scholarly journals AN APPROXIMATE SOLUTION FOR LORENTZIAN SPHERICAL TIMELIKE CURVES

2020 ◽  
Vol 20 (3) ◽  
pp. 587-596
Author(s):  
TUBA AGIRMAN AYDIN
Keyword(s):  
Differential Equation ◽  
Approximate Solution ◽  
Initial Conditions ◽  
Numerical Technique ◽  
Hermite Polynomials ◽  
Equation System ◽  
Variable Coefficients ◽  
Third Order ◽  
Sample Application ◽  
Hermite Matrix

In this article, the differential equation of lorentzian spherical timelike curves is obtained in E14. It is seen that the differential equation characterizing Lorentzian spherical timelike curves is equivalent to a linear, third order, differential equation with variable coefficients. It is impossible to solve these equations analytically. In this article, a new numerical technique based on hermite polynomials is presented using the initial conditions for the approximate solution. This method is called the modified hermite matrix-collocation method. With this technique, the solution of the problem is reduced to the solution of an algebraic equation system and the approximate solution is obtained. In addition, the validity and applicability of the technique is explained by a sample application.

scholarly journals A New Approach for Solving the Undamped Helmholtz Oscillator for the Given Arbitrary Initial Conditions and Its Physical Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Alvaro H. Salas S ◽  
Jairo E. Castillo H ◽  
Darin J. Mosquera P
Keyword(s):  
Differential Equation ◽  
Approximate Solution ◽  
Analytical Solution ◽  
Initial Conditions ◽  
Negative Ions ◽  
Nonlinear Problems ◽  
New Approach ◽  
Weierstrass Elliptic Function ◽  
Electronegative Plasma ◽  
The Given

In this paper, a new analytical solution to the undamped Helmholtz oscillator equation in terms of the Weierstrass elliptic function is reported. The solution is given for any arbitrary initial conditions. A comparison between our new solution and the numerical approximate solution using the Range Kutta approach is performed. We think that the methodology employed here may be useful in the study of several nonlinear problems described by a differential equation of the form z ″ = F z in the sense that z = z t . In this context, our solutions are applied to some physical applications such as the signal that can propagate in the LC series circuits. Also, these solutions were used to describe and investigate some oscillations in plasma physics such as oscillations in electronegative plasma with Maxwellian electrons and negative ions.

A further method for the evaluation of zeros of Bessel functions and some new asymptotic expansions for zeros of functions of large order

1951 ◽  
Vol 47 (4) ◽  
pp. 699-712 ◽  
Author(s):  
F. W. J. Olver
Keyword(s):  
Differential Equation ◽  
Bessel Functions ◽  
Numerical Technique ◽  
Third Order ◽  
New Approach ◽  
The Third ◽  
Zeros Of Bessel Functions ◽  
Zeros Of Functions ◽  
Linear Differential ◽  
Image Position

In a recent paper (1) I described a method for the numerical evaluation of zeros of the Bessel functions Jn(z) and Yn(z), which was independent of computed values of these functions. The essence of the method was to regard the zeros ρ of the cylinder functionas a function of t and to solve numerically the third-order non-linear differential equation satisfied by ρ(t). It has since been successfully used to compute ten-decimal values of jn, s, yn, s, the sth positive zeros* of Jn(z), Yn(z) respectively, in the ranges n = 10 (1) 20, s = 1(1) 20. During the course of this work it was realized that the least satisfactory feature of the new method was the time taken for the evaluation of the first three or four zeros in comparison with that required for the higher zeros; the direct numerical technique for integrating the differential equation satisfied by ρ(t) becomes unwieldy for the small zeros and a different technique (described in the same paper) must be employed. It was also apparent that no mere refinement of the existing methods would remove this defect and that a new approach was required if it was to be eliminated. The outcome has been the development of the method to which the first part (§§ 2–6) of this paper is devoted.

On the existence of periodic solutions of a certain third-order differential equation

1960 ◽  
Vol 56 (4) ◽  
pp. 381-389 ◽  
Author(s):  
J. O. C. Ezeilo
Keyword(s):  
Differential Equation ◽  
Periodic Function ◽  
Periodic Solutions ◽  
Order Differential Equation ◽  
Initial Conditions ◽  
Continuous Periodic Function ◽  
Third Order ◽  
Third Order Differential Equation ◽  
Existence Of Periodic Solutions ◽  
Image Position

In this paper we shall be concerned with the differential equationin which a and b are constants, p(t) is a continuous periodic function of t with a least period ω, and dots indicate differentiation with respect to t. The function h(x) is assumed continuous for all x considered, so that solutions of (1) exist satisfying any assigned initial conditions. In an earlier paper (2) explicit hypotheses on (1) were established, in the two distinct cases:under which every solution x(t) of (1) satisfieswhere t0 depends on the particular x chosen, and D is a constant depending only on a, b, h and p. These hypotheses are, in the case (2),or, in the case (3),In what follows here we shall refer to (2) and (H1) collectively as the (boundedness) hypotheses (BH1), and to (3) and (H2) as the hypotheses (BH2). Our object is to examine whether periodic solutions of (1) exist under the hypotheses (BH1), (BH2).

