Innovation and jobs: evidence from manufacturing firms

This paper is aimed at structurally assessing the employment effects of the innovative activities of firms. We estimate firm level displacement and compensation effects in a model in which the stock of knowledge capital raises firm relative efficiency through process innovations and firm demand through product innovations. Displacement is estimated from the elasticity of employment with respect to innovation in the (conditional or Hicksian) demand for labour. Compensation effects are estimated from a firm-specific demand relationship. We also assess the enlargement and weakening of these effects due to firm agents’ behaviour aimed at appropriating innovation rents. We find that the potential employment compensation effect of process innovations surpasses the displacement effect, both in the short and long run (when competitors react), and that product innovation doubles the expanding impact by unit of expenditure, but also that agents’ behaviour can seriously reduce these effects. The actual elasticity of employment to knowledge capital is estimated, however, not far from unity, while “passive” productivity growth is suggested to have null or negative employment effects

Linear Assignment Maps for Correlated System-Environment States

An assignment map is a mathematical operator that describes initial system-environment states for open quantum systems. We reexamine the notion of assignments, introduced by Pechukas, and show the conditions assignments can account for correlations between the system and the environment, concluding that assignment maps can be made linear at the expense of positivity or consistency is more reasonable. We study the role of other conditions, such as consistency and positivity of the map, and show the effects of relaxing these. Finally, we establish a connection between the violation of positivity of linear assignments and the no-broadcasting theorem.Comment: 6 pages, 1 tabl

Unification of witnessing initial system-environment correlations and witnessing non-Markovianity

We show the connection between a witness that detects dynamical maps with initial system-environment correlations and a witness that detects non-Markovian open quantum systems. Our analysis is based on studying the role that state preparation plays in witnessing violations of contractivity of open quantum system dynamics. Contractivity is a property of some quantum processes where the trace distance of density matrices decrease with time. From this, we show how a witness of initial-correlations is an upper bound to a witness of non-Markovianity. We discuss how this relationship shows further connections between initial system-environment correlations and non-Markovianity at an instance of time in open quantum systems.Comment: 5 page

Non-gaussianity at tree and one-loop levels from vector field perturbations

We study the spectrum P_\zeta and bispectrum B_\zeta of the primordial curvature perturbation \zeta when the latter is generated by scalar and vector field perturbations. The tree-level and one-loop contributions from vector field perturbations are worked out considering the possibility that the one-loop contributions may be dominant over the tree level terms (both (either) in P_\zeta and (or) in B_\zeta) and viceversa. The level of non-gaussianity in the bispectrum, f_{NL}, is calculated and related to the level of statistical anisotropy in the power spectrum, g_\zeta. For very small amounts of statistical anisotropy in the power spectrum, the level of non-gaussianity may be very high, in some cases exceeding the current observational limit.Comment: LaTeX file, 11 pages, Main body: 8 pages, References: 3 pages. v2: Minor corrections. References added. Conclusions unchanged. v3: Minor corrections. Some references added and others updated. Version accepted for publication in Physical Review

Vanishing quantum discord is not necessary for completely-positive maps

The description of the dynamics of a system that may be correlated with its environment is only meaningful within the context of a specific framework. Different frameworks rely upon different assumptions about the initial system-environment state. We reexamine the connections between complete-positivity and quantum discord within two different sets of assumptions about the relevant family of initial states. We present an example of a system-environment state with non-vanishing quantum discord that leads to a completely-positive map. This invalidates an earlier claim on the necessity of vanishing quantum discord for completely-positive maps. In our final remarks we discuss the physical validity of each approach.Comment: close to published versio

Operational Markov condition for quantum processes

We derive a necessary and sufficient condition for a quantum process to be Markovian which coincides with the classical one in the relevant limit. Our condition unifies all previously known definitions for quantum Markov processes by accounting for all potentially detectable memory effects. We then derive a family of measures of non-Markovianity with clear operational interpretations, such as the size of the memory required to simulate a process, or the experimental falsifiability of a Markovian hypothesis.Comment: 5+3 pages, 4 figures; split off from earlier version of arXiv:1512.0058

The evaluation of a Problem-Based Learning approach in a graduate Agrarian Constructions program

En este trabajo se exponen los resultados de una aplicación y evaluación de la Metodología didáctica específica denominada Aprendizaje Basado en Problemas (ABP) en estudiantes de Construcciones Agrarias. El trabajo se ha efectuado durante el curso 2015-16 en dos grupos de alumnos del Grado de Ingeniería Agrícola de la Escuela Técnica Superior de Ingeniería de la Universidad de Huelva (España). El estudio incluyó la aplicación de la metodología didáctica específica y su evaluación. La evaluación se ha efectuado empleando un método cuasi-experimental. El diseño del ABP ha requerido una programación cuidadosa, incluyendo una parte significativa de trabajo autónomo por el estudiante. Los resultados muestran que el ABP es preferible a otra didáctica tradicional expositiva ya que se observa una diferencia significativa en la adquisición de conocimientos por los alumnos.This paper presents the results of a study into the implementation and evaluation of problem-based learning (PBL) methodology in an Agrarian Constructions program. The study was carried out during the academic year 2015-2016 with two groups of students of the degree in Agricultural Engineering of the School of Engineering at the University of Huelva in Spain. The study included the implementation of this novel approach and its evaluation. The evaluation was performed using a quasi-experimental method. Programming a course of PBL demands careful planning and the inclusion of a significant amount of selfdirected work by students. The results indicated that there is a significant difference in the acquisition of knowledge by students, suggesting that PBL should be preferred instead of the more traditional lecturebased approaches

On the Issue of the \zeta Series Convergence and Loop Corrections in the Generation of Observable Primordial Non-Gaussianity in Slow-Roll Inflation. Part II: the Trispectrum

We calculate the trispectrum T_\zeta of the primordial curvature perturbation \zeta, generated during a {\it slow-roll} inflationary epoch by considering a two-field quadratic model of inflation with {\it canonical} kinetic terms. We consider loop contributions as well as tree level terms, and show that it is possible to attain very high, {\it including observable}, values for the level of non-gaussianity \tau_{NL} if T_\zeta is dominated by the one-loop contribution. Special attention is paid to the claim in JCAP {\bf 0902}, 017 (2009) [arXiv:0812.0807 [astro-ph]] that, in the model studied in this paper and for the specific inflationary trajectory we choose, the quantum fluctuations of the fields overwhelm the classical evolution. We argue that such a claim actually does not apply to our model, although more research is needed in order to understand the role of quantum diffusion. We also consider the probability that an observer in an ensemble of realizations of the density field sees a non-gaussian distribution. In that respect, we show that the probability associated to the chosen inflationary trajectory is non-negligible. Finally, the levels of non-gaussianity f_{NL} and \tau_{NL} in the bispectrum B_\zeta and trispectrum T_\zeta of \zeta, respectively, are also studied for the case in which \zeta is not generated during inflation.Comment: LaTex File, 27 pages, 8 figures. v2: Previous Section 2 has been removed. Two new sections (3 and 4) discussing the classicality condition given by Byrnes, Choi, and Hall, in JCAP 0902, 017 (2009), and the probability that an observer sees a non-gaussian distribution have been added. v3: Version accepted for publication in Physical Review