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350 Results Found

  • Article
  • Open Access
8 Citations
2,132 Views
14 Pages

Our purpose is to introduce a notion of weak solution for a class of abstract fractional differential equations. We point out that the time fractional derivative occurring in the equations is in the sense of the Caputo derivative. We prove existence...

  • Article
  • Open Access
2 Citations
1,971 Views
9 Pages

24 July 2021

One of the most intriguing issues in the mathematical theory of the stationary Navier–Stokes equations is the regularity of weak solutions. This problem has been deeply investigated for homogeneous fluids. In this paper, the regularity of the solutio...

  • Article
  • Open Access
164 Views
20 Pages

22 December 2025

This paper investigates the long-term asymptotic behavior of solutions to the initial-boundary value problem for the three-dimensional incompressible viscous magnetohydrodynamic (MHD) equations in general unbounded domains. Addressing the difficulty...

  • Article
  • Open Access
5 Citations
7,818 Views
20 Pages

13 January 2021

We give a rather short and self-contained presentation of the global existence for Leray-Hopf weak solutions to the three dimensional incompressible Navier-Stokes equations, with constant density. We give a unified treatment in terms of the domains a...

  • Article
  • Open Access
1,037 Views
20 Pages

13 April 2024

This paper deals with a phase transition model with polarization which describes the thermodynamic, electromagnetic, and polarization properties of ferromagnetic–ferroelectric materials. The existence of the global weak solution for the phase t...

  • Article
  • Open Access
565 Views
14 Pages

14 August 2025

In this paper, we establish the global boundedness of weak solutions to fractional nonlocal equations using the fractional Moser iteration argument and some other ideas. Our results not only extend the boundedness result of Ros-Oton-Serra to general...

  • Feature Paper
  • Article
  • Open Access
4 Citations
1,399 Views
18 Pages

13 July 2023

The basic model motivating this work is that of contaminant transport in the Earth’s subsurface, which contains layers in which analytical and semi-analytical solutions of the corresponding advection–dispersion equations could be derived....

  • Article
  • Open Access
1 Citations
993 Views
27 Pages

12 June 2024

We consider evolution (non-stationary) spatially-periodic solutions to the n-dimensional non-linear Navier–Stokes equations of anisotropic fluids with the viscosity coefficient tensor variable in spatial coordinates and time and satisfying the...

  • Article
  • Open Access
8 Citations
5,247 Views
13 Pages

22 February 2022

The main goal of this article is to provide estimates of mild solutions of Navier–Stokes equations with arbitrary external forces in Rn for n≥2 on proposed weak Herz-type Besov–Morrey spaces. These spaces are larger than known Besov&nd...

  • Article
  • Open Access
1 Citations
1,751 Views
28 Pages

29 June 2021

The existence of weak time-periodic solutions to Navier–Stokes equations in three dimensional whole-space with time-periodic forcing terms are established. The solutions are constructed in such a way that the structural properties of their kinetic en...

  • Article
  • Open Access
1 Citations
578 Views
14 Pages

3 April 2025

This study investigates the existence and multiplicity of weak solutions for a class of degenerate weighted quasilinear elliptic equations that incorporate nonlocal nonlinearities, a double Hardy term, and variable exponents. The problem encompasses...

  • Article
  • Open Access
3 Citations
2,087 Views
21 Pages

30 October 2022

As is known to all, Lipschitz condition, which is very important to guarantee existence and uniqueness of solution for differential equations, is not frequently satisfied in real-world problems. In this paper, without the Lipschitz condition, we inte...

  • Article
  • Open Access
1 Citations
2,697 Views
9 Pages

4 March 2020

We study the large-time behavior of solutions to the nonlinear exterior problem L u ( t , x ) = κ | u ( t , x ) | p , ( t , x ) ∈ ( 0 , ∞ ) × D c under the nonhomegeneous Neumann boundary condition...

