Results 1 to 10 of about 388 (126)
Al-Mustansiriyah Journal of Science, 2021 In this paper, we present two gyroarea formulas (Möbius-Bretschneider’s formula and Möbius-Cagnoli’s formula) for Möbius gyroquadrilaterals in the Poincaré disc model of hyperbolic geometry.
Gülcan Balakan, Oğuzhan Demirel
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Global phase portraits of a predator–prey system
Electronic Journal of Qualitative Theory of Differential Equations, 2022 We classify the global dynamics of a family of Kolmogorov systems depending on three parameters which has ecological meaning as it modelizes a predator–prey system.
Érika Diz-Pita +2 more
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The Beckman–Quarles Theorem in Hyperbolic Geometry
Journal of Mathematics, 2021 In this paper, we present the counterpart of the Beckman–Quarles theorem in the Poincaré disc model of hyperbolic geometry to characterize the gyroisometries (hyperbolic isometries) with a single nonzero distance a∈0,1 satisfying a2∈ℚ.
Oğuzhan Demirel +2 more
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Phase Portraits of Families VII and VIII of the Quadratic Systems
Axioms, 2023 The quadratic polynomial differential systems in a plane are the easiest nonlinear differential systems. They have been studied intensively due to their nonlinearity and the large number of applications.
Laurent Cairó, Jaume Llibre
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An Extension of Poincare Model of Hyperbolic Geometry with Gyrovector Space Approach [PDF]
Mathematics Interdisciplinary Research, 2016 The aim of this paper is to show the importance of analytic hyperbolic geometry introduced in [9]. In [1], Ungar and Chen showed that the algebra of the group SL(2, C) naturally leads to the notion of gyrogroups and gyrovector spaces for dealing ...
Mahfouz Rostamzadeh +1 more
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Confocal Families of Hyperbolic Conics via Quadratic Differentials
Axioms, 2023 We apply the theory of quadratic differentials, to present a classification of orthogonal pairs of foliations of the hyperbolic plane by hyperbolic conics.
Joel Langer, David Singer
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Singular points and limit cycles of the generalized Kukles polynomial differential system
Известия высших учебных заведений. Поволжский регион: Физико-математические науки, 2022 Background. Searching of numbers of Poincare limit cycles of polynomial dynamic systems belongs to second part of the 16th Gilbert problem, which is not solved in general.
I.N. Mal'kov, V.V. Machulis
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Neuromodulation: Technology at the Neural Interface, EarlyView., 2021 Abstract Background Posttraumatic stress disorder (PTSD) is associated with autonomic dysfunction as indicated by deficits in the sympathetic and parasympathetic nervous systems. These abnormalities are expressed as elevated heart rate and reduced heart rate variability (HRV), respectively.
Camila Cosmo +4 more
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Demonstratio Mathematica, 2023 The classification of the phase portraits is one of the classical and difficult problems in the qualitative theory of polynomial differential systems in R2{{\mathbb{R}}}^{2}, particularly for quadratic systems.
Benterki Rebiha, Belfar Ahlam
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Structure and Function of a Multi‐Megadalton Virus‐Like Proteolytic Dodecahedron
Angewandte Chemie, EarlyView.Zuzalysin, a virulence metallopeptidase of the periodontal pathogen Porphyromonas gingivalis, is secreted as a latent, flexible ≈95‐kDa monomer. Calcium triggers cysteine‐switch activation and hierarchical assembly into pentamers, bipentamers, tripentamers, and a ≈5.6‐MDa, ≈355‐Å dodecahedron. Structures at 1.8–3.6 Å reveal a virus‐sized catalytic cage
Mariusz Madej +20 more
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