Results 11 to 20 of about 3,885 (102)

Stability of singular limit cycles for Abel equations revisited [PDF]

Journal of Differential Equations, 2023
A criterion is obtained for the semi-stability of the isolated singular positive closed solutions, i.e., singular positive limit cycles, of the Abel equation $x'=A(t)x^3+B(t)x^2$, where $A,B$ are smooth functions with two zeros in the interval $[0,T ...
J. L. Bravo, M. Fern'andez, I. Ojeda
semanticscholar   +1 more source

Correspondence between Electrostatics and Contact Mechanics with Further Results in Equilibrium Charge Distributions

Annalen der Physik, Volume 535, Issue 12, December 2023., 2023
The authors review the connections existing, based on potential theory, between contact mechanics and equilibrium electrostatics. This little known correspondence is exploited so that problems scattered in many works can be easily solved by bringing to light their “duals” in elastic theory.
Josep Batle, Oleksandr Vlasiuk, Orion Ciftja   +2 more
wiley   +1 more source

Cosmic Inflation and Genetic Algorithms

Fortschritte der Physik, Volume 71, Issue 1, January 2023., 2023
Abstract Large classes of standard single‐field slow‐roll inflationary models consistent with the required number of e‐folds, the current bounds on the spectral index of scalar perturbations, the tensor‐to‐scalar ratio, and the scale of inflation can be efficiently constructed using genetic algorithms.
Steve A. Abel, Andrei Constantin, Thomas R. Harvey, Andre Lukas   +3 more
wiley   +1 more source

Sixth‐Kind Chebyshev and Bernoulli Polynomial Numerical Methods for Solving Nonlinear Mixed Partial Integrodifferential Equations with Continuous Kernels

Journal of Function Spaces, Volume 2023, Issue 1, 2023., 2023
In the present paper, a new efficient technique is described for solving nonlinear mixed partial integrodifferential equations with continuous kernels. Using the separation of variables, the nonlinear mixed partial integrodifferential equation is converted to a nonlinear Fredholm integral equation. Then, using different numerical methods, the Bernoulli
Abeer M. Al-Bugami, Mohamed A. Abdou, Amr M. S. Mahdy, Adel A. Attiya   +3 more
wiley   +1 more source

Novel Explosive and Super Fractional Nonlinear Schrödinger Structures

Journal of Mathematics, Volume 2023, Issue 1, 2023., 2023
The fractional nonlinear Schrödinger equation solutions have been investigated via fraction space‐time derivative sense. We applied the unified technique for this model to extract new structures of waves. The fractional property structures were obtained from the model in form of hyperbolic, soliton, shock, explosive, superperiodic, and trigonometric ...
H. G. Abdelwahed, A. F. Alsarhan, E. K. El-Shewy, Mahmoud A. E. Abdelrahman, Mubashir Qayyum   +4 more
wiley   +1 more source

A phase‐field based model for coupling two‐phase flow with the motion of immersed rigid bodies

International Journal for Numerical Methods in Engineering, Volume 123, Issue 16, Page 3757-3780, 30 August 2022., 2022
Abstract The interaction of immersed rigid bodies with two‐phase flow is of high interest in many applications. A model for the coupling of a Hohenberg–Halperin type model for two‐phase flow and a fictitious domain method for consideration of rigid bodies is introduced leading to a full multiphase‐field method to address the overall problem.
Martin Reder, Paul W. Hoffrogge, Daniel Schneider, Britta Nestler   +3 more
wiley   +1 more source

A New Global Ionospheric Electron Density Model Based on Grid Modeling Method

Space Weather, Volume 20, Issue 6, June 2022., 2022
Abstract Based on nearly 4.6 million radio occultation (RO) ionospheric profile data from Constellation Observing System for Meteorology, Ionosphere, and Climate satellites in 2006–2020, a global three‐dimensional ionospheric electron density model was constructed with a new concept.
Huijun Le, Tingwei Han, Qiaoling Li, Libo Liu, Yiding Chen, Hui Zhang   +5 more
wiley   +1 more source

A 3D Empirical Model of Electron Density Based on CSES Radio Occultation Measurements

Space Weather, Volume 20, Issue 5, May 2022., 2022
Abstract China Seismo‐Electromagnetic Satellite (CSES) was successfully launched in February 2018. About 280 thousand ionospheric radio occultation (RO) electron density profiles (EDP) have been accumulated till the end of 2020. The CSES is a Sun‐synchronous orbit satellite with descending and ascending nodes around 14:00 and 02:00 LT, respectively, at
He Huang, Jian Lin, Song Xu, Huijun Le, Feng Guo, Zhima Zeren, Libo Liu, Xuhui Shen   +7 more
wiley   +1 more source

Collocation Approach Based on an Extended Cubic B‐Spline for a Second‐Order Volterra Partial Integrodifferential Equation

Journal of Function Spaces, Volume 2022, Issue 1, 2022., 2022
This paper focuses on an efficient spline‐based numerical technique for numerically addressing a second‐order Volterra partial integrodifferential equation. The time derivative is discretized using a finite difference scheme, while the space derivative is approximated using the extended cubic B‐spline basis.
Reny George, Muhammad Yaseen, Sana Khan, Youssri Hassan Youssri   +3 more
wiley   +1 more source

Rational limit cycles of Abel differential equations [PDF]

Electronic Journal of Qualitative Theory of Differential Equations, 2023
We study the number of rational limit cycles of the Abel equation x ′ = A ( t ) x 3 + B ( t ) x 2 , where A ( t ) and B ( t ) are real trigonometric polynomials.
J. L. Bravo, Luis Ángel Calderón, I. Ojeda   +2 more
semanticscholar   +1 more source