetic Form Factor in the Framework of Coupled Schwinger-Dyson and Bethe-Salpeter Formulation

    Institute of Scientific and Technical Information of China (English)

    WANG ZhiGang; WAN ShaoLong; WANG KeLin

    2001-01-01

    The kaon electromagnetic form factor is calculated in the framework of coupled Schwinger-Dyson equation in rainbow approximation and Bethe-Salpeter equation in ladder approximation with the modified fiat-bottom potential,which is the combination of the flat-bottom potential with considerations for the infrared and ultraviolet asymptotic behaviours of the effective quark-gluon coupling. All our numerical results give good fit to experimental values and other theoretical results.``

  19. Glassy behaviour of random field Ising spins on Bethe lattice in external magnetic field

    Institute of Scientific and Technical Information of China (English)

    Khalid Bannora; Galal Ismail; Wafaa Hassan

    2011-01-01

    The thermodynamics and the phase diagram of random field Ising model (RFIM) on Bethe lattice are studied by using a replica trick. This lattice is placed in an external magnetic field (B). A Gaussian distribution of random field (hi) with zero mean and variance = H2RF is considered. The free-energy (F), the magnetization (M) and the order parameter (q) are investigated for several values of coordination number (z). The phase diagram shows several interesting behaviours and presents tricritical point at critical temperature TC = J/k and when HRF = 0 for finite z. The free-energy (F) values increase as T increases for different intensities of random field (HRF) and finite z. The internal energy (U) has a similar behaviour to that obtained from the Monte Carlo simulations. The ground state of magnetization decreases as the intensity of random field HRF increases. The ferromagnetic (FM)-paramagnetic (PM) phase boundary is clearly observed only when z →∞. While FM-PM-spin glass (SG) phase boundaries are present for finite z. The magnetic susceptibility (X) shows a sharp cusp at TC in a small random field for finite z and rounded different peaks on increasing HRF.

  20. Solving the inhomogeneous Bethe-Salpeter equation in Minkowski space: the zero-energy limit

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Tobias [Instituto Tecnologico de Aeronautica, DCTA, Dept. de Fisica, Sao Paulo (Brazil); Salme, Giovanni [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma (Italy); Viviani, Michele [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa (Italy)

    2015-08-15

    The inhomogeneous Bethe-Salpeter equation for an interacting system, composed of two massive scalars exchanging a massive scalar, is numerically investigated in the ladder approximation directly in Minkowski space, by using for the first time in the continuum an approach based on the Nakanishi integral representation. In this paper, the limiting case of zero-energy states is considered, thus extending an approach that has already been successfully applied to bound states. The numerical values of scattering lengths, are calculated for several values of the Yukawa coupling constant, by using two different integral equations that stem from the Nakanishi framework. Those low-energy observables are compared with (1) the analogous quantities recently obtained in literature, within a totally different framework, and (2) the non-relativistic evaluations, to illustrate the relevance of a nonperturbative, genuine field theoretical treatment in Minkowski space, even in the low-energy regime. Moreover, dynamical functions, like the Nakanishi weight functions and the distorted part of the zero-energy light-front wave functions are also presented. Interestingly, a highly non-trivial issue related to the abrupt change in the width of the support of the Nakanishi weight function, when the zero-energy limit is approached, is elucidated, ensuring a sound basis to the forthcoming evaluation of phase shifts. (orig.)

  1. Heavy quarkonium potential from Bethe-Salpeter wave function on the lattice

    CERN Document Server

    Kawanai, Taichi

    2013-01-01

    We propose a novel method for the determination of the interquark potential together with quark "kinetic mass'' $m_Q$ from the equal-time $Q\\bar{Q}$ Bethe-Salpeter (BS) amplitude in lattice QCD. Our approach allows us to calculate spin-dependent $Q\\bar{Q}$ potentials, e.g. the spin-spin potential, as well. In order to investigate several systematic uncertainties on such $Q\\bar{Q}$ potentials, we carry out lattice QCD simulations using quenched gauge configurations generated with the single plaquette gauge action with three different lattice spacings, $a \\approx$ 0.093, 0.068 and 0.047 fm, and two different physical volumes, $L \\approx$ 2.2 and 3.0 fm. For heavy quarks, we employ the relativistic heavy quark (RHQ) action which can control large discretization errors introduced by large quark mass $m_Q$. The spin-independent central $Q\\bar{Q}$ potential for the charmonium system yields the "Coulomb plus linear'' behavior with good scaling and small volume dependence. We explore the quark mass dependence over th...

  2. An exact solution on the ferromagnetic face-cubic spin model on a Bethe lattice

    Science.gov (United States)

    Ohanyan, V. R.; Ananikyan, L. N.; Ananikian, N. S.

    2007-04-01

    The lattice spin model with Q-component discrete spin variables restricted to have orientations orthogonal to the faces of Q-dimensional hypercube is considered on the Bethe lattice, the recursive graph which contains no cycles. The partition function of the model with dipole-dipole and quadrupole-quadrupole interaction for arbitrary planar graph is presented in terms of double graph expansions. The latter is calculated exactly in case of trees. The system of two recurrent relations (RR) which allows to calculate all thermodynamic characteristics of the model is obtained. The correspondence between thermodynamic phases and different types of fixed points of the RR is established. Using the technique of simple iterations the plots of the zero field magnetization and quadrupolar moment are obtained. Analyzing the regions of stability of different types of fixed points of the system of recurrent relations the phase diagrams of the model are plotted. For Q⩽2 the phase diagram of the model is found to have three tricritical points, whereas for Q>2 there are one triple and one tricritical points.

  3. Bethe ansatz solution for a defect particle in the asymmetric exclusion process

    Science.gov (United States)

    Derrida, B.; Evans, M. R.

    1999-07-01

    The asymmetric exclusion process on a ring in one dimension is considered with a single defect particle. The steady state has previously been solved by a matrix product method. Here we use the Bethe ansatz to solve exactly for the long time limit behaviour of the generating function of the distance travelled by the defect particle. This allows us to recover steady state properties known from the matrix approach such as the velocity, and obtain new results such as the diffusion constant of the defect particle. In the case where the defect particle is a second-class particle we determine the large deviation function and show that in a certain range the distribution of the distance travelled about the mean is Gaussian. Moreover, the variance (diffusion constant) grows as L1/2 where L is the system size. This behaviour can be related to the superdiffusive spreading of excess mass fluctuations on an infinite system. In the case where the defect particle produces a shock, our expressions for the velocity and the diffusion constant coincide with those calculated previously for an infinite system by Ferrari and Fontes.

  4. Effects of the projectile electronic structure on Bethe-Bloch stopping parameters for Ag

    Energy Technology Data Exchange (ETDEWEB)

    Moussa, D., E-mail: djamelmoussa@gmail.co [USTHB, Faculte de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria); Damache, S. [Division de Physique, CRNA, 02 Bd. Frantz Fanon, B.P. 399 Alger-gare, Algiers (Algeria); Ouichaoui, S., E-mail: souichaoui@gmail.co [USTHB, Faculte de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria)

    2010-06-15

    Energy losses of protons and alpha particles in silver have been accurately measured under the same experimental conditions over the velocity range E{sub lab}=(0.192-2.595) MeV/amu using the transmission method. Deduced S(E) stopping powers are compared to most accurate ones from the literature, to values generated by the SRIM-2008 computer code and to ICRU-49 compilation. They were analyzed in the framework of modified Bethe-Bloch theory for extracting Ag target mean excitation and ionization potential, I, and Barkas effect parameter, b. Values of (466{+-}5) eV and 1.20{+-}0.01 for these two parameters were inferred from the proton S(E) data while the alpha particle data yielded values of (438{+-}4) eV and 1.38{+-}0.01, respectively. The (I, b) stopping parameters thus exhibit opposite variations as the projectile charge increases, similarly as we have found previously for nickel . This can be ascribed only to an effect of the projectile electronic structure at low velocities. The obtained results are discussed in comparison to previous ones reported in the literature.

  5. Pressure-velocity relations in reservoir rocks: Modified MacBeth's equation

    Science.gov (United States)

    Grana, Dario

    2016-09-01

    The knowledge of the saturation and pressure effects on elastic properties is a key factor in reservoir monitoring. The relation between saturation changes and velocity variations is well known in rock physics and at seismic frequency it can be satisfactorily described by Gassmann's equations. The pressure effect still requires deeper investigations in order to be included in rock physics models for 4D studies. Theoretical models of velocity-pressure relations often do not match lab measurements, or contain empirical constants or theoretical parameters that are difficult to calibrate or do not have a precise physical meaning. In this work, I present a new model to describe the pressure sensitivity of elastic moduli for clastic rocks. The proposed model is an extension of MacBeth's relations. These equations are then integrated within a complete rock physics model to describe the relation between rock properties (porosity and clay content), dynamic attributes (saturation and pressure) and elastic properties. The proposed model is calibrated with laboratory measurements of dry samples over a wide range of pressure variations and then applied to well data to simulate different production scenarios. The complete rock physics model can then be used in time-lapse inversion to predict the distribution of dynamic property changes in the reservoir within an inversion workflow for reservoir monitoring.

  6. A study of the bilayer Bethe lattice for spin-32 Ising model

    Energy Technology Data Exchange (ETDEWEB)

    Albayrak, Erhan [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)]. E-mail: albayrak@erciyes.edu.tr; Yilmaz, Saban [Department of Physics, Erciyes University, 38039 Kayseri (Turkey); Akkaya, Seyma [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)

    2007-03-15

    The spin-32 Ising model on the bilayer Bethe lattice is studied in terms of the exact recursion relations with the intralayer bilinear interactions J{sub 11} and J{sub 22} of the two layers with ferromagnetic coupling and interlayer bilinear interaction J{sub 12} between the layers with ferromagnetic or antiferromagnetic coupling. We first have obtained the ground state configurations of the model on the (J{sub 22}/vertical barJ{sub 11}vertical bar,J{sub 12}/qvertical barJ{sub 11}vertical bar) planes for J{sub 11}<0 and J{sub 11}>0. Then the thermal behaviors of the order-parameters, the total and staggered magnetizations of the two layers and also the spin-spin correlation function between the nearest-neighbor spins of the adjacent layers, are studied to obtain the phase diagrams of the model on the (kT/J{sub 11},J{sub 12}/J{sub 11}) plane for given values of J{sub 22}/J{sub 11} and the coordination number q. As a result, a few types of the critical temperatures of the model are obtained.

  7. Beth Lanham on Six Sigma in healthcare. Interview by Luc R. Pelletier.

    Science.gov (United States)

    Lamham, Beth

    2003-01-01

    Beth Lanham, BSN RN, is a Six Sigma Coordinator in the department of quality management, staff development and safety, at Froedtert Hospital in Milwaukee, WI. Ms. Lanham received her bachelor's degree from Otterbein College in Westerville, OH and has an extensive clinical and management background in critical care nursing. In April 2000, Ms. Lanham completed the Six Sigma Black Belt training program through the American Society for Quality. She is currently working as a Six Sigma Black Belt and is actively involved with numerous committees and projects aimed at reducing medical errors and enhancing patient safety. Ms. Lanham has presented Six Sigma initiatives at the International Quality Congress sponsored by the American Society for Quality, the University Healthcare Consortium National Conference, the International Quality and Productivity Center National Conference on Six Sigma for Healthcare Providers, and the American Hospital Association Patient Safety Leadership Fellowship Retreat. Six Sigma projects at Froedtert Hospital are aimed at reducing errors associated with patient controlled analgesia pumps, continuous intravenous infusions, narcotic sedation in postoperative patients, insulin therapy, and handling of laboratory specimens. Six Sigma has also been applied toward reducing falls on a rehabilitation unit.

  8. Mass of \\emph{Y}(4140) in Bethe-Salpeter equation for quarks

    CERN Document Server

    Chen, Xiaozhao; Shi, Renbin; Guo, Xiurong

    2015-01-01

    Using the general form of the Bethe-Salpeter wave functions for the bound states consisting of two vector fields given in our previous work, we investigate the molecular state composed of $D^{*+}_s$$D^{*-}_s$. However, for the SU(3) symmetry the component $D^{*+}_s$$D^{*-}_s$ is coupled with the other components $D^{*0}$$\\bar{D}^{*0}$ and $D^{*+}$$D^{*-}$. Then we interpret the internal structure of the observed \\emph{Y}(4140) state as a mixed state of pure molecule states $D^{*0}$$\\bar{D}^{*0}$, $D^{*+}$$D^{*-}$ and $D^{*+}_s$$D^{*-}_s$ with quantum numbers $J^P=0^+$. In this paper, the operator product expansion is used to introduce the nonperturbative contribution from the vacuum condensates into the interaction between two heavy mesons. The calculated mass of \\emph{Y}(4140) is consistent with the experimental value, and we conclude that it is a more reasonable scenario to explain the structure of Y (4140) as a mixture of pure molecule states.

  9. Fast and Accurate Electronic Excitations in Cyanines with the Many-Body Bethe-Salpeter Approach.

    Science.gov (United States)

    Boulanger, Paul; Jacquemin, Denis; Duchemin, Ivan; Blase, Xavier

    2014-03-11

    The accurate prediction of the optical signatures of cyanine derivatives remains an important challenge in theoretical chemistry. Indeed, up to now, only the most expensive quantum chemical methods (CAS-PT2, CC, DMC, etc.) yield consistent and accurate data, impeding the applications on real-life molecules. Here, we investigate the lowest lying singlet excitation energies of increasingly long cyanine dyes within the GW and Bethe-Salpeter Green's function many-body perturbation theory. Our results are in remarkable agreement with available coupled-cluster (exCC3) data, bringing these two single-reference perturbation techniques within a 0.05 eV maximum discrepancy. By comparison, available TD-DFT calculations with various semilocal, global, or range-separated hybrid functionals, overshoot the transition energies by a typical error of 0.3-0.6 eV. The obtained accuracy is achieved with a parameter-free formalism that offers similar accuracy for metallic or insulating, finite size or extended systems.

  10. Unified approach to thermodynamic Bethe ansatz and finite size corrections for lattice models and field theories

    CERN Document Server

    Destri, C

    1994-01-01

    We present a unified approach to the Thermodynamic Bethe Ansatz (TBA) for magnetic chains and field theories that includes the finite size (and zero temperature) calculations for lattice BA models. In all cases, the free energy follows by quadratures from the solution of a {\\bf single} non-linear integral equation (NLIE). [A system of NLIE appears for nested BA]. We derive the NLIE for: a) the six-vertex model with twisted boundary conditions; b) the XXZ chain in an external magnetic field h_z and c) the sine-Gordon-massive Thirring model (sG-mT) in a periodic box of size \\b \\equiv 1/T using the light-cone approach. This NLIE is solved by iteration in one regime (high T in the XXZ chain and low T in the sG-mT model). In the opposite (conformal) regime, the leading behaviors are obtained in closed form. Higher corrections can be derived from the Riemann-Hilbert form of the NLIE that we present.

  11. Meson masses in large Nf QCD from Bethe-Salpeter equation

    CERN Document Server

    Harada, M; Yamawaki, K; Harada, Masayasu; Kurachi, Masafumi; Yamawaki, Koichi

    2003-01-01

    We solve the homogeneous Bethe-Salpeter (HBS) equation for the scalar, pseudoscalar, vector and axial-vector bound states of quark and anti-quark in large Nf QCD with the improved ladder approximation in the Landau gauge. Quark mass function in the HBS equation is obtained from the Schwinger-Dyson (SD) equation in the same approximation for the consistency with the chiral symmetry. Amazingly, due to the fact that the two-loop running coupling of large Nf QCD is explicitly written in terms of an analytic function, large Nf QCD turns out to be the first example in which the SD equation can be solved in the complex plane and hence the HBS equation directly in the time-like region. We find that approaching the chiral phase transition point from the broken phase, the scalar, vector and axial-vector meson masses vanish to zero with the same scaling behavior, all degenerate with the massless pseudoscalar meson. This may suggest a new type of manifestation of the chiral symmetry restoration in large Nf QCD.

  12. Calculation of excitonic properties of conjugated polymers using the Bethe-Salpeter equation

    Science.gov (United States)

    van der Horst, J.-W.; Bobbert, P. A.; Michels, M. A. J.; Bässler, H.

    2001-04-01

    The excitonic spectra of a number of conjugated polymers, polythiophene (PT), polyphenylenevinylene (PPV), ladder-type poly-para-phenylene (LPPP), trans-polyacetylene (PA), and polydiacetylene (PDA), are calculated by solving the Bethe-Salpeter equation for the two-body Green function of the electron-hole pair. The only input to the calculation is the bulk dielectric constant. We find intermediate binding energies of 0.4-0.6 eV for the lowest optical 1 1Bu exciton, obtaining good agreement with recent experiments for each polymer individually. The agreement for the singlet-triplet splittings and the 1 1Bu polarizabilities is satisfactory. This also holds for the 1 1Bu-21Ag splittings in PT, LPPP, and PPV. For PA and PDA we find the 2 1Ag exciton above the 1 1Bu exciton, in contrast with experiment; a possible explanation for this discrepancy is the absence of lattice relaxation effects and double excitations in our calculations.

  13. Numerical Generalization of the Bethe-Weizs\\"{a}cker Mass Formula

    CERN Document Server

    Mavrodiev, S Cht

    2016-01-01

    Based on the AME2012 nuclear database and the semi-empirical mass formula of Bethe and von Weizs\\"{a}cker we formulated and solved the inverse problem for its numerical generalization in step by step way. The established parametrization describes the measured nuclear masses of 2564 isotopes with an accuracy better than 2.6 MeV, starting from the number of protons $Z=1$ and number of neutrons $N=1$. The set of parameters $\\{a_{i}\\}$, $i=1,\\dots, {N}_{\\rm{total}}$ of our fit represent the solution of an overdetermined system of algebraic equations, which represent equalities between the binding energy $E_{B}^{\\rm{Expt}}(A_{j},Z_{j})$ and its model $E_{B}^{\\rm{Th}}(A_{j},Z_{j},\\{a_{i}\\})$, where $j=1,\\dots,2564$. The solution of the overdetermined system of equations has been obtained with the help of the Aleksandrov's auto-regularization method of Gauss-Newton type for ill-posed problems (Dubna FORTRAN code REGN). The explicit form of unknown functions was discovered in a step-by-step way using the LCH procedur...

  14. 撒拉族发祥地街子镇空间和风貌特征初探%Preliminary Study of Space and Landscape Characteristics of Tuanjie Town (the Birthplace of Sarah's Family)

    Institute of Scientific and Technical Information of China (English)

    周婕; 张雨蝉

    2013-01-01

    循化县是我国唯一的撒拉尔族自治县,撒拉尔族全民信教--伊斯兰教。宗教在组织其社会生活、城市空间布局、城市建设中,发挥了巨大的作用,也因此产生了极具特色的城市风貌。文章试图通过这个案例让我们对当代城市规划设计的理论和方法有所反思。%In China, Xunhua is the only town where the Sarah ethnic people, all having the same Islamic faith, reside in. Religion plays an important role in the daily lives of the Sarah people, and because of this, heavily impacts the design and planning of the area, resulting in the unique urban space and landscape. Using the Sarah case study, this article attempts to reflect on current urban design theories and methodologies.

  15. Simple polynomial approximation to modified Bethe formula low-energy electron stopping powers data

    Energy Technology Data Exchange (ETDEWEB)

    Taborda, A., E-mail: ana.taborda@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-HOM/SDI/LEDI, BP-17, 92262 Fontenay-aux-Roses (France); Desbrée, A. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-HOM/SDI/LEDI, BP-17, 92262 Fontenay-aux-Roses (France); Reis, M.A. [C" 2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, EN10 km139.7, 2685-066 Bobadela LRS (Portugal)

    2015-08-01

    A recently published detailed and exhaustive paper on cross-sections for ionisation induced by keV electrons clearly shows that electron phenomena occurring in parallel with X-ray processes may have been dramatically overlooked for many years, mainly when low atomic number species are involved since, in these cases, the fluorescence coefficient is smaller than the Auger yield. An immediate problem is encountered while attempting to tackle the issue. Accounting for electron phenomena requires the knowledge of the stopping power of electrons within, at least, a reasonably small error. Still, the Bethe formula for stopping powers is known to not be valid for electron energies below 30 keV, and its use leads to values far off experimental ones. Recently, a few authors have addressed this problem and both detailed tables of electron stopping powers for various atomic species and attempts to simplify the calculations, have emerged. Nevertheless, its implementation in software routines to efficiently calculate keV electron effects in materials quickly becomes a bit cumbersome. Following a procedure already used to establish efficient methods to calculate ionisation cross-sections by protons and alpha particles, it became clear that a simple polynomial approximation could be set, which allows retrieving the electronic stopping powers with errors of less than 20% for energies above 500 eV and less than 50% for energies between 50 eV and 500 eV. In this work, we present this approximation which, based on just six parameters, allows to recover electron stopping power values that are less than 20% different from recently published experimentally validated tabulated data.

  16. Efficient implementation of core-excitation Bethe-Salpeter equation calculations

    Science.gov (United States)

    Gilmore, K.; Vinson, John; Shirley, E. L.; Prendergast, D.; Pemmaraju, C. D.; Kas, J. J.; Vila, F. D.; Rehr, J. J.

    2015-12-01

    We present an efficient implementation of the Bethe-Salpeter equation (BSE) method for obtaining core-level spectra including X-ray absorption (XAS), X-ray emission (XES), and both resonant and non-resonant inelastic X-ray scattering spectra (N/RIXS). Calculations are based on density functional theory (DFT) electronic structures generated either by ABINIT or QuantumESPRESSO, both plane-wave basis, pseudopotential codes. This electronic structure is improved through the inclusion of a GW self energy. The projector augmented wave technique is used to evaluate transition matrix elements between core-level and band states. Final two-particle scattering states are obtained with the NIST core-level BSE solver (NBSE). We have previously reported this implementation, which we refer to as OCEAN (Obtaining Core Excitations from Ab initio electronic structure and NBSE) (Vinson et al., 2011). Here, we present additional efficiencies that enable us to evaluate spectra for systems ten times larger than previously possible; containing up to a few thousand electrons. These improvements include the implementation of optimal basis functions that reduce the cost of the initial DFT calculations, more complete parallelization of the screening calculation and of the action of the BSE Hamiltonian, and various memory reductions. Scaling is demonstrated on supercells of SrTiO3 and example spectra for the organic light emitting molecule Tris-(8-hydroxyquinoline)aluminum (Alq3) are presented. The ability to perform large-scale spectral calculations is particularly advantageous for investigating dilute or non-periodic systems such as doped materials, amorphous systems, or complex nano-structures.

  17. Hans A. Bethe Prize: Neutron Stars and Core-Collapse Supernovae

    Science.gov (United States)

    Lattimer, James

    2015-04-01

    Core-collapse supernovae lead to the formation of neutron stars, and both are sensitive to the dense matter equation of state. Hans Bethe first recognized that the matter in the collapsing core of a massive star has a relatively low entropy which prevents nuclear dissociation until nuclei merge near the nuclear saturation density. This recognition means that collapse continues until the core exceeds the saturation density. This prediction forms the foundation for modern simulations of supernovae. These supernovae sample matter up to about twice nuclear saturation density, but neutron stars are sensitive to the equation of state both near the saturation density and at several times higher densities. Two important recent developments are the discovery of two-solar mass neutron stars and refined experimental determinations of the behavior of the symmetry energy of nuclear matter near the saturation density. Combined with the assumption of causality, they imply that the radii of observed neutron stars are largely independent of their mass, and that this radius is in the range of 11 to 13 km. These theoretical results are not only consistent with expectations from theoretical studies of pure neutron matter, but also accumulated observations of both bursting and cooling neutron stars. In the near future, new pulsar timing data, which could lead to larger measured masses as well as measurements of moments of inertia, X-ray observations, such as from NICER, of bursting and other sources, and gravitational wave observations of neutron stars in merging compact binaries, will provide important new constraints on neutron stars and the dense matter equation of state. DOE DE-FG02-87ER-40317.

