Second Order Perturbations in the Randall-Sundrum Infinite Brane-World Model

We discuss the non-linear gravitational interactions in the Randall-Sundrum single brane model. If we naively write down the 4-dimensional effective action integrating over the fifth dimension with the aid of the decomposition with respect to eigen modes of 4-dimensional d'Alembertian, the Kaluza-Klein mode coupling seems to be ill-defined. We carefully analyze second order perturbations of the gravitational field induced on the 3-brane under the assumption of the static and axial-symmetric 5-dimensional metric. It is shown that there remains no pathological feature in the Kaluza-Klein mode coupling after the summation over all different mass modes. Furthermore, the leading Kaluza-Klein corrections are shown to be sufficiently suppressed in comparison with the leading order term which is obtained by the zero mode truncation. We confirm that the 4-dimensional Einstein gravity is approximately recovered on the 3-brane up to second order perturbations.Comment: 15 pages, 2 figures, comment and reference added, typos correcte

Does service learning affect the development of intercultural sensitivity? A study comparing students' progress in two different methodologies

Numerous studies have highlighted Intercultural Sensitivity (IS) as a key competence in an increasingly multicultural society. This study examined the extent to which a cohort of first year undergraduate students enrolled on the same Didactics course, and in two different training modalities Service Learning (SL) and non-Service Learning (non-SL) developed IS. It was based on a quasi-experimental design of repeated pre-test and post-test measures, comparing the two groups. The sample consisted of 233 Spanish students at higher education institutions, and data was collected using the Intercultural Development Inventory (IDI). The SL group displayed significantly higher levels of IS in all factors except in the denial/defence and minimization stages. Results indicated the effectiveness of SL regarding specific subscales within the IDI instrument. The findings add new depth to our understanding regarding which teaching methodologies contribute to the development of IS and to the training of active citizens in Spanish university students. The discussion focuses on the need for intercultural service experiences to promote IS. The results have broad implications for policymakers and educators who are interested in enhancing transformative educational experiences and effective teaching methodologies for developing students' IS in higher education.Universidad Pablo de Olavide de Sevilla. Departamento de Educación y Psicología Socia