51 research outputs found

    A d-summable approach to Deng information dimension of complex networks

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    Several new network information dimension definitions have been proposed in recent decades, expanding the scope of applicability of this seminal tool. This paper proposes a new definition based on Deng entropy and d-summability (a concept from geometric measure theory). We will prove to what extent the new formulation will be useful in the theoretical and applied points of view

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

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    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

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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

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    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

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    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

    Aldo Ramirez-Arellano's Quick Files

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    The Quick Files feature was discontinued and it’s files were migrated into this Project on March 11, 2022. The file URL’s will still resolve properly, and the Quick Files logs are available in the Project’s Recent Activity

    Classification of Literary Works: Fractality and Complexity of the Narrative, Essay, and Research Article

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    A complex network as an abstraction of a language system has attracted much attention during the last decade. Linguistic typological research using quantitative measures is a current research topic based on the complex network approach. This research aims at showing the node degree, betweenness, shortest path length, clustering coefficient, and nearest neighbourhoods’ degree, as well as more complex measures such as: the fractal dimension, the complexity of a given network, the Area Under Box-covering, and the Area Under the Robustness Curve. The literary works of Mexican writers were classify according to their genre. Precisely 87% of the full word co-occurrence networks were classified as a fractal. Also, empirical evidence is presented that supports the conjecture that lemmatisation of the original text is a renormalisation process of the networks that preserve their fractal property and reveal stylistic attributes by genre

    Scaffolding Matters? Investigating Its Role in Motivation, Engagement and Learning Achievements in Higher Education

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    In higher education, students’ engagement plays an essential role in determining learning success. Several studies have focused on identifying the relationship between engagement and learning achievements. However, comprehensive studies that include engagement, motivation, and scaffolding have yet to be performed. This article introduced a concept of metacognitive and learning engagement based on the frontiers between metacognition and cognition previously established in the literature. A conceptual model including cognitive, behavioural, emotional, scaffolding, and motivation and the two new definitions (metacognitive and learning engagement) was proposed and validated in 220 university students using structural equation modelling. The findings support the conjecture that cognitive engagement is directly influenced by metacognitive engagement. Learning engagement is influenced by cognitive engagement, and all of them are triggered by motivation. Furthermore, scaffolding enhances emotional engagement. Teachers’ support fosters students’ emotions of being enthusiastic, interested in class, joyful in learning activities, and proud of their learning achievements

    Scaffolding Matters? Investigating Its Role in Motivation, Engagement and Learning Achievements in Higher Education

    No full text
    In higher education, students’ engagement plays an essential role in determining learning success. Several studies have focused on identifying the relationship between engagement and learning achievements. However, comprehensive studies that include engagement, motivation, and scaffolding have yet to be performed. This article introduced a concept of metacognitive and learning engagement based on the frontiers between metacognition and cognition previously established in the literature. A conceptual model including cognitive, behavioural, emotional, scaffolding, and motivation and the two new definitions (metacognitive and learning engagement) was proposed and validated in 220 university students using structural equation modelling. The findings support the conjecture that cognitive engagement is directly influenced by metacognitive engagement. Learning engagement is influenced by cognitive engagement, and all of them are triggered by motivation. Furthermore, scaffolding enhances emotional engagement. Teachers’ support fosters students’ emotions of being enthusiastic, interested in class, joyful in learning activities, and proud of their learning achievements
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