Measuring Gravitational Wave Speed and Lorentz Violation with the First Three Gravitational-Wave Catalogs

The speed of gravitational waves $v_g$ can be measured with the time delay between gravitational-wave detectors. Our study provides a more precise measurement of $v_g$ using gravitational-wave signals only, compared with previous studies. We select 52 gravitational-wave events that were detected with high confidence by at least two detectors in the first three observing runs (O1, O2, and O3) of Advanced LIGO and Advanced Virgo. We use Markov chain Monte Carlo and nested sampling to estimate the $v_g$ posterior distribution for each of those events. We then combine their posterior distributions to find the 90% credible interval of the combined $v_g$ distribution for which we obtain $0.99^{+0.02}_{-0.02}c$ without the use of more accurate sky localization from the electromagnetic signal associated with GW170817. Restricting attention to the 50 binary black hole events generates the same result, while the use of the electromagnetic sky localization for GW170817 gives a tighter constraint of $0.99^{+0.01}_{-0.02}c$. The abundance of gravitational wave events allows us to apply hierarchical Bayesian inference on the posterior samples to simultaneously constrain all nine coefficients for Lorentz violation in the nondispersive, nonbirefringent limit of the gravitational sector of the Standard-Model Extension test framework. We compare the hierarchical Bayesian inference method with other methods of combining limits on Lorentz violation in the gravity sector that are found in the literature.Comment: 17 pages, 4 figures, 3 table

Outcomes at late childhood of Chinese-speaking preschoolers with developmental language disorders comorbid with behavioral-emotional

As part of an ongoing clinical service program for children with developmental delay in morphosyllabic Chinese-speaking Taiwan, we investigated the late childhood cognitive, functional and psychiatric outcomes of a specific cohort of preschool children with developmental language delay comorbi d wi th behavi oral-emoti onal problems. The institutional database of a developmental clinic was reviewed and preschoolers meeting the inclusion criteria were invited to be subjects. Follow-up evaluations included Wechsler Intelligence tests, parents’ version of the Child Behavioral Checklist and psychiatric interview of the adolescents themselves. Of the eligible subjects (initial preschool visit at average of 3.8 ± 1.3 years old), 44 individuals completed follow-up evaluations at average of 11.8 ± 1.5 years old. The follow-up results showed that 75% of the late childhood children still had problems in language and 38.6% had problems in academic performance. The mean nonverbal cognitive score at follow-up was 83.9 ± 15.4 while the mean verbal cognitive measure was 83 ±17.3. Total 75% of the subjects had current psychiatric disorders and the most frequent di agnosi s was attenti on defici t/hyperactivity disorder, which was noted to be increased from 50% in the preschool period to 70.5% in late childhood. We concluded that the majority of Chinese-speaking preschoolers with language delay and behavioral-emotional problems turned out to have communication and psychiatric conditions when they reached late childhood. Western researches on developmental course of preschool children with alphabetic language impairment could be extended to morphosyllabic Chinese. Specialized services are warranted for this group of preschool children to lessen prolonged vulnerabilities. Our findings may be helpful in the context of an Asian developing country, so that priorities can be established for the allocation of finite resources for intervention

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

Comparative Study of Early Childhood High-Function Autism and Developmental Mixed Receptive-Expressive Language Disorder

Verbal cognitive profile and general social functioning were compared between two groups of children aged 5 to 7 years, one with high-function autism and the other with developmental mixed receptive-expressive language disorders. The two groups, totaling 50 children, were matched for age and non-verbal IQ (mean, 90). Both groups had impaired verbal cognitive profile and social adaptive functioning, with no statistically significant differences between the two groups. The implications of our findings are discussed. Current preschool and early childhood medical-educational intervention programs in Taiwan must design and implement curricula in which children with language delay, whether autistic or not, can develop essential social skills

Healthrelated quality of life and cognitive outcomes among child and adolescent survivors of leukemia. Supportive Care in

