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

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

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

Modernity, Remixed: Music as Memory in Rap Galsen

Drawing on 14 months of ethnographic research in Dakar, Senegal as well as an 18-month focused case study with Senegalese rappers in Los Angeles, this dissertation explores Senegalese hip hop production as the performative negotiation of postcolonial urban space. Engaging tradition as a discursive strategy, it considers hip hop tracks as aural palimpsest memories that are constructed through practices of lyrical, discursive, linguistic, and musical intertextuality, practices that strategically layer invented traditions of local performance and U.S. hip hop. Although scholarly and popular media accounts of Senegalese hip hop privilege internationally successful rappers' narratives of hip hop as stemming from local griot traditions, the "underground" majority of rappers rejects this narrative to instead ground their music in hip hop's mythologized history of racialized socio-economic struggle. Through hip hop-mediated understandings of similitude between African American and Senegalese urban experience, they strategically and self-consciously position themselves within an alternative, globally articulating modernity and against a local, traditionally inflected one. In positing hip hop production as the (re)production of memory, I argue against hybridity as a potentially colonizing framework to insist instead on an analysis grounded in local narratives that erase hybridity's prerequisite difference. Depending on their positionality vis-à-vis local and international markets, Senegalese rappers position hip hop either as always already indigenous, or as necessarily and definitely black American. In the processes and products of hip hop production, they draw on multiple mythologized pasts, creating interlocking, performative narratives of sameness and historicity through which they negotiate situated experiences of modernity

Modernity, Remixed: Music as Memory in Rap Galsen

Drawing on 14 months of ethnographic research in Dakar, Senegal as well as an 18-month focused case study with Senegalese rappers in Los Angeles, this dissertation explores Senegalese hip hop production as the performative negotiation of postcolonial urban space. Engaging tradition as a discursive strategy, it considers hip hop tracks as aural palimpsest memories that are constructed through practices of lyrical, discursive, linguistic, and musical intertextuality, practices that strategically layer invented traditions of local performance and U.S. hip hop. Although scholarly and popular media accounts of Senegalese hip hop privilege internationally successful rappers' narratives of hip hop as stemming from local griot traditions, the "underground" majority of rappers rejects this narrative to instead ground their music in hip hop's mythologized history of racialized socio-economic struggle. Through hip hop-mediated understandings of similitude between African American and Senegalese urban experience, they strategically and self-consciously position themselves within an alternative, globally articulating modernity and against a local, traditionally inflected one. In positing hip hop production as the (re)production of memory, I argue against hybridity as a potentially colonizing framework to insist instead on an analysis grounded in local narratives that erase hybridity's prerequisite difference. Depending on their positionality vis-à-vis local and international markets, Senegalese rappers position hip hop either as always already indigenous, or as necessarily and definitely black American. In the processes and products of hip hop production, they draw on multiple mythologized pasts, creating interlocking, performative narratives of sameness and historicity through which they negotiate situated experiences of modernity

The children\u27s brain tumor network (CBTN) - Accelerating research in pediatric central nervous system tumors through collaboration and open science

Pediatric brain tumors are the leading cause of cancer-related death in children in the United States and contribute a disproportionate number of potential years of life lost compared to adult cancers. Moreover, survivors frequently suffer long-term side effects, including secondary cancers. The Children\u27s Brain Tumor Network (CBTN) is a multi-institutional international clinical research consortium created to advance therapeutic development through the collection and rapid distribution of biospecimens and data via open-science research platforms for real-time access and use by the global research community. The CBTN\u27s 32 member institutions utilize a shared regulatory governance architecture at the Children\u27s Hospital of Philadelphia to accelerate and maximize the use of biospecimens and data. As of August 2022, CBTN has enrolled over 4700 subjects, over 1500 parents, and collected over 65,000 biospecimen aliquots for research. Additionally, over 80 preclinical models have been developed from collected tumors. Multi-omic data for over 1000 tumors and germline material are currently available with data generation for \u3e 5000 samples underway. To our knowledge, CBTN provides the largest open-access pediatric brain tumor multi-omic dataset annotated with longitudinal clinical and outcome data, imaging, associated biospecimens, child-parent genomic pedigrees, and in vivo and in vitro preclinical models. Empowered by NIH-supported platforms such as the Kids First Data Resource and the Childhood Cancer Data Initiative, the CBTN continues to expand the resources needed for scientists to accelerate translational impact for improved outcomes and quality of life for children with brain and spinal cord tumors

The children's brain tumor network (CBTN) - Accelerating research in pediatric central nervous system tumors through collaboration and open science

Pediatric brain tumors are the leading cause of cancer-related death in children in the United States and contribute a disproportionate number of potential years of life lost compared to adult cancers. Moreover, survivors frequently suffer long-term side effects, including secondary cancers. The Children's Brain Tumor Network (CBTN) is a multi-institutional international clinical research consortium created to advance therapeutic development through the collection and rapid distribution of biospecimens and data via open-science research platforms for real-time access and use by the global research community. The CBTN's 32 member institutions utilize a shared regulatory governance architecture at the Children's Hospital of Philadelphia to accelerate and maximize the use of biospecimens and data. As of August 2022, CBTN has enrolled over 4700 subjects, over 1500 parents, and collected over 65,000 biospecimen aliquots for research. Additionally, over 80 preclinical models have been developed from collected tumors. Multi-omic data for over 1000 tumors and germline material are currently available with data generation for > 5000 samples underway. To our knowledge, CBTN provides the largest open-access pediatric brain tumor multi-omic dataset annotated with longitudinal clinical and outcome data, imaging, associated biospecimens, child-parent genomic pedigrees, and in vivo and in vitro preclinical models. Empowered by NIH-supported platforms such as the Kids First Data Resource and the Childhood Cancer Data Initiative, the CBTN continues to expand the resources needed for scientists to accelerate translational impact for improved outcomes and quality of life for children with brain and spinal cord tumors