Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

School, sport and leisure : three dimensions of adolescence

ix, 179 p.; 21 cm

Jóvenes, tecnología y cambio; ¿Comprendiendo el sistema?

This paper begins by offering a brief outline of recent societal changes, emphasising the powerful, global impact of the arrival of information technology in all our lives. It then examines the research evidence about the positive and negative influences of information technology on young people, presenting findings on the following aspects of information technology: • As a leisure time activity• As a source of information• For social networking The paper concludes by suggesting what the findings may mean for parents and those who work professionally with young people; why it is important to utilise a systemic framework in analysing the issues and by suggesting a range of possible approaches and interventions to improve the usage of information technology by both young people and adults.Este artículo comienza ofreciendo una visión general somera de los cambios sociales recientes, destacando el fuerte impacto global de la llegada de la tecnología de la información a nuestras vidas. A continuación, examina la evidencia de la investigación sobre las influencias positivas y negativas de la tecnología de la información en los jóvenes, aportando hallazgos sobre los siguientes aspectos de la misma: • Como actividad de tiempo libre• Como fuente de información• Para las relaciones sociales El documento concluye sugiriendo lo que los resultados pueden significar para los progenitores y para los que trabajan profesionalmente con los jóvenes; por qué es importante utilizar un marco sistémico en el análisis de los problemas, y propone una serie de posibles enfoques e intervenciones para mejorar el uso de tecnologías de la información por parte de jóvenes y adultos

An elaboration of non-linear, non-ergodic and self-organizing processes.: Understanding the bumps and jumps in adolescent development

Adolescent development is characterized by turbulence and irregularity. Developmental processes in adolescence take place at different domains at the same time and these domains influence each other in complex ways. Some processes take place at high speed, while others are slow, and in some domains no development is visible. Moreover, this development takes place in an environment that is complex and changing as well. As a result developmental trajectories in individuals are characterized by fluctuations, bumps, regressive periods, and other seemingly chaotic patterns. The common approach to development tends to focus on normative development and in development in subgroups, and often neglects the irregularities of developmental processes as resulting from random influences and noise, and our methodology is not well suited to grasp jumping and bumping adolescent development. However, these irregularities are at the core of the developmental processes, and we miss a lot of relevant knowledge if we ignore them. In this chapter I elaborate that to understand the characteristics of these developmental processes we need another conceptual framework - the dynamic systems perspective - and related to that, other methods to analyze these processes. I discuss the theoretical implications of a complex dynamic approach that can help us to get more profound insight in the developmental processes. I focus on three different but related characteristics of the developmental process: non-linearity, non-ergodicity, and self-organization. The most important consequence of each of these three characteristics is that we need to study individual development. To start with, I therefore elaborate how our knowledge expands if we focus on intra individual dynamic processes. The three types of studies I describe coincide with the more general phases in the research in developmental psychology (see Côté, this volume). In the first phase theories intended to describe normative, population-level development; in the second phase these theories were criticized for not identifying group differences and interaction effects. In this phase much research focus on these differences/effects; in the third phase, emerging in the last decades, ways of thinking came up that stated that the previous approaches neglected the intra-individual developmental processes that follow different principles. Today, we see research belonging to each of these phases, as illustrated in the first section of the chapter

School Victimization: Family Environment, Self-esteem, and Life Satisfaction from a Gender Perspetive

This study analyzed from a gender perspective relationships between perceived family climate, self-esteem, life satisfaction, and adolescent victimization by peers in school. The associations between variables were analyzed with a sample of 1,884 adolescents (52% boys and 48% girls), aged 11 through 17 years (M = 13.7, DT = 1.4). Results structural equation modeling analysis showed that family environment, self-esteem, and life satisfaction were significantly and negatively related to school victimization. Multigroup analyses showed that relationships between variables were not different for boys and girls. We discuss the implications of these results

The Curtain rises: A Brief overview of the book

The first chapter provides some background and some information on the two contending approaches debated in the book. Demographic and economic changes influencing the lives of young people in recent decades are noted. The limitations of 20th-century stage theories are described (e.g., Erikson, Havighurst). Then the two theoretical approaches of this book are presented. Arnett\u27s and Tanner\u27s approach presents emerging adulthood as a new life stage, distinct from the adolescence that precedes it or the young adulthood that follows, but also emphasizes that there are many paths through emerging adulthood depending on culture, social class, ethnicity, and gender. In contrast, Kloep and Hendry argue against stage theories generally and emerging adulthood in particular, favoring instead an understanding of development that focuses on processes