We identify a symplectic potential for general relativity in tetrad and connection variables that is fully gauge-invariant, using the freedom to add surface terms. When torsion vanishes, it does not lead to surface charges associated with the internal Lorentz transformations, and reduces exactly to the symplectic potential given by the Einstein-Hilbert action. In particular, it reproduces the Komar form when the variation is a Lie derivative, and the geometric expression in terms of extrinsic curvature and 2d corner data for a general variation. The additional surface term vanishes at spatial infinity for asymptotically flat spacetimes, thus the usual Poincaré charges are obtained. We prove that the first law of black hole mechanics follows from the Noether identity associated with the covariant Lie derivative, and that it is independent of the ambiguities in the symplectic potential provided one takes into account the presence of non-trivial Lorentz charges that these ambiguities can introduce.

Background: At the beginning of 2020, a pandemic caused by a new strain of coronavirus occurred. On March 9th, the Italian population was forced to lockdown to prevent the spread of this new virus. This event forced families and cohabitants to spend their entire days and weeks in the same physical space, interacting with partners and children with a very different degree of intimacy than in the earlier situation. The present study investigated the effects of being forced to live together on different family patterns, on various dimensions such as stress, coping strategies, time perception and quality evaluation of cohabitation. Method: A total sample consisting of 1750 individuals was recruited through a random sample of probability across the Italian country. Due to the lockdown condition, an online questionnaire was set up; several validated scales were chosen, and some open-ended items were included for the thoughts of the participants. Results: The results showed statistically significant differences between the three family patterns examined. Conclusion: During the forced period of living together, a positive effect could be inferred as given by the presence of children and the collaborative coping strategies that have been adopted; the results have been discussed according to the literature on the topic.

Abstract:We discuss the Hamiltonian dynamics of general relativity with real connection variables on a null foliation, and use the Newman-Penrose formalism to shed light on the geometric meaning of the various constraints. We identify the equivalent of Sachs' constraint-free initial data as projections of connection components related to null rotations, i.e. the translational part of the ISO(2) group stabilising the internal null direction soldered to the hypersurface. A pair of second-class constraints reduces these connection components to the shear of a null geodesic congruence, thus establishing equivalence with the second-order formalism, which we show in details at the level of symplectic potentials. A special feature of the first-order formulation is that Sachs' propagating equations for the shear, away from the initial hypersurface, are turned into tertiary constraints; their role is to preserve the relation between connection and shear under retarded time evolution. The conversion of wave-like propagating equations into constraints is possible thanks to an algebraic Bianchi identity; the same one that allows one to describe the radiative data at future null infinity in terms of a shear of a (non-geodesic) asymptotic null vector field in the physical spacetime. Finally, we compute the modification to the spin coefficients and the null congruence in the presence of torsion.

We prove that a conserved effective energy-momentum tensor for Einstein-Cartan theory can be identified from the Noether identities of the matter Lagrangian, using the torsion field equations relating them. More precisely, a one-parameter family labelled by the Immirzi parameter. We use this result and the contorsion description to show that Jacobson's thermodynamical derivation of the Einstein equations follows as in the metric theory, namely from the equilibrium Clausius relation and the fact that a Killing horizon is metric-geodetic. Our derivation works for an arbitrary torsion field. In the course of our discussion we review the laws of black hole mechanics and their dependence on torsion.

The global pandemic caused by a new strain of Coronavirus has brought the Italian government to adopt quarantine, isolation, and lockdown strategies as restrictive measures to reduce the virus spread. Being forced to stay at home could significantly increase the likelihood of episodes of home-based violence and could also be accompanied by a limited possibility of complaints or defense by the victim. The present study aimed to document, through the use of newspaper articles, the characteristics of domestic violence during the lockdown period related to COVID-19 in Italy (from 9 March 2020 up to 18 May 2020) and compare the results with the same period in 2019. The results showed an increase in domestic violence during the lockdown period compared to the same period the year before and highlighted the differences between the dynamics and violent behavior between the two periods examined. The results and limitations of this research are discussed with reference to the literature.

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Most of the available literature has shown that gambling disorder (GD) is often associated with several psychiatric conditions. Comorbidities with mood disorders, impulsiveness, personality traits, and impairments in cognitive function have also been frequently investigated. However, it is currently uncommon to study this disorder in individuals without comorbid substance abuse; therefore, the primary aim of our study was to compare the psychological profile of individuals with GD with and without substance use disorder. A total of 60 participants (100% male), including 20 individuals with GD, 20 substance-dependent gamblers (SDGs), and 20 healthy controls (HCs), were assessed with several clinical measures to investigate impulsivity, hostility, mood, and personality traits, as well as with cognitive tasks (i.e., decision-making tasks). Our results showed differences in both experimental groups compared with the HC group in mood disorders, impulsivity, and hostility traits. The ‘‘pure’’ GD group differed from the SDG group only in characteristics related to mood disorders (e.g., State-Trait Anxiety Inventory-Y2, Beck Depression Inventory-II, and assault dimension), whereas greater impairment in decision making processes related to risky choices was shown in the SDG group. This study suggests the importance of studying pure GD to clarify the underlying mechanisms without the neurotoxic effects of the substances. This could provide an important contribution to the treatment and understanding of this complex disorder.

BackgroundExtensive research showed that multitasking negatively affects driving performance. Multitasking activities can range from talking and texting to listening to music; particularly among young drivers, multitasking behavior is caused mainly from mobile phone use while driving which is one of the main causes of road accidents.ObjectiveThe main purpose of this study was to investigate whether some variables (e.g., Sensation-Seeking, preferences of Multitasking) could affect mobile phone use while driving in young drivers and whether any gender differences were present among the examined variables.Setting and participantsThe sample consists of 424 Italian students (56% males) with an age range of 18–21 years. A self-report questionnaire was specifically developed to assess variables such as: Attitude toward Multitasking, Perceived Self-efficacy in Multitasking, Accident Risk Perception, General Multitasking Habits, and Sensation Seeking.ResultsThrough SEM modeling, we found the attitude to multitasking while driving to be largely explained by the considered variables. Using multigroup analysis (MGSEM), the model we developed appears to be suitable for explaining the behaviors of both male and female young drivers. Furthermore, data comparison showed that females were more likely to risk perception toward multitasking, and risk perception when using a mobile phone while driving, while males obtained higher mean scores in Sensation Seeking, Perceived Self-Efficacy in Multitasking, and in Multitasking caused by mobile phone use while driving.ConclusionOur research showed how some variables may influence the inclination of some subjects to engage in multitasking while driving. Furthermore, we discussed the importance of considering these variables in the implementation of effective road safety education projects on driving multitasking.