A lattice Monte Carlo study of Inverse Symmetry Breaking in a two-scalar model in three dimensions

We carry a Monte Carlo study of the coupled two-scalar $\lambda\phi^2_1 \phi^2_2$ model in three dimensions. We find no trace of Inverse Symmetry Breaking in the region of negative $\lambda$'s for which the one-loop effective potential predicts this phenomenon. Moreover, for $\lambda$'s negative enough, but still in the stability region for the potential, one of the transitions turns out to be of first order, both for zero and finite temperature.Comment: 23 pages, 7 figures included, Latex, epsfig. Minor changes in Sec.3 and in the conclusions. In press on Nuc.Phys.

Continuum limit of finite temperature λϕ34\lambda\phi^4_3 from lattice Monte Carlo

The $\phi^4_3$ model at finite temperature is simulated on the lattice. For fixed $N_t$ we compute the transition line for $N_s \to \infty$ by means of Finite Size Scaling techniques. The crossings of a Renormalization Group trajectory with the transition lines of increasing $N_t$ give a well defined limit for the critical temperature in the continuum. By considering different RG trajectories, we compute $T^c/g$ as a function of the renormalized parameters.Comment: 26 pages, Latex, epsfig, 8 figures include

Emotional and educational accompaniment through dialogic literary gatherings: a volunteer project for families who suffer digital exclusion in the context of COVID-19

In order to improve educational conditions of families lacking digital resources during the home lockdown associated with the COVID-19 crisis, a project of educational and emotional support through books featuring Dialogic Literary Gatherings was carried out, with the name “Books that Bring People Together”. We present the main results of the impact of this activity from the point of view of n = 63 volunteers who participated in it. Using Student’s t-test for related samples, the differences in volunteers’ competencies before (pre-test) and after (post-test) the experience were tested, in order to analyze whether the activity had also exerted an impact on these competencies. Moreover, a correlation analysis was applied between the items for evaluating family participation by the volunteers, volunteer skills, and training, with the aim of testing the relationships between those variables as a result of participation in the experience. Results show that families found that accompaniment improved the quality of life of their children, making them feel loved and accompanied. In addition, the family atmosphere was improved, as did the children’s interest in reading. This mode of training led to greater involvement, motivation, and interest, thereby complying with a transversal axis of the process—community participation

3D Spin Glass and 2D Ferromagnetic XY Model: a Comparison

We compare the probability distributions and Binder cumulants of the overlap in the 3D Ising spin glass with those of the magnetization in the ferromagnetic 2D XY model. We analyze similarities and differences. Evidence for the existence of a phase transition in the spin glass model is obtained thanks to the crossing of the Binder cumulant. We show that the behavior of the XY model is fully compatible with the Kosterlitz-Thouless scenario. Finite size effects have to be dealt with by using great care in order to discern among two very different physical pictures that can look very similar if analyzed without large attention.Comment: 14 pages and 6 figures. Also available at http://chimera.roma1.infn.it/index_papers_complex.htm

Simulation of 3d Ising spin glass model using three replicas: study of Binder cumulants

We have carried out numerical simulations of the three-dimensional Ising spin glass model with first neighbour Gaussian couplings using three replicas for each sample of couplings. We have paid special attention to the measure of two types of Binder cumulant that can be constructed from the three possible overlaps between the replicas. We obtain new information about the possible phase transition and perform an initial analysis of the ultrametricity issue.Comment: 14 pages and 7 figures, available at http://chimera.roma1.infn.it/index_papers_complex.htm

Numerical Simulations of the 4D Edwards-Anderson Spin Glass with Binary Couplings

We present numerical results that allow a precise determination of the transition point and of the critical exponents of the 4D Edwards-Anderson Spin Glass with binary quenched random couplings. We show that the low T phase undergoes Replica Symmetry Breaking. We obtain results on large lattices, up to a volume $V=10^4$: we use finite size scaling to show the relevance of our results in the infinite volume limit.Comment: 18 pages + 17 figures, revised bibliography and minor typos. Added Journal Re