  • Article
  • Open Access
7 Citations
2,317 Views
17 Pages

Solvability Issues of a Pseudo-Parabolic Fractional Order Equation with a Nonlinear Boundary Condition

  • Serik E. Aitzhanov,
  • Abdumauvlen S. Berdyshev and
  • Kymbat S. Bekenayeva

This paper is devoted to the fundamental problem of investigating the solvability of initial-boundary value problems for a quasi-linear pseudo-parabolic equation of fractional order with a sufficiently smooth boundary. The difference between the stud...

  • Article
  • Open Access
1 Citations
2,338 Views
11 Pages

In this paper, we study the regularity of the weak solution of the coupled system derived from the microwave heating model with frequency variable. We first show that the weak solution E of the system is Hölder continuous near the boundary...

  • Article
  • Open Access
76 Citations
5,150 Views
11 Pages

A Regularity Criterion in Weak Spaces to Boussinesq Equations

  • Ravi P. Agarwal,
  • Sadek Gala and
  • Maria Alessandra Ragusa

In this paper, we study the regularity of weak solutions to the incompressible Boussinesq equations in R 3 × ( 0 , T ) . The main goal is to establish the regularity criterion in terms of one velocity component and the gradient of te...

  • Article
  • Open Access
8 Citations
4,433 Views
12 Pages

25 April 2019

Using the Laplace transform technique, we investigate the generalized solutions of the third-order Cauchy-Euler equation of the form t 3 y ′ ′ ′ ( t ) + a t 2 y ′ ′ ( t ) + b y ′ ( t ) + c y...

  • Feature Paper
  • Article
  • Open Access
10 Citations
2,057 Views
10 Pages

10 July 2019

We consider nonlinear Boussinesq-type equations that model the heat transfer and steady viscous flows of weakly concentrated water solutions of polymers in a bounded three-dimensional domain with a heat source. On the boundary of the flow domain, the...

  • Article
  • Open Access
6 Citations
2,642 Views
10 Pages

8 April 2021

In this paper, we investigate the regularity of weak solutions to the 3D incompressible MHD equations. We provide a regularity criterion for weak solutions involving any two groups functions (∂1u1,∂1b1), (∂2u2,∂2b2) and (∂3u3,∂3b3) in anisotropic Lor...

  • Article
  • Open Access
8 Citations
1,703 Views
17 Pages

10 September 2022

The main aim of this paper is to investigate the solvability of the steady-state flow model for low-concentrated aqueous polymer solutions with a damping term in a bounded domain under the no-slip boundary condition. Mathematically, the model under c...

  • Article
  • Open Access
5 Citations
1,537 Views
15 Pages

3 March 2024

In this paper, we investigate the solvability of a boundary value problem for a heat and mass transfer model with the spatially averaged Rayleigh function. The considered model describes the 3D steady-state non-isothermal flow of a generalized Newton...

  • Article
  • Open Access
4 Citations
1,147 Views
25 Pages

30 April 2025

This work investigates the inverse problem of identifying a time-dependent source term in a time-fractional semi-linear degenerate parabolic equation using integral measurement data. We establish the unique solvability of the inverse problem within a...

  • Article
  • Open Access
2 Citations
1,521 Views
14 Pages

17 February 2024

In this paper, we establish a structural inequality of the ∞-subLaplacian ▵0,∞ in a class of the semi-simple Lie group endowed with the horizontal vector fields X1,…,X2n. When 1<p≤4 with n=1 and 1<p<3+1n−1 w...

  • Article
  • Open Access
1 Citations
2,187 Views
17 Pages

27 December 2022

Consider the time-periodic viscous incompressible fluid flow past a body with non-zero velocity at infinity. This article gives sufficient conditions such that weak solutions to this problem are smooth. Since time-periodic solutions do not have finit...