  18. “Knaller-Sex für alle”: Popfeminist Body Politics in Lady Bitch Ray, Charlotte Roche, and Sarah Kuttner

    Directory of Open Access Journals (Sweden)

    Carrie Smith-Prei

    2011-01-01

    Full Text Available Germany has seen a recent upsurge in publications proclaiming that feminism is again an urgent matter for a new generation of women. Faced with the reactionary demography debate and the hegemony of second-wave feminism, young writers, musicians, journalists, and critics call for new models of feminism relevant to women today. As one of these viable models, popfeminism draws on dominant trends in mass culture, on pop’s forty-year history as a cultural prefix in Germany, and on traditional feminism in order to create a new, ostensibly apolitical, feminist subculture based in self-stylization and individual autonomy. Shared by many popfeminist sources is the depiction of negatively coded female corporeality. This article begins with a theoretical analysis of writings on sexuality and the body in recent (popfeminist nonfiction. It then examines the negative corporeal self-stylizations in Turkish-German rapper Lady Bitch Ray’s performances since 2006, in former music video host Charlotte Roche’s novel Feuchtgebiete (2008, and in media personality Sarah Kuttner’s novel Mängelexemplar (2009. Ultimately, these negatively coded bodies are shown to uncover popfeminism’s political intent.

  19. The Description of the Costumes in Sarah Waters'Novels%沃特斯小说中的服饰描写

    Institute of Scientific and Technical Information of China (English)

    杨艳

    2016-01-01

    Sarah Waters is a famous British contemporary female writer,and there are excellent descriptions of characters'costumes in her novels. Centered on the costumes as gifts,the thesis will analyze the characters' subordinate and constrained living situations,psychology including transferring emotions,weaving illusion and asking for return,as well as the symbolic meaning reflected in the description of the costumes as gifts,in order to explore the discourse function in the costumes.%英国当代著名女作家萨拉·沃特斯每一部小说中对作为礼物的服饰都有精彩描写。围绕沃特斯小说中作为礼物的服饰,分析这些服饰描写在人物从属、压抑的境遇,试图传递情感、编织幻象、索取回报等的人物心理及对过去的象征意义三方面体现出的作用,探讨服饰在小说中重要的言说功能。

  20. Lorentz contraction of the equal-time Bethe-Salpeter amplitude in two-dimensional massless quantum electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Radozycki, Tomasz [Cardinal Stefan Wyszynski University, Faculty of Mathematics and Natural Sciences, College of Sciences, Warsaw (Poland)

    2015-09-15

    The Lorentz transformation properties of the equal-time bound-state Bethe-Salpeter amplitude in the two-dimensional massless quantum electrodynamics (the so-called Schwinger model) are considered. It is shown that while boosting a bound state (a 'meson') this amplitude is subject to approximate Lorentz contraction. The effect is exact for large separations of constituent particles ('quarks'), while for small distances the deviation is more significant. For this phenomenon to appear, the full function, i.e. with the inclusion of all instanton contributions, has to be considered. The amplitude in each separate topological sector does not exhibit such properties. (orig.)

  1. Magnetization process in the exactly solved spin-1/2 Ising-Heisenberg model on decorated Bethe lattices

    Directory of Open Access Journals (Sweden)

    J. Strečka

    2012-12-01

    Full Text Available The spin-1/2 Ising-Heisenberg model on diamond-like decorated Bethe lattices is exactly solved in the presence of the longitudinal magnetic field by combining the decoration-iteration mapping transformation with the method of exact recursion relations. In particular, the ground state and low-temperature magnetization process of the ferrimagnetic version of the considered model is investigated in detail. Three different magnetization scenarios with up to two consecutive fractional magnetization plateaus were found, whereas the intermediate magnetization plateau may either correspond to the classical ferrimagnetic spin arrangement and/or the field-induced quantum ferrimagnetic spin ordering without any classical counterpart.

  2. Relevance of various Dirac covariants in hadronic Bethe-Salpeter wave functions in electromagnetic decays of ground state vector mesons

    CERN Document Server

    Bhatnagar, Shashank; Mengesha, Yikdem

    2013-01-01

    In this work we have employed Bethe-Salpeter equation (BSE) under covariant instantaneous ansatz (CIA) to study electromagnetic decays of ground state equal mass vector mesons: $\\rho$, $\\omega$, $\\phi$, $\\psi$ and $Y$ through the process $V\\rightarrow\\gamma*\\rightarrow e^+ + e^-$. We employ the generalized structure of hadron-quark vertex function $\\Gamma$ which incorporates various Dirac structures from their complete set order-by-order in powers of inverse of meson mass. The electromagnetic decay constants for the above mesons are calculated using the leading order (LO) and the next-to-leading order (NLO) Dirac structures. The relevance of various Dirac structures in this calculation is studied.

  3. Generalized structure of hadron-quark vertex function in Bethe- Salpeter framework: Applications to leptonic decays of V-mesons

    CERN Document Server

    Bhatnagar, S; Bhatnagar, Shashank; Li, Shi-Yuan

    2006-01-01

    We employ the framework of Bethe-Salpeter equation under Covariant Instantaneous Ansatz (CIA) to study the leptonic decays of vector mesons. The calculations of decay constants f_v for rho, phi and omega mesons have been performed adopting a generalized structure of the hadron-quark vertex function Gamma which is generalized to include various Dirac covariants (other than the leading covariant i gamma cdot epsilon) from the complete set of covariants in accordance with a naive power counting rule, which allows the incorporation of them order by order in powers of the inverse of the meson mass.

  4. Web-based description of the space radiation environment using the Bethe-Bloch model

    Science.gov (United States)

    Cazzola, Emanuele; Calders, Stijn; Lapenta, Giovanni

    2016-01-01

    Space weather is a rapidly growing area of research not only in scientific and engineering applications but also in physics education and in the interest of the public. We focus especially on space radiation and its impact on space exploration. The topic is highly interdisciplinary, bringing together fundamental concepts of nuclear physics with aspects of radiation protection and space science. We give a new approach to presenting the topic by developing a web-based application that combines some of the fundamental concepts from these two fields into a single tool that can be used in the context of advanced secondary or undergraduate university education. We present DREADCode, an outreach or teaching tool to rapidly assess the current conditions of the radiation field in space. DREADCode uses the available data feeds from a number of ongoing space missions (ACE, GOES-13, GOES-15) to produce a first order approximation of the radiation dose an astronaut would receive during a mission of exploration in deep space (i.e. far from the Earth’s shielding magnetic field and from the radiation belts). DREADCode is based on an easy-to-use GUI interface available online from the European Space Weather Portal (www.spaceweather.eu/dreadcode). The core of the radiation transport computation to produce the radiation dose from the observed fluence of radiation observed by the spacecraft fleet considered is based on a relatively simple approximation: the Bethe-Bloch equation. DREADCode also assumes a simplified geometry and material configuration for the shields used to compute the dose. The approach is approximate and sacrifices some important physics on the altar of rapid execution time, which allows a real-time operation scenario. There is no intention here to produce an operational tool for use in space science and engineering. Rather, we present an educational tool at undergraduate level that uses modern web-based and programming methods to learn some of the most important

  5. Range-separated time-dependent density-functional theory with a frequency-dependent second-order Bethe-Salpeter correlation kernel

    CERN Document Server

    Rebolini, Elisa

    2015-01-01

    We present a range-separated linear-response time-dependent density-functional theory (TDDFT) which combines a density-functional approximation for the short-range response kernel and a frequency-dependent second-order Bethe-Salpeter approximation for the long-range response kernel. This approach goes beyond the adiabatic approximation usually used in linear-response TDDFT and aims at improving the accuracy of calculations of electronic excitation energies of molecular systems. A detailed derivation of the frequency-dependent second-order Bethe-Salpeter correlation kernel is given using many-body Green-function theory. Preliminary tests of this range-separated TDDFT method are presented for the calculation of excitation energies of four small molecules: N2, CO2, H2CO, and C2H4. The results suggest that the addition of the long-range second-order Bethe-Salpeter correlation kernel overall slightly improves the excitation energies.

  6. Strengthening and stretching for rheumatoid arthritis of the hand (SARAH: design of a randomised controlled trial of a hand and upper limb exercise intervention - ISRCTN89936343

    Directory of Open Access Journals (Sweden)

    Adams Jo

    2012-11-01

    Full Text Available Abstract Background Rheumatoid Arthritis (RA commonly affects the hands and wrists with inflammation, deformity, pain, weakness and restricted mobility leading to reduced function. The effectiveness of exercise for RA hands is uncertain, although evidence from small scale studies is promising. The Strengthening And Stretching for Rheumatoid Arthritis of the Hand (SARAH trial is a pragmatic, multi-centre randomised controlled trial evaluating the clinical and cost effectiveness of adding an optimised exercise programme for hands and upper limbs to best practice usual care for patients with RA. Methods/design 480 participants with problematic RA hands will be recruited through 17 NHS trusts. Treatments will be provided by physiotherapists and occupational therapists. Participants will be individually randomised to receive either best practice usual care (joint protection advice, general exercise advice, functional splinting and assistive devices or best practice usual care supplemented with an individualised exercise programme of strengthening and stretching exercises. The study assessors will be blinded to treatment allocation and will follow participants up at four and 12 months. The primary outcome measure is the Hand function subscale of the Michigan Hand Outcome Questionnaire, and secondary outcomes include hand and wrist impairment measures, quality of life, and resource use. Economic and qualitative studies will also be carried out in parallel. Discussion This paper describes the design and development of a trial protocol of a complex intervention study based in therapy out-patient departments. The findings will provide evidence to support or refute the use of an optimised exercise programme for RA of the hand in addition to best practice usual care. Trial registration Current Controlled Trials ISRCTN89936343

  7. “A horror so deep only ritual can contain it”: The art of dying in the theatre of Sarah Kane

    Directory of Open Access Journals (Sweden)

    Sara Soncini

    2010-10-01

    Full Text Available Death is an overarching presence in Sarah Kane's dramatic universe, peopled by characters charging towards death, and usually encountering it in scenes of Grand Guignol excess and grotesque violence. Death is ambivalently presented as the only escape from the nightmare of living and, at the same time, as that which makes living a nightmare; as the moment of "complete sanity and humanity" in which "everything suddenly connects", and as the ultimate, irrevocable and unredeemable act of self-annihilation. Following Kane's turn towards a more poetic form of drama, in her last two plays this discourse of death is handed over to the words nameless characters or unidentified voices who are likewise engaged in a long, painful quest for selfhood pivoting on the awareness of mortality and the simultaneous dread of and longing for death it engenders. This essay focuses on the ritual quality of the death scenes and/or narratives that crowd Kane's drama. Throughout her work, dying is never an easy, straightforward business, but rather a long, complicated, and at times frustrating mise en scène which also entails rehearsing a repertory of traditional rituals and, once their shortcomings become apparent, devising and testing new ones. The amount of theatricality involved in the art of dying is foregrounded through a web of intertextual references to other literary and/or dramatic sources; this dialogue ties in with a self-reflexive probing of the theatre's ability to provide a ritual that will be capable of "contain[ing] the horror" by supplying a formal framework to express, embody and experience death collectively.

  8. Bethe-Salpeter Approach for the $P_{33}$ Elastic Pion-Nucleon Scattering in Heavy Baryon Chiral Perturbation Theory

    CERN Document Server

    Nieves, J

    2001-01-01

    Heavy Baryon Chiral Perturbation Theory (HBChPT) to leading order provides a kernel to solve the Bethe-Salpeter equation for the $P_{33}$ ($\\Delta(1232)$-channel) $\\pi-N$ system, in the infinite nucleon mass limit. Crossed Born terms include, when iterated within the Bethe-Salpeter equation, both {\\it all} one- and {\\it some} two-pion intermediate states, hence preserving elastic unitarity below the two-pion production threshold. This suggests searching for a solution with the help of dispersion relations and suitable subtraction constants, when all in-elasticities are explicitly neglected. The solution allows for a successful description of the experimental phase shift from threshold up to $\\sqrt{s}=1500$ MeV in terms of four subtraction constants. Next-to-leading order HBChPT calculations are also used to estimate the unknown subtraction constants which appear in the solution. Large discrepancies are encountered which can be traced to the slow convergence rate of HBChPT.

  9. THE MISSIONARY WOMEN IN THE INLAND OF AUSTRALIA AND THE AUSTRALIAN INLAND MISSION AS REPRESENTED IN BETH BECKETT’S LIFE MEMOIR

    Directory of Open Access Journals (Sweden)

    Evi Eliyanah

    2010-08-01

    Full Text Available This article looks at the gender dimension of religious missions administered by the Presbyterian Church in the inland Australia as represented in Beth Beckett’s life memoir written in 1947-1955. It is aimed at obtaining general ideas on the involvement of women, as the wives of missionaries, Focusing on the experience of Beth Beckett, it argues that her position as a wife of a missionary is problematic: on the one hand she did transgress the traditional idea of staying-home wife by choosing to travel along with her husband, but at the same time, she was still bound by the domestic side of the job.

  10. Multiple integral formulae for the scalar product of on-shell and off-shell Bethe vectors in SU(3)-invariant models

    CERN Document Server

    Wheeler, M

    2013-01-01

    We study the scalar product S_{l,m} between an on-shell and an off-shell Bethe state in models with SU(3)-invariance, where l and m denote the cardinalities of the two sets of Bethe roots. We construct recursion relations relating S_{l,m} to scalar products of smaller dimension, namely S_{l-1,m} and S_{l,m-1}. Solving these recursion relations we obtain new multiple integral expressions for S_{l,m}, whose integrands are (l+m) \\times (l+m) determinants, and closely related to the Slavnov determinant expression for the SU(2) scalar product.

  11. VESPRO: An Individual Patient Data Prospective Meta-Analysis of Selective Internal Radiation Therapy Versus Sorafenib for Advanced, Locally Advanced, or Recurrent Hepatocellular Carcinoma of the SARAH and SIRveNIB Trials

    Science.gov (United States)

    Gibbs, Emma; Gandhi, Mihir; Chatellier, Gilles; Dinut, Aurelia; Pereira, Helena; Chow, Pierce KH; Vilgrain, Valérie

    2017-01-01

    Background Untreated advanced hepatocellular carcinoma (HCC) has an overall poor prognosis. Currently there are 2 ongoing prospective randomized controlled trials that are evaluating the efficacy and safety of sorafenib and selective internal radiation therapy (SIRT) with yttrium-90 resin microspheres in patients with advanced HCC. The SorAfenib versus Radioembolisation in Advanced Hepatocellular carcinoma (SARAH; 459 patients) trial is being performed in Europe and the SIRt VErsus SorafeNIB (SIRveNIB; 360 patients) trial in the Asia Pacific region. Prospectively combining the results, these trials will not only allow for increased precision to estimate efficacy (in terms of survival), but will also provide increased statistical power for subgroup analyses. Objective To ensure the prospectivity and transparency of the meta-analysis. Methods The sirVEnib and SARAH merge PROject (VESPRO) is an individual, patient-data prospective meta-analysis of the SIRveNIB and SARAH randomized trials. The VESPRO protocol includes prespecified hypotheses, inclusion criteria, and outcome measures. The primary outcome measure is overall survival and secondary outcomes include tumor response rate, progression-free survival, progression in the liver as first event, and disease control in the liver. Pooling of toxicity results will allow for robust safety profiles to be established for both therapies, and provides increased statistical power to investigate treatment effects in key subgroups. Analyses will be performed in the intent-to-treat population stratified by trial. Results Both studies are expected to demonstrate a survival benefit for SIRT together with a better toxicity profile compared with sorafenib. It is also anticipated that liver progression as the first event would be longer in the intervention compared with the control. Conclusions As the results of the 2 trials are not yet known, the methodological strength is enhanced, as biases inherent in conventional meta

  12. VESPRO: An Individual Patient Data Prospective Meta-Analysis of Selective Internal Radiation Therapy Versus Sorafenib for Advanced, Locally Advanced, or Recurrent Hepatocellular Carcinoma of the SARAH and SIRveNIB Trials.

    Science.gov (United States)

    Gebski, Val; Gibbs, Emma; Gandhi, Mihir; Chatellier, Gilles; Dinut, Aurelia; Pereira, Helena; Chow, Pierce Kh; Vilgrain, Valérie

    2017-02-15

    Untreated advanced hepatocellular carcinoma (HCC) has an overall poor prognosis. Currently there are 2 ongoing prospective randomized controlled trials that are evaluating the efficacy and safety of sorafenib and selective internal radiation therapy (SIRT) with yttrium-90 resin microspheres in patients with advanced HCC. The SorAfenib versus Radioembolisation in Advanced Hepatocellular carcinoma (SARAH; 459 patients) trial is being performed in Europe and the SIRt VErsus SorafeNIB (SIRveNIB; 360 patients) trial in the Asia Pacific region. Prospectively combining the results, these trials will not only allow for increased precision to estimate efficacy (in terms of survival), but will also provide increased statistical power for subgroup analyses. To ensure the prospectivity and transparency of the meta-analysis. The sirVEnib and SARAH merge PROject (VESPRO) is an individual, patient-data prospective meta-analysis of the SIRveNIB and SARAH randomized trials. The VESPRO protocol includes prespecified hypotheses, inclusion criteria, and outcome measures. The primary outcome measure is overall survival and secondary outcomes include tumor response rate, progression-free survival, progression in the liver as first event, and disease control in the liver. Pooling of toxicity results will allow for robust safety profiles to be established for both therapies, and provides increased statistical power to investigate treatment effects in key subgroups. Analyses will be performed in the intent-to-treat population stratified by trial. Both studies are expected to demonstrate a survival benefit for SIRT together with a better toxicity profile compared with sorafenib. It is also anticipated that liver progression as the first event would be longer in the intervention compared with the control. As the results of the 2 trials are not yet known, the methodological strength is enhanced, as biases inherent in conventional meta-analyses are avoided. This has the effect of providing

  13. Optical properties of bulk semiconductors and graphene/boron nitride: the Bethe-Salpeter equation with derivative discontinuity-corrected density functional energies

    DEFF Research Database (Denmark)

    Yan, Jun; Jacobsen, Karsten W.; Thygesen, Kristian S.

    2012-01-01

    We present an efficient implementation of the Bethe-Salpeter equation (BSE) for optical properties of materials in the projector augmented wave method Grid-based projector-augmented wave method (GPAW). Single-particle energies and wave functions are obtained from the Gritsenko, Leeuwen, Lenthe...

  14. Exact Bethe ansatz solution for a quantum field model of interacting scalar fields in quasi-two dimensions

    CERN Document Server

    Kundu, Anjan

    2016-01-01

    Integrable quantum field models are known to exist mostly in one space-dimension. Exploiting the concept of multi-time in integrable systems and a Lax matrix of higher scaling order, we construct a novel quantum field model in quasi-two dimensions involving interacting fields. The Yang-Baxter integrability is proved for the model by finding a new kind of commutation rule for its basic fields, representing nonstandard scalar fields along the transverse direction. In spite of a close link with the quantum Landau-Lifshitz equation, the present model differs widely from it, in its content and the result obtained. Using further the algebraic Bethe ansatz we solve exactly the eigenvalue problem of this quantum field model for all its higher conserved operators. The idea presented here should instigate the construction of a novel class of integrable field and lattice models and exploration of a new type of underlying algebras.

  15. Real-time approach to the optical properties of solids and nanostructures: Time-dependent Bethe-Salpeter equation

    Science.gov (United States)

    Attaccalite, C.; Grüning, M.; Marini, A.

    2011-12-01

    Many-body effects are known to play a crucial role in the electronic and optical properties of solids and nanostructures. Nevertheless, the majority of theoretical and numerical approaches able to capture the influence of Coulomb correlations are restricted to the linear response regime. In this work, we introduce an approach based on a real-time solution of the electronic dynamics. The proposed approach reduces to the well-known Bethe-Salpeter equation in the linear limit regime and it makes it possible, at the same time, to investigate correlation effects in nonlinear phenomena. We show the flexibility and numerical stability of the proposed approach by calculating the dielectric constants and the effect of a strong pulse excitation in bulk h-BN.

  16. Optical properties of Cu-chalcogenide photovoltaic absorbers from self-consistent G W and the Bethe-Salpeter equation

    Science.gov (United States)

    Körbel, Sabine; Kammerlander, David; Sarmiento-Pérez, Rafael; Attaccalite, Claudio; Marques, Miguel A. L.; Botti, Silvana

    2015-02-01

    Self-consistent G W calculations and the solution of the Bethe-Salpeter equation are to date the best available approaches to simulate electronic excitations in a vast class of materials, ranging from molecules to solids. However, up to now numerical instabilities made it impossible to use these techniques to calculate optical absorption spectra of the best-known thin-film absorbers for solar cells: Cu(In ,Ga )(S ,Se ) 2 chalcopyrites and Cu2ZnSn(S ,Se ) 4 kesterites/stannites. We show here how to solve this problem using a finite-difference method in k space to evaluate the otherwise diverging dipole matrix elements, obtaining an excellent agreement with experiments. Having established the validity of this approach, we use it then to calculate the optical response of the less studied, but promising, Cu2ZnGe(S ,Se ) 4 compounds, opening the way to predictive calculations of still unknown materials.

  17. Resolution of the GL(3) - O(3) state labelling problem via O(3)-invariant Bethe subalgebra of the twisted Yangian

    CERN Document Server

    Jarvis, P D

    2004-01-01

    The labelling of states of irreducible representations of GL(3) in an O(3) basis is well known to require the addition of a single O(3)-invariant operator, to the standard diagonalisable set of Casimir operators in the subgroup chain GL(3) - O(3) - O(2). Moreover, this `missing label' operator must be a function of the two independent cubic and quartic invariants which can be constructed in terms of the angular momentum vector and the quadrupole tensor. It is pointed out that there is a unique (in a well-defined sense) combination of these which belongs to the O(3) invariant Bethe subalgebra of the twisted Yangian Y(GL(3);O(3)) in the enveloping algebra of GL(3).

  18. Fast iterative solution of the Bethe-Salpeter eigenvalue problem using low-rank and QTT tensor approximation

    Science.gov (United States)

    Benner, Peter; Dolgov, Sergey; Khoromskaia, Venera; Khoromskij, Boris N.

