1,720,959 research outputs found
Lax representation for two-particle dynamics splitting on two tori
No full textThe Lax representation in terms of 2 x 2 matrices is constructed for separable multiply-periodic systems splitting on two tori. Hyperelliptic Kleinian functions and their reduction to elliptic functions are used
ON THE CALCULATION OF THE ENERGY-SPECTRUM OF QUANTUM INTEGRABLE SYSTEMS
No full textWe show that for quantum systems integrable by QISM, the spectrum can be obtained from a set of linear equations for the symmetric functions of the solutions of the Bethe equations. The compatibility condition of such a system gives rise to algebraic equations for the spectrum which in some cases are simpler to solve than the corresponding Bethe equations. We illustrate the method with two specific examples
ON THE QUANTUM INVERSE SCATTERING METHOD FOR THE DST DIMER
No full textThe quantum inverse scattering method is used to solve the spectral problem of the discrete self-trapping dimer, in the case of both a quadratic and a linear r-matrix algebra representation. The first case is solved by the algebraic Bethe ansatz, while in the case of the linear r-matrix algebra we use the method of separation of variables. In this last case it is shown that the wave functions of the quantum discrete self-trapping dimer are related to the solutions of a Heun's type equation and that the system is equivalent to the two-site hyperbolic Gaudin magnet separable in elliptic coordinates
CANONICAL TRANSFORMATION BETWEEN INTEGRABLE HENON-HEILES SYSTEMS
No full textA canonical transformation between two known integrable cases of the Henon-Heiles systems is given and the separation of variables for the corresponding Hamilton-Jacobi equations is discussed
ALTERNATE QUANTIZATIONS OF THE DISCRETE SELF-TRAPPING DIMER
No full textIn this paper we study the classical and quantum two freedoms Discrete Self-Trapping system by the Inverse Scattering Method. We develop the algebraic approach in terms of the classical r-matrix and quantum R-matrix and give an interpretation of the commutation relations in terms of Sklyanin's quadratic algebra. The quantization is then developed in detail and the first energy levels are obtained. The results are compared with those obtained from the quantization scheme of Scott and Eilbeck
THERES MORE THAN ONE WAY TO SKIN SCHRODINGER CAT
No full textTwo methods for studying quantum discrete dynamical systes (i.e. with a finite or countably infinite number of degrees of freedom) are described and compared for: (i) The discrete self-trapping (DST) equation, (ii) The Ablowitz-Ladik (AL) equation, and (iii) A fermionic polaron (FP) model. The first method, called the quantum inverse scattering method (QISM), emphasizes the relationship between the quantum theory and classical integrability The second method, which we call the number state method (NSM), cam be extended to systems that are not classically integrable. Thus the two methods are not equivalent
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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