  • Article
  • Open Access
4 Citations
2,555 Views
16 Pages

16 November 2020

This article studies the stochastic evolution of incompressible non-Newtonian fluids of differential type. More precisely, we consider the equations governing the dynamic of a third grade fluid filling a three-dimensional bounded domain O, perturbed...

  • Article
  • Open Access
1,918 Views
14 Pages

20 July 2022

In this paper, based on the Euler equation and mass conservation equation in spherical coordinates, the ratio of the stratospheric average width to the planetary radius and the ratio of the vertical velocity to the horizontal velocity are selected as...

  • Article
  • Open Access
9 Citations
2,762 Views
16 Pages

3 August 2020

We study an initial-boundary value problem for a fractional wave equation of time distributed-order with a nonlinear source term. The coefficients of the second order differential operator are dependent on the spatial and time variables. We show the...

  • Article
  • Open Access
1 Citations
938 Views
24 Pages

In this paper, we propose an approach for constructing quasiparticle-like asymptotic solutions within the weak diffusion approximation for the generalized population Fisher–Kolmogorov–Petrovskii–Piskunov (Fisher–KPP) equation,...

  • Article
  • Open Access
2 Citations
3,095 Views
51 Pages

7 April 2019

In this article, I consider local solutions of the 3D Navier–Stokes equations and its properties such as an existence of global and smooth solution, uniform boundedness. The basic role is assigned to a special invariant class of solenoidal vect...

  • Article
  • Open Access
326 Views
21 Pages

Fuzzified Matrix Space and Solvability of Matrix Equations

  • Vanja Stepanović and
  • Andreja Tepavčević

27 November 2025

A fuzzified matrix space consists of a collection of matrices with a fuzzy structure, modeling the cases of uncertainty on the part of values of different matrices, including the uncertainty of the very existence of matrices with the given values. Th...

  • Article
  • Open Access
1 Citations
2,281 Views
19 Pages

6 August 2021

The aim of this work is to prove the well-posedness of some linear and nonlinear mixed problems with integral conditions defined only on two parts of the considered boundary. First, we establish for the associated linear problem a priori estimate and...

  • Article
  • Open Access
4 Citations
2,060 Views
14 Pages

A 3D Non-Stationary Micropolar Fluids Equations with Navier Slip Boundary Conditions

  • Cristian Duarte-Leiva,
  • Sebastián Lorca and
  • Exequiel Mallea-Zepeda

26 July 2021

Micropolar fluids are fluids with microstructure and belong to a class of fluids with asymmetric stress tensor that called Polar fluids, and include, as a special case, the well-established Navier–Stokes model. In this work we study a 3D micropolar f...

  • Article
  • Open Access
4 Citations
1,567 Views
18 Pages

In this paper, we prove the existence of at least two weak solutions to a class of singular two-phase problems with variable exponents involving a ψ-Hilfer fractional operator and Dirichlet-type boundary conditions when the term source is depende...

  • Article
  • Open Access
516 Views
21 Pages

Stability Properties of Distributional Solutions for Nonlinear Viscoelastic Wave Equations with Variable Exponents

  • Mouhssin Bayoud,
  • Mohamed Karek,
  • Khaled Zennir,
  • Keltoum Bouhali and
  • Loay Alkhalifa

22 March 2025

A system of nonlinear wave equations in viscoelasticity with variable exponents is considered. It is assumed that the kernel included in the integral term of the equations depends on both the time and the spatial variables. Using the Faedo–Gale...

  • Article
  • Open Access
1 Citations
2,162 Views
11 Pages

30 September 2024

Miller (Arch. Rational Mech. Anal., 2020) posed the question of whether it is possible to prove the Navier–Stokes regularity criterion using only one entry of the strain tensor Sij. Although this paper does not fully address this question, we d...

  • Article
  • Open Access
14 Citations
5,240 Views
9 Pages

1 February 2018

In this article, three numerical iterative schemes, namely: Jacobi, Gauss–Seidel and Successive over-relaxation (SOR) have been proposed to solve a fuzzy system of linear equations (FSLEs). The convergence properties of these iterative schemes have b...