    2017-04-01

    In this paper, we propose and study two approaches to approximate the solution of the Bethe-Salpeter equation (BSE) by using structured iterative eigenvalue solvers. Both approaches are based on the reduced basis method and low-rank factorizations of the generating matrices. We also propose to represent the static screen interaction part in the BSE matrix by a small active sub-block, with a size balancing the storage for rank-structured representations of other matrix blocks. We demonstrate by various numerical tests that the combination of the diagonal plus low-rank plus reduced-block approximation exhibits higher precision with low numerical cost, providing as well a distinct two-sided error estimate for the smallest eigenvalues of the Bethe-Salpeter operator. The complexity is reduced to O (Nb2) in the size of the atomic orbitals basis set, Nb, instead of the practically intractable O (Nb6) scaling for the direct diagonalization. In the second approach, we apply the quantized-TT (QTT) tensor representation to both, the long eigenvectors and the column vectors in the rank-structured BSE matrix blocks, and combine this with the ALS-type iteration in block QTT format. The QTT-rank of the matrix entities possesses almost the same magnitude as the number of occupied orbitals in the molecular systems, No

  19. Interview With Dr. Sarah Jarvis

    Directory of Open Access Journals (Sweden)

    J. Sawicki

    2016-06-01

    Full Text Available ...... “I’ve been a GP trainer for 20 years, and I hope that I’ve been a role model to some of them. Over the years, about seven of my female trainees have ended up working at the practice with me. So I certainly think I must have been doing something right. “I would very much say to a woman going into medicine today, you can do absolutely everything that a man can do. Some women do take time out to have babies that does not make you a second class citizen and it absolutely does not mean, by any means, that you can’t do everything that you want to do. You should, just maybe not do it all at once. It depends on the person.” .......

  20. Reduction of the Bethe-Salpeter equation for the scattering amplitude of the particles with spin 1 to system of the integral equations for invariant functions

    CERN Document Server

    Loginov, A Y

    2002-01-01

    Bethe-Salpeter equation for the massive particles with spin 1 is considered. The scattering amplitude decomposition of the particles with spin 1 by relativistic tensors is derived. The transformation coefficients from helicity amplitudes to invariant functions is found. The integral equations system for invariant functions is obtained and partial decomposition of this system is performed. Equivalent system of the integral equation for the partial helicity amplitudes is presented.

  1. Prediction of electric field frequency correlations for randomly scattering slabs in the nondiffusive regime with the scalar Bethe-Salpeter equation.

    Science.gov (United States)

    Gaind, Vaibhav; San, Aung K; Lin, Dergan; Webb, Kevin J

    2014-01-01

    We show that a scalar Bethe-Salpeter equation model captures the measured copolarized electric field frequency correlation magnitude for randomly scattering slabs in the weakly scattering, nondiffusive regime. Consequently, the model could be used to form images of tissue on the millimeter and submillimeter length scale, and for environmental sensing with comparable scatter, as dictated by the optical scattering length in relation to the scattering domain size.

  2. Resonant enhancement of thermoelectric properties by correlated hopping for the Falicov-Kimball model on Bethe lattice

    Science.gov (United States)

    Dobushovskyi, D. A.; Shvaika, A. M.; Zlatić, V.

    2017-03-01

    The effect of correlated hopping on the charge and heat transport of strongly correlated particles is studied for the Falicov-Kimball model on the Bethe lattice. Exact solutions for the one-particle density of states (DOS) and two-particle transport function (the "quasiparticle" scattering time) are derived using dynamical mean-field theory. For a wide range of the correlated hopping, the transport function exhibits singularities due to the resonant two-particle contribution, whereas the one-particle DOS does not show any anomalous features. By tuning the number of itinerant electrons, so as to bring the Fermi level close to the resonant frequency, we get a large increase of the electrical and thermal conductivities, and the thermoelectric power. When the hopping amplitude between the occupied sites is reduced sufficiently, the itinerant electrons localize in the clusters of sites occupied by f electrons. This gives rise to an additional narrow band in the DOS between the lower and upper Hubbard bands but has only a minor effect on the thermoelectric properties.

  3. Asymptotic Bethe Ansatz on the GKP vacuum as a defect spin chain: scattering, particles and minimal area Wilson loops

    CERN Document Server

    Fioravanti, Davide; Rossi, Marco

    2015-01-01

    Moving from Beisert-Staudacher equations, the complete set of Asymptotic Bethe Ansatz equations and $S$-matrix for the excitations over the GKP vacuum is found. The resulting model on this new vacuum is an integrable spin chain of length $R=2\\ln s$ ($s=$ spin) with particle rapidities as inhomogeneities, two (purely transmitting) defects and $SU(4)$ (residual R-)symmetry. The non-trivial dynamics of ${\\cal N}=4$ SYM appears in elaborated dressing factors of the 2D two-particle scattering factors, all depending on the 'fundamental' one between two scalar excitations. From scattering factors we determine bound states. In particular, we study the strong coupling limit, in the non-perturbative, perturbative and giant hole regimes. Eventually, from these scattering data we construct the $4D$ pentagon transition amplitudes (perturbative regime). In this manner, we detail the multi-particle contributions (flux tube) to the MHV gluon scattering amplitudes/Wilson loops (OPE or BSV series) and re-sum them to the Thermo...

  4. Electronic excitation energies of molecular systems from the Bethe-Salpeter equation: Example of the H2 molecule

    CERN Document Server

    Rebolini, Elisa; Savin, Andreas

    2013-01-01

    We review the Bethe-Salpeter equation (BSE) approach to the calculation of electronic excitation energies of molecular systems. We recall the general Green's function many-theory formalism and give the working equations of the BSE approach within the static GW approximation with and without spin adaptation in an orbital basis. We apply the method to the pedagogical example of the H2 molecule in a minimal basis, testing the effects of the choice of the starting one-particle Green's function. Using the non-interacting one-particle Green's function leads to incorrect energy curves for the first singlet and triplet excited states in the dissociation limit. Starting from the exact one-particle Green's function leads to a qualitatively correct energy curve for the first singlet excited state, but still an incorrect energy curve for the triplet excited state. Using the exact one-particle Green's function in the BSE approach within the static GW approximation also leads to a number of additional excitations, all of t...

  5. 3D-4D Interlinkage Of qqq Wave Functions Under 3D Support For Pairwise Bethe-Salpeter Kernels

    CERN Document Server

    Mitra, A N

    1998-01-01

    Using the method of Green's functions within a Bethe-Salpeter framework characterized by a pairwise qq interaction with a Lorentz-covariant 3D support to its kernel, the 4D BS wave function for a system of 3 identical relativistic spinless quarks is reconstructed from the corresponding 3D form which satisfies a fully connected 3D BSE. This result is a 3-body generalization of a similar 2-body result found earlier under identical conditions of a 3D support to the corresponding qq-bar BS kernel under Covariant Instaneity (CIA for short). (The generalization from spinless to fermion quarks is straightforward). To set the CIA with 3D BS kernel support ansatz in the context of contemporary approaches to the qqq baryon problem, a model scalar 4D qqq BSE with pairwise contact interactions to simulate the NJL-Faddeev equations is worked out fully, and a comparison of both vertex functions shows that the CIA vertex reduces exactly to the NJL form in the limit of zero spatial range. This consistency check on the CIA ve...

  6. Numerical study of the mixed spin-1 and spin-5/2 BEG model on the Bethe lattice

    Science.gov (United States)

    Yessoufou, R. A.; Bekhechi, S.; Hontinfinde, F.

    2011-05-01

    The mixed spin- 1 and spin-5/2 ferromagnetic Ising model with bilinear ( J) and biquadratic ( K) nearest-neighbor exchange interactions and a single-ion potential or crystal-field interaction ( D) is studied on the Bethe lattice by means of exact recursion equations. First, the phase diagram of the system at zero temperature is obtained in the (D/Jq, K/Jq) plane, where q denotes the coordination number of the lattice. Second, the sublattice magnetizations as functions of the temperature, the crystal-field and the biquadratic interaction strengths are thoroughly investigated. For q = 3, the resulting phase diagrams show first and second order phase transitions as well as compensation points where the net magnetization of the whole lattice should vanish in the antiferromagnetic version of the model. One interesting feature of the model concerns the presence of tricritical points. Our calculations show that at non-zero temperature, none of the sublattice can order separately. However, under an external magnetic field, some interesting phase diagrams with partially ordered phases arise.

  7. Effect of the Bethe surface description on the electronic excitations induced by energetic proton beams in liquid water and DNA

    Energy Technology Data Exchange (ETDEWEB)

    Abril, Isabel, E-mail: ias@ua.e [Departament de Fisica Aplicada, Universitat d' Alacant, Apartat 99, E-03080 Alacant (Spain); Denton, Cristian D.; Vera, Pablo de [Departament de Fisica Aplicada, Universitat d' Alacant, Apartat 99, E-03080 Alacant (Spain); Kyriakou, Ioanna; Emfietzoglou, Dimitris [Medical Physics Laboratory, University of Ioannina Medical School, Ioannina 451 10 (Greece); Garcia-Molina, Rafael [Departamento de Fisica - CIOyN, Universidad de Murcia, Apartado 4021, E-30080 Murcia (Spain)

    2010-06-15

    The irradiation of biological systems by energetic ion beams has multiple applications in medical physics and space radiation health, such as hadrontherapy for cancer treatment or protection of astronauts against space radiation. Therefore, for a better control and understanding of the effects of radiation damage in living tissues, it is necessary to advance an accurate description of the energy loss from the ion beam to the target. In the present work we use the dielectric formalism to calculate the probability for an energetic proton to produce electronic excitations in two targets of high biological interest, namely, liquid water and DNA. Also, the mean energy of the electronic excitations in these targets is found as a function of the incident proton energy. The electronic response of the target, characterized by its energy-loss function (ELF), is described by several models that fit the available experimental optical data (at zero momentum transfer), but use different approaches to obtain the Bethe surface, that is, to extend the ELF to any energy and momentum transferred.

  8. Effect of the Bethe surface description on the electronic excitations induced by energetic proton beams in liquid water and DNA

    Science.gov (United States)

    Abril, Isabel; Denton, Cristian D.; de Vera, Pablo; Kyriakou, Ioanna; Emfietzoglou, Dimitris; Garcia-Molina, Rafael

    2010-06-01

    The irradiation of biological systems by energetic ion beams has multiple applications in medical physics and space radiation health, such as hadrontherapy for cancer treatment or protection of astronauts against space radiation. Therefore, for a better control and understanding of the effects of radiation damage in living tissues, it is necessary to advance an accurate description of the energy loss from the ion beam to the target. In the present work we use the dielectric formalism to calculate the probability for an energetic proton to produce electronic excitations in two targets of high biological interest, namely, liquid water and DNA. Also, the mean energy of the electronic excitations in these targets is found as a function of the incident proton energy. The electronic response of the target, characterized by its energy-loss function (ELF), is described by several models that fit the available experimental optical data (at zero momentum transfer), but use different approaches to obtain the Bethe surface, that is, to extend the ELF to any energy and momentum transferred.

  9. Study of parent-child communication in joint-reading process according the investigation of Beth Ann Beschorner, foreign researcher

    Directory of Open Access Journals (Sweden)

    Maksimova A.A.

    2016-01-01

    Full Text Available The article presents the analysis carried out by Ph. D. Beth Ann Beschorner (University of Iowa, USA which concerns the training program for parents aimed at teaching them how to arrange the Dialogic reading with their childrenand and which makes it possible to conclude that due to the experience and direct contact with the written language in preschool age the idea of literacy was being formed. The article compares the empirical data obtained independently in different areas of scientific knowledge, i.e., philosophy and psychology: the study of B.A. Beschorner has a lot in common with the principles of cultural-historical psychology, formulated by L. Vygotsky, M. Lisina and other national psychologists. Although B. A. Beschorner do not stick directly to cultural-historical and activity theory, her results correspond with the basic provisions of these theories. The analysis of B.A. Beschorner’s works confirms the commonality of her findings to those obtained in terms of the cultural-historical theory. It proves that scientific thoughts even going in independent ways, may lead to similar results, which ultimately demonstrates the validity of the findings and the versatility of approaches to the problem

  10. Hans A. Bethe Prize: Cosmic Collisions Online - Compact Binary Mergers, Gravitational Waves and Gamma-Ray Bursts

    Science.gov (United States)

    Shapiro, Stuart

    2017-01-01

    Hans A. Bethe elucidated our understanding of the fundamental forces of Nature by exploring and explaining countless phenomena occurring in nuclear laboratories and in stars. With the dawn of gravitational wave astronomy we now can probe compact binary mergers - Nature's cosmic collision experiments - to deepen our understanding, especially where strong-field gravitation is involved. In addition to gravitational waves, some mergers are likely to generate observable electromagnetic and/or neutrino radiation, heralding a new era of multimessenger astronomy. Robust numerical algorithms now allow us to simulate these events in full general relativity on supercomputers. We will describe some recent magnetohydrodynamic simulations that show how binary black hole-neutron star and neutron star-neutron star mergers can launch jets, lending support to the idea that such mergers could be the engines that power short gamma-ray bursts. We will also show how the magnetorotational collapse of very massive stars to spinning black holes immersed in magnetized accretion disks can launch jets as well, reinforcing the belief that such ``collapsars'' are the progenitors of long gamma-ray bursts. Computer-generated movies highlighting some of these simulations will be shown. We gratefully acknowledge support from NSF Grants 1300903 and 1602536 and NASA Grant NNX13AH44G.

  11. Spectrum for heavy quarkonia and mixture of the relevant wave functions within the framework of Bethe-Salpeter equation

    Institute of Scientific and Technical Information of China (English)

    CHANG; ChaoHsi

    2010-01-01

    Considering the fact that some excited states of the heavy quarkonia (charmonium and bottomonium) are still missing in experimental observations and potential applications of the relevant wave functions of the bound states,we re-analyze the spectrum and the relevant wave functions of the heavy quarkonia within the framework of Bethe-Salpeter (B.S.) equation with a proper QCDinspired kernel.Such a kernel for the heavy quarkonia,relating to potential of the non-relativistic quark model,is instantaneous,so we call the corresponding B.S.equation as BS-In equation throughout the paper.Particularly,a new way to solve the B.S.equation,which is different from the traditional ones,is proposed here,and with it not only the known spectrum for the heavy quarkonia is re-generated,but also an important issue is brought in,i.e.,the obtained solutions of the equation ‘automatically’ include the ‘fine’,‘hyperfine’ splittings and the wave function mixture,such as S-D wave mixing in J PC = 1-states,P-F wave mixing in J PC = 2 ++ states for charmonium,bottomonium etc.It is pointed out that the best place to test the wave mixture probably is at Z-factory (e + e-collider running at Z-boson pole with extremely high luminosity).

  12. Thermodynamic Bethe ansatz for non-equilibrium steady states: exact energy current and fluctuations in integrable QFT

    Science.gov (United States)

    Castro-Alvaredo, Olalla; Chen, Yixiong; Doyon, Benjamin; Hoogeveen, Marianne

    2014-03-01

    We evaluate the exact energy current and scaled cumulant generating function (related to the large-deviation function) in non-equilibrium steady states with energy flow, in any integrable model of relativistic quantum field theory (IQFT) with diagonal scattering. Our derivations are based on various recent results of Bernard and Doyon. The steady states are built by connecting homogeneously two infinite halves of the system thermalized at different temperatures Tl, Tr, and waiting for a long time. We evaluate the current J(Tl, Tr) using the exact QFT density matrix describing these non-equilibrium steady states and using Zamolodchikov’s method of the thermodynamic Bethe ansatz (TBA). The scaled cumulant generating function is obtained from the extended fluctuation relations which hold in integrable models. We verify our formula in particular by showing that the conformal field theory (CFT) result is obtained in the high-temperature limit. We analyze numerically our non-equilibrium steady-state TBA equations for three models: the sinh-Gordon model, the roaming trajectories model, and the sine-Gordon model at a particular reflectionless point. Based on the numerics, we conjecture that an infinite family of non-equilibrium c-functions, associated with the scaled cumulants, can be defined, which we interpret physically. We study the full scaled distribution function and find that it can be described by a set of independent Poisson processes. Finally, we show that the ‘additivity’ property of the current, which is known to hold in CFT and was proposed to hold more generally, does not hold in general IQFT—that is, J(Tl, Tr) is not of the form f(Tl) - f(Tr).

  13. Bethe Ansatz, Inverse Scattering Transform and Tropical Riemann Theta Function in a Periodic Soliton Cellular Automaton for A_n^{(1}

    Directory of Open Access Journals (Sweden)

    Atsuo Kuniba

    2010-01-01

    Full Text Available We study an integrable vertex model with a periodic boundary condition associated with U_q(A_n^{(1} at the crystallizing point q=0. It is an (n+1-state cellular automaton describing the factorized scattering of solitons. The dynamics originates in the commuting family of fusion transfer matrices and generalizes the ultradiscrete Toda/KP flow corresponding to the periodic box-ball system. Combining Bethe ansatz and crystal theory in quantum group, we develop an inverse scattering/spectral formalism and solve the initial value problem based on several conjectures. The action-angle variables are constructed representing the amplitudes and phases of solitons. By the direct and inverse scattering maps, separation of variables into solitons is achieved and nonlinear dynamics is transformed into a straight motion on a tropical analogue of the Jacobi variety. We decompose the level set into connected components under the commuting family of time evolutions and identify each of them with the set of integer points on a torus. The weight multiplicity formula derived from the q=0 Bethe equation acquires an elegant interpretation as the volume of the phase space expressed by the size and multiplicity of these tori. The dynamical period is determined as an explicit arithmetical function of the n-tuple of Young diagrams specifying the level set. The inverse map, i.e., tropical Jacobi inversion is expressed in terms of a tropical Riemann theta function associated with the Bethe ansatz data. As an application, time average of some local variable is calculated.

  14. Edge-to-site reduction of Bethe-Peierls approximation for nearest neighbor exclusion cubic lattice particle systems and thermodynamic modeling of liquid silicates.

    Science.gov (United States)

    Vladimirov, Igor; Jak, Eugene

    2007-04-28

    We study an interacting particle system on the simple cubic lattice satisfying the nearest neighbor exclusion (NNE) which forbids any two nearest sites to be simultaneously occupied. Under the constraint, we develop an edge-to-site reduction of the Bethe-Peierls entropy approximation of the cluster variation method. The resulting NNE-corrected Bragg-Williams approximation is applied to statistical mechanical modeling of a liquid silicate formed by silica and a univalent network modifier, for which we derive the molar Gibbs energy of mixing and enthalpy of mixing and compare the predictions with available thermodynamic data.

  15. On the Dressing Factors, Bethe Equations and Yangian Symmetry of Strings on AdS3 x S3 x T4

    CERN Document Server

    Borsato, Riccardo; Sfondrini, Alessandro; Stefanski, Bogdan; Torrielli, Alessandro

    2016-01-01

    Integrability is believed to underlie the AdS3/CFT2 correspondence with sixteen supercharges. We elucidate the role of massless modes within this integrable framework. Firstly, we find the dressing factors that enter the massless and mixed-mass worldsheet S matrix. Secondly, we derive a set of all-loop Bethe Equations for the closed strings, determine their symmetries and weak-coupling limit. Thirdly, we investigate the underlying Yangian symmetry in the massless sector and show that it fits into the general framework of Yangian integrability. In addition, we compare our S matrix in the near-relativistic limit with recent perturbative worldsheet calculations of Sundin and Wulff.

  16. Separation of contributions from deeply virtual Compton scattering and its interference with the Bethe-Heitler process in measurements on a hydrogen target

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor MI (United States). Randall Lab. of Physics; Akopov, N. [Yerevan Physics Institue (Armenia); Akopov, Z. [DESY, Hamburg (DE)](and others)

    2009-09-15

    Hard exclusive leptoproduction of real photons from an unpolarized proton target is studied in an effort to elucidate generalized parton distributions. The data accumulated during the years 1996-2005 with the HERMES spectrometer are analyzed to yield asymmetries with respect to the combined dependence of the cross section on beam helicity and charge, thereby revealing previously unseparated contributions from deeply virtual Compton scattering and its interference with the Bethe-Heitler process. The integrated luminosity is sufficient to show correlated dependences on two kinematic variables, and provides the most precise determination of the dependence on only the beam charge. (orig.)

  17. Quark-antiquark composite systems:the Bethe--Salpeter equation in the spectral-integration technique in the case of the different quark masses

    CERN Document Server

    Anisovich, A V; Markov, V N; Matveev, M A; Sarantsev, A V

    2004-01-01

    The Bethe--Salpeter equations for the quark-antiquark composite systems with different quark masses, such as $q\\bar s$ (with $q=u$,$d$), $q\\bar Q$ and $s \\bar Q$ (with $Q=c$,$b$), are written in terms of spectral integrals. For the mesons characterized by the mass $M$, spin $J$ and radial quantum number $n$, the equations are presented for the $(n,M^2)$-trajectories with fixed $J$. In the spectral-integral technique one can use the energy-dependent forces and get beyond instantaneous approximation. The mixing between states with different quark spin $S$ and angular momentum $L$ are also discussed.

  18. A New Interpretation on the Character Image of Sarah in The French Lieutenant′s Woman%《法国中尉的女人》中莎拉的人物形象新解

    Institute of Scientific and Technical Information of China (English)

    仝露华

    2015-01-01

    This paper sets out from the oriental Buddhism and Zen′s thought to re-interpret the character image of Sarah,one from The French Lieutenant′s Woman.It starts from analyzing her close relationship with nature to link her image to Buddhism and Zen′s thought.Then it analyzes her image of a Buddhist "suffering masses"and "assis-ting and enlightening sage".Sarah represents the suffering mass and she has the personality of helping others out of distress.In the last two endings of this novel,Zen′s beliefs of "impermanence"and "life or death detachment"are shadowed from the choice she makes.Her choice in the third ending is a kind of spiritual detachment and self-satis-faction representing her supreme ideological level of Buddhism and Zen′s thought.%从东方佛禅思想入手,重新解读《法国中尉的女人》中莎拉的人物形象。通过分析她与自然的紧密联系,构建她与佛禅的关系,进而指出她所折射出的佛家“受苦受难的众生”形象和“普度众生的圣僧”形象。莎拉身上有受苦大众的影子,也有救苦救难的济世者特质。她在小说后两种结局里的命运折射出了禅宗“诸行无常”和“超脱生死”的观念。她在第三种结局里的选择反映了其精神上的超脱和自我满足,达到了佛禅思想的至高境界。

  19. MacBeth.

    Science.gov (United States)

    Krauskopf, Carl H., III

    This unit for 10th grade students on "Macbeth" is intended for college bound students. It was developed as a part of a series by the Public Education Religion Studies Center at Wright State University. In the seven-week unit, students examine the Elizabethan cultural background of Shakespeare's "Macbeth," including the political, social and…

  20. Extrapolation of the Bethe equation for electron stopping powers to intermediate and low electron energies by empirical simulation of target effective mean excitation energy and atomic number

    Energy Technology Data Exchange (ETDEWEB)

    Maglevanny, I.I., E-mail: sianko@list.ru [Volgograd State Social Pedagogical University, 27 Lenin Avenue, Volgograd 400131 (Russian Federation); Smolar, V.A.; Nguyen, H.T.T. [Volgograd State Technical University, 28 Lenin Avenue, Volgograd 400131 (Russian Federation)

    2013-12-01

    A series of simple stopping power (SP) formulas, modified from the relativistic Bethe equation, is presented that is based on the concepts of target effective atomic number and mean excitation energy (MEE). The analytical model function is constructed to approximate experimental or calculated SPs at low electron energies and tend asymptotically to the relativistic Bethe function at high energies. The energy dependencies of our effective values, in contrast with theoretical approaches, are defined empirically by parametrization with tuning parameters. A least-squares fitting routine based on the Levenberg–Marquardt algorithm was developed. We utilize the material parameters and numerical calculations of SPs from optical data using the full Penn-algorithm. Our formula is thought to be applicable for energies above 60 eV. Our simulations of SPs for 41 elemental solids are found to be in good agreement with published numerical results. The flexibility of a general empirical formula is shown. Shortened formulas were developed that are applicable for particular energy ranges, and effective MEEs are proposed that differ from previously recommended values. The presented formulas may be used for analytical calculation of SPs over a broad projectile energy region.

