Sterile neutrinos and right-handed currents in KATRIN

Kurie-plot experiments allow for neutrino-mass measurements based on kinematics in an almost model-independent manner. A future tritium-based KATRIN-like experiment can be sensitive to light sterile neutrinos with masses below 18 keV, which are among the prime candidates for warm dark matter. Here we consider such keV neutrinos in left--right symmetric extensions, i.e. coupled to right-handed currents, which allow for an enhanced contribution to beta decay even for small active--sterile mixing, without violating astrophysical X-ray constraints. The modified spectral shape is in principle distinguishable from the standard contribution---especially for sterile neutrino masses below 9 keV, which can lead to a distinct peak. We compare the sensitivity to constraints from the LHC and neutrinoless double beta decay.Comment: 21 pages, 10 figures; minor changes, added references. Matches published versio

Labour flexibility and productivity in the hotel sector

In this paper, we analyze the effect of labour flexibility on productivity in the Andalusian hotel industry using raw data of our own database and applying an expanded version of the standard production function by distinguishing between part-time, temporary, and full-time labour inputs. Our results show that productivity is lower the higher the percentage of temporary and part-time workers and there are no differences between the impacts on productivity of both types of labour contract. Future studies should analyze the differential impact of all the types of contracts discussed on the mean cost per employee in this sector.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The Use of Led Technology and Biomass to Power Public Lighting in a Local Context: The Case of Baeza (Spain)

The impact of public lighting on consumed energy, financial cost, use of raw materials, and the environment is a major concern nowadays. The high amounts of energy needed to satisfy the increasing demands of cities around the world has led researchers to look for alternatives to classical fossil sources, with low implementation in public lighting up to date. In this context, circular economy (CE) proposes a new perspective of engineering based on smart design for the future life of products where even wastes have an added value as technological nutrients for other applications. A convergent consideration of CE and the urgent necessity of more sustainable public lighting leads to this proposal. The ad hoc use of a local biomass plant for powering the public lighting of one small city is considered, and important conclusions reinforcing the link between lighting and CE are presented.This research was supported by the European Regional Development Fund (European Union), the Government of Spain (Research Project ECO2013-47027-P and ECO2017-84138-P), the Regional Government of Andalusia (Research Project P11-SEJ-7294), and SEJ 232 Research Group Management and Organization for Competitiveness

Effect of labour flexibility on productivity in the andalusian hotel industry

In this work, we analyze the effect of labour flexibility on productivity in the Andalusian hotel industry. For this purpose, we use the data obtained by the Quality, Productivity and Competitiveness in the Hospitality Industry for Andalusia project (PO7/SEJ-02889). Using a expanded version of the Cobb-Douglas production function, the model distinguishes two employment shares: full-time permanent (standard work) and temporary plus part-time employees (non-standard work). Our results indicate that productivity in Andalusian hotels is lower the higher the percentage of temporary and part-time workers. Furthermore, there are no statistically significant differences between the negative impact on productivity of both types of labour contract. However, since the costs associated with both temporary and part-time workers are lower than those of workers with full-time permanent contracts, future studies should analyze the differential impact of all the types of contracts discussed on the mean cost per employee in hotels.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Higher index focus-focus singularities in the Jayne-Cummings-Gaudin model : symplectic invariants and monodromy

We study the symplectic geometry of the Jaynes-Cummings-Gaudin model with $n=2m-1$ spins. We show that there are focus-focus singularities of maximal Williamson type $(0,0,m)$. We construct the linearized normal flows in the vicinity of such a point and show that soliton type solutions extend them globally on the critical torus. This allows us to compute the leading term in the Taylor expansion of the symplectic invariants and the monodromy associated to this singularity.Comment: 39 page

Evolution in the Design and Functionality of Rubrics: from “Square” Rubrics to “Federated” Rubrics

The assessment of learning remains one of the most controversial and challenging aspects for teachers. Among some recent technical solutions, methods and techniques like eRubrics emerge in an attempt to solve the situation. Understanding that all teaching contexts are different and there can be no single solution for all cases, specific measures are adapted to contexts where teachers receive support from institutions and communities of practice. This paper presents the evolution of the eRubric service [1] which started from a first experience with paper rubrics, and, with time and after several I+D+R [2] educational projects, has evolved thanks to the support of a community of practice [3] and the exchange of experiences between teachers and researchers. This paper shows the results and functionality of the eRubrics service up to the date of publicationa.) Project I+D+i EDU2010-15432: eRubric federated service for assessing university learning http://erubrica.uma.es/?page_id=434. b.) Centre for the Design of eRubrics. National Distance Education System -Sined- Mexico. [http://erubrica.uma.es/?page_id=389

An operator representation for Matsubara sums

In the context of the imaginary-time formalism for a scalar thermal field theory, it is shown that the result of performing the sums over Matsubara frequencies associated with loop Feynman diagrams can be written, for some classes of diagrams, in terms of the action of a simple linear operator on the corresponding energy integrals of the Euclidean theory at T=0. In its simplest form the referred operator depends only on the number of internal propagators of the graph. More precisely, it is shown explicitly that this \emph{thermal operator representation} holds for two generic classes of diagrams, namely, the two-vertex diagram with an arbitrary number of internal propagators, and the one-loop diagram with an arbitrary number of vertices. The validity of the thermal operator representation for diagrams of more complicated topologies remains an open problem. Its correctness is shown to be equivalent to the correctness of some diagrammatic rules proposed a few years ago.Comment: 4 figures; references added, minor changes in notation, final version accepted for publicatio