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

A Sociological Look at the Growth of the Emerging Spirituality in Tabriz

The conversion of a large number of people to the emerging spiritual sect (hereafter mentioned as “the M sect” in the current study) indicates a socio-cultural trend and the current study attempts to identify its causes and effective factors. Qualitative methodology in the form of Grounded Theory has been applied. Data were collected through distributing a semi-structured questionnaire in an in-depth interview from fourteen participants. Findings constitute a two-step paradigm model where the dimensions and major elements include: A) preliminary conditions: stresses of religious life in the modern age, lack of acceptability in the traditional religious culture, emotional detachment; B) causal conditions: spiritual needs, epistemic crisis, physical or mental illnesses; C1) The central phenomenon and context: the feeling of distress with regard to intensity, continuity, and diversity; D1) Strategy: reference to traditional religious texts, medical treatment, psychotherapy, counseling, exercise; E1) intervening conditions: lack of acceptability in the religious culture; F1) Result: inefficient or partially efficient of strategy and continuity of the feeling of distress; C2) the feeling of distress with desperation; D2) choosing the spiritual method proposed by M; E2) value system, religious socialization and lack of congruence with the religious culture, the congruence of the sect with the general culture, having fresh viewpoints and the acceptability of explanations provided by the sect, objective reports on the effectiveness of the practices in the sect, open membership, and the quality and quantity of the network of relations with members in the sect; F2) Conversion that has instrumental and ultimate interpretations

Growth, yield and antioxidant capacity of strawberry under various K+:Ca++ ratios in hydroponic culture

Optimisation of the mineral composition of the nutrient solution is one of the most important factors affecting crop productivity and quality under hydroponic cultivation. Considering the role of minerals in nutrition and the lack of studies on the K+:Ca++ ratio of nutrient solution on fruit quality, a study was carried out to evaluate the effects of K+:Ca++ ratios on growth, yield, vitamin C content of the fruit and total carbohydrate and phenolic compounds of the \u2018Paros\u2019 strawberry under hydroponic conditions. The highest total phenolic compounds, photosynthetic capacity, including leaf area, photosynthetic pigments, stomatal conductance and yield were observed at the 1.4 ratio (K > Ca). Enzymatic (peroxidase, superoxide dismutase and catalase) and non-enzymatic (total phenol, phenolic compounds and anthocyanin) antioxidant capacities were affected significantly by the K+:Ca++ ratio. The highest antioxidant capacity was observed in ratios with K > Ca in the solution. We recommend growers to maintain an appropriate K+:Ca++ ratio in the nutrient solution, as this affects growth parameters, productivity and strawberry quality