The nonlinear dynamics of cosmological perturbations of an irrotational collisionless fluid is analyzed within general relativity. Relativistic and Newtonian solutions are compared, stressing the different role of boundary conditions in the two theories. Cosmological implications of relativistic effects, already present at second order in perturbation theory, are studied and the dynamical role of the magnetic part of the Weyl tensor is elucidated.

In this article, we discuss the development and the administration of a multiple-choice test, which we named Test of Calculus and Vectors in Mathematics and Physics (TCV-MP), aimed at comparing students’ ability to answer questions on derivatives, integrals, and vectors in a purely mathematical context and in the context of physics. The comparison between the two contexts was achieved by using parallel (isomorphic) questions in mathematics and physics. The final version of the test contains 34 items (17 in a purely mathematical context and 17 in the context of physics) involving different representations (graphs, words, numbers, and formal expressions) of the concepts covered by the test. The test was administered in Spring 2018 to 1252 first-year students enrolled in 23 different degree programs of the School of Science and the School of Engineering of the University of Padua. We assessed the validity, reliability, and discriminatory power of the test both as a whole and at the single-item level, obtaining values within the desired ranges. The analysis of students’ answers to individual items and the comparison between parallel mathematics and physics items provides insights into the factors that affect students’ ability to use derivatives, integrals, and vectors in the context of introductory physics. We believe that the instrument we have developed can be useful not only for research purposes, but also for instructors and for students.

This paper focuses on results of an interview based survey of first-year university physics students, carried out within the EU Horizons in Physics Education (HOPE) project ( http://hopenetwork.eu/ ). 94 interviews conducted in 13 universities have been analyzed to investigate the factors that inspire young people to study physics. In particular, the main motivational factor, which was proven to consist of personal interest and curiosity, was unfolded into different categories and detailed interest profiles were produced. The results are arguably useful to help academic curriculum developers and teaching personnel in physics departments to provide guidance to students in developing and focusing their interest towards specific sub-fields and/or to design targeted recruitment and outreach initiatives.

This study contributes to the literature on the role of communities of learners in the professional development of physics teachers. It offers insights from the Collabora—A Community of Learners on Laboratory Work program, designed to enhance the use of laboratories in secondary school physics teaching. The program’s foundation rested upon two pillars: a learning community approach and action research, grounded in the findings of physics education research. Furthermore, the program was structured to encompass the core features of effective professional development as outlined in the literature (content focus, active learning opportunities, coherence with teachers’ needs, and sufficient duration). The program spanned 2 years. During the first year, teachers engaged with and discussed different types of experiments, reflected on the assessment of scientific practices, and participated in action research aimed at improving laboratory activities in their classrooms. In the second year, they focused on integrating laboratory work within teaching-learning sequences developed through a backward design process. The research questions of this study were centered on examining the role and relevance of program features, with particular emphasis on the learning community and action research components, and on investigating the changes reported by teachers as a result of participating in the program. The findings emphasize the pivotal role of the teacher community, with reciprocal training identified as the “truly developmental” element. Moreover, they corroborate the relevance of action research in fostering a sense of ownership of research-based innovations. Over the course of the program, teachers reported changes in the personal domain, in the domain of practice, and, particularly in the second year, also in the domain of student outcomes. These changes included the use of different types of experiments, a greater sense of self-efficacy in the laboratory, and an increased focus on the design and assessment of laboratory work. We studied changes through a “growth” lens, both at the group level and within a subset of individual case studies. The latter analysis highlights different possible productive pathways to teachers’ growth, supporting a view of teacher professional development as complex and multifaceted. The program structure facilitated the processes of “enactment” and “reflection” that mediated the various changes.