Completeness and Nonclassicality of Coherent States for Generalized Oscillator Algebras

The purposes of this work are (1) to show that the appropriate generalizations of the oscillator algebra permit the construction of a wide set of nonlinear coherent states in unified form; and (2) to clarify the likely contradiction between the nonclassical properties of such nonlinear coherent states and the possibility of finding a classical analog for them since they are P-represented by a delta function. In (1) we prove that a class of nonlinear coherent states can be constructed to satisfy a closure relation that is expressed uniquely in terms of the Meijer G-function. This property automatically defines the delta distribution as the P-representation of such states. Then, in principle, there must be a classical analog for them. Among other examples, we construct a family of nonlinear coherent states for a representation of the su(1,1) Lie algebra that is realized as a deformation of the oscillator algebra. In (2), we use a beam splitter to show that the nonlinear coherent states exhibit properties like anti-bunching that prohibit a classical description for them. We also show that these states lack second order coherence. That is, although the P-representation of the nonlinear coherent states is a delta function, they are not full coherent. Therefore, the systems associated with the generalized oscillator algebras cannot be considered `classical' in the context of the quantum theory of optical coherence.Comment: 26 pages, 10 figures, minor changes, misprints correcte

Interplay between Riccati, Ermakov and Schroedinger equations to produce complex-valued potentials with real energy spectrum

Nonlinear Riccati and Ermakov equations are combined to pair the energy spectrum of two different quantum systems via the Darboux method. One of the systems is assumed Hermitian, exactly solvable, with discrete energies in its spectrum. The other system is characterized by a complex-valued potential that inherits all the energies of the former one, and includes an additional real eigenvalue in its discrete spectrum. If such eigenvalue coincides with any discrete energy (or it is located between two discrete energies) of the initial system, its presence produces no singularities in the complex-valued potential. Non-Hermitian systems with spectrum that includes all the energies of either Morse or trigonometric Poeschl-Teller potentials are introduced as concrete examples.Comment: 21 pages, 12 figure

Interplay between Riccati, Ermakov, and Schrödinger equations to produce complex‐valued potentials with real energy spectrum

Producción CientíficaNonlinear Riccati and Ermakov equations are combined to pair the energy spectrum of 2 different quantum systems via the Darboux method. One of the systems is assumed Hermitian, exactly solvable, with discrete energies in its spectrum. The other system is characterized by a complex‐valued potential that inherits all the energies of the former one and includes an additional real eigenvalue in its discrete spectrum. If such eigenvalue coincides with any discrete energy (or it is located between 2 discrete energies) of the initial system, its presence produces no singularities in the complex‐valued potential. Non‐Hermitian systems with spectrum that includes all the energies of either Morse or trigonometric Pöschl‐Teller potentials are introduced as concrete examples.2019-06-06Ministerio de Economía, Industria y Competitividad (Project MTM2014-57129-C2-1-P)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA057U16)CONACyT Scholarships. Grant Numbers: 45454, 48985

Latin America 2060: consolidation or crisis?

This repository item contains a single issue of the Pardee Center Task Force Reports, a publication series that began publishing in 2009 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future.Latin America has produced vigorous ideas throughout its history, expressed in narratives about its struggles and successes, or its weaknesses and failures. Together, these have shaped a multi-faceted vision of the region and its peoples. Some of its expositors, finding the story to be neither complete nor precise, work toward reformulations, some quite radical. Such generation of knowledge in different fields seems destined to yield a variety of distinct outcomes, at least in part because some of the emerging social and cultural movements are not yet very well structured. This Task Force Report project seeks to harness ideas about the region’s future into a coherent and policy useful discourse. A Workshop and a Task Force meeting was held at Boston University on November 18-19, 2010. A select group of invited experts – a mix of academic scholars and practitioners – were asked to turn their ideas into short ‘Think Pieces’ essays. Each Think Piece focuses on a specific topical issue for the region as a whole, instead of looking only at particular countries. These Think Piece essays are compiled and edited by the Task Force coordinator and published by the Pardee Center as a Task Force Report

Completeness and Nonclassicality of Coherent States for Generalized Oscillator Algebras