Abstract Purpose Long-term survival of childhood leukemia has become a reality with treatment advancement; hence, the need to assess the survivors' health-related quality of life (HRQL) is essential. Although a growing number of Western studies have documented the considerable impact of diagnosis and treatment on HRQL in pediatric leukemia survivors, little finding has been reported in non-Western developing countries. Methods We used a previously validated 14-dimensional questionnaire, Child Health Questionnaire 50-item Parent Form (CHQ-PF 50), to examine the perceived HRQL of 32 child/adolescent survivors, currently aged 13.17±2.49 years, who had experienced first complete continuous remission from leukemia for at least 3 years. The HRQL status was compared with that obtained from community subjects (N=154) and survivors' nonadult siblings (N=30). Intelligence quotients (IQ) and computerized neuropsychological assessments were performed for subjects. Results The HRQL of leukemia survivors was noted to be worse than that of community children and nonadult siblings as reflected by significantly lower scores in both the physical summary and the psychosocial summary score of CHQ-PF 50. 15.6% of the survivors had impaired intelligence (estimated IQ below 70). 27.8% of the adolescents were impaired in the cognitive domains as assessed by neuropsychological tests. Conclusions In this Taiwanese single institution experience, pediatric leukemia survivors carried a morbidity burden into their teen years as reflected by worse HRQL than controls. These findings may guide the support required by this population

Callous–Unemotional Traits among Adolescents with Autism Spectrum Disorder, Attention-Deficit/Hyperactivity Disorder, or Typical Development: Differences between Adolescents’ and Parents’ Views

This study examined parent–adolescent agreement on the callous, uncaring, and unemotional dimensions of callous–unemotional (CU) traits and the differences in adolescent-reported and parent-reported CU traits among 126 adolescents with autism spectrum disorder (ASD), 207 adolescents with attention-deficit/hyperactivity disorder (ADHD), and 203 typically developing (TD) adolescents. Adolescent-reported and parent-reported CU traits on the three dimensions of the Inventory of Callous and Unemotional Traits were obtained. The strength of CU traits and the differences between adolescent-reported and parent-reported traits were compared among the three groups using analysis of covariance. Parent–adolescent agreement was examined using intraclass correlation. The results reveal that both adolescent-reported and parent-reported callousness and uncaring traits in the ASD and ADHD groups were significantly stronger than those in the TD group. Parent–adolescent agreement on the uncaring trait was fair across the three groups, whereas that on callousness was poor across all three groups. Parent–adolescent agreement on unemotionality was fair in the TD group but poor in the ADHD and ASD groups. ASD and ADHD groups had significantly greater differences in scores reported by parents and adolescents on the callousness trait than the TD group. The parent–adolescent score differences in the uncaring trait were also larger in the ASD group than in the TD group. Thus, these results support the application of a multi-informant approach in CU trait assessment, especially for adolescents with ASD or ADHD

Absence of gender effect on children with attention-deficit/hyperactivity disorder as assessed by optimized voxel-based morphometry

Brain abnormalities, as determined by structural magnetic resonance imaging (MRI), have been reported in patients with attention-deficit hyperactivity disorder (ADHD); however, female subjects have been underrepresented in previous reports. In this study, we used optimized voxel-based morphometry to compare the total and regional gray matter volumes between groups of 7- to 17-year-old ADHD and healthy children (total 114 subjects). Fifty-seven children with ADHD (n=57, 35 males and 22 females) and healthy children (n=57) received MRI scans. Segmented brain MRI images were normalized into standardized stereotactic space, modulated to allow volumetric analysis, smoothed and compared at the voxel level with statistical parametric mapping. Global volumetric comparisons between groups revealed that the total brain volumes of ADHD children were smaller than those of the control children. As for the regional brain analysis, the brain volumes of ADHD children were found to be bilaterally smaller in the following regions as compared with normal control values: the caudate nucleus and the cerebellum. There were two clusters of regional decrease in the female brain, left posterior cingulum and right precuneus, as compared with the male brain. Brain regions showing the interaction effect of diagnosis and gender were negligible. These results were consistent with the hypothesized dysfunctional systems in ADHD, and they also suggested that neuroanatomical abnormalities in ADHD were not influenced by gender