Libera Università Maria SS. Assunta

We develop a second-order cosmological perturbation theory on a background geometry expressed in terms of light-cone coordinates, extending the first-order analyses available in the literature. In particular, we investigate the gauge transformations of second-order perturbative quantities on the light-cone and establish their connection with standard perturbation theory. Through a consistent matching procedure, we identify the second-order gauge fixing that corresponds to the non-linear Geodesic Light-Cone gauge within standard perturbation theory, known as the Observational Synchronous Gauge. We then emphasize its conceptual similarities and differences w.r.t. the standard Synchronous Gauge. Finally, within this new perturbative framework, and adopting a fully gauge-invariant approach, we compute the luminosity distance-redshift relation up to second order with anisotropic stress as seen by a free-falling observer. Remarkably, we show how divergences at the observer position can be eliminated in a completely model-independent way. These results validate our perturbative framework and establish it as a novel formalism for evaluating cosmological observables at second order.

Child and adolescent victimization can impact cognitive processes and individuals’ subsequent social adjustment. These early experiences may affect the presence of biases in social information processing skills, increasing aggressive and maladaptive behaviors in children and adolescents. The aim of this study was to explore the associations between direct and indirect victimization experienced by a group of adolescents and their social information processing skills and engagement in antisocial behaviors over the last year. The sample comprised 364 adolescents from a high school in Spain. Aggressive self-efficacy has an indirect mediating effect on the relation between childhood and adolescent victimization and the development of antisocial behaviors. Indirect victimization is a slightly stronger predictor of antisocial behaviors than direct victimization. Understanding the behavioral and cognitive repercussions of childhood and adolescent victimization may help design and/or perfect interventions to avoid biased processing patterns being perpetuated and behavioral problems becoming chronic.

This chapter examines the pervasive threat of digital disinformation, with a specific focus on AI-generated content as a paradigmatic challenge to contemporary governance. The analysis blends ethical and legal perspectives to assess existing mitigation strategies. AIGC occupies a critical intersection of advanced technical capability, complex social meaning-making, and often conflicting legal protection frameworks. Consequently, effective responses require an interdisciplinary approach that integrates conceptual clarity, technical standards, robust legal instruments, and widespread social interventions to preserve public trust and protect vulnerable individuals.

Abstract Pangenome-based genotyping of structurally complex loci remains challenging at low sequencing depths, particularly when samples are of low quality, such as in ancient DNA. We present COSIGT (COsine SImilarity-based GenoTyper), a method that infers structural genotypes by matching short-read coverage patterns to pangenome haplotypes using cosine similarity. COSIGT maintains robust accuracy at low coverage (1-2X), outperforming existing methods where depth-sensitive approaches degrade. We demonstrate scalability to thousands of modern and ancient genomes, enabling population-scale analyses of complex variation from low-coverage data.

This study aims to explore the interplay between pathological narcissism, reflective functioning (RF), and peer exclusion (vs. inclusion) among adolescents. The study hypothesizes that peer exclusion (vs. inclusion) is associated with greater post-task difficulties in reflective functioning and higher rejection-related emotions, and tests whether these associations vary as a function of pathological narcissism. A sample of 204 adolescents (aged 14-18) participated in an experimental task simulating social media interactions using the Social Media Ostracism Paradigm (SMOP). Participants were assigned to one of three experimental conditions: Over-Inclusion (OI), Neutral (N), and Over-Exclusion (OE). Pathological narcissism was assessed using the Pathological Narcissism Inventory (PNI), and reflective functioning and rejection-related emotions were evaluated post-task. High-risk narcissistic adolescents exhibited significantly lower RF scores than their low-risk peers (F(1, 198) = 13.72, p < .001), particularly in the OE condition (F(2, 198) = 6.76, p < .001). Low-risk adolescents in the OI condition demonstrated better RF. Social exclusion significantly impacted rejection-related emotions (F(2, 198) = 13.890, p < .001), with OE participants reporting higher distress than N and OI groups. However, narcissism did not significantly moderate emotional responses. Pathological narcissism was associated with greater RF difficulties, which were most evident under exclusion. However, rejection distress appears to be a broadly shared response in adolescence and may function as a normative signal of threatened belongingness, relatively independent of narcissism levels. These results emphasize the importance of targeted interventions focusing on mentalization and peer dynamics, particularly for adolescents with high-risk narcissism traits.

Abstract The experimental literature in economics largely acknowledges the role of social capital in social payoff enhancing behavior and/or voluntary provision of public goods. However, social capital is often measured using different proxies that, in principle, may have different impacts on contributions. In this article, we unpack social capital in three dimensions (i.e., school, family, and friends) and we analyze which dimension matters for contributions in economic experiments. We collect data from an ultimatum game, a trust game, and a public good game carried out with children in primary and secondary schools in Sicily, Italy. To measure social capital, we also collect detailed information on social attitudes related to different contexts. We find that, as expected, social capital matters for contributions. More interestingly, we find that the only component that affects contributions is social capital at school. Our findings shed a light on how the school environment may be extremely important for the formation of social capital, especially when this is linked to behavior within the same environment.

The French National Rally's 2024 legislative campaign is an example of how political parties strategically leverage new media, to reconfigure political engagement especially among younger demographics. This study investigates the role of TikTok in political communication strategies during the 2024 French legislative campaign, with a particular focus on how the National Rally is reshaping its image through specific communicative approaches. Grounded in theories of politainment, political personalization, and pop politics, this research examines how the communication strategies of Jordan Bardella, Gabriel Attal (Renaissance), and Jean-Luc Mélenchon (La France Insoumise) engage with pop culture, highlighting both their divergences and points of convergence. The study employs audiovisual content analysis on 131 TikTok videos produced by these political actors during the campaign. The analysis examines how TikTok's affordances are leveraged, including the use of viral sounds, meme-based engagement, and informal storytelling. It also explores several key dimensions to understand the interaction between pop culture and political communication. Findings suggest Bardella’s use of TikTok aligns closely with the logic of politainment, effectively merging traditional party values with contemporary digital communication practices. Unlike Attal and Mélenchon, whose strategies remain more traditional, Bardella leverages pop culture references, informal aesthetics, and emotional appeal to establish a relatable and community-oriented political presence. This study contributes to the growing body of literature on social media politainment by illustrating how TikTok redefines political interaction. Future research could explore cross-national comparisons to better understand how political leaders interpret and model political interaction with new generations.