Numerical test of the Cardy-Jacobsen conjecture in the site-diluted Potts model in three dimensions

We present a microcanonical Monte Carlo simulation of the site-diluted Potts model in three dimensions with eight internal states, partly carried out on the citizen supercomputer Ibercivis. Upon dilution, the pure model’s first-order transition becomes of the second order at a tricritical point. We compute accurately the critical exponents at the tricritical point. As expected from the Cardy-Jacobsen conjecture, they are compatible with their random field Ising model counterpart. The conclusion is further reinforced by comparison with older data for the Potts model with four states.

Adaptación psicométrica de los cuestionarios "Trauma Symptom Checklist for Children" (TSCC) y "Trauma Symptom Checklist for Young Children" (TSCYC) en una muestra española de víctimas de abuso sexual infantil

El maltrato infantil y el abuso sexual, como tipo de maltrato en la infancia, supone un problema social que ha estado presente a lo largo de la historia, en todos los países, culturas, estratos sociales. El abuso sexual infantil ha presentado dificultades para su definición al no existir un acuerdo único y darse diferencias sobre los criterios definitorios. Las definiciones propuestas han sido múltiples, algunas son más restrictivas, mientras que otras tienen una perspectiva más amplia. Una de las definiciones más ampliamente usada y aceptada internacionalmente ha sido la propuesta por la OMS (2001), al incorporar los criterios de que el menor se encuentra inmerso en actividades o comportamientos para los que no se encuentra preparado ni física ni psicológicamente, sin disponer de la capacidad de consentimiento, transgrediendo la legislación vigente en cada país (Stoltenborgh, Van Ijendoorn, Euser y Bakermans-Kranenbirg, 2011, en Amado, Arce y Herraiz, 2015). En el campo de la investigación social, la mayoría de profesionales hacen uso de los criterios propuestos por Finkelhor y Hotaling (1984), ratificados en España por López (1994). Dichos conceptos han sido el de coerción y la asimetría de edad o diferencias a nivel madurativo, lo que conlleva a una incapacidad a una libre decisión. Dado que el abuso sexual se suele dar en la más estricta intimidad, resulta realmente complicado cuantificar y estimar su prevalencia e incidencia, dada la denominada “cifra negra” de este tipo de situaciones, puesto que parte de los casos no se han denunciado o ni siquiera se han notificado. A pesar de ello, algunos estudios, como el meta-analítico realizado por Pereda, Guilera, Forns y Gómez-Benito (2009), han notificado una prevalencia de entre 7,4% en el caso de los niños y del 19,2% en las niñas...

Critical properties of the four-state commutative random permutation glassy Potts model in three and four dimensions

We investigate the critical properties of the four-state commutative random permutation glassy Potts model in three and four dimensions by means of Monte Carlo simulations and a finite-size scaling analysis. By using a field programmable gate array, we have been able to thermalize a large number of samples of systems with large volume. This has allowed us to observe a spin-glass ordered phase in d=4 and to study the critical properties of the transition. In d=3, our results are consistent with the presence of a Kosterlitz-Thouless transition, but also with different scenarios: transient effects due to a value of the lower critical dimension slightly below 3 could be very important.

Fetichismo de la subjetividad: individualización, malestar y consumo

Capitalism, like the universe, expands; it is foreseen as without limit and historically presented as if from the outside while paradoxically, unlike the universe, capitalism is an historical and contingent emergence. Many have suggested that its naturalization now leave it easier to imagine the end of the world than the end of capitalism. In consumer capitalism, subjectivity has become a commodity. Thus it is possible to say that consumer society is characterized by a "fetish of subjectivity", in which individualization (as lifestyle) and malaise (as symptom) are combined. The fetish of subjectivity may be one of the most important historical achievements of the relationship between capitalism and subjectivity, promoting highly individualized and intensive rules and requiring a consciousness in terms of the consumer society, a success-oriented life, competition and almost total autonomy in achieving the only goals and objectives culturally defined as legitimate and valid, experienced as decisions taken by each individual. Today’s individualization is is individualistic by nature, and it tends to weaken traditional forms of social ties and to strain social cohesion. Sociology is constituted as a discipline which has studied the problematic relationship between modernity and capitalism, which in turn has also been problematic for sociology itself. Especially the associated processes of modernization have favored the emergence of society as a distinctive phenomenon, of the individual and social action, and of subjectivity, a recurring dimension although not always explicit in its problematic. The nation-state has been a historic, formal and spatial expression of dimensions that express the historical relationship between modernity and capitalism...

Phase Transitions in Disordered Systems: The Example of the Random-Field Ising Model in Four Dimensions

By performing a high-statistics simulation of the D = 4 random-field Ising model at zero temperature for different shapes of the random-field distribution, we show that the model is ruled by a single universality class. We compute to a high accuracy the complete set of critical exponents for this class, including the correction-to-scaling exponent. Our results indicate that in four dimensions (i) dimensional reduction as predicted by the perturbative renormalization group does not hold and (ii) three independent critical exponents are needed to describe the transition.

Lump solitons in a higher-order nonlinear equation in 2+1 dimensions

We propose and examine an integrable system of nonlinear equations that generalizes the nonlinear Schrodinger equation to 2 + 1 dimensions. This integrable system of equations is a promising starting point to elaborate more accurate models in nonlinear optics and molecular systems within the continuum limit. The Lax pair for the system is derived after applying the singular manifold method. We also present an iterative procedure to construct the solutions from a seed solution. Solutions with one-, two-, and three-lump solitons are thoroughly discussed.