  1. Is the Bethe-Salpeter Formalism Accurate for Excitation Energies? Comparisons with TD-DFT, CASPT2, and EOM-CCSD.

    Science.gov (United States)

    Jacquemin, Denis; Duchemin, Ivan; Blase, Xavier

    2017-03-21

    Developing ab initio approaches able to provide accurate excited-state energies at a reasonable computational cost is one of the biggest challenges in theoretical chemistry. In that framework, the Bethe-Salpeter equation approach, combined with the GW exchange-correlation self-energy, which maintains the same scaling with system size as TD-DFT, has recently been the focus of a rapidly increasing number of applications in molecular chemistry. Using a recently proposed set encompassing excitation energies of many kinds [J. Phys. Chem. Lett. 2016, 7, 586-591], we investigate here the performances of BSE/GW. We compare these results to CASPT2, EOM-CCSD, and TD-DFT data and show that BSE/GW provides an accuracy comparable to the two wave function methods. It is particularly remarkable that the BSE/GW is equally efficient for valence, Rydberg, and charge-transfer excitations. In contrast, it provides a poor description of triplet excited states, for which EOM-CCSD and CASPT2 clearly outperform BSE/GW. This contribution therefore supports the use of the Bethe-Salpeter approach for spin-conserving transitions.

  2. A Study of point of view in Sarah Waters' Victorian Trilogy%沃特斯“维多利亚三部曲”叙事视角研究

    Institute of Scientific and Technical Information of China (English)

    杨艳

    2016-01-01

    萨拉•沃特斯“维多利亚三部曲”以19世纪的伦敦为背景,生动描写中下层女性生活。围绕该系列三部小说,结合热奈特、申丹叙事视角类型,分析作者采用的叙事视角及其效果,有助于把握沃特斯早期小说的叙事特色。%Sarah Waters'Victorian Trilogy vividly describes the life of women from the middle and lower class in London in 19th century.Based on the three novels,the thesis analyzes point of view employed by Waters and its effects from the types of viewpoint offered by Genette and Shen Dan, so as to have a better understanding of the author's narrative characteristics in her early works.

  3. Developing a managerial framework for e-contracting in the agricultural business environment / J. Aubrey Marais

    OpenAIRE

    2013-01-01

    The aim of this study is to conduct a thorough theoretical study on developing a managerial framework for replacing paper based contracts with e-contracts in the agriculture environment in the North-West Province. Every business should adapt to the current economic environment, especially new technology, and need to consider the risk and reward within the industry. Businesses should analyse any new processes and investigate its impact and whether a competitive advantage is created. An e...

  4. Exact Bethe ansatz solution of a nonlinear quantum field model in quasi-two dimensions linked to the Landau-Lifshitz equation

    Science.gov (United States)

    Kundu, Anjan

    2016-12-01

    Integrable quantum field models are known to exist mostly in one space-dimension. Exploiting the concept of multi-time in integrable systems and a Lax matrix of higher scaling order, we construct a novel quantum field model in quasi-two dimensions involving interacting fields. The Yang-Baxter integrability is proved for the model by finding a new kind of commutation rule for its basic fields, representing nonstandard scalar fields along the transverse direction. In spite of a close link with the quantum Landau-Lifshitz equation, the present model differs widely from it, in its content and the result obtained. Using further the algebraic Bethe ansatz we solve exactly the eigenvalue problem of this quantum field model for all its higher conserved operators. The idea presented here should instigate the construction of a novel class of integrable field and lattice models and exploration of a new type of underlying algebras.

  5. Exact Bethe ansatz solution of a nonlinear quantum field model in quasi-two dimensions linked to the Landau–Lifshitz equation

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Anjan, E-mail: anjan.kundu@saha.ac.in

    2016-12-15

    Integrable quantum field models are known to exist mostly in one space-dimension. Exploiting the concept of multi-time in integrable systems and a Lax matrix of higher scaling order, we construct a novel quantum field model in quasi-two dimensions involving interacting fields. The Yang–Baxter integrability is proved for the model by finding a new kind of commutation rule for its basic fields, representing nonstandard scalar fields along the transverse direction. In spite of a close link with the quantum Landau–Lifshitz equation, the present model differs widely from it, in its content and the result obtained. Using further the algebraic Bethe ansatz we solve exactly the eigenvalue problem of this quantum field model for all its higher conserved operators. The idea presented here should instigate the construction of a novel class of integrable field and lattice models and exploration of a new type of underlying algebras.

  6. Phase diagram of a spin-1 magnetic bilayer by cluster variational theory: Exact results for a BEG model on a Bethe lattice with five-fold coordination

    Science.gov (United States)

    Tucker, J. W.; Balcerzak, T.; Gzik, M.; Sukiennicki, A.

    1998-09-01

    The complete global phase diagram for a magnetic spin-1 bilayer, whose interactions are described by the Blume Emery Griffiths model (BEG), is studied by cluster variational theory within the pair approximation. The results obtained, are also the exact results pertaining to the BEG model on a Bethe lattice having coordination number, z=5. Useful analytic expressions are derived for trajectories in phase space containing the second-order (continuous) phase boundaries. The physical existence of these second-order boundaries, together with the location of the first-order phase boundaries, are determined from a Gibbs free energy analysis. Detailed comparison of the results with those of other workers on this, and closely related systems, is made.

  7. 一位近代西方来华女性的中国观——萨拉·康格和她的《北京信札》%Sarah Conger and Her Letters from Peking, with Particular Reference to the Empress Dowager and the Women of China

    Institute of Scientific and Technical Information of China (English)

    郑永福; 郑丹群

    2009-01-01

    萨拉·康格(Sarah Pike Conger)(《北京信札》(沈春蕾等译,南京出版社,2006年版)是一本值得玩味的书。该书与绝大多数西方来华人士的视角不同,因而看到了一个与众不同的中国,也表达了与众不同的中国观。

  8. Three Sovereigns for Sarah: Sorcery and Sources.

    Science.gov (United States)

    Miller, Charlotte

    1986-01-01

    In describing a public television program about the Salem witch trials, this article discusses the authenticity of props, the accuracy of events, and some errors in the production. It also points out some inaccuracies in sources and other sources that would be valuable for teaching seventeenth century colonial history. (SRT)

  9. Scalar composite boson masses in the SU(2){sub TC} x SU(3){sub L} x U(1){sub x} model and the normalized Bethe-Salpeter equation

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Adriano Doff Sotta [Universidade Tecnologica Federal do Parana (UTFPR), Pato Branco, PR (Brazil)

    2011-07-01

    Full text: Scalar composite boson masses have been computed in QCD and Technicolor theories with the help of the homogeneous Bethe-Salpeter equation (BSE), resulting in a scalar mass that is twice the dynamically generated fermion or technifermion mass (m{sub dyn}). In the A. Doff, A. A. Natale and P. S. Rodrigues da Silva, Phys. Rev. D 80, 055005 (2009) we study the effect of the normalization condition on the determination of scalar boson masses in dynamically broken gauge theories and verify that the normalization condition does not modify the value of the scalar boson mass when its wave function has the asymptotic behavior exactly as predicted by the OPE. However in walking (or quasi-conformal) gauge theories the asymptotic behavior of fermionic self-energies and the wave function of scalar bound states are dominated by higher order interactions and are characterized by a much harder decrease with the momentum, therefore, in this case, we show that the normalization condition of the BSE do constrain the scalar masses. In this work we apply some results obtained in the cited reference to the model described in A. Doff, Phys. Rev. D 81, 117702 (2010), in particular we compute the Higgs boson masses generated in the model assuming the effects of mixing in the wave function of scalar bound states due to the U(1){sub x} interaction of U' and D' techniquarks. (author)

  10. Dynamic mean field theory for lattice gas models of fluids confined in porous materials: higher order theory based on the Bethe-Peierls and path probability method approximations.

    Science.gov (United States)

    Edison, John R; Monson, Peter A

    2014-07-14

    Recently we have developed a dynamic mean field theory (DMFT) for lattice gas models of fluids in porous materials [P. A. Monson, J. Chem. Phys. 128(8), 084701 (2008)]. The theory can be used to describe the relaxation processes in the approach to equilibrium or metastable states for fluids in pores and is especially useful for studying system exhibiting adsorption/desorption hysteresis. In this paper we discuss the extension of the theory to higher order by means of the path probability method (PPM) of Kikuchi and co-workers. We show that this leads to a treatment of the dynamics that is consistent with thermodynamics coming from the Bethe-Peierls or Quasi-Chemical approximation for the equilibrium or metastable equilibrium states of the lattice model. We compare the results from the PPM with those from DMFT and from dynamic Monte Carlo simulations. We find that the predictions from PPM are qualitatively similar to those from DMFT but give somewhat improved quantitative accuracy, in part due to the superior treatment of the underlying thermodynamics. This comes at the cost of greater computational expense associated with the larger number of equations that must be solved.

  11. Optical properties of bulk semiconductors and graphene/boron nitride: The Bethe-Salpeter equation with derivative discontinuity-corrected density functional energies

    Science.gov (United States)

    Yan, Jun; Jacobsen, Karsten W.; Thygesen, Kristian S.

    2012-07-01

    We present an efficient implementation of the Bethe-Salpeter equation (BSE) for optical properties of materials in the projector augmented wave method Grid-based projector-augmented wave method (GPAW). Single-particle energies and wave functions are obtained from the Gritsenko, Leeuwen, Lenthe, and Baerends potential [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.51.1944 51, 1944 (1995)] with the modifications from Kuisma [Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.82.115106 82, 115106 (2010)] GLLBSC functional which explicitly includes the derivative discontinuity, is computationally inexpensive, and yields excellent fundamental gaps. Electron-hole interactions are included through the BSE using the statically screened interaction evaluated in the random phase approximation. For a representative set of semiconductors and insulators we find excellent agreement with experiments for the dielectric functions, onset of absorption, and lowest excitonic features. For the two-dimensional systems of graphene and hexagonal boron-nitride (h-BN) we find good agreement with previous many-body calculations. For the graphene/h-BN interface we find that the fundamental and optical gaps of the h-BN layer are reduced by 2.0 and 0.7 eV, respectively, compared to freestanding h-BN. This reduction is due to image charge screening which shows up in the GLLBSC calculation as a reduction (vanishing) of the derivative discontinuity.

  12. Health-hazard-evaluation determination report No. HHE-78-6-503, Cumberland Outpatient Department of Beth Israel Hospital, Brooklyn, New York

    Energy Technology Data Exchange (ETDEWEB)

    Messite, J.; Fannick, N.L.

    1978-07-01

    In response to a request from a representative of the nursing staff, an investigation was made of possible methadone exposures at the Cumberland Outpatient Department of Beth Israel Hospital, Brooklyn, New York, a methadone-dispensing clinic. The distribution room measured 12 feet in all dimensions and was enclosed on three sides. Methadone had previously been received in prepackaged doses, but more recently the nurses had to count the contents of each 100-count bottle of methadone hydrochloride and separate tablets or diskets into individual doses. Nurses involved in dispensing the medication reported intermittent sleepiness, itching of the face, nose, and eyes, and dryness of skin on the hands and face. Urine studies indicated no detectable methadone or methadone metabolites at a limit of 1 microgram per milliliter. There is no evidence of methadone absorption; however, they recommend that skin contact with the tablets and diskets be kept to a minimum by use of instruments for moving the pills on the counting tray, frequent clean up of dust, and periodic hand washing.

  13. Isotope shifts and transition frequencies for the S and P states of lithium: Bethe logarithms and second-order relativistic recoil

    Science.gov (United States)

    Wang, L. M.; Li, Chun; Yan, Z.-C.; Drake, G. W. F.

    2017-03-01

    Isotope shifts and total transition frequencies are calculated for the 2 2S-3 2S transition of the lithium isotopes 6Li, 7Li, 8Li, 9Li, and the halo nucleus 11Li. The accuracy is improved for previously calculated relativistic and quantum electrodynamic corrections, and in particular a disagreement for the Bethe logarithm is resolved for the ground 2S state. Our previous result is confirmed for the 2 2P state. We use the pseudostate expansion method to perform the sum over virtual intermediate states. Results for the second-order relativistic recoil term of order α2(μ/M ) 2 Ry are shown to make a significant contribution relative to the theoretical uncertainty, but because of accidental cancellations the final result for the isotope shift is nearly unchanged. However, the spin-orbit term makes an unexpectedly large contribution to the splitting isotope shift (SIS) for the 2 1/2 2P -2 3/2 2P fine structure, increasing the theoretical value for the 6Li-7Li isotopes to 0.556 31 (7 )±0.001 MHz. A comparison is made with high-precision measurements and other calculations for the SIS and for the total 2 2S-3 2S transition frequency.

  14. In vitro anticancer activities of the ursolic acid isoluted from salvia chinensis beth%中药石见穿提取物熊果酸体外抑制肿瘤细胞增殖的实验研究

    Institute of Scientific and Technical Information of China (English)

    钱晓萍; 徐敬宣; 林黎; 薛姣; 胡静; 杨阳; 胡文静; 刘宝瑞

    2012-01-01

    目的:考察从石见穿醇提物氯仿部位提取分离得到的熊果酸对5株人肿瘤细胞株的体外增殖抑制作用,为开发新的抗癌药物提供理论依据.方法:使用95%工业酒精对石见穿饮片进行提取,然后分别用石油醚、乙酸乙酯、氯仿和正丁醇依次对乙醇提取部位进行分段萃取,采用系统溶剂法、梯度洗脱、柱色谱分离、重结晶等方法,从石见穿醇提物氯仿部位中分离得到熊果酸.采用MTT法测定熊果酸对体外培养的5株人肿瘤细胞株的增殖抑制作用.结果:在体外,熊果酸对于5株细胞株具有较强的增殖抑制作用.结论:熊果酸是石见穿醇提物、氯仿部位发挥体外抗肿瘤作用的主要有效成分之一.%Objective:To investigate in vitro anticancer activities of ursolic acid isoluted from salvia chinensis beth. MethodS;The extraction from salvia chinensis beth. with 95% ethanol and then from the ethanol extraction part in turn with petroleum ether, ethyl acetate, trichloromethane and n - butanol was conducted. The means of systematic solvent extraction, gradient elution, column chromatography and recrystallization were used to separate the trichlo-romethane extraction part from salvia chinensis beth. The inhibitory effects of ursolic acid on 5 human tumor lines were measured by MTT assay. Results: The ursolic acid isoluted from salvia chinensis beth. had more effective inhibitory effects on 5 human tumor lines in vitro. Conclusion: The ursolic acid is main anticancer effective component of etha-nol extraction part and trichloromethane extraction part from salvia chinensis beth. in vitro.

  15. Medium modifications of mesons. Chiral symmetry restoration, in-medium QCD sum rules for D and ρ mesons, and Bethe-Salpeter equations

    Energy Technology Data Exchange (ETDEWEB)

    Hilger, Thomas Uwe

    2012-04-11

    The interplay of hadron properties and their modification in an ambient nuclear medium on the one hand and spontaneous chiral symmetry breaking and its restoration on the other hand is investigated. QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D- anti D and B- anti B mesons as a function of the nuclear matter density and investigate the impact of various condensates in linear density approximation. The analysis also includes D{sub s} and D{sup *}{sub 0} mesons. QCD sum rules for chiral partners in the open-charm meson sector are presented at nonzero baryon net density or temperature. We focus on the differences between pseudo-scalar and scalar as well as vector and axial-vector D mesons and derive the corresponding Weinberg type sum rules. Based on QCD sum rules we explore the consequences of a scenario for the ρ meson, where the chiral symmetry breaking condensates are set to zero whereas the chirally symmetric condensates remain at their vacuum values. The complementarity of mass shift and broadening is discussed. An alternative approach which utilizes coupled Dyson-Schwinger and Bethe-Salpeter equations for quark-antiquark bound states is investigated. For this purpose we analyze the analytic structure of the quark propagators in the complex plane numerically and test the possibility to widen the applicability of the method to the sector of heavy-light mesons in the scalar and pseudo-scalar channels, such as the D mesons, by varying the momentum partitioning parameter. The solutions of the Dyson-Schwinger equation in the Wigner-Weyl phase of chiral symmetry at nonzero bare quark masses are used to investigate a scenario with explicit but without dynamical chiral symmetry breaking.

  16. Beth Starts Like Brown Bear!

    Science.gov (United States)

    Fawcett, Gay

    1994-01-01

    Recounts a reading teacher's illuminating experience with a first grader who enjoyed reading Bill Martin's "Brown Bear" books, despite being labeled as dyslexic. Dyslexia is an elusive condition that is biological in origin and distinct from other reading problems. New research shows that reading difficulties, including dyslexia, occur as part of…

  17. From ‘Nerve Fiber Regeneration’ to ‘Functional Changes’ in the Human Brain—On the Paradigm-Shifting Work of the Experimental Physiologist Albrecht Bethe (1872–1954) in Frankfurt am Main

    Science.gov (United States)

    Stahnisch, Frank W.

    2016-01-01

    Until the beginning 1930’s the traditional dogma that the human central nervous system (CNS) did not possess any abilities to adapt functionally to degenerative processes and external injuries loomed large in the field of the brain sciences (Hirnforschung). Cutting-edge neuroanatomists, such as the luminary Wilhelm Waldeyer (1836–1921) in Germany or the Nobel Prize laureate Santiago Ramón y Cajal (1852–1934) in Spain, debated any regenerative and thus “plastic” properties in the human brain. A renewed interest arose in the scientific community to investigate the pathologies and the healing processes in the human CNS after the return of the high number of brain injured war veterans from the fronts during and after the First World War (1914–1918). A leading research center in this area was the “Institute for the Scientific Study of the Effects of Brain Injuries,” which the neurologist Ludwig Edinger (1855–1918) had founded shortly before the war. This article specifically deals with the physiological research on nerve fiber plasticity by Albrecht Bethe (1872–1954) at the respective institute of the University of Frankfurt am Main. Bethe conducted here his paradigmatic experimental studies on the pathophysiological and clinical phenomena of peripheral and CNS regeneration. PMID:26941616

  18. From ‘Nerve Fiber Regeneration’ to ‘Functional Changes’ in the Human Brain – On the Paradigm-Shifting Work of the Experimental Physiologist Albrecht Bethe (1872-1954 in Frankfurt am Main

    Directory of Open Access Journals (Sweden)

    Frank W Stahnisch

    2016-02-01

    Full Text Available Until the beginning 1930s the traditional dogma that the human central nervous system did not possess any abilities to adapt functionally to degenerative processes and external injuries loomed large in the field of the brain sciences (Hirnforschung. Cutting-edge neuroanatomists, such as the luminary Wilhelm Waldeyer (1836–1921 in Germany or the Nobel Prize laureate Santiago Ramón y Cajal (1852–1934 in Spain, debated any regenerative and thus plastic properties in the human brain. A renewed interest arose in the scientific community to investigate the pathologies and the healing processes in the human central nervous system after the return of the high number of brain injured war veterans from the fronts during and after the First World War (1914–1918. A leading research center in this area was the Institute for the Scientific Study of the Effects of Brain Injuries, which the neurologist Ludwig Edinger (1855–1918 had founded shortly before the war. This article specifically deals with the physiological research on nerve fiber plasticity by Albrecht Bethe (1872–1954 at the respective institute of the University of Frankfurt am Main. Bethe conducted here his paradigmatic experimental studies on the pathophysiological and clinical phenomena of peripheral and central nervous system regeneration.

  19. Structural Transformation and Historical Expression in Dynastic Legend of Early China---Review of Sarah Allan’s Study on the Ancient Legends of China in The Heir and The Sage

    Institute of Scientific and Technical Information of China (English)

    Yang Jie; Zhang Yuan

    2016-01-01

    As an important scholar of contem-porary sinology, Sarah Allan’s research on Chinese ancient history, on the basis of continuing the tra-dition of historical studies and archaeology, used Claude Lévi-Strauss’ theory and method of struc-turalism for reference, and opened a new path for western Sinological research. Her study of ancient legends initiated wide interest in the circles of si-nology, and was considered to be both special and very innovative. In her masterpiece The Heir and the Sage: Dynastic Legend in Early China, Allan used a method for analyzing mythology which is transformed from anthropological structuralism. She made an in-depth and systematic research on the dynastic legends from the legendary period of Tang Yao to the periods of Yin and Zhou which were recorded in the classical literature of the pre-Qin period, and discussed heuristically the his-torical perception, structure characteristics of the expressions, as well as the values of the subject in the legendary records. By summarizing the theoret-ical logic and main ideas of The Heir and the Sage, this article attempts to open a preliminary discus-sion on how to promote anthropological research on the legendary period of early China using the meth-odology of structuralism. In her Sinological re-search works which are dedicated to the study of the legendary period of ancient China, such as The Heir and the Sage: Dynastic Legend in Early Chi-na,The Shape of the Turtle:Myth ,Art and Cosmos in Early China, and The Way of Water and Sprouts of Virtue:Root Metaphor in Early Chinese Philo-sophical Thought, Allan has tried to use the meth-odology of structuralism to analyze the historical expressions and ideas contained in ancient Chinese literature. In so doing, she is seeking to re -ex-plain the historical consciousness and philosophy of ancient China. It could be said that Allan’s Sino-logical research has pronounced anthropological features concerning her problems, consciousness, and

  20. Rootsi saamid võitlevad õiguse eest maale / Sarah Edmonds

    Index Scriptorium Estoniae

    Edmonds, Sarah

    2007-01-01

    Rootsi saamide parlamendil on 1. jaanuarist õigus määrata kohalikud piirid ja jagada abiraha loomasööda ostmiseks ja kompensatsioonide maksmiseks. Nüüd soovivad saamid maaga seotud küsimuste lahendamist. Lisa: Rootsi tõrjub põlisasukate konventsiooni

  1. Suurbritannia tutvustab end Paides / Sarah Squire ; interv. Signe Kalberg

    Index Scriptorium Estoniae

    Squire, Sarah

    2002-01-01

    Paides toimub Briti saatkonna, Briti Nõukogu Suurbritannia ja Euroopa päev. Suursaadik vastab küsimustele Euroopa päeva kohta 8. mail, Suurbritannia ja EL-i suhete kohta, oma diplomaatilise tegevuse kohta

  2. Suurbritannia tutvustab end Paides / Sarah Squire ; interv. Signe Kalberg

    Index Scriptorium Estoniae

    Squire, Sarah

    2002-01-01

    Paides toimub Briti saatkonna, Briti Nõukogu Suurbritannia ja Euroopa päev. Suursaadik vastab küsimustele Euroopa päeva kohta 8. mail, Suurbritannia ja EL-i suhete kohta, oma diplomaatilise tegevuse kohta

  3. Rootsi saamid võitlevad õiguse eest maale / Sarah Edmonds

    Index Scriptorium Estoniae

    Edmonds, Sarah

    2007-01-01

    Rootsi saamide parlamendil on 1. jaanuarist õigus määrata kohalikud piirid ja jagada abiraha loomasööda ostmiseks ja kompensatsioonide maksmiseks. Nüüd soovivad saamid maaga seotud küsimuste lahendamist. Lisa: Rootsi tõrjub põlisasukate konventsiooni

  4. Fast analytic solver of rational Bethe equations

    CERN Document Server

    Marboe, Christian

    2016-01-01

    In this note we propose an approach for a fast analytic determination of all possible eigenstates of rational GL(N|M) integrable spin chains of given not too large length, in terms of Baxter Q-functions. We observe that all exceptional solutions, if any, are automatically correctly accounted. The key intuition behind the approach is that the equations on the Q-functions are determined solely by the Young diagram, and not by the choice of the rank of the GL symmetry. Hence we can choose arbitrary N and M that accommodate the desired representation. Then we consider all distinguished Q-functions at once, not only those following a certain Kac-Dynkin path.

