Vol. 2 No. 6 (2024)

This issue will present several cutting-edge studies, covering water wave scattering, gravitational wave calculations, dynamical systems, fractional differential equations, and the transmission dynamics of tuberculosis. These studies not only demonstrate the profound connection between mathematics and physics but also enrich relevant theories. Readers will learn from this issue how to use innovative mathematical thinking to understand and deal with complex problems in the real world. It is hoped that these findings would encourage more researchers to continue researching and developing in their respective professions.

  • Open Access

    Article

    Article ID: 2043

    A water wave scattering problem: Revisited

    by Gour Das, Sudeshna Banerjea, B. N. Mandal

    Journal of AppliedMath, Vol.2, No.6, 2024; 136 Views, 61 PDF Downloads

    The problem of water wave scattering by a thin vertical wall with a gap submerged in deep water is studied using singular integral equation formulation. The corresponding boundary value problem is reduced to a Cauchy type singular integral equation of first kind in two disjoint intervals where the unknown function satisfying the integral equation has square root zero at the end points of the two intervals. In this case the solution exists if the forcing function satisfies two solvability conditions. The reflection coefficient is determined here using the solvability conditions without solving the integral equation and also the boundary value problem.

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  • Open Access

    Article

    Article ID: 1949

    From computer algebra to gravitational waves

    by J.-F. Pommaret

    Journal of AppliedMath, Vol.2, No.6, 2024; 168 Views, 69 PDF Downloads

    The first finite length differential sequence has been introduced by Janet (1920). Thanks to the first book of Pommaret (1978), the Janet algorithm has been extended by Blinkov, Gerdt, Quadrat, Robertz, Seiler and others who introduced Janet and Pommaret bases in computer algebra. Also, new intrinsic tools have been developed by Spencer in the study of Lie pseudogroups or by Kashiwara in differential homological algebra. The achievement has been to define differential extension modules through the systematic use of differential double duality. Roughly, if D = K[d] is the non-commutative ring of differential operators with coefficients in a differential field K, let D be a linear differential operator with coefficients in K. A direct problem is to find the generating compatibility conditions (CC) in the form of a differential operator D1 such that Dξ = η implies D1η = 0 and so on. Taking the adjoint operators, we have ad(D) ◦ ad(D1) = ad(D1 ◦ D) = 0 but ad(D) may not generate all the CC of ad(D1). If M is the D-module defined by D and N is the D-module defined by ad(D) with torsion submodule t(N), then t(N) = ext 1 (M) “measures” this gap that only depends on M and not on the way to define it. Also, R = homK(M, K) is a differential module for the Spencer operator d : R → T ⊗ R, first introduced by Macaulay with his  inverse systems (1916). When D : T → S2T : ξ → L(ξ)ω = Ω is the Killing operator for the Minkowski metric ω with perturbation Ω, then N is the differential module defined by the Cauchy = ad(Killing) operator and t(N) = ext 1 (M) = 0 because the Spencer sequence is isomorphic to the tensor product of the Poincaré sequence by a Lie algebra. The Cauchy operator can be thus parametrized by stress functions having nothing to do with Ω, like the Airy function for plane elasticity. This result is thus pointing out the terrible confusion done by Einstein (1915) while ”adapting” to space-time the work done by Beltrami (1892) for space only. both of them using the same Einstein operator but ignoring it was self-adjoint in the framework of differential double duality (1995). Though unpleasant it is, we shall prove that the mathematical foundations of General Relativity are not coherent with these new results which are also illustrated by many other explicit examples.