The purposes of this work are (1) to show that the appropriate generalizations of the oscillator algebra permit the construction of a wide set of nonlinear coherent states in unified form and (2) to clarify the likely contradiction between the nonclassical properties of such nonlinear coherent states and the possibility of finding a classical analog for them since they are -represented by a delta function. In (1) we prove that a class of nonlinear coherent states can be constructed to satisfy a closure relation that is expressed uniquely in terms of the Meijer -function. This property automatically defines the delta distribution as the -representation of such states.Then, in principle, theremust be a classical analog for them. Among other examples, we construct a family of nonlinear coherent states for a representation of the su(1, 1) Lie algebra that is realized as a deformation of the oscillator algebra. In (2), we use a beamsplitter to showthat the nonlinear coherent states exhibit properties like antibunching that prohibit a classical description for them.We also show that these states lack second-order coherence. That is, although the -representation of the nonlinear coherent states is a delta function, they are not full coherent.Therefore, the systems associated with the generalized oscillator algebras cannot be considered “classical” in the context of the quantum theory of optical coherence

Evaluation of emergency remote teaching during covid-19 lockdown in a Spanish university

The lockdown caused by the pandemic resulted in the closure of schools and universities. Professors had to adapt their subjects to be taught remotely to continue their classes, and students had to cope with various personal situations such as isolation, and returning to their countries. Ensuring that the quality of teaching was maintained would usually have required months of planning and design. In contrast, these changes had to be made in a few days, which is why this situation could be considered as Emergency Remote Teaching (ERT). The objective of this article is to evaluate the teaching of our faculty during this period using the CIPP model (Context, Input, Procedure and Product), which is especially focused on educational projects among others. The university was able to maintain teaching during this period despite the difficulties of the transition. In addition, evaluation surveys show that the satisfaction of professors and students was also maintained. This was possible thanks to the order and clarity transmitted from university authorities and the commitment of the professors, despite their increased workload. This knowledge is important to ensure a better response by universities in future emergencies

Ace In Space

Videogame development is an intense process that includes the creation of layouts, characters, art, and logic. In our Video Game Creation class, we have been continuously learning valuable skills to implement our game, “Ace in Space.” Research Objectives: Understand 3D design for both characters and objects utilizing Sketchup (a 3D modeling software for objects and characters) and Unity (a game engine that uses the C# programing language), along with implementing and understanding the C# programming language using Visual Studio Code to develop our game “Ace In Space”

Exploration of the Activation Mechanism of the Epigenetic Regulator MLL3: A QM/MM Study

The mixed lineage leukemia 3 or MLL3 is the enzyme in charge of the writing of an epigenetic mark through the methylation of lysine 4 from the N-terminal domain of histone 3 and its deregulation has been related to several cancer lines. An interesting feature of this enzyme comes from its regulation mechanism, which involves its binding to an activating dimer before it can be catalytically functional. Once the trimer is formed, the reaction mechanism proceeds through the deprotonation of the lysine followed by the methyl-transfer reaction. Here we present a detailed exploration of the activation mechanism through a QM/MM approach focusing on both steps of the reaction, aiming to provide new insights into the deprotonation process and the role of the catalytic machinery in the methyl-transfer reaction. Our finding suggests that the source of the activation mechanism comes from conformational restriction mediated by the formation of a network of salt-bridges between MLL3 and one of the activating subunits, which restricts and stabilizes the positioning of several residues relevant for the catalysis. New insights into the deprotonation mechanism of lysine are provided, identifying a valine residue as crucial in the positioning of the water molecule in charge of the process. Finally, a tyrosine residue was found to assist the methyl transfer from SAM to the target lysine

Tat-SF1 Is Not Required for Tat Transactivation but Does Regulate the Relative Levels of Unspliced and Spliced HIV-1 RNAs

.To directly address the involvement of Tat-SF1 in HIV-1 gene expression, we depleted Tat-SF1 in HeLa cells by conventional expression of shRNAs and in T- Rex -293 cells containing tetracycline-inducible shRNAs targeting Tat-SF1. We achieved efficient depletion of Tat-SF1 and demonstrated that this did not affect cell viability. HIV-1 infectivity decreased in Tat-SF1-depleted cells, but only when multiple rounds of infection occurred. Neither Tat-dependent nor basal transcription from the HIV-1 LTR was affected by Tat-SF1 depletion, suggesting that the decrease in infectivity was due to a deficiency at a later step in the viral lifecycle. Finally, Tat-SF1 depletion resulted in an increase in the ratio of unspliced to spliced viral transcripts.Tat-SF1 is not required for regulating HIV-1 transcription, but is required for maintaining the ratios of different classes of HIV-1 transcripts. These new findings highlight a novel, post-transcriptional role for Tat-SF1 in the HIV-1 life cycle