  5. Cubierta plegada para el templo Beth Torah

    Directory of Open Access Journals (Sweden)

    Spolter, Gerald

    1963-10-01

    Full Text Available Quite recently, at the North Miami Beach Jewish park in Florida, a new temple has been completed, which is remarkable because of its metal roof structure, which is quite original, within present day trends of contemporary architecture. It has been sought to convey the impression that this roof floats on its supports, which consist of stone walls and four stiffeners. The folds shown by the roof externally are also visible from the inside. The building extends along two axes, which coincide with the two gables; along which run two beams made up of laminated sections reinforced by four angle sections. At certain points the roof cantilevers nearly 8 metres beyond its supports. The main entrance consists of a kind of arch closed with a panel into which a number of star shaped openings have been left. This is an arrangement that has both charm and an obvious symbolism. The building was initiated by setting up the gable beams with the aid of an auxiliary scaffolding, and the rest of the structure was erected in subsequent stages.El nuevo parque judío de North Miami Beach, en Florida, Estados Unidos, cuenta recientemente con un nuevo templo con cubierta de estructura metálica, muy original y, arquitectónicamente, dentro de las actuales tendencias. El sistema ha sido calificado de cubierta plegada por unos y de estructura especial por otros; aparte su denominación, una vez terminada, presenta un aspecto agradable y una interesante aplicación. Se ha tratado el conseguir dar la sensación de que esta cubierta flota sobre sus apoyos, constituidos por muros de mampostería y cuatro estribos. En el interior el techo acusa los pliegues que aparecen en el exterior. El edificio presenta dos direcciones principales, cuyos ejes coinciden con los de los caballetes Las vigas que constituyen las dos cumbreras son perfiles laminados reforzados con cuatro angulares. Algunas partes de la cubierta vuelan hasta 7,9 m, en forma de ménsulas. La entrada principal está constituida por una especie de arco, cerrado con una pantalla en la que se han dejado unos huecos en forma de estrella que tienen gracia y simbolismo indudables. La construcción se inició montando las cumbreras convenientemente apoyadas con un entramado auxiliar y siguiendo después el montaje del resto de los elementos estructurales.

  6. A Systems Evaluation of the Environmental Impact of the Aubrey Reservoir Project on Elm Fork of the Trinity River in North Texas.

    Science.gov (United States)

    1972-06-01

    viridis 5 3 1 Morus rubra 13 1 Ulmus americana 2 2 Maclura pomifera 2 Cercis canadensis 6 Acer negundo 1 1 Carya illinoensis 1 Ulmus alata 9 Ulmus rubra... Carya illinoensis 4.6 0 0.0 0.1 Ulmus alata 0.4 0.4 13.6 0 0.0 0.4 Ulmus rubra 0.3 0.4 4.6 0 0.0 0.1 q .4 228 Y I Table 17. The species of trees found...viridis 0.3 1.0 13.6 7.2 0.8 1.1 Cercis canadensis 0.1 0.3 9.1 4.4 0.5 0.4 Ulmus rubra 0.1 0.3 4.6 3.2 0.4 0.4 Carya illinoensis 0.2 4.6 7.5 0.9 0.2 229

  7. From Bethe-Salpeter Wave functions to Generalised Parton Distributions

    Science.gov (United States)

    Mezrag, C.; Moutarde, H.; Rodríguez-Quintero, J.

    2016-09-01

    We review recent works on the modelling of generalised parton distributions within the Dyson-Schwinger formalism. We highlight how covariant computations, using the impulse approximation, allows one to fulfil most of the theoretical constraints of the GPDs. Specific attention is brought to chiral properties and especially the so-called soft pion theorem, and its link with the Axial-Vector Ward-Takahashi identity. The limitation of the impulse approximation are also explained. Beyond impulse approximation computations are reviewed in the forward case. Finally, we stress the advantages of the overlap of lightcone wave functions, and possible ways to construct covariant GPD models within this framework, in a two-body approximation.

  8. From Bethe-Salpeter Wave Functions to Generalised Parton Distributions

    CERN Document Server

    Mezrag, C; Rodriguez-Quintero, J

    2016-01-01

    We review recent works on the modelling of Generalised Parton Distributions within the Dyson-Schwinger formalism. We highlight how covariant computations, using the impulse approximation, allows one to fulfil most of the theoretical constraints of the GPDs. Specific attention is brought to chiral properties and especially the so-called soft pion theorem, and its link with the Axial-Vector Ward-Takahashi identity. The limitation of the impulse approximation are also explained. Beyond impulse approximation computations are reviewed in the forward case. Finally, we stress the advantages of the overlap of lightcone wave functions, and possible ways to construct covariant GPD models within this framework, in a two-body approximation.

  9. Hans A. Bethe Prize: Mergers of Binary Compact Objects

    Science.gov (United States)

    Kalogera, Vassiliki

    2016-03-01

    The inspiral and eventual merger of two compact objects in binary systems are important in astrophysics across the electromagnetic spectrum and as potential gravitational-wave sources. In this talk I will select a few topics of current interest to highlight compact-object mergers, including in the context of multi-messenger astrophysics.

  10. KP and Toda tau functions in Bethe ansatz

    CERN Document Server

    Takasaki, Kanehisa

    2010-01-01

    Recent work of Foda and his group on a connection between classical integrable hierarchies (the KP and 2D Toda hierarchies) and some quantum integrable systems (the 6-vertex model with DWBC, the finite XXZ chain of spin 1/2, the phase model on a finite chain, etc.) is reviewed. Some additional information on this issue is also presented.

  11. Kp and Toda Tau Functions in Bethe Ansatz

    Science.gov (United States)

    Takasaki, Kanehisa

    2011-10-01

    Recent work of Foda and his group on a connection between classical integrable hierarchies (the KP and 2D Toda hierarchies) and some quantum integrable systems (the 6-vertex model with DWBC, the finite XXZ chain of spin 1/2, the phase model on a finite chain, etc.) is reviewed. Some additional information on this issue is also presented.

  12. Hans A. Bethe Prize Talk: The Physics of Stars

    Science.gov (United States)

    Arnett, David

    2009-05-01

    John von Neumann speculated that computers might become sufficiently powerful that they could be used to solve analytically intractable problems numerically (he gave turbulence as an example), and that those ``numerical experiments" could be used to provide the insight necessary to develop analytic solutions. A case study will be presented in which we attempt in this way to use computer simulations of 3D turbulent flow in presupernova stars. We find that we can reproduce the simulations surprisingly well---on average---if we replace the viscous term with an effective damping which turns out to be similar to that inferred by Kolmogorov for a turbulent cascade. Stars are gravitationally-controlled thermonuclear reactors. Abundance change (and hence evolution) occurs because of nuclear burning, and mixing. It is now possible to treat this coupled problem in a self-consistent way, free of astronomically calibrated parameters. Implications for stellar evolution, nucleosynthesis yields, core collapse, supernova explosions, helio-seismology, and solar neutrinos will be discussed. It is argued that advances in the treatment of stellar fluid dynamics, along with new developments in laboratory astrophysics, now allow far more reliable predictions of how stars behave.

  13. Sarah Bernhardt's 'Doctor God': Jean-Samuel Pozzi (1846-1918).

    Science.gov (United States)

    de Costa, Caroline; Miller, Francesca

    2007-10-01

    Samuel Pozzi was a major figure in the early development of modern gynaecological surgery. His textbook, A Treatise on Gynaecology, published in French in 1890 and rapidly translated into five other languages, was the first internationally acclaimed text integrating modern principles of anaesthesia, antisepsis, diagnosis, surgical technique and postoperative care, and in later editions remained a standard reference up to the 1930s. He was the author of more than 400 papers on gynaecological and general abdominal surgery and his technical expertise drew surgeons from all over the world to his theatre in the Hospital Broca, in one of the poorer parts of Paris. He was equally successful in several professional fields apart from medicine. However, his name is now little known in the English-speaking world. This short biography aims to re-introduce Pozzi to readers of English.

  14. Sarah Kay, Terence Cave & Malcolm Bowie, eds. A Short History of French Literature

    Directory of Open Access Journals (Sweden)

    Anne-Marie SMITH-DI BIASIO

    2006-06-01

    Full Text Available At once kaleidoscopic and telescopic, the book presents three periods of French literature, the Middle Ages, the Early Modern and the Modern, in both overview and close-up. A triptych by three authors, each an eminent academic, and indeed emblematic specialist in their field, it condenses a remarkable amount of scholarship, close reading and critical practice. If three distinct voices emerge, they also converse, since there are echoes and overlaps between sections.This is a carefully crafted,...

  15. Preparing our Paralympians: research and development at Ossur, UK. Interview by Sarah A. Curran.

    Science.gov (United States)

    Hirons, Richard

    2012-09-01

    In the last 25 years, the continuous evolution in the design of prostheses for individuals with transfemoral and transtibial amputations has been remarkable. Mirroring this development is the dependency and expectancy of the prosthesis technology by the athletes, coaches and other personnel involved in creating Paralympians of today and the future. Össur is recognised as a leader in designing innovative prosthetic products that have contributed worldwide to developing leading Paralympians. The opening section of this article presents an overview of the new Össur products for 2012. Discussion is also focussed on how Össur's high-function prosthetic products are integrated into an athlete's training regime. With involvement of the clinical team discussion is also expanded to recognise the important contribution coaching staff has on optimising performance of a Paralympian's training regime. The dialogue continues with a viewpoint on whether Oscar Pistorius, the face of Össur who wears Flex-Foot Cheetah blades, should participate in the Olympics and Paralympics. While the conclusion of this article may leave more questions than answers, the technology and products offered by Össur provide for a credible foundation and preparation for future challenges beyond the London 2012 Paralympic Games.

  16. Sarah Le Menestrel. La voie des Cadiens. Tourisme et identité en Louisiane.

    Directory of Open Access Journals (Sweden)

    Nathalie Dessens

    2006-03-01

    Full Text Available Cet ouvrage, publié dans la collection « Histoire et Société, Cultures Américaines », est une belle étude ethnologique du récent renouveau de la culture cadienne en Louisiane. L’introduction explique clairement les cadres méthodologiques de cette étude de terrain, menée au sein même de la communauté cadienne. Elle évoque aussi les divers problèmes inhérents à l’enquête anthropologique, entre autres celui du rôle et des implications du chercheur. Le corps de l’ouvrage se compose de trois parti...

  17. 大杀伤力女人

    Institute of Scientific and Technical Information of China (English)

    刘伟民

    2008-01-01

    <正>三个女人一台戏,二十三个女人,而且每个唱家班,怎会不是件大杀伤力武器?而能够驾驭Anastacia、Angelique Kidjo、Beth Gibbons、Beth Orton、Beverly Knight、Bonnie Raitt、Céline Dion、Dido、Faith Hill、Fengie、GladysKnight、Isobel Campbell、Joss Stone、k.d.lang、KT Tunstall、Madonna、Martha Wainwright、Melissa Etheridge、Pink、Sarah McLachlan、Shakira、Shingai Shoniwa和Sugababes,将每个巨星变成自己的和唱小歌女,相信只有Annie Lennox。

  18. A longitudinal, qualitative study exploring sustained adherence to a hand exercise programme for Rheumatoid Arthritis evaluated in the SARAH Trial

    OpenAIRE

    2016-01-01

    Purpose:\\ud This study explores the experience of participants taking part in a hand exercise programme for people with rheumatoid arthritis with a focus on adherence. The exercise programme was tested in a randomised controlled trial. This parallel qualitative study will inform future implementation into clinical practice. \\ud \\ud Method:\\ud Twenty-seven semi-structured interviews from 14 participants were undertaken at 2 time points (4 and 12 months after randomisation). We collected data o...

  19. Sarah Mombin, Michèle Rossellini (dir.), Usages des vies. Le biographique hier et aujourd’hui (xviie-

    OpenAIRE

    Crépel, Pierre

    2014-01-01

    Histoire et biographie ont partie liée de mille façons. De Plutarque à Paris-Match, en passant par La Vie de Beethoven de Romain Rolland et le monumental Dictionary of Scientific Biography, dirigé par C.C. Gillispie (1970-1980), on voit bien que la biographie ne se limite pas à un seul « genre ». Les hommes politiques en vue, les historiens, les romanciers, les psychanalystes, les académiciens, les journalistes, les érudits locaux, les « savants sur le retour », ont tous leurs façons d’écrire...

  20. BOOK REVIEW - Sarah Spencer, The migration debate The Policy Press, University of Bristol, 2011, 278 pages, ISBN 978 1 847422859

    Directory of Open Access Journals (Sweden)

    Romana Emilia CRAMARENCO

    2012-12-01

    Full Text Available The migration issue is a debatable one not only from a theoretical point of view but from the policy options as well. The progress in explaining various aspects of international migration such as migration strategy, from individual to family strategy, the way of entering the new country, from “chain” to “network migration” and trans-nationality etc. has not always been followed by the most appropriate policy options. Because of political interest, policy makers are more sensitive to the public opinion perception on migration than to the scientific opinions concerning the balance between advantages and disadvantages of migrants’ presence.

  1. Should This Patient Have Weight Loss Surgery?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center.

    Science.gov (United States)

    Smetana, Gerald W; Jones, Daniel B; Wee, Christina C

    2017-06-06

    Obesity is an important public health priority in the United States. One third of U.S. adults are obese and therefore can expect higher rates of diabetes mellitus, other obesity-related comorbidities, and mortality. In 2013, the American Association of Clinical Endocrinologists, the Obesity Society, and the American Society for Metabolic and Bariatric Surgery issued a guideline that recommended weight loss (bariatric) surgery for all patients with a body mass index (BMI) of 40 kg/m2 or higher and for those with a BMI of 35 kg/m2 or greater in the presence of at least 1 obesity-related comorbidity. Among the 3 most commonly performed surgeries, the amount of excess weight reduction ranges from 49% for laparoscopic adjustable gastric banding to 76% for Roux-en-Y gastric bypass. In accredited centers, perioperative mortality averages 0.3%. In this Beyond the Guidelines, 2 experts in obesity management, a bariatric surgeon and a general internist, discuss the role of weight loss surgery versus dietary and lifestyle modification, both in general and for a specific patient who is eligible for surgery. Ethnic and age-related variability in the effects of obesity on mortality, as well as potential long-term benefits and risks of weight loss surgery for patient subgroups, are discussed.

  2. Should We Screen for Type 2 Diabetes?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center.

    Science.gov (United States)

    Smetana, Gerald W; Abrahamson, Martin J; Rind, David M

    2016-10-04

    The prevalence of diabetes in the United States is rising. Twelve percent of U.S. adults have diabetes and another 37% have impaired fasting glucose or impaired glucose tolerance. Diabetes is a major risk factor for such outcomes as cardiovascular disease, blindness, chronic kidney disease, and limb amputation. An important consideration is whether screening for abnormal glucose levels or diabetes reduces cardiovascular or all-cause morbidity and mortality. In October 2015, the U.S. Preventive Services Task Force published recommendations on screening for abnormal blood glucose and concluded that intensive lifestyle interventions have a moderate benefit in reducing progression to diabetes in patients who have abnormal blood glucose levels detected by screening. It found inadequate evidence that such screening reduces cardiovascular or all-cause mortality and no evidence of psychological or other harms from screening. The Task Force recommends glucose screening every 3 years for adults aged 40 to 70 years who are overweight or obese and do not have symptoms of diabetes. In this article, we present the case of a man who meets these criteria and explore his preferences and concerns regarding screening. Two experts then debate screening merits and benefits, the significance of abnormal blood glucose levels and diabetes as cardiovascular risk factors, and application of the guidelines to this particular patient.

  3. Should This Patient Receive an Antidepressant?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center.

    Science.gov (United States)

    Burns, Risa B; Smetana, Gerald W; Brady, Roscoe

    2017-08-01

    Depression is a major public health problem and a common cause of disability. To help physicians choose among available treatment options, the American College of Physicians recently issued a guideline titled "Nonpharmacologic Versus Pharmacologic Treatment of Adult Patients with Major Depressive Disorder." The evidence review done for the guideline found no statistically significant difference in the efficacy of second-generation antidepressants (SGAs) versus most other treatments for this disorder. However, rates of adverse events and discontinuation were generally higher in patients treated with SGAs. This Beyond the Guidelines reviews the guideline and includes a discussion between 2 experts on how they would apply it to a 64-year-old man with depression who is reluctant to begin medication. They review the data on which the guideline is based, discuss the limitations of applying the data to real-world settings, review how they would incorporate patient preferences when making treatment decisions, and outline options for patients in whom first-line therapy has failed.

  4. An experimental investigation of charge-dependent deviations from the Bethe stopping power formula

    DEFF Research Database (Denmark)

    Andersen, H.H.; Simonsen, H.; Sørensen, H.

    1969-01-01

    The stopping powers of aluminiun and tantalum for 5–13.5 MeV protons and deuterons and 8–20 MeV 3He and 4He have been measured. At identical velocities, the ratio between the stopping powers for the double-charged and the single-charged ions is systematically higher than the factor four predicted...

  5. Web-based description of the space radiation environment using the Bethe-Bloch model

    CERN Document Server

    Cazzola, Emanuele; Lapenta, Giovanni

    2015-01-01

    Space weather is a rapidly growing area not only in scientific and engineering applications but also in physics education and in the interest of the public. We focus especially on space radiation and its impact on space exploration. The topic is highly interdisciplinary bringing together fundamental concepts of nuclear physics with aspects of radiation protection and space science. We present a new approach to presenting the topic by developing a web-based tool that combines some of the fundamental concepts from these two fields in a single tool that can be developed in the context of advanced secondary or undergraduate university education. We present DREADCode, an outreach or teaching tool to asses rapidly the current conditions of the radiation field in space. DREADCode uses the available data feeds from a number of ongoing space missions to produce a first order approximation of the dose an astronaut would receive during a mission of exploration in deep space. DREADcode is based on a intuitive GUI interfa...

  6. Nuclear matter hole spectral function in the Bethe-Brueckner-Goldstone approach

    CERN Document Server

    Baldo, Marcello

    2002-01-01

    The hole spectral function is calculated in nuclear matter to assess the relevance of nucleon-nucleon short range correlations. The calculation is carried out within the Brueckner scheme of many-body theory by using several nucleon-nucleon realistic interactions. Results are compared with other approaches based on variational methods and transport theory. Discrepancies appear in the high energy region, which is sensitive to short range correlations, and are due to the different many-body treatment more than to the specific N-N interaction used. Another conclusion is that the momentum dependence of the G-matrix should be taken into account in any self consistent approach.

  7. Algebraic Bethe Ansatz for the Osp(1|2) Model with Reflecting Boundaries

    Institute of Scientific and Technical Information of China (English)

    YUE Rui-Hong; XIONG Chuan-Hua

    2001-01-01

    In the framework of graded quantum inverse scattering method, we obtain the eigenvalues and the eigenvectors of the Osp(l|2) model with reflecting boundary conditions in FBF background. The corresponding Bathe ansatz equations are obtained.

  8. Zero-order crystallization in the Bethe-Fermi homework and electron gas problems

    Science.gov (United States)

    Cambiaggio, M. C.; De Llano, M.; Plastino, A.; Szybisz, L.; Ramírez, S.

    1980-04-01

    Single-determinantal states consisting of localized, non-overlapping single-particle orbitals are used in comparison with those made up of plane wave ones to show that neutron matter prefers a "crystalline" configuration beyond a density of around 0.07 fm -3 for the ν0 homework potential. The total energy is not too high above the best Jastrow-correlated calculations. No such effect is found for the ν1 homework potential. The analogous question for the electron gas is also studied.

  9. Innovation in education : the concept of radical innovation adoption / Mary Beth Klinger

    Index Scriptorium Estoniae

    Klinger, Mary Beth

    2004-01-01

    Autor käsitleb organisatsiooni nelja ressursi - organisatsiooniline õppimine, turuorientatsioon, orientatsioon äriprotsessile, tehnoloogiline oportunism - mõju radikaalsete uuenduste ning elektroonilise äri rakendamisele haridusasutustes. Skeem

  10. Innovation in education : the concept of radical innovation adoption / Mary Beth Klinger

    Index Scriptorium Estoniae

    Klinger, Mary Beth

    2004-01-01

    Autor käsitleb organisatsiooni nelja ressursi - organisatsiooniline õppimine, turuorientatsioon, orientatsioon äriprotsessile, tehnoloogiline oportunism - mõju radikaalsete uuenduste ning elektroonilise äri rakendamisele haridusasutustes. Skeem

  11. Hans Bethe and Physics in/of the 20th Century

    Energy Technology Data Exchange (ETDEWEB)

    Schweber, Silvan [Brandeis University

    2012-12-12

    I will present some facets of Hans Bethe’s life to illustrate how I have used biography to narrate certain aspects of the history of twentieth century physics. I will focus on post World War II quantum field theory, on the relation between solid state/condensed matter physics and high energy physics, and make some observations regarding certain “top down” views in solid state physics in postmodernity.

  12. The Bethe roots of Regge cuts in strongly coupled N=4 SYM theory

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, J. [II. Institute for Theoretical Physics, Hamburg University,Luruper Chaussee 149, 22671 Hamburg (Germany); Schomerus, V. [DESY Hamburg, Theory Group,Notkestraße 85, 22607 Hamburg (Germany); Sprenger, M. [DESY Hamburg, Theory Group,Notkestraße 85, 22607 Hamburg (Germany); Institute for Theoretical Physics, ETH Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland)

    2015-07-20

    We describe a general algorithm for the computation of the remainder function for n-gluon scattering in multi-Regge kinematics for strongly coupled planar N=4 super Yang-Mills theory. This regime is accessible through the infrared physics of an auxiliary quantum integrable system describing strings in AdS{sub 5}×S{sup 5}. Explicit formulas are presented for n=6 and n=7 external gluons. Our results are consistent with expectations from perturbative gauge theory. This paper comprises the technical details for the results announced in http://dx.doi.org/10.1007/JHEP10(2014)067.

  13. Nonlinear Bethe-Heitler Pair Creation in an Intense Two-Mode Laser Field

    CERN Document Server

    Augustin, Sven

    2013-01-01

    We investigate electron-positron pair creation in the interaction of a nuclear Coulomb field and a highly intense two-mode laser field. For bichromatic laser fields, we examine the differences arising for commensurable and incommensurable frequencies in a continuous variation of the laser frequency ratio and the quantum interference effects, which may occur in the commensurable case. We show that the interference manifests in the angular distributions and the total pair-production rates of the created particles. Additionally, by varying the amplitudes of the two modes we study pair creation in a monochromatic laser wave of arbitrarily elliptical polarization.

  14. Nonperturbative Bethe-Heitler pair creation in combined high- and low-frequency laser fields

    CERN Document Server

    Augustin, Sven

    2014-01-01

    The nonperturbative regime of electron-positron pair creation by a relativistic proton beam colliding with a highly intense bichromatic laser field is studied. The laser wave is composed of a strong low-frequency and a weak high-frequency mode, with mutually orthogonal polarization vectors. We show that the presence of the high-frequency field component can strongly enhance the pair-creation rate. Besides, a characteristic influence of the high-frequency mode on the angular and energy distributions of the created particles is demonstrated, both in the nuclear rest frame and the laboratory frame.

