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Abstract: Bottlenose dolphins’ broadband click vocalizations are well studied in the literature with respect to their echolocation function. Their use for communication among conspecifics has long been speculated, but not conclusively established so far. In this study we categorize dolphins’ click productions into types on the basis of their amplitude contour and analyze the distribution of individual clicks and click sequences against their duration and length. We demonstrate that the repertoire and composition of clicks and click sequences follow three key linguistic laws of efficient communication, namely, Zipf’s rank-frequency law, the law of brevity and Menzerath-Altmann law. Conforming to the rank-frequency law suggests that clicks may form a linguistic code that is subject to selective pressures for unification, on the one hand, and diversification, on the other. Conforming to the other two laws also implies that dolphins use clicks in accord with the compression criterion, or minimization of code length without loss of information. Our results furnish novel evidence for conformity to the linguistic laws in this type of dolphins’ signal and in the realm of animal vocalizations more generally.
Keywords: bottlenose dolphin, clicks, Menzerath law of communication, Zipf law of communication, information compression
Published in RUNG: 10.02.2025; Views: 593; Downloads: 3
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Abstract: ABSTRACT We present a search for luminous long-duration ambiguous nuclear transients (ANTs) similar to the unprecedented discovery of the extreme ambiguous event AT2021lwx with a $\gt 150$ d rise time and luminosity $10^{45.7}$ erg s$^{-1}$. We use the Lasair transient broker to search Zwicky Transient Facility (ZTF) data for transients lasting more than one year and exhibiting smooth declines. Our search returns 59 events, 7 of which we classify as ANTs assumed to be driven by accretion onto supermassive black holes. We propose the remaining 52 are stochastic variability from regular supermassive black hole accretion rather than distinct transients. We supplement the seven ANTs with three nuclear transients in ZTF that fail the light curve selection but have clear single flares and spectra that do not resemble typical active galactic nucleus. All of these 11 ANTs have a mid-infrared flare from an assumed dust echo, implying the ubiquity of dust around the black holes giving rise to ANTs. No events are more luminous than AT2021lwx, but one (ZTF19aamrjar) has twice the duration and a higher integrated energy release. On the other extreme, ZTF20abodaps reaches a luminosity close to AT2021lwx with a rise time $\lt 20$ d and that fades smoothly in $\gt 600$ d. We define a portion of rise-time versus flare amplitude space that selects ANTs with $\sim 50$ per cent purity against variable AGNs. We calculate a volumetric rate of $\gtrsim 3\times 10^{-11}$ Mpc$^{-1}$ yr$^{-1}$, consistent with the events being caused by tidal disruptions of intermediate and high-mass stars.
Keywords: tidal disruption events, accretion
Published in RUNG: 06.02.2025; Views: 583; Downloads: 8
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Abstract: This Special Issue explores cutting-edge advancements in computational algebra, coding theory, and cryptography, emphasizing both theoretical foundations and practical applications. Topics covered in this Special Issue include algebraic structures in coding theory, cryptographic protocols, error-correcting codes, and their intersections with mathematical frameworks.
Keywords: algebraic structures, coding theory, cryptography, linear codes, quantum codes, polycyclic codes, self-dual codes, Hermitian codes, quasicyclic codes, codes over rings
Published in RUNG: 03.02.2025; Views: 596; Downloads: 1
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Keywords: Avant-Garde, Yugoslav Avant-Garde, Transnational Networks, Peripheral Modernism, European Modernism, Cultural Dissemination, Yugo-Futurism, Alternative Modernities
Published in RUNG: 03.02.2025; Views: 588; Downloads: 2
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Keywords: topological insulator, platinum, interface, thin film, TEM, intermetallic
Published in RUNG: 28.01.2025; Views: 694; Downloads: 5
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