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  • Open Access

    Article

    Article ID: 1977

    On the qualitative analysis of the boundary value problem of the Ψ-Caputo implicit fractional pantograph differential equation

    by Rahman Ullah Khan, Maria Samreen, Gohar Ali, Ioannis Argyros

    Journal of AppliedMath, Vol.2, No.6, 2024; 184 Views, 46 PDF Downloads

    In this manuscript, the primary objective is to analyze a Ψ-Caputo fractional pantograph implicit differential equation using the Ψ-Caputo fractional derivative. We employ a newly developed method based on fixed-point theorems to explore the existence and uniqueness of the solution to our proposed problem. Furthermore, we investigate the stability of the proposed problem. Finally, we provide an example that illustrates the application of our newly obtained results, confirming their practical significance.

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  • Open Access

    Article

    Article ID: 2209

    Multistability and organization of chaos and quasiperiodicity in a memristor-based Shimizu-Morioka oscillator under two-frequency excitation

    by Paulo C. Rech

    Journal of AppliedMath, Vol.2, No.6, 2024; 110 Views, 53 PDF Downloads

    In this paper we investigate the organization of chaos and quasiperiodicity in a parameter plane of a continuous-time three-dimensional nonautonomous dynamical system. More specifically, we investigate a memristor-based Shimizu-Morioka oscillator, where the external excitation is represented by the sum of two different sinusoidal functions with angular frequencies ω1 and ω2. Through a scan carried out in the (ω1, ω2) parameter plane, with the dynamical behavior of each point in the phase-space being characterized by the Lyapunov exponents spectrum, we show that this system presents chaos and quasiperiodicity regions, without presenting, however, periodicity regions. Parameter regions for which the multistability phenomenon was detected, also are observed. Basins of attraction of coexisting chaotic and quasiperiodic attractors, as well as the attractors themselves, are reported.

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  • Open Access

    Article

    Article ID: 1870

    Analysis and modelling of the transmission dynamics of tuberculosis in the presence of latent and active populations

    by Aliyu Ibrahim, Mahdi Audu Janda, Stella Nyambura Kahianyu, Ass Gueye, Peter Chola Nkandu, Eugene Tettey Ayerkain

    Journal of AppliedMath, Vol.2, No.6, 2024; 276 Views, 60 PDF Downloads

    Tuberculosis, a chronic infectious disease caused by Mycobacterium tuberculosis, remains a significant global health challenge, particularly in developing countries. This project investigates the dynamic transmission of tuberculosis, focusing on the interplay between latent and active populations. We develop and analyze an (Susceptible, Latent, Infectious, Recovered) compartmental mathematical model to examine key parameters affecting TB transmission dynamics. Our study employs stability and sensitivity analyses to provide critical insights into the basic reproduction number and equilibrium points of the TB transmission model. Through numerical simulations, we explore how various intervention strategies impact the spread of tuberculosis. The model yields an approximate reproduction number of 0.3, suggesting that under the current conditions represented in the model, TB would naturally decline in the population. Key findings emphasize the importance of maintaining a low transmission rate and improving the recovery rate to expedite the elimination of tuberculosis. The model demonstrates the complex interplay between susceptible, infected, latent, and recovered populations over time, highlighting the persistent nature of TB due to factors such as latent activation and loss of immunity in recovered individuals. This project provides a robust foundation for public health strategies aimed at controlling and ultimately eliminating tuberculosis. Our results underscore the need for targeted interventions focusing on reducing transmission, managing latent infections, and enhancing treatment efficacy. These insights can inform policy decisions and resource allocation in TB control programs, contributing to the global effort to combat this persistent disease.

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  • Open Access

    Article

    Article ID: 2152

    Distribution of lattice points in the shifted balls

    by Ilgar Jabbarov, Jeyhun Abdullayev

    Journal of AppliedMath, Vol.2, No.6, 2024; 28 Views, 15 PDF Downloads

    In this work we study the mean value of the difference between the number of integer points and the volume of a ball as a function of the center of a ball in the unit cube [0, 1]3, applying new method. This mean value is estimated by its possible exact value. Using methods of Fourier analysis, we lead the question to the estimates of double trigonometric integrals. This method allows consider the question on lattice points in domains of arbitrary nature without any symmetry.

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