  15. Interference Effects in Bethe-Heitler Pair Creation in a Bichromatic Laser Field

    CERN Document Server

    Augustin, Sven

    2013-01-01

    We study the creation of electron-positron pairs in the superposition of a nuclear Coulomb field and a two-color laser field of high intensity. Our focus lies on quantum interference effects, which may arise if the two laser frequencies are commensurable. We show that the interference manifests in the angular distributions of the created particles, which are discussed in the nuclear rest frame and the laboratory frame. Additionally, we demonstrate that the total pair-production rates can be affected by interference and identify the relative phase between the two laser modes, which optimizes the pair-production yield.

  16. Markov-Yukawa Transversality Principle And 3D-4D Interlinkage Of Bethe-Salpeter Amplitudes

    CERN Document Server

    Mitra, A N

    2000-01-01

    This article is designed to focus attention on the Markov-Yukawa Transversality Principle (MYTP) as a novel paradigm for an exact 3D-4D interlinkage between the corresponding BSE amplitudes, with a closely parallel treatment of $q{\\bar q}$ and $qqq$ systems, stemming from a common 4-fermion Lagrangian mediated by gluon (vector)-like exchange. This unique feature of MYTP owes its origin to a Lorentz- covariant 3D support to the BS kernel, which acts as a sort of `gauge principle' and distinguishes it from most other 3D approaches to strong interaction dynamics. Some of the principal approaches in the latter category are briefly reviewed so as to set the (less familiar) MYTP in their context. Two specific types of MYTP which provide 3D support to the BSE kernel, are considered: a) Covariant Instantaneity Ansatz (CIA); b) Covariant LF/NP ansatz (Cov.LF). Both lead to formaly identical 3D BSE reductions but produce sharply different 4D structures: Under CIA, the 4D loop integrals suffer from Lorentz mismatch of t...

  17. Conformal partition functions of critical percolation from D 3 thermodynamic Bethe Ansatz equations

    Science.gov (United States)

    Morin-Duchesne, Alexi; Klümper, Andreas; Pearce, Paul A.

    2017-08-01

    Using the planar Temperley-Lieb algebra, critical bond percolation on the square lattice can be reformulated as a loop model. In this form, it is incorporated as {{ L}}{{ M}}(2, 3) in the Yang-Baxter integrable family of logarithmic minimal models {{ L}}{{ M}}( p, p\\prime) . We consider this model of percolation in the presence of boundaries and with periodic boundary conditions. Inspired by Kuniba, Sakai and Suzuki, we rewrite the recently obtained infinite Y-system of functional equations. In this way, we obtain nonlinear integral equations in the form of a closed finite set of TBA equations described by a D 3 Dynkin diagram. Following the methods of Klümper and Pearce, we solve the TBA equations for the conformal finite-size corrections. For the ground states of the standard modules on the strip, these agree with the known central charge c  =  0 and conformal weights Δ1, s for \\renewcommand≥≥slant} s\\in {{ Z}≥slant 1} with Δr, s=\\big((3r-2s){\\hspace{0pt}}^2-1\\big)/24 . For the periodic case, the finite-size corrections agree with the conformal weights Δ0, s , Δ1, s with \\renewcommand{≥{≥slant} s\\in\\frac{1}{2}{{ Z}≥slant 0} . These are obtained analytically using Rogers dilogarithm identities. We incorporate all finite excitations by formulating empirical selection rules for the patterns of zeros of all the eigenvalues of the standard modules. We thus obtain the conformal partition functions on the cylinder and the modular invariant partition function (MIPF) on the torus. By applying q-binomial and q-Narayana identities, it is shown that our refined finitized characters on the strip agree with those of Pearce, Rasmussen and Zuber. For percolation on the torus, the MIPF is a non-diagonal sesquilinear form in affine u(1) characters given by the u(1) partition function Z2, 3(q)=Z2, 3{Circ}(q) . The u(1) operator content is {{ N}}Δ, \\barΔ=1 for Δ=\\barΔ=-\\frac{1}{24}, \\frac{35}{24} and {{ N}}Δ, \\barΔ=2 for Δ=\\barΔ=\\frac{1}{8}, \\frac{1}{3}, \\frac{5}{8} and (Δ, \\barΔ)=(0, 1), (1, 0) . This result is compatible with the general conjecture of Pearce and Rasmussen, namely Zp, p\\prime(q)=Z{Proj}p, p\\prime(q)+np, p\\prime Z{Min}p, p\\prime(q) with np, p\\prime\\in {{ Z}} , where the minimal partition function is Z{Min}2, 3(q)=1 and the lattice derivation fixes n 2,3  =  -1.

  18. Hans A. Bethe Prize: Astrophysical, observational and nuclear-physics aspects of r-process nucleosynthesis

    Science.gov (United States)

    Kratz, Karl-Ludwig

    2014-03-01

    Guided by the Solar System (S.S.) abundance peaks at A ~= 130 and A ~= 195, the basic mechanisms for the rapid neutron-capture process (the r-process) have been known for over 50 years. However, even today, all proposed scenarios and sites face problems with astrophysical conditions as well as with the necessary nuclear-physics input. In my talk, I will describe efforts in experimental and theoretical nuclear-structure data for modeling today's three groups of r-process ``observables'', i.e. the bulk S.S. isotopic abundances, the elemental abundances in metal-poor halo stars, and peculiar isotopic patterns measured in certain cosmic stardust grains. To set a historical basis, I will briefly recall our site-independent ``waiting-point'' model, with superpositions of neutron-density components and the use of the first global, unified nuclear input based on the mass model FRDM(1992). This approach provided a considerable leap forward in the basic understanding of the required astrophysical conditions, as well as of specific shell-structure properties far from stability. Starting in the early millenium, the above simple model has been replaced by more realistic, dynamical parameter studies within the high-entropy wind scenario of core-collapse supernovae, now with superpositions of entropy (S) and electron-fraction (Ye) components. Furthermore, an improved, global set of nuclear-physics data is used today, based on the new mass model FRDM(2012). With this nuclear and astrophysics parameter combination, a new fit to the S.S. r-abundances will be shown, and its improvements and remaining deficiencies in terms of underlying shell structure will be discussed. Concerning the abundance patterns in metal-poor halo stars, an interpretation of the production of ``r-rich'' (e.g. CS 22892-052) and ``r-poor'' (e.g. HD 122563) stars in terms of different (Ye), S combinations will be presented. Finally, for the third group of ``r-observables'', a possible origin of the anomalous Xe-H pattern in presolar nanodiamonds by the ``main'' component of a ``cold'' r-process is suggested.

  19. The replica symmetric solution for orthogonally constrained Heisenberg model on Bethe lattice

    Science.gov (United States)

    Concetti, Francesco

    2017-02-01

    In this paper, we study the thermodynamic properties of a system of D-components classical Heisenberg spins lying on the vertices of a random regular graph, with an unconventional first neighbor non-random interaction J{{≤ft({{\\mathbf{S}}i}\\centerdot {{\\mathbf{S}}k}\\right)}2} . We can consider this model as a continuum version of anti-ferromagnetic D-states Potts model. We compute the paramagnetic free energy, using a new approach, presented in this paper for the first time, based on the replica method. Through the linear stability analysis, we obtain an instability line on the temperature-connectivity plane that provides a bound to the appearance of a phase transition. We also argue about the character of the instability observed.

  20. Cognitive systems engineering in health care

    CERN Document Server

    Bisantz, Ann M; Fairbanks, Rollin J

    2014-01-01

    Cognitive Engineering for Better Health Care Systems, Ann M. Bisantz, Rollin J. Fairbanks, and Catherine M. BurnsThe Role of Cognitive Engineering in Improving Clinical Decision Support, Anne Miller and Laura MilitelloTeam Cognitive Work Analysis as an Approach for Understanding Teamwork in Health Care, Catherine M. BurnsCognitive Engineering Design of an Emergency Department Information System, Theresa K. Guarrera, Nicolette M. McGeorge, Lindsey N. Clark, David T. LaVergne, Zachary A. Hettinger, Rollin J. Fairbanks, and Ann M. BisantzDisplays for Health Care Teams: A Conceptual Framework and Design Methodology, Avi ParushInformation Modeling for Cognitive Work in a Health Care System, Priyadarshini R. PennathurSupport for ICU Clinician Cognitive Work through CSE, Christopher Nemeth, Shilo Anders, Jeffrey Brown, Anna Grome, Beth Crandall, and Jeremy PamplinMatching Cognitive Aids and the "Real Work" of Health Care in Support of Surgical Microsystem Teamwork, Sarah Henrickson Parker and Shawna J. PerryEngageme...

  1. Editorial, Volume 7, Issue 2

    Directory of Open Access Journals (Sweden)

    Kristy L Archuleta

    2016-12-01

    Full Text Available This issue features four articles, two profiles, and one book review. Each article adds a new contribution to the field of financial therapy. First, Dr. Asebedo applies a conflict resolution framework to money arguments. Next, Drs. Rea, Zuiker, and Mendenhall explore financial management practices among emerging adult couples. In the third paper, Drs. Ann Woodyard and Cliff Robb help to add further description of financial satisfaction. Then, Dr. Russell James offers a unique theoretical analysis of mortality salience and financial decisions. This issue also features a practitioner profile of Beth Crittenden and a scholar profile of Sarah Asebedo. Finally, we conclude with a review by Neal VanZutphen about a book entitled, The Seven Principles for Making Marriage Work.

  2. Brain Basics

    Medline Plus

    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle- ... harder for Sarah to recover normally from her low mood. It's important to remember that everyone gets " ...

  3. Euroopa püüab toime tulla idatööliste marsiga läände / Sarah Laitner, Stefan Wagstyl

    Index Scriptorium Estoniae

    Laitner, Sarah

    2006-01-01

    Mitmed EL-i nn. vanad riigid kõhklevad, kas kaotada piirangud Ida-Euroopa tööjõule. Briti valitsuse väitel on riigi majandus tööturu piirangu kaotamisest kasu saanud, samas on suurenenud noorte pikaajaline töötus. Ida-Euroopas on aga mõnes valdkonnas tekkinud tööjõupuudus. Lisa: Iiri pelgab olukorda tööjõuturul. Tabel: Riikide suhtumine tööjõu vaba liikumise piirangutesse

  4. Euroopa püüab toime tulla idatööliste marsiga läände / Sarah Laitner, Stefan Wagstyl

    Index Scriptorium Estoniae

    Laitner, Sarah

    2006-01-01

    Mitmed EL-i nn. vanad riigid kõhklevad, kas kaotada piirangud Ida-Euroopa tööjõule. Briti valitsuse väitel on riigi majandus tööturu piirangu kaotamisest kasu saanud, samas on suurenenud noorte pikaajaline töötus. Ida-Euroopas on aga mõnes valdkonnas tekkinud tööjõupuudus. Lisa: Iiri pelgab olukorda tööjõuturul. Tabel: Riikide suhtumine tööjõu vaba liikumise piirangutesse

  5. How"Stalker Sarah" Takes Thousands of selfies with stars%追星狂人萨拉的追星之路

    Institute of Scientific and Technical Information of China (English)

    Sarah Gerard; 赵越(译)

    2014-01-01

    追星的人很多,中学生也不例外。有的通过各种渠道搜集偶像资料,了解其最新动态,一说起自己的偶像就滔滔不绝;有的把自己的零花钱全都攒起来,偶像的专辑、电影、海报、签名T恤等东西无一不想收入囊中;有的甚至因为偶像的事逃课、和父母吵架、做一些很极端的事。不过凡事都有特例,美国女孩萨拉虽然追星也十分狂热,但却并未因此而迷失自我。这个普普通通的少女喜欢到处追着自己喜欢的明星合影,四年多的时间里和明星合影多达6200张,到后来甚至有些明星都主动与她合影,然而如此疯狂追星的萨拉却始终门门功课全优。萨拉究竟是怎样的一个女孩?又是如何做到追星如此成功的呢?

  6. Development and delivery of an exercise intervention for rheumatoid arthritis: strengthening and stretching for rheumatoid arthritis of the hand (SARAH) trial.

    Science.gov (United States)

    Heine, P J; Williams, M A; Williamson, E; Bridle, C; Adams, J; O'Brien, A; Evans, D; Lamb, S E

    2012-06-01

    This paper describes the development and implementation of a hand exercise intervention for rheumatoid arthritis (RA) as part of a large multi-centred randomised controlled trial in a U.K. National Health Service (NHS) setting. Participants are eligible if diagnosed with RA according to American College of Rheumatology criteria, have a history of disease activity, functional deficit or impairment in the hand and/or wrist, and have been on a stable medication regime for at least 3 months. The intervention development was informed by the current evidence base, published guidelines, clinician and expert opinion, and a pilot study. The exercise programme targets known, potentially modifiable physical impairments of the hand with 5 exercise sessions and a home exercise component over a 12 week period. The intervention will be provided to 240 participants along with usual care. A further 240 will receive usual care only as part of the control arm. Specific details of the treatments delivered are described. [ISRCTN no: 89936343].

  7. High-G Gimbal Technology Studies

    Science.gov (United States)

    1979-07-01

    will verify the proposed High-G platform concept technology. 20 a -_ REFERENCES I. Invention Disclosure "High-G Gimbal Platform,* AMPC 37b6, 30 August...1977, Aubrey Rodgers. 2. Invention Disclosure "Snap-Lock Mechanism for High-G Gimbal Platform," AMPC 3831, 24 February 1978, Aubrey Rodgers. 3...Invention Disclosure "Rea.•tion Jet Torquer," AMPC 3832, 24 February 1978, Aubrey Rodgers and Eacar L. Bailey. 21 DISTRIBUTION No. of Copies Defense

  8. Screening for lung cancer with low-dose computed tomography: grand rounds discussion from the Beth Israel Deaconess Medical Center.

    Science.gov (United States)

    Smetana, Gerald W; Boiselle, Phillip M; Schwartzstein, Richard M

    2015-04-21

    In December 2013, the U.S. Preventive Services Task Force recommended screening for lung cancer with low-dose computed tomography (LDCT) for selected current and former smokers. The Task Force based the recommendation primarily on the results of the NLST (National Lung Screening Trial). In this trial, patients randomly assigned to LDCT screening for 3 years had lower rates of both lung cancer-specific mortality and all-cause mortality (relative risk reduction, 6.7% [95% CI, 1.2% to 13.6%]; absolute risk reduction, 0.46% [CI, 0% to 0.9%]). Clinicians and health systems confront questions and challenges as they begin to implement lung cancer screening. This paper summarizes a conference during which an internist and a radiologist discuss the application of the Task Force recommendation to an individual patient.

  9. Should We Screen for Coronary Heart Disease in Asymptomatic Persons?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center.

    Science.gov (United States)

    Smetana, Gerald W; Cutlip, Donald E; Pinto, Duane S

    2016-04-05

    In March 2015, the American College of Physicians (ACP) released a clinical guideline on the value of screening for coronary heart disease (CHD) in asymptomatic persons. The guideline authors found that results of screening studies are unlikely to change patient management or the intensity of risk factor reduction strategies. Most events occur in patients who are at low to intermediate risk for CHD; and in low-risk asymptomatic patients, percutaneous coronary intervention in "screen-positive" patients does not improve outcomes and creates unnecessary risks. As a result, the ACP recommended against screening for asymptomatic patients who are at low risk for CHD. Instead, it recommended a focus on proven strategies, such as treatment of hypertension and hypercholesterolemia, to reduce risk in appropriately selected asymptomatic persons. Two discussants weigh the evidence for and against screening for CHD in asymptomatic patients with varying degrees of risk and provide recommendations for a specific patient who is uncertain whether to proceed to screening.

  10. Generalized parton distributions of the pion in a covariant Bethe-Salpeter model and light-front models

    CERN Document Server

    Frederico, T; Pasquini, B; Salme', G

    2009-01-01

    The generalized parton distributions of the pion are studied within different light-front approaches for the quark-hadron and quark-photon vertices, exploring different kinematical regions in both the valence and non-valence sector. Moments of the generalized parton distributions which enter the definition of generalized form factors are also compared with recent lattice calculations.

  11. Cultivating Culturally Fluent Leaders for the Future of Kinesiology. 2016 NAKHE Hally Beth Poindexter Young Scholar Award

    Science.gov (United States)

    James-Hassan, Martha J.

    2016-01-01

    This article posits that each content area that falls under the umbrella of kinesiology must develop a future cadre of professionals who are competent in their content knowledge and are trained as leaders who are able to understand the essential impacts of culture on their work. The intentional development of culturally fluent leaders should be a…

  12. Bethe-Heitler cascades as a plausible origin of hard spectra in distant TeV blazars

    CERN Document Server

    Zheng, Y G; Kang, S J

    2016-01-01

    Context. Very high-energy (VHE) $\\gamma$-ray measurements of distant TeV blazars can be nicely explained by TeV spectra induced by ultra high-energy cosmic rays. Aims. We develop a model for a plausible origin of hard spectra in distant TeV blazars. Methods. In the model, the TeV emission in distant TeV blazars is dominated by two mixed components. The first is the internal component with the photon energy around 1 TeV produced by inverse Compton scattering of the relativistic electrons on the synchrotron photons (SSC) with a correction for extragalactic background light absorbtion and the other is the external component with the photon energy more than 1 TeV produced by the cascade emission from high-energy protons propagating through intergalactic space. Results. Assuming suitable model parameters, we apply the model to observed spectra of distant TeV blazars of 1ES 0229+200. Our results show that 1) the observed spectrum properties of 1ES 0229+200, especially the TeV $\\gamma$-ray tail of the observed spect...

  13. Assembling the Past: Studies in the Professionalization of Archaeology, edited by Alice B Kehoe and Mary Beth Emmerichs, 1999

    Directory of Open Access Journals (Sweden)

    David L. Browman

    2000-11-01

    Full Text Available The Assembling The Past volume, which focuses upon the issues of discrimination and marginalization in archaeology, is the delayed publication of two 1989 symposia dedicated to the history of archaeology - one in January of that year at the First Joint Archaeological Congress in Baltimore, chaired by Alice Kehoe and Jane Waldbaum, and the other in November at the 88th annual meetings of the American Anthropological Association, chaired by Nathan Reyman. Because of the time delay, in some cases the chapter authors have already published later papers, building on their presentations, so that the reader may already be familiar with part of the arguments presented. Nevertheless, I evaluate this work as a "must have" for any student of the history of Americanist archaeology.

  14. Bethe subalgebras in affine Birman-Murakami-Wenzl algebras and flat connections for q-KZ equations

    Science.gov (United States)

    Isaev, A. P.; Kirillov, A. N.; Tarasov, V. O.

    2016-05-01

    Commutative sets of Jucys-Murphy elements for affine braid groups of {A}(1),{B}(1),{C}(1),{D}(1) types were defined. Construction of R-matrix representations of the affine braid group of type {C}(1) and its distinguished commutative subgroup generated by the {C}(1)-type Jucys-Murphy elements are given. We describe a general method to produce flat connections for the two-boundary quantum Knizhnik-Zamolodchikov equations as necessary conditions for Sklyanin's type transfer matrix associated with the two-boundary multicomponent Zamolodchikov algebra to be invariant under the action of the {C}(1)-type Jucys-Murphy elements. We specify our general construction to the case of the Birman-Murakami-Wenzl algebras (BMW algebras for short). As an application we suggest a baxterization of the Dunkl-Cherednik elements {Y}\\prime {{s}} in the double affine Hecke algebra of type A. Dedicated to Professor Rodney Baxter on the occasion of his 75th Birthday.

  15. Superconductivity a new approach based on the Bethe-Salpeter equation in the mean-field approximation

    CERN Document Server

    Malik, G P

    2016-01-01

    Given the Debye temperature of an elemental superconductor (SC) and its Tc, BCS theory enables one to predict the value of its gap 0 at T = 0, or vice versa. This monograph shows that non-elemental SCs can be similarly dealt with via the generalized BCS equations (GBCSEs) which, given any two parameters of the set {Tc, 10, 20 > 10}, enable one to predict the third. Also given herein are new equations for the critical magnetic field and critical current density of an elemental and a non-elemental SC — equations that are derived directly from those that govern pairing in them. The monograph includes topics that are usually not covered in any one text on superconductivity, e.g., BCS-BEC crossover physics, the long-standing puzzle posed by SrTiO3, and heavy-fermion superconductors — all of which are still imperfectly understood and therefore continue to avidly engage theoreticians. It suggests that addressing the Tcs, s and other properties (e.g., number densities of charge carriers) of high-Tc SCs via GBCSE...

  16. G/G gauged WZW-matter model, Bethe Ansatz for q-boson model and Commutative Frobenius algebra

    Energy Technology Data Exchange (ETDEWEB)

    Okuda, Satoshi [Department of Physics, Rikkyo University,Toshima, Tokyo 171-8501 (Japan); Yoshida, Yutaka [High Energy Accelerator Research Organization (KEK),Tsukuba, Ibaraki 305-0801 (Japan)

    2014-03-03

    We investigate the correspondence between two dimensional topological gauge theories and quantum integrable systems discovered by Moore, Nekrasov, Shatashvili. This correspondence means that the hidden quantum integrable structure exists in the topological gauge theories. We showed the correspondence between the G/G gauged WZW model and the phase model in JHEP 11 (2012) 146 (arXiv:1209.3800). In this paper, we study a one-parameter deformation for this correspondence and show that the G/G gauged WZW model coupled to additional matters corresponds to the q-boson model. Furthermore, we investigate this correspondence from the viewpoint of the commutative Frobenius algebra, the axiom of the two dimensional topological quantum field theory.

  17. Hans A. Bethe Prize Talk: Neutron stars and stellar collapse: the physics of strongly interacting Fermi systems

    Science.gov (United States)

    Pethick, C. J.

    2011-04-01

    The talk will touch on a number of themes in the application of many-body theory to neutron stars and stellar collapse. One of these will be the composition and equation of state of nuclear matter. Specific topics will include nuclei in neutron stars, superfluidity and superconductivity of nuclear matter, and inhomogeneous phases of nuclear matter. A second major theme will be neutrino processes in dense matter: neutrino emission is the most powerful cooling mechanism for young neutron stars, and rates of neutrino processes are a key ingredient in simulations of stellar collapse.

  18. Cultivating Culturally Fluent Leaders for the Future of Kinesiology. 2016 NAKHE Hally Beth Poindexter Young Scholar Award

    Science.gov (United States)

    James-Hassan, Martha J.

    2016-01-01

    This article posits that each content area that falls under the umbrella of kinesiology must develop a future cadre of professionals who are competent in their content knowledge and are trained as leaders who are able to understand the essential impacts of culture on their work. The intentional development of culturally fluent leaders should be a…

  19. An Empirical Test of a Comprehensive Model for Predicting Successful Information Systems Implementation

    Science.gov (United States)

    1989-12-01

    among the issues related to IS implementation success. A study by Albert Lederer and Aubrey Mendelow concentrates on just that issue. Specifically, they...Wiley & Sons, 1987. 26. Lederer, Albert L. and Aubrey L. Mendelow . "Information Systems Planning: Top Management Takes Control, Business Horizons, 31

  20. Sherry Ortner

    Directory of Open Access Journals (Sweden)

    Sergio Daniel López

    2006-01-01

    Full Text Available A photograph of Franz Boas posing in a Kwakiutl Ceremonial Dance and a copy of the Universal Declaration of Human Rights greets visitors in Sherry Beth Ortner’s office in the Department of Anthropology at the University of California, Los Angeles (UCLA. Professor Sherry Ortner received her Ph.D. from University of Chicago, and began her extensive field work with the Sherpas in Nepal. In 1972, her article “Is Female to Male as Nature is to Culture” became one of the seminal works in feminist anthropology. Ortner is currently a Distinguished Professor of Anthropology at UCLA, where she teaches courses on Critical Social Theory and Ethnographic Imagination. She has taught at Sarah Lawrence College, University of Michigan, University of California, Berkeley, and Columbia University. In this interview we discuss Ortner’s academic and personal life, from her initial field work experiences to her current research on the Hollywood industry, including her interests in feminist anthropology and her work on capitalism and social change. We had the opportunity to meet both a brilliant anthropologist and a joyful person.