  • Article
  • Open Access
651 Views
18 Pages

28 February 2025

This study considers a class of backward stochastic semi-linear Schrödinger equations with Poisson jumps in Rd or in its bounded domain of a C2 boundary, which is associated with a stochastic control problem of nonlinear Schrödinger equatio...

  • Article
  • Open Access
2 Citations
2,425 Views
15 Pages

1 March 2020

This paper proposes some formulations of weak local residuals of shallow-water-type equations, namely, one-, one-and-a-half-, and two-dimensional shallow water equations. Smooth parts of numerical solutions have small absolute values of weak local re...

  • Article
  • Open Access
2 Citations
1,123 Views
22 Pages

Two-Phase Incompressible Flow with Dynamic Capillary Pressure in a Heterogeneous Porous Media

  • Mohamed Lamine Mostefai,
  • Abdelbaki Choucha,
  • Salah Boulaaras and
  • Mufda Alrawashdeh

28 September 2024

We prove the existence of weak solutions of a two-incompressible immiscible wetting and non-wetting fluids phase flow model in porous media with dynamic capillary pressure. This model is a coupled system which includes a nonlinear parabolic saturatio...

  • Article
  • Open Access
7 Citations
1,922 Views
16 Pages

20 February 2023

In this paper, we first present an overview of the results related to energy conservation in spaces of Hölder-continuous functions for weak solutions to the Euler and Navier–Stokes equations. We then consider families of weak solutions to...

  • Article
  • Open Access
1,017 Views
19 Pages

23 January 2025

This paper concerns the viscous Boussinesq equations without a dissipation term and their relation to the temperature equation related to the exterior of a ball with a smooth boundary. We first prove the global existence of weak solutions on the boun...

  • Article
  • Open Access
216 Views
12 Pages

26 December 2025

We consider a system of parabolic partial differential equations with a cross-diffusion phenomenon. Previous results showed that a weak solution exists to the semiconductor model with electron-hole scattering. In this work, we show that this weak sol...

  • Article
  • Open Access
1 Citations
1,942 Views
15 Pages

29 August 2021

We introduce new necessary conditions for the existence and uniqueness of stationary weak solutions and the existence of the weak solutions for the evolution problem in the system arising from the modeling of the bioconvective flow problem. Our analy...

  • Article
  • Open Access
1 Citations
1,650 Views
21 Pages

9 November 2020

In this paper, we consider an initial boundary value problem for nonlinear Love equation with infinite memory. By combining the linearization method, the Faedo–Galerkin method, and the weak compactness method, the local existence and uniqueness...

  • Article
  • Open Access
3 Citations
1,719 Views
15 Pages

15 July 2022

This article studies the 3D incompressible micropolar fluids with rapidly oscillating terms. The authors prove that the trajectory statistical solutions of the oscillating fluids converge to that of the homogenized fluids provided that the oscillatin...

  • Article
  • Open Access
5 Citations
1,490 Views
13 Pages

2 February 2024

We study the solvability of the Ionkin problem for some differential equations with one space variable. These equations include parabolic and quasiparabolic, hyperbolic and quasihyperbolic, pseudoparabolic and pseudohyperbolic, elliptic and quasielli...

  • Article
  • Open Access
2,236 Views
8 Pages

21 September 2021

The paper deals with a Volterra integral equation with delay. In order to apply the w-weak generalized contraction theorem for the study of existence and uniqueness of solutions, we rewrite the equation as a fixed point problem. The assumptions take...

  • Article
  • Open Access
3 Citations
2,378 Views
29 Pages

28 July 2021

In 1981, Foias, Guillopé and Temam proved a priori estimates for arbitrary-order space derivatives of solutions to the Navier–Stokes equation. Such bounds are instructive in the numerical investigation of intermittency that is often observed in simul...

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