Satellite-Based Assessment of Grassland Conversion and Related Fire Disturbance in the Kenai Peninsula, Alaska

Spruce beetle-induced (Dendroctonus rufipennis (Kirby)) mortality on the Kenai Peninsula has been hypothesized by local ecologists to result in the conversion of forest to grassland and subsequent increased fire danger. This hypothesis stands in contrast to empirical studies in the continental US which suggested that beetle mortality has only a negligible effect on fire danger. In response, we conducted a study using Landsat data and modeling techniques to map land cover change in the Kenai Peninsula and to integrate change maps with other geospatial data to predictively map fire danger for the same region. We collected Landsat imagery to map land cover change at roughly five-year intervals following a severe, mid-1990s beetle infestation to the present. Land cover classification was performed at each time step and used to quantify grassland encroachment patterns over time. The maps of land cover change along with digital elevation models (DEMs), temperature, and historical fire data were used to map and assess wildfire danger across the study area. Results indicate the highest wildfire danger tended to occur in herbaceous and black spruce land cover types, suggesting that the relationship between spruce beetle damage and wildfire danger in costal Alaskan forested ecosystems differs from the relationship between the two in the forests of the coterminous United States. These change detection analyses and fire danger predictions provide the Kenai National Wildlife Refuge (KENWR) ecologists and other forest managers a better understanding of the extent and magnitude of grassland conversion and subsequent change in fire danger following the 1990s spruce beetle outbreak

A Monte Carlo study of Inverse Symmetry Breaking

We make a Monte Carlo study of the coupled two-scalar $\lambda\phi^2_1\phi^2_2$ model in four dimensions at finite temperature. We find no trace of Inverse Symmetry Breaking for values of the renormalized parameters for which perturbation theory predicts this phenomenon.Comment: 4 pages, revtex, 3 figures include

On the Phase Structure of the 3D Edwards Anderson Spin Glass

We characterize numerically the properties of the phase transition of the three dimensional Ising spin glass with Gaussian couplings and of the low temperature phase. We compute critical exponents on large lattices. We study in detail the overlap probability distribution and the equilibrium overlap-overlap correlation functions. We find a clear agreement with off-equilibrium results from previous work. These results strongly support the existence of a continuous spontaneous replica symmetry breaking in three dimensional spin glasses.Comment: 30 pages and 17 figures. Final version to be published in PR

La formación como variable de calidad del envejecimiento en el empleo en entornos organizacionales tecnificados

En el marco de los cambios tecnológicos introducidos en la industria 4.0, el estudio analiza a nivel organizativo las relaciones entre innovación tecnológica, calidad del empleo, formación, posición organizacional y edad de las/os trabajadoras/es. A partir de la observación de un impacto neutral de la introducción de tecnologías avanzadas sobre la mayoría de dimensiones que componen el constructo “calidad del trabajo”, el estudio se basa en un análisis mediante modelos de ecuaciones estructurales realizados utilizando datos de una muestra de 907 empleadas/os de 9 empresas de la industria 4.0 de Aragón. Los resultados de los modelos testados permiten observar que la introducción de nuevas tecnologías puede provocar un decrecimiento de la calidad percibida de la experiencia de trabajo asociada al paso de tiempo, y que la formación atenúa de manera relevante dicho efecto negativo, sobre todo en los entornos menos tecnificados. Within the framework of the technological changes introduced by the Industry 4.0, the study aims to analyse at an organizational level the relationships between technological innovation, job quality, training, organizational position and age of the workers. Starting from the observation of a neutral impact of the introduction of advanced technologies on the majority of dimensions that make up the construct ‘quality of work’, the study is based on an analysis through models of structural equations carried out using data from a sample of 907 employees from 9 companies of Industry 4.0 of Aragon. The results of the tested models allow to observe that the introduction of new technologies can cause a decrease in the perceived quality of the work experience associated with the passage of time, and that training significantly attenuates this negative effect especially in organisational environments relatively less technified