  1. Sarah Dellmann: Widerspenstige Körper. Körper, Kino, Sprache und Subversion in Tod Brownings FREAKS und Filmen mit Lon Chaney. Marburg: Schüren Verlag 2009.

    Directory of Open Access Journals (Sweden)

    Fabian Tietke

    2010-11-01

    Full Text Available Im vorliegenden Band werden Filme des in den 1920er und 1930er Jahren sehr erfolgreichen Regisseurs Tod Browning analysiert, insbesondere sein heute bekanntestes Werk Freaks. Mithilfe historischer Kontextualisierungen und eines filmwissenschaftlichen Instrumentariums untersucht Dellmann die These, dass sich in diesem Werk Spuren eines heute verloren gegangenen Körperverständnisses finden lassen – vor allem andere Repräsentationen von Behinderung und behinderten männlichen Körpern.The present anthology analyzes several movies of the director Tod Browning (who was very successful in the 1920s and 1930s, particularly the movie Freaks which, today, is his most well-known work. Using historical contextualizations and a Film Studies background, Dellmann explores the thesis that this work shows traces of an understanding of the body that today no longer exist, above all the representation of disabilities and disabled male bodies.

  2. Brain Basics

    Medline Plus

    Full Text Available ... sends impulses and extends from cell bodies to meet and deliver impulses to another nerve cell. Axons ... in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle-aged woman who ...

  3. Brain Basics

    Medline Plus

    Full Text Available ... history. Epigenetic changes from stress or early-life experiences may have made it harder for Sarah to ... has joined an online support group. Sharing her experiences with others also dealing with depression helps Sarah ...

  4. Brain Basics

    Medline Plus

    Full Text Available ... affects the Brain Meet Sarah Sarah is a middle-aged woman who seemed to have it all. ... However, recent research points to a possible new class of antidepressants that can relieve symptoms of the ...

  5. Brain Basics

    Medline Plus

    Full Text Available ... Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... blues" from time to time. In contrast, major depression is a serious disorder that lasts for weeks. ...

  6. Brain Basics

    Medline Plus

    Full Text Available ... he saw, Sarah's husband took her to the doctor, who ran some tests. After deciding her symptoms ... a stroke, brain tumor, or similar conditions, Sarah's doctor referred her to a psychiatrist, a type of ...

  7. Brain Basics

    Medline Plus

    Full Text Available ... lead to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons ... affects the Brain Meet Sarah Sarah is a middle-aged woman who seemed to have it all. ...

  8. Brain Basics

    Medline Plus

    Full Text Available ... Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... blues" from time to time. In contrast, major depression is a serious disorder that lasts for weeks. ...

  9. Treatment of blood cholesterol to reduce risk for atherosclerotic cardiovascular disease: grand rounds discussion from the beth Israel Deaconess Medical Center.

    Science.gov (United States)

    Mittleman, Murray A; Taylor, William C; Smetana, Gerald; Burns, Risa B

    2015-08-18

    In November 2013, the American College of Cardiology and the American Heart Association released a clinical practice guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular disease (ASCVD) risk in adults. The recommendation identifies 4 patient groups with strong evidence that the benefits of reduction in ASCVD events from statin therapy exceed adverse events. For these patients, initiating statin therapy of an appropriate intensity to reduce ASCVD risk and minimize adverse effects is recommended. A new risk estimator based on a pooled cohort equation is presented for estimating 10-year ASCVD risk. There is also a recommendation to engage in a clinician-patient discussion before initiating a statin, especially for primary prevention of ASCVD. This paper summarizes a discussion between a cardiologist and an internist about how each clinician would balance these factors and what treatment they would suggest for an individual patient.

  10. Three-Quark Bethe-Salpeter Vertex Function Under Pairwise Gluon-Exchange-Like Interaction Application to n-p Mass Difference

    CERN Document Server

    Sharma, A

    1997-01-01

    A qqq BSE formalism based on an input 4-fermion Lagrangian of "current" u,d quarks, is employed for the construction of a relativistic qqq-wave function) via the BSE. Chiral invariance is ensured by the vector character of the gluonic propagator in the infrared regime, while the `constituent' masses are the low momentum limits of the dynamicalmass function generated by standard DB{\\chi}. The Covariant Instantaneity Ansatz (CIA) gives an exact 3D reduction of the BSE for baryon spectroscopy, while the reconstructed 4D form identifies the baryon quark vertex function reconstructed through a reversal of steps offered by the CIA structure. It is employed for the quark loop integrals for the neutron - proton mass difference which receives contributions from two sources : i) the strong SU(2) effect arising from the $u-d$ mass difference (4 MeV); ii) the e.m. effect of the respective quark charges. The resultant n-p difference works out at 1.28 MeV (vs. 1.29 expt), with only two free parameters characterizing the in...

  11. Baryon Self-Energy With QQQ Bethe-Salpeter Dynamics In The Non-Perturbative QCD Regime n-p Mass Difference

    CERN Document Server

    Mitra, A N

    1999-01-01

    A qqq BSE formalism based on DB{\\chi}S of an input 4-fermion Lagrangian of `current' u,d quarks interacting pairwise via gluon-exchange-propagator in its self-energy via quark-loop integrals. To that end the baryon-qqq vertex function is derived under Covariant Instantaneity Ansatz (CIA), using Green's function techniques. This is a 3-body extension of an earlier q{\\bar q} (2-body) result on the exact 3D-4D interconnection for the respective BS wave functions under 3D kernel support, precalibrated to both q{\\bar q} and qqq spectra plus other observables. The quark loop integrals for the neutron (n) - proton (p) mass difference receive contributions from : i) the strong SU(2) effect arising from the d-u mass difference (4 MeV); ii) the e.m. effect of the respective quark charges. The resultant n-p difference comes dominantly from d-u effect (+1.71 Mev), which is mildly offset by e.m.effect (-0.44), subject to gauge corrections. To that end, a general method for QED gauge corrections to an arbitrary momentum de...

  12. The ancestors of Norman Bethune (1890-1939) traced back to the Bethunes of Skye, leading members of the MacBeth/Beaton medical dynasty.

    Science.gov (United States)

    Munro, A; Macintyre, I M C

    2013-01-01

    Norman Bethune became famous through his work in the Spanish Civil War, his advocacy of socialised medicine in North America and his association with Mao Zedong's revolutionary movement in China. It has been suggested that he may have been descended from the Bethune or Beaton medical dynasty, who for generations served as physicians to kings of Scotland, the Lords of the Isles and to some of the larger Scottish clans. This paper traces his lineage back to the Isle of Skye. In the absence of old parish records as aids to tracing genealogy, other available evidence has confirmed that Bethune was indeed in the direct line of descent from the Bethunes or Beatons of Husabost, in Skye, one of the largest branches of this medical kindred, who were physicians to the MacLeods of Dunvegan.

  13. Entrevista a Sherry Ortner

    Directory of Open Access Journals (Sweden)

    Sergio Daniel López

    2006-01-01

    Full Text Available Una histórica fotografía de Franz Boas interpretando una danza ceremonial kwakiutl y La Declaración Universal de los Derechos Humanos, dan la bienvenida al despacho de Sherry Beth Ortner, en el Departamento de Antropología de la Universidad de California, Los Angeles (UCLA. Doctora en antropología por la Universidad de Chicago, Sherry Ortner trabajó durante gran parte de su carrera con los sherpas, en Nepal. La publicación de su artículo “¿Es la mujer con respecto al hombre lo que la naturaleza con respecto a la cultura?” en 1972, marcó un antes y un después en la antropología académica feminista y en los estudios de género. Ortner ha sido profesora en el Sarah Lawrence College, en la Universidad de California, Berkeley, en la Universidad de Columbia y dirigió el Departamento de Antropología de la Universidad de Michigan. Actualmente es Profesora Honoraria de UCLA, donde imparte cursos sobre imaginación etnográfica y teoría social crítica. En esta entrevista le hemos preguntado sobre sus distintas etapas investigadoras, desde sus primeros trabajos de campo hasta su actual investigación sobre la industria cinematográfica en Hollywood, pasando por su relación con la antropología feminista y sus trabajos sobre capitalismo y cambio social. Sherry Ortner es una antropóloga alegre, muy cordial, inquieta y capaz de captar en todo momento el pulso de la sociedad occidental a través de sus obras.

  14. Attention-Deficit/Hyperactivity Disorder-Related Impulsivity and Cyberbullying in Social Media.

    Science.gov (United States)

    Reilly, Marie; Fogler, Jason; Selkie, Ellen; Augustyn, Marilyn

    2016-01-01

    Sarah is a 13-year-old eighth grader who was recently diagnosed for the first time with attention-deficit/hyperactivity disorder (ADHD)-inattentive type, and the family elected to treat her with behavioral interventions to help her organization and attention. She had struggled with distractibility and disorganization since the fourth grade. At home, Sarah's mother described her as "spacey" and unable to complete the morning routine without constant supervision. Over time, her mother observed that it seemed as if Sarah had given up on school.As Sarah became an adolescent, her self-esteem suffered because of her academic struggles, and she placed increasing emphasis on her appearance, including focus on remaining thin and refusing to leave the house without makeup. It was in this context that Sarah recently posted photographs of herself in various stages of undress and/or drinking alcohol on Snapchat, a photograph-sharing application in which users can send "snaps"-photographs that disappear soon after opening. However, snap recipients can take a screenshot or photograph of the snap, thereby saving the image. For unknown reasons, Sarah's close female friend took screenshots of these provocative photographs and sent them to their classmates and Sarah's older brother.Sarah's family contacted the police and has been working with her school to address this incident. This experience resulted in significant family stress and distrust of Sarah. For example, her mother took away her cell phone and laptop and has "grounded her" for a month from all out of school activities.Sarah's family seeks guidance regarding teaching Sarah about using social media responsibly and preventing this from happening again. Sarah's mom comes to your urgent care session asking for help because she does not feel that Sarah has "learned her lesson." What would you do next?

  15. 微笑与个性——分析《法国中尉的女人》中的莎拉

    Institute of Scientific and Technical Information of China (English)

    赵莉

    2009-01-01

    The French Lieutenant's Woman has presented to the reader a mysterious, courageous and independent woman figure named Sarah. Throughout the book, Sarah rarely smiles while the most common expression on her face is calmness, melancholy and wildness.However, from her rare smiles, we can still get a glimpse of her character-rebellious, independent and wild. This paper aims at deploring Sarah's character by analyzing her three smiles.

  16. 78 FR 42522 - Change in Bank Control Notices; Acquisitions of Shares of a Bank or Bank Holding Company

    Science.gov (United States)

    2013-07-16

    ... Lenox, Illinois. B. Federal Reserve Bank of Minneapolis (Jacqueline G. King, Community Affairs Officer..., individually; Sarah Beuning, Springfield, Illinois, Steven Beuning, ] Edina, Minnesota, Eric Beuning,...

  17. Suursaadikud Keskerakonna peakorteris

    Index Scriptorium Estoniae

    2001-01-01

    Ameerika Ühendriikide suursaadik Melissa Wells kohtus Edgar Savisaare, Peeter Kreitzbergi ja Sven Mikseriga. Kommentaarid suursaadik Melissa Wells'ilt. Suurbritannia suursaadik Sarah Squire Keskerakonna peakorteris

  18. McCain valis asemikuks konservatiivse naise / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2008-01-01

    USA vabariiklaste asepresidendikandidaadist Alaska kubernerist Sarah Palinist. Vt. samas: Poliitiline teater on harva olnud nii suurejooneline. USA demokraatide presidendikandidaadi Barack Obama Denveris peetud kõnest

  19. Naiste kolmevõistlus : Briti leedid valimisheitluses

    Index Scriptorium Estoniae

    2005-01-01

    Suurbritannia kolme suurema partei liidri - toor Michael Howardi, leiborist Tony Blairi ja sotsiaaldemokraat Charles Kennedy - naiste - Sandra Howardi, Cherie Blairi ja Sarah Kennedy - rollist meeste peaministriks kandideerimise valimiskampaanias

  20. 78 FR 48773 - Quarterly Publication of Individuals, Who Have Chosen To Expatriate, as Required by Section 6039G

    Science.gov (United States)

    2013-08-09

    ... MORGENTHALER LINDA KATRIN MORIN ANNE KOURAKINE MORLEY SARAH MARION MORRICE JEANNINE ISABEL MORRIN MARIELLA... NAYAN PARMANAND PARK CHINWON PARK REBECCA JANE PARKEL THOMAS CLAUDE PATE WILLIAM FREDERICK PATERSON...

  1. Harsh Parenting Can Backfire with Bad Behavior from Teens

    Science.gov (United States)

    ... Development. SOURCES: Rochelle Hentges, Ph.D., postdoctoral fellow, psychology department, University of Pittsburgh; Sarah Feuerbacher, Ph.D., clinic director, Southern Methodist University Center for Family Counseling, ...

  2. Kas McCain haarab liidrirolli? / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2008-01-01

    USA demokraatide kandidaadi Barack Obama esinemisest Denveris partei kongressil ja vabariiklaste partei presidendikandidaadi McCaini üllatavast otsusest nimetada asepresidendikandidaadiks Sarah Palin

  3. Staarkleidid / Lee Hanael

    Index Scriptorium Estoniae

    Hanael, Lee

    2008-01-01

    10 maailma kuulsamat kleiti kuulusid Marilyn Monroele, Audrey Hepburnile, printsess Dianale, Vivien Leighle, Tina Turnerile, Julia Robertsile, Liz Hurleyle, Sarah Jessica Parkerile, Keira Knightleyle, Jacqueline Kennedyle

  4. Prime Contractors with Awards over $25,000 by Name, Location, and Contract Number. Part 3 (Donovan Electric, Offutt AFB, Nebraska -- Hauptle [Mary Beth] DDS, Groton, Connecticutt), FY1991

    Science.gov (United States)

    1991-01-01

    1t- LomC . C >N ,c (n ~ ~ ~ ~ ~ ~ ~ 1 -O D 7 Wt -( -rL - )W% O L ) rmu ’t cc-4Ll Do ~ jr c Cr-~ ~ ~ ~ ~ ~~. r- -D()( , u8 c> m- - m ol(1)r- g 0’T D t...N0 r >t t )DMI i D.mNt O OIN Dma >I .NtID O - LOmC >9 C O ws cr C -,V 0 ) 0-4tNOHN 0Iwo 8C-> < U-) t)J H 0- N IDo 0nVO v .00000 O 0n0W(0 ) m m m 0 0)0

  5. Comment on "Depth-discrete specific storage in fractured sedimentary rock using steady-state and transient single-hole hydraulic tests" by Patryk M. Quinn, John A. Cherry, Beth L. Parker, J. Hydrol. 542 (2016) 756-771

    Science.gov (United States)

    Çimen, Mesut

    2017-03-01

    Quinn et al. (2016) presented a method to estimate storativity (S) of fractured sedimentary rock from straddle packer tests after transmissivity (T) of aquifer was determined from low-flow constant-head (CH) step tests. Constant-rate pumping tests were carried out to determine S by using the Cooper and Jacob (1946) approximation. Estimating the aquifer parameters depends on a matching of observation data to theoretical response which is mathematically obtained from a physical model. The results of both constant rate injection and withdrawal tests in the borehole C6zone17 cannot show this simulation. This comment proposes a reasonable procedure to estimate storativity.

  6. Ekspressiv Kulturformidling - i teori og praksis?

    DEFF Research Database (Denmark)

    Studerendes bidrag til forskningsprojektet Ekspressiv kulturformidling. Indledning og redaktion af Gitte Balling og Beth Juncker.......Studerendes bidrag til forskningsprojektet Ekspressiv kulturformidling. Indledning og redaktion af Gitte Balling og Beth Juncker....

  7. Medline Plus

    Full Text Available ... Hysterectomy (Baptist Hospital, Miami, FL, 10/17/2013) Mastectomy Breast Reconstruction: Deep Inferior Epigastric Perforator (Beth Israel ... Orthopedics Center, State College, PA, 8/21/2014) Mastectomy Breast Reconstruction: Deep Inferior Epigastric Perforator (Beth Israel ...

  8. Medline Plus

    Full Text Available ... 5/08/2008) Testicular Disorders Varicocele Surgery (Beth Israel Medical Center, New York, NY, 2/24/2009) ... Reconstruction Breast Reconstruction: Deep Inferior Epigastric Perforator (Beth Israel Medical Center, New York, NY, 1/11/2008) ...

  9. Medline Plus

    Full Text Available ... Birmingham, AL, 3/17/2014) Female Reproductive System Breast Reconstruction Breast Reconstruction: Deep Inferior Epigastric Perforator (Beth ... Chicago Medical Center, Chicago, IL, 6/26/2014) Breast Reconstruction Breast Reconstruction: Deep Inferior Epigastric Perforator (Beth ...

  10. Second Reference State and Complete Eigenstates of Open XYZ Chain

    Institute of Scientific and Technical Information of China (English)

    FENG Jun; CHEN Xi; HAO Kun; HOU Bo-Yu; SHI Kang-Jie; SUN Cheng-Yi; YANG Wen-Li

    2011-01-01

    The second reference state of the open XYZ spin chain with non-diagonal boundary terms is studied. The associated Bethe states exactly yield the second set of eigenvalues proposed recently by functional Bethe Ansatz.

  11. Integrability of a New Type of Deformed XXZ Model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new type of deformed XXZ model was constructed and diagonalized by the coordinate Bethe ansatz method. We obtained the energy and the Bethe ansatz equations of the model and also discussed some thermodynamics of the model.

  12. Libraries Demonstrate Low Adherence to Virtual Reference Service Guidelines. A Review of: Shachaf, Pnina, and Sarah M. Horowitz. “Virtual Reference Service Evaluation: Adherence to RUSA Behavioral Guidelines and IFLA Digital Reference Guidelines.” Library & Information Science Research 30.2 (2008: 122-37.

    Directory of Open Access Journals (Sweden)

    Elise Cogo

    2009-06-01

    Full Text Available Objectives – This study evaluates the level to which virtual (asynchronous e-mail reference services adhere to professional guidelines. Specifically, it addresses the following research questions:1 To what extent do virtual reference services adhere to the American Library Association (ALA Reference and User Services Association (RUSA and the International Federation of Library Associations (IFLA guidelines?2 How does the level of adherence to RUSA or IFLA guidelines vary based on request type, user name, and institution?3 Is there a correlation between outcome measures of reference transactions (accuracy, completeness, and satisfaction and the level of adherence to RUSA or IFLA guidelines?Design – Unobtrusive evaluation of researcher-generated queries.Setting – Fifty-four academic libraries in North America.Subjects – A total of 324 queries were sent to the 54 libraries, with each library receiving six different types of requests from six different user names.Methods – Researchers developed two coding schemes for the guidelines (34 codes and 12 attributes for the RUSA guidelines and 33 codes and 10 attributes for the IFLA guidelines. Each of the six user names used represented an ethnic and/or religious group identity: Mary Anderson (Caucasian, Christian, Moshe Cohen (Caucasian, Jewish, Ahmed Ibrahim (Arab, Latoya Johnson (African American, Rosa Manuz (Hispanic, and Chang Su (Asian. The six request types were designed so that three would be answered (questions 1-3 and three would be out of scope and not answered (questions 4-6. The following queries were sent, individualized for each institution: 1 Dissertation query; 2 Sports team query; 3 Population query; 4 Subject query; 5 Article query; 6 Request for a PDF copy. The 324 queries were uploaded into NVivo 2 software, and all e-mail transactions were coded and analyzed.Main Results – Analysis of the 324 transactions from 54 libraries showed the following results:1 Low levels of adherence to both sets of guidelines;2 Varied levels of adherence based on request types and user names on both sets of guidelines;3 Variation in institutional rank according to different sets of guidelines;4 No correlation between user satisfaction and adherence to either set of guidelines.Conclusion – This study suggests that higher levels of virtual reference service effectiveness could be achieved by automatically integrating some less observed behaviours (e.g., thank you notes into replies sent to users and by increasing librarians’ awareness of professional guidelines through training and detailed institutional policies. The authors also suggest that librarians should be aware of their tendencies to react differently to different user groups, and that administrators can facilitate this by providing diversity workshops.

  13. Purchase of Journal Portfolios by Research Libraries is not Cost-Effective and May Lead to Normalization of Collections. A Review of: Murphy, Sarah Ann. “The Effects of Portfolio Purchasing on Scientific Subject Collections.” College & Research Libraries July 2008: 332-40.

