Search results for "creation"
showing 10 items of 704 documents
Occupation Number Representation
2007
The first two chapters of this book presented angular momentum algebra as the basic tool of nuclear theory. That includes angular momentum coupling coefficients, spherical tensor operators and reduced matrix elements. In the preceding chapter we introduced the mean-field concept, along with associated many-nucleon wave functions, Slater determinants, describing configurations of non-interacting particles in mean-field single-particle orbitals.
Adiabatic regularization for spin-1/2 fields
2013
We extend the adiabatic regularization method to spin-1/2 fields. The ansatz for the adiabatic expansion for fermionic modes differs significantly from the WKB-type template that works for scalar modes. We give explicit expressions for the first adiabatic orders and analyze particle creation in de Sitter spacetime. As for scalar fields, the adiabatic method can be distinguished by its capability to overcome the UV divergences of the particle number operator. We also test the consistency of the extended method by working out the conformal and axial anomalies for a Dirac field in a Friedmann-Lemaitre-Robertson-Walker spacetime, in exact agreement with those obtained from other renormalization…
Connection between certain massive and massless diagrams
1996
A useful connection between two-loop massive vacuum integrals and one-loop off-shell triangle diagrams with massless internal particles is established for arbitrary values of the space-time dimension {ital n}. {copyright} {ital 1996 The American Physical Society.}
Multiparticle correlations in the Schwinger mechanism
2009
We discuss the Schwinger mechanism in scalar QED and derive the multiplicity distribution of particles created under an external electric field using the LSZ reduction formula. Assuming that the electric field is spatially homogeneous, we find that the particles of different momenta are produced independently, and that the multiplicity distribution in one mode follows a Bose-Einstein distribution. We confirm the consistency of our results with an intuitive derivation by means of the Bogoliubov transformation on creation and annihilation operators. Finally we revisit a known solvable example of time-dependent electric fields to present exact and explicit expressions for demonstration.
The quantum relativistic harmonic oscillator: generalized Hermite polynomials
1991
A relativistic generalisation of the algebra of quantum operators for the harmonic oscillator is proposed. The wave functions are worked out explicitly in configuration space. Both the operator algebra and the wave functions have the appropriate c→∞ limit. This quantum dynamics involves an extra quantization condition mc2/ωℏ = 1, 32, 2, … of a topological character.
Multi-rogue waves solutions to the focusing NLS equation and the KP-I equation
2011
Abstract. We construct a multi-parametric family of quasi-rational solutions to the focusing NLS equation, presenting a profile of multiple rogue waves. These solutions have also been used by us to construct a large family of smooth, real localized rational solutions of the KP-I equation quite different from the multi-lumps solutions first constructed in Bordag et al. (1977). The physical relevance of both equations is very large. From the point of view of geosciences,the focusing NLS equation is relevant to the description of surface waves in deep water, and the KP-I equation occurs in the description of capillary gravitational waves on a liquid surface, but also when one considers magneto…
A Symmetry Adapted Approach to the Dynamic Jahn-Teller Problem
2011
In this article we present a symmetry-adapted approach aimed to the accurate solution of the dynamic Jahn-Teller (JT) problem. The algorithm for the solution of the eigen-problem takes full advantage of the point symmetry arguments. The system under consideration is supposed to consist of a set of electronic levels \({\Gamma }_{1},{\Gamma }_{2}\ldots {\Gamma }_{n}\) labeled by the irreducible representations (irreps) of the actual point group, mixed by the active JT and pseudo JT vibrational modes \({\Gamma }_{1},{\Gamma }_{2}\ldots {\Gamma }_{f}\) (vibrational irreps). The bosonic creation operators b +(Γγ) are transformed as components γ of the vibrational irrep Γ. The first excited vibra…
Schools: wrong spaces face the ones desired by the students
2017
ResumenEste trabajo estudia las ideas que algunos estudiantes tienen sobre la mejora de su espacio, es decir, las proyecciones de los deseos de escolares hacia su propio centro educativo. Este estudio sobre la calidad estética se desarrolla gracias a la participación de tres colegios de Educación Infantil y Educación Primaria de Alicante, en España. La metodología es mixta pues combina la investigación educativa basada en las Artes Visuales y la investigación basada en imágenes para obtener mediante métodos gráficos la voz visual infantil. Los productos son diversos dibujos y collages que expresan información y contenido comunicativo analizado de manera cualitativa y cuantitativa. Con base …
Plagiarists by chance or by choice? Literature and film tell plagiarism
2019
The notion of plagiarism is so controversial and richly stratified that it fascinates scholars from many different disciplines. For the boundary between plagiarism and similar notions is rather hard to be established. Originality is threatened from any direction: consider imitation, copy, theft. Many forgers are around: some start from afar, some others simply seize the opportunity. Then fatally, the threshold between fiction and reality is trespassed: novels’ plots are about plagiarism, and also cinema easily takes that obsession over. There are plenty of stories that concern a literary theft. This set is so large that it justifies a more general question: how plagiarism can be told? This …
When value co-creation turns to co-destruction: Users' experiences of augmented reality mobile games
2018
Service-dominant logic (SDL) provides a well-established lens for understanding services as value co-creation processes. However, also value co-destruction can occur in service processes, but the literature on value co-destruction remains scattered and more studies are called for. We address this research gap with a classification of users’ subjective reasoning for value co-destructive experiences while playing the augmented reality (AR) mobile game Pokémon GO. We conduct laddering interviews with Pokémon GO players to uncover their value co-destruction experiences. Employing clustering analysis, we investigate users’ reasoning for value co-destruction experiences, and argue that value co-d…