scholarly journals The Laplace-Adomian-Pade Technique for the ENSO Model

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Yi Zeng
Keyword(s):  
Differential Equation ◽  
Exact Solution ◽  
Approximate Solution ◽  
Differential Equations ◽  
Nonlinear Differential Equation ◽  
Initial Conditions ◽  
Approximate Solutions ◽  
Decomposition Methods ◽  
High Accuracy ◽  
Padé Method

The Laplace-Adomian-Pade method is used to find approximate solutions of differential equations with initial conditions. The oscillation model of the ENSO is an important nonlinear differential equation which is solved analytically in this study. Compared with the exact solution from other decomposition methods, the approximate solution shows the method’s high accuracy with symbolic computation.

scholarly journals Implementation of the variation of the luni-solar acceleration into GLONASS orbit calculus

2021 ◽  
Vol 65 (03) ◽  
pp. 459-471
Author(s):  
Sid Ahmed Medjahed ◽  
Abdelhalim Niati ◽  
Noureddine Kheloufi ◽  
Habib Taibi
Keyword(s):  
Differential Equation ◽  
Fourth Order ◽  
Initial Conditions ◽  
Equation System ◽  
Satellite System ◽  
Linear Functions ◽  
Differential Equation System ◽  
Interface Control ◽  
Runge Kutta ◽  
Fourth Order Method

In the differential equation system describes the motion of GLONASS satellites (rus. Globalnaya Navigazionnaya Sputnikovaya Sistema, or Global Navigation Satellite System ), the acceleration caused by the luni-solar traction is often taken as a constant during the period of the integration. In this work-study, we assume that the acceleration due to the luni-solar traction is not constant but varies linearly during the period of integration following this assumption; the linear functions in the three axes of the luni-solar acceleration are computed for an interval of 30 min and then implemented into the differential equations. The use of the numerical integration of Runge-Kutta fourth-order is recommended in the GLONASS-ICD (Interface Control Document) to solve for the differential equation system in order to get an orbit solution. The computation of the position and velocity of a GLONASS satellite in this study is performed by using the Runge-Kutta fourth-order method in forward and backward integration, with initial conditions provided in the broadcast ephemerides file.

scholarly journals Analysis of the Luminous Field in Fluorescent Optical Layers with Quantum Dots Based on CdSe/CdS/ZnS

2019 ◽  
pp. 82-87
Author(s):  
Sergei A. Pavlov ◽  
Alexei S. Pavlov ◽  
Elena Yu. Maksimova ◽  
Anton V. Alekseenko ◽  
Alexander V. Pavlov ◽  
...  
Keyword(s):  
Differential Equation ◽  
Quantum Dots ◽  
Diffuse Reflectance ◽  
Fluorescent Sensor ◽  
Numerical Technique ◽  
Equation System ◽  
Optimal Parameters ◽  
Differential Equation System ◽  
Flux Approximation ◽  
Physical Thickness

The structure of a luminous field in a fluorescence layer containing CdSe/CdS/ZnS-based quantum dots and acting as a transducer in an optical fluorescent sensor is described on the basis of three-flux approximation. Differential equation system of three-flux approximation is solved by numerical technique. It is found that diffuse reflectance of the layer extremely depends on concentration of quantum dots in the layer and its physical thickness. Optimal parameters of the layer required for forming of maximum analytical layer are determined.

scholarly journals Research of a third-order nonlinear differential equation in the vicinity of a moving singular point for a complex plane

2021 ◽  
Vol 263 ◽  
pp. 03019
Author(s):  
Victor Orlov ◽  
Magomedyusuf Gasanov
Keyword(s):  
Differential Equation ◽  
Approximate Solution ◽  
Nonlinear Differential Equation ◽  
A Priori Estimates ◽  
A Priori ◽  
Third Order ◽  
Modified Method ◽  
Order Nonlinear Differential Equation ◽  
Priori Estimates ◽  
The Right

This article generalizes the previously obtained results of existence and uniqueness theorems for the solution of a third-order nonlinear differential equation in the vicinity of moving singular points in the complex domain, as well as constructs an analytical approximate solution, and obtains a priori estimates of the error of this approximate solution. The study was carried out using the modified method of majorants to solve this equation, which differs from the classical theory, in which this method is applied to the right-hand side of the equation The final point of the article is to conduct a numerical experiment to test the theoretical positions obtained.

scholarly journals NEW APPROACH ON THE GENERAL SHAPE EQUATION OF AXISYMMETRIC VESICLES

1999 ◽  
Vol 13 (01) ◽  
pp. 13-18 ◽  
Author(s):  
ZHAN-NING HU
Keyword(s):  
Differential Equation ◽  
Equation System ◽  
Variable Coefficients ◽  
General Shape ◽  
General Constraint ◽  
New Approach ◽  
Shape Equation ◽  
Equilibrium Shapes ◽  
Linear Differential ◽  
Lipid Bilayer Vesicles

The general Helfrich shape equation determined by minimizing the curvature free energy describes the equilibrium shapes of the axisymmetric lipid bilayer vesicles in different conditions. It is a nonlinear differential equation with variable coefficients. In this letter, by analyzing the unique property of the solution, we change this shape equation into a system of the two differential equations. One of them is a linear differential equation. This equation system contains all of the known rigorous solutions of the general shape equation. And the more general constraint conditions are found for the solution of the general shape equation.

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