    Directory of Open Access Journals (Sweden)

    Stephanie Walker

    2009-03-01

    Full Text Available Objectives – To determine whether the purchase of journal portfolios (i.e., packages of journals purchased as a group from publishers, such as Elsevier’s ScienceDirect from publishers is an effective means of meeting research needs for faculty in the life, medical, physical, and applied sciences, and to determine the effects of such purchases on research library collections.Design – Citation analysis.Setting – Ohio State University libraries in the life, medical, physical, and applied sciences.Subjects – A total of 253,604 citations from 6,815 articles published between the years 2003 and 2005 by Ohio State University faculty in the life, medical, physical, and applied sciences were analyzed using the Bradford distribution (an explanation of the Bradford Distribution is provided later in this review.Methods – Using ISI’s Science Citation Index,the author generated a list of articles published by Ohio State University (OSU faculty in the life, medical, physical, and applied sciences between the years 2003 and 2005. The author then assigned each article to a specific discipline, according to the OSU College of the first OSU author listed. For example, if an article was written by several co-authors, and the first OSU author listed was a faculty member in OSU’s College of Dentistry, the article would be designated a Dentistry article. Multi-disciplinary works were assigned to the college of the first OSU author listed. (The OSU Colleges considered to be part of the study were the College of Biological Sciences; the College of Dentistry; the College of Engineering; Food, Agriculture, and Environmental Sciences; the College of Mathematical and Physical Sciences; the College of Medicine; the College of Optometry; the College of Pharmacy; and the College of Veterinary Medicine. Books, conference proceedings, theses, and other non-journal materials were excluded from the set of citations considered. Next, the author pulled journal citations from each article, again utilizing Science Citation Index. The references were analyzed to determine the number of times each individual journal had been cited. The author then created a list of journals which had been cited in articles by OSU faculty in the various colleges, grouped by college. The journals were arranged in descending order, according to the number of times each journal had been cited. Thus there would be, for example, a list of all journals cited in articles published by faculty members in the OSU College of Dentistry between 2003 and 2005.Most journals had been cited only once over the three-year period. A total of 2,407 journal titles were cited 10 or more times. In total, the author analyzed 253,604 citations from 6,815 articles. A Bradford distribution of journal citations was calculated, and journals were divided into three categories. The three categories were called Zones 1, 2, and 3, with Zone 1 being corej ournals for the faculty, Zone 2 being more secondary titles, and Zone 3 being those cited least frequently. For those not familiar with this type of analysis, a definition of Bradford’s law is available on the U.S. National Institute for Standards and Technology website. It is included here for ease of reference: “Journals in a field can be divided into three parts, each with about one-third of all articles: 1 a core of a few journals; 2 a second zone, with more journals ;and 3 a third zone, with the bulk of journals. The number of journals is 1:n:n². Note that Bradford formulated his law after studying a bibliography of geophysics, covering 326 journals in the field. He discovered that 9 journals contained 429 articles, 59 contained 499 articles, and 258 contained 404 articles. Although Bradford's Law is not statistically accurate, librarians commonly use it as a guideline” (Black. The author then determined how the OSU Libraries purchased access to each title. The three options analyzed were: 1 through OHIOLink (through which OSU Libraries purchase the bulk of the journal portfolios to which they subscribe,2 through the independent purchase of an electronic subscription, or 3 through the independent purchase of a print subscription. The cost for each title was calculated by taking the amount paid for OHIOLink subscriptions and removing the cost of non-scientific journals from the total amount. Pricing for the non-scientific journals was obtained using EBSCO’s Librarian’s Handbook 2006-2007 and Ulrich’s Periodical Directory. To account for inflation, any 2007 prices were adjusted by 6. The above activities were designed to calculate both the cost of each title as purchased through OHIOLink, and what the OSU Libraries would have paid for each individual title if it had been purchased separately.Main Results – Of all journals cited by OSU faculty in the life, medical, physical, and applied sciences during the years studied, only 7% were available in print format only. The percentage of cited journal titles that were included in portfolio purchases varied considerably across the colleges. The college for which the greatest percentage of cited journals were obtained via OHIOLink was the College of Mathematical and Physical Sciences; 85.7% of journals cited by this College were purchased via OHIOLink. Overall figures for the cited journals analyzed were as follows: 52.0% were purchased via OHIOLink portfolio purchases, and 26.3% were purchased individually in electronic format by the OSU Libraries. Of all journals listed in Zone 1 (those designated as “core journals” for the fields in question,100% had electronic versions, though OSU Libraries continued to subscribe to the print version in addition to the electronic version for five titles, due to embargoes of 4-12 months in the electronic subscriptions. In terms of how the Zone 1 journals were acquired, 35.5% were purchased via OHIOLink as part of a portfolio purchase, and 62.2% were individually purchased. For the College of Biological Sciences; the College of Food, Agricultural, and Environmental Sciences; the College of Medicine; the College of Nursing; the College of Pharmacy; and the College of Veterinary Medicine, fewer than 40% of the Zone 1 (core, most highly cited titles for their disciplines were purchased via OHIOLink. For the Collegeo f Mathematical and Physical Sciences, 75.5% of Zone 1 titles were purchased via OHIOLink. This figure was 60.5% in the College of Engineering. By contrast, over 50% of the titles in Zone 1 for the Colleges of Dentistry, Nursing, Pharmacy, and Veterinary Medicine were purchased individually, and not via portfolio purchases from OHIOLink. The author notes that in these fields, the majority of research is published in journals from professional societies or smaller publishers, which have neither the high profile nor the market that some journals in other fields have, and thus are frequently not included in portfolios available via consortia such as OHIOLink. The author also provides a numerical breakdown, showing exactly how many titles in each of Zones 1, 2, and 3 were purchased via OHIOLink, how many were purchased directly by OSU in electronic form, and how many were purchased in print form, for each college and for all colleges combined. For all colleges combined, the overall results are as follows: Zone 1 included 45 cited journal titles. Of these, 16 were purchased via OHIOLink, 28 were purchased in electronic format directly by OSU, none were purchased in print, and one was considered “Other” (not at OSU, ceased, or cancelled. Zone 2 included 299 cited journal titles. Of these, 167 were purchased via OHIOLink, 109 were purchased in electronic format directly by OSU, 13 were purchased in print, and 10 fell under “Other”. Zone 3 included 2,063 cited journal titles. Of these, 1,068 were purchased via OHIOLink, 497 were purchased in electronic format directly by OSU, 155 were purchased in print, and 343 fell under “Other”. The author also provides a list of the top 50 journals cited, including the number of citations linked to each title and how the title was purchased. Of the top 50 journals, 32 were purchased directly by OSU Libraries in electronic format, and only 18 were purchased via OHIOLink. Interestingly, however, 70% of OSU Libraries’ total expenditures on titles in the life, medical, physical, and allied sciences are devoted to OHIOLink. The author notes that if OSU had not had OHIOLink, they would have paid 61.4% more to directly purchase the journals cited in this analysis which they currently obtain by portfolio purchases. However, if they purchased only those titles which the faculty in question had cited 10 or more times, the cost would be 30% more. If they purchased only the titles which had been cited 15 or more times, OSU would only have paid an 8.9% premium to buy the titles directly from the publisher rather than through OHIOLink.Conclusion – As the author points out, her findings raise the question as to whether the large amount of content provided by buying into the “Big Deal” portfolio purchases (as they are frequently called is really worth it for OSU Libraries. The author notes that other articles have asserted that portfolio purchases form a significant barrier to libraries wishing to purchase individual titles, as the amount spent on portfolio purchases can limit a library’s financial flexibility. Even when other individual titles may more closely meet faculty needs, it can be difficult to justify cancelling portfolio purchases that offer a larger number of journals in the field. The advantages and disadvantages of portfolio purchasing at Ohio State University Libraries are clear from the author’s research: while some fields are well-served by portfolio purchases, others are not, with large percentages of the journals which are most important in their fields not being available through such portfolios. Furthermore, due to the percentage of the OSU Libraries’ budget dedicated to OHIOLink portfolio purchases, flexibility to purchase titles not in portfolios is indeed limited. The author’s pricing calculations lead to the conclusion that OSU Libraries pay between an 8.9%-30.0% premium to maintain access to 3,813 titles (75.4% which were cited fewer than 10 times over the three year period between 2003 and 2005. The author concludes that the premium paid to access over three-quarters of the journals available in portfolios should be reconsidered, as they are relatively infrequently used and thus may not be meeting faculty research needs. The author recommends that large research libraries(including OSU Libraries consider a return to à la carte purchasing. Additionally, the author notes that purchase of portfolios by a large percentage of research libraries may lead to normalization of library collections and loss of the ability to support non-commercial publishers who publish strong research in specialized fields.

  14. Virtual Racism Rears its Head: Uncovering Librarian Bias in E-mail Reference Services. A review of: Shachaf, Pnina, and Sarah Horowitz. “Are Virtual Reference Services Color Blind?” Library & Information Science Research 28.4 (Sept. 2006: 501‐20.

    Directory of Open Access Journals (Sweden)

    Wendy Furlan

    2007-06-01

    Full Text Available Objective – To examine whether librarians provide equitable virtual reference services to diverse user groups.Design – Unobtrusive method of defined scenarios submitted via e-mail.Setting – Twenty‐three Association of Research Libraries (ARL member libraries from across the United States. All ARL member libraries were invited to participate, with the 23 acceptances providing 19% participation.Subjects – Anonymous librarians from the 23 participating libraries’ virtual e‐mail reference services. Up to 6 librarians from each library may have been involved. Six fictitious personas were developed to represent particular ethnic or religious groups, whereby the ethnic or religious affiliation was only indicated by the name chosen for each user and the correspondinge‐mail address. Names were selected from lists of names or baby names available online: Latoya Johnson (African‐American, Rosa Manuz (Hispanic, Chang Su (Asian ‐Chinese, Mary Anderson(Caucasian/Christian, Ahmed Ibrahim (Muslim, and Moshe Cohen(Caucasian/Jewish. These personas were used to submit reference queries via e‐mail to the virtual reference services taking part in the study.Methods – Five different types of reference queries were developed for use in this study. Three were based on prior published research as they were deemed to be answerable by the majority of libraries. They included a dissertation query, a sports team query, and a population query all designed to be tailored to the target institution. The other 2 queries were developed with participating institutions’ virtual reference guidelines in mind, and were thought to not be answered by the target institutions when submitted by unaffiliated users. They consisted of a subject query on a special collection topic that asked for copies of relevant articles to be sent out, and an article query requesting that a copy of a specific article be e‐mailed to the patron. The study was conducted over a 6 week period beginning the second week of September, 2005. Each week, 1 fictitious persona was used to e‐mail a reference query to the virtual reference service of each of the 23 participating institutions. Five of each type of query were sent by each persona. During September and October 2005, a total of 138 queries were sent. Each institution received a different query for each of the first 5 weeks, and in the sixth week they received a repeat of a previous request with details of title or years altered. All other text in every request sent was kept consistent. Each institution only received 1 request from each persona during the study. In order to eliminate any study bias caused by an informed decision regarding the order in which personas were used, they were randomly arranged (alphabetically by surname. Furthermore, to avoid suspicions from responding librarians, queries were emailed on different days of the week at different times. This created some limitations in interpretating response times as some queries were submitted on weekends. All queries were analysed by Nvivo software in order to identify attributes and patterns to aid qualitative analysis. Each transaction (a single query and any related responses was classified according to 12 attributes and 59 categories based on various associations’ digital reference guidelines. Transactions were coded and then 10% re‐coded by a different coder. This led to the clarification and refinement of the coding scheme, resulting in the number of categories used being reduced to 23. Coding was then performed in 3 iterations until 90%agreement between the 2 coders was reached. The final inter‐coder reliability was 92%. The study did not support cross tabulation among user groups on most content categories due to the small sample size.Main results – Response times varied greatly between users. Moshe (Caucasian/Jewish received an average turn‐around of less than a day. At the other end of the spectrum, Ahmed’s (Muslimresponses took an average of 3.5 days. Both Ahmed and Latoya (African‐American sent queries which took over 18 days to receive a response. The length (number of words of replies also indicated a differing level of service with Mary (Caucasian/Christianand Moshe receiving far lengthier responses than the other 4 personas. Number of replies (including automatic replies was examined in comparison with the number of replies which answered the question, and again indicated Mary and Moshe were receiving a better level of service. The way in which the user was addressed by the librarian was examined as another measure of service, i.e. first name, full name, honorific. This again mirrored the low level of service received by Ahmed. The professional endings used by librarians in their replies also reinforced the high quality of service received by Moshe across other categories. Results for Rosa (Latino and Chang (Asian ‐Chinese were average for most categories presented.Conclusion – In this study, a discriminatory pattern was clearly evident, with the African‐American and Muslim users receiving poor levels of service from virtual reference librarians across all dimensions of quality evaluated. The Caucasian (Christian and Jewish users also noticeably received the best level of service. It is noted, however, that the sample size of the study is not large enough for generalisations to be drawn and that future, more statistically significant studies are warranted. Many other questions are raised by the study for possible future research into racism exhibited by library staff and services.

  15. Evidence Based Research Activities, Interests and Opportunities Exist for Practitioners in all Library Sectors in the British Isles. A review of: McNicol, Sarah. “Is Research an Untapped Resource in the Library and Information Profession?” Journal of Librarianship and Information Science 36.3 (September 2004:119-26.

    Directory of Open Access Journals (Sweden)

    Julie McKenna

    2006-03-01

    Full Text Available Objective – To scope the range, nature and challenges of present, planned and future research by practitioners within libraries in the British Isles. Design – A series of survey questionnaires sent by mail. Setting – Public, academic, health, special and school libraries of the British Isles. Subjects – A total of 2384 questionnaires were sent out and 334 responses were received. 62 academic libraries, 83 health libraries, 78 public libraries, 63 school libraries and 48 special libraries participated in the study. Methods – This study was undertaken in 2003 by a research team at the University of Central England. Survey questionnaires were sent by mail to library directors in all public library authorities, academic libraries, health libraries and special libraries in England, Wales, Scotland, Northern Ireland and the Republic of Ireland. In addition, questionnaires were sent to the librarians in all state and independent schools within a sample of nine local education authorities. Each participant was asked to identify past and future research issues of interest and the barriers to research practice within their library. Research was defined to include work on both externally funded and inhouse projects and examples of the types of activities that this might include were provided. Main results – Half the respondents reported that they had been involved in some form of research in the past two years, with the lowest level of involvement from school libraries and the highest in public libraries. Generally, only the library directly involved in conducting the research made use of the findings and a gap in the dissemination of results was identified across sectors. User surveys were the most common form of research undertaken across libraries and slightly fewer respondents intended to carry out research in the coming twelve months than had in the past (the area most commonly mentioned was user surveys. Information and communications technology (ICT was an area of planned future research in all libraries, as were user needs and user behaviour. The most frequently cited barriers to research activity across all sectors were lack of time and financial resources. Staff skills and the lack of focus on practical problems to solve were indicated as a barrier in health, public and academic libraries. Libraries reported a range of common uses for the research findings including: informing strategic and service planning; providing benchmarking data and measuring the effectiveness of services; identification of marketing and public relations opportunities; discovery of staff training needs; and use of the results to demonstrate the value of libraries to funding bodies. Conclusion – This study provides insight into practitioner‐focused areas of research interest and possible areas for future investigation. As the author reports in her conclusion, the survey results cannot be considered representative of the wider population. Since research interests often overlap, a sector wide or cross‐sectoral research approach should be considered to allow library staff to identify and resolve common problems. Wide dissemination of research results within the practitioner community would be of benefit to all. Greater communication between practitioner and information science communities is also encouraged, as these communities’ work is mutually beneficial.

  16. Mère et fille - des relations en question, ou la liberté à tout prix : Isabel Allende, La casa de los espíritus ; Nicole Brossard, Le désert mauve ; Sarah Kofman, Rue Ordener, rue Labat ; Margaret Laurence, The diviners

    OpenAIRE

    2013-01-01

    The mother-daughter relationship is dual, ambivalent, a hall of mirrors; it is at once the site of the womb and maternity, a veritable matrix of meaning. The mother-daughter pairing moves through the body, constantly calling attention to its origins and valorising a transmission au féminin even from within a patriarchal society. However, it can also prove catastrophic. Though the mother is the first person with whom the daughter identifies—her first link to life—the daughter not only reacts t...

  17. 魔法之源与三维建构——布鲁斯波洛克与萨拉斯坦沃克的艺术%Origin of Magic and 3D Construction: the Art of Bruce Pollock and Sarah Steinwachs

    Institute of Scientific and Technical Information of China (English)

    覃京侠

    2010-01-01

    @@ 2009年初,深圳市文体旅游局参与主办、深圳美术馆参与承办的"墨非墨--中国当代水墨艺术请展"赴美国费城德雷塞尔大学美术馆展出,为了进一步促进中美之间的文化艺术交流,丰富深圳市民的文化生活,作为这次艺术交流活动的延续,我们邀请费城家前来深圳举办展览,旨在通过展览这种最为直接的方式,向中国的艺术家和艺术好者介绍国外不同文化艺术传统下的创作现状.

  18. Zhit v televizore opasnei vsehh boleznei

    Index Scriptorium Estoniae

    2004-01-01

    Briti teadlaste (King's College) Tim Crayford'i, Richard Hooper'i ja Sarah Evans'i poolt läbi viidud uurimusest, milles nad tegid statistikat teleseriaalide kangelaste surmapõhjuste, sünnituste, psüühhiliste häirete kohta. Kommentaar ka arst Sarah Clement'ilt

  19. Feasibility of a Novel Optoacoustic Device to Precisely Localize Endotracheal Tube Positioning in a Cadaver Model

    Science.gov (United States)

    2016-11-02

    Model Napoleon Roux, Chandler Sours, Jeffrey Lodermeier, Jason Pasley, Sarah Wade , Catriona Miller, Samuel Galvagno, Raymond Fang...Jeffrey Lodermeier, Jason Pasley, Sarah Wade , Catriona Miller, Samuel Galvagno, Raymond Fang 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK

  20. NDIA13th Annual Small Business Conference. Held in McLean, Virginia on 2-3 December 2009

    Science.gov (United States)

    2009-12-03

    Distinguished Scholar & Associate Professor of Finance, The University of North Carolina at Chapel Hill, Kennan -Flagler Business School 5:00 PM THE...Plan Preventative Maintenance Contingency Operations Buyer Commodity (New) 608582 AMEREX CORPORATION Fire Extinguishers SCHMOLDT, TERRY Tom Enz kent ...NICK Sarah Guerrero kevin sebo Andy Hove (?) Fred Monville SARAH GUERRERO 616823 FIRETRACE AEROSPACE, Fire Suspression LEY, JONATHAN Mike Anderson kent

  1. On-line measurement of food viscosity during flow

    DEFF Research Database (Denmark)

    Mason, Sarah Louise; Friis, Alan

    2006-01-01

    Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time.......Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time....

  2. On-line measurement of food viscosity during flow

    DEFF Research Database (Denmark)

    Mason, Sarah Louise; Friis, Alan

    2006-01-01

    Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time.......Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time....

  3. Brain Basics

    Medline Plus

    Full Text Available ... Sarah's doctor referred her to a psychiatrist, a type of medical doctor who is an expert on mental disorders. Other medical professionals who can diagnose mental disorders are psychologists or clinical social workers. The psychiatrist asked Sarah and her husband ...

  4. 76 FR 14300 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2011-03-16

    ...-mail at peggy.murphy@noaa.gov ; or, for waters off the U.S. West Coast, Sarah Williams, 206-526-4646, e-mail at sarah.williams@noaa.gov . SUPPLEMENTARY INFORMATION: Background The IPHC has promulgated... authority under the Halibut Act. The PFMC also exercises authority in a CSP allocating halibut among...

  5. On the Feminism in French Lieutenant's Woman

    Institute of Scientific and Technical Information of China (English)

    苏琴

    2010-01-01

    Sarah in The French Lieutenant's Woman has been regarded as a representative of feminism in modern literature field.Undoubtedly, Sarah is an independent woman ahead of her time.The paper is attempted to focus on the feminism in The French Lieutenant's Woman from many aspects and analyze the reasons of such kind of feminism.

  6. Zhit v televizore opasnei vsehh boleznei

    Index Scriptorium Estoniae

    2004-01-01

    Briti teadlaste (King's College) Tim Crayford'i, Richard Hooper'i ja Sarah Evans'i poolt läbi viidud uurimusest, milles nad tegid statistikat teleseriaalide kangelaste surmapõhjuste, sünnituste, psüühhiliste häirete kohta. Kommentaar ka arst Sarah Clement'ilt

  7. Brain Basics

    Medline Plus

    Full Text Available ... pituitary-adrenal (HPA) axis. Brain Basics in Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah ... having trouble coping with the stresses in her life. She began to think of suicide because she ...

  8. 论《法国中尉的女人》中失败的规训和惩罚

    Institute of Scientific and Technical Information of China (English)

    李旭

    2011-01-01

    With the help of the vicar, Sarah was employed by a pretentious lady called Mrs. Poulmey. In this process Mrs. Poulmey who believed in hell, tried to discipline and punish Sarah' s free soul through the control of her body. With the implicit and confirmedly skillful techniques, Sarah resisted the manipulation of Mrs. Poulmey and got the final success.

  9. Extending the Educational Franchise: The Social Contract of Australia's Public Universities, 1850-1890

    Science.gov (United States)

    Horne, Julia; Sherington, Geoffrey

    2010-01-01

    This article introduces the notion of the "educational franchise" of Australia's public universities established in the mid-nineteenth century. In his recently published study of the public university and social access in the United States, John Aubrey Douglass suggests that from the mid-nineteenth century a social contract was formed…

  10. Nearshore Sand Transport.

    Science.gov (United States)

    1987-01-01

    Born November 19, 1956 - Peoria, Illinois 1978 B.S., Civil Engineering, University of Miami, Coral Gables, Florida 1978 B.S., Physics, University of...Aubrey, 1985, "Theoretical and observational estimates of nearshore bedload transport rates," Marino Geology, v 64, p 91-111. Guza, R.T., N.C. Clifton

  11. 76 FR 6157 - Meeting of the National Park System Advisory Board

    Science.gov (United States)

    2011-02-03

    ..., Leavenworth, KS. Maine Olson House, Cushing, ME. Minnesota Grand Mound, Koochiching County, MN. Split Rock Light Station, Lake County, MN. New York Woodlawn Cemetery, Bronx, NY. North Dakota Lynch Quarry Site... Indian Agricultural School, Kay County, OK. Platt National Park, Murray County, OK. Oregon Aubrey...

  12. Life Cycle Leadership Theory vs. Theory on the Phases of Small Group Discussion: Comparisons, Contrasts, and Examples.

    Science.gov (United States)

    Preston, Charles Thomas, Jr.

    The work of Paul Hersey and Kenneth Blanchard on life-cycle leadership was compared and contrasted to three studies on group phase theories. The studies on group phases were conducted by Robert Bales and Fred Strodtbeck in 1951, Thomas Scheidel and Laura Crowell in 1964, and B. Aubrey Fisher in 1970. The two theoretical approaches were found to…

  13. Remembering "Brown": Silence, Loss, Rage, and Hope

    Science.gov (United States)

    Banks, James A.

    2004-01-01

    The author was in the seventh grade at the Newsome Training School in Aubrey, Arkansas when the Supreme Court handed down "Brown v. Board of Education" on May 17, 1954. His most powerful memory of the "Brown" decision is that he has no memory of it being rendered or mentioned by his parents, teachers, or preachers. In his rural…

  14. Chelsea Flower Show 2007 / Merilen Mentaal

    Index Scriptorium Estoniae

    Mentaal, Merilen, 1972-

    2007-01-01

    Uusimaid aiatrende Londonist. Enimkasutatud materjalid puit, eri vormi ja struktuuriga kivid ning vesi. Võiduaiaks kivifirma Bradstone'i aed "600 päeva Bradstone'iga", disainer Sarah Eberle. 15 värv. ill

  15. Mapping posthumanism: an exchange

    OpenAIRE

    2004-01-01

    Introduction: posthumanism in question Noel Castree, Catherine Nash Mapping posthumanism Neil Badmington Modalities of posthumanism Bruce Braun Humanising posthumanism Jonathan Murdoch Humanism's excess: some thoughts on the 'post-human/ist' agenda Sarah Whatmore Organisors: Noel Castree, Catherine Nash

  16. Most Americans Favor Larger Health Warnings on Cigarette Packs

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_164398.html Most Americans Favor Larger Health Warnings on Cigarette Packs ... According to the study's first author, Sarah Kowitt, "Most adults, including smokers, have favorable attitudes towards larger ...

  17. Brain Basics

    Medline Plus

    Full Text Available ... ACC has many different roles, from controlling blood pressure and heart rate to responding when we sense ... and her husband questions about Sarah's symptoms and family medical history. Epigenetic changes from stress or early- ...

  18. Understanding Dyslexia

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Understanding Dyslexia KidsHealth > For Teens > Understanding Dyslexia A A A ... realize is that Sarah has dyslexia. What Is Dyslexia? Dyslexia (pronounced: dis-LEK-see-uh) is a ...

  19. Brain Basics

    Medline Plus

    Full Text Available ... all. She was happily married and successful in business. Then, after a serious setback at work, she ... and her husband questions about Sarah's symptoms and family medical history. Epigenetic changes from stress or early- ...

  20. Download this PDF file

    African Journals Online (AJOL)

    Image

    e.g. Njoroge (1996). Text in this study refers to written forms drawn from newspaper .... 'Morphosyntactic Structures in the Written English of First Year. Undergraduate Students in Kenya', Unpublished MA Thesis, Kenyatta University. 194 Sarah ...