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Discrete fractional models with reaction-diffusion have gained significance in the scientific field in recent years, not only due to the need for numerical simulation but also due to the stated biological processes. In this paper, we investigate the problem of synchronization-control in a fractional discrete nonlinear bacterial culture reaction-diffusion model using the Caputo h-difference operator and a second-order central difference scheme and an L1 finite difference scheme after deriving the discrete fractional version of the well-known Degn–Harrison system and Lengyel–Epstein system. Using appropriate techniques and the direct Lyapunov method, the conditions for full synchronization are determined.Furthermore, this research shows that the L1 finite difference scheme and the second-order central difference scheme may successfully retain the properties of the related continuous system. The conclusions are proven throughout the paper using two major biological models, and numerical simulations are carried out to demonstrate the practical use of the recommended technique. [ABSTRACT FROM AUTHOR]

In this article, we introduce and study the behavior of the modules of the first two coefficients for the classes N Σ (γ , λ , δ , μ ; α) and N Σ * (γ , λ , δ , μ ; β) of normalized holomorphic and bi-univalent functions that are connected with the prestarlike functions. We determine the upper bounds for the initial Taylor–Maclaurin coefficients | a 2 | and | a 3 | for the functions of each of these families, and we also point out some special cases and consequences of our main results. The study of these classes is closely connected with those of Ruscheweyh who in 1977 introduced the classes of prestarlike functions of order μ using a convolution operator and the proofs of our results are based on the well-known Carathédory's inequality for the functions with real positive part in the open unit disk. Our results generalize a few of the earlier ones obtained by Li and Wang, Murugusundaramoorthy et al., Brannan and Taha, and could be useful for those that work with the geometric function theory of one-variable functions. [ABSTRACT FROM AUTHOR]

The study of the blow-up phenomenon for fractional reaction–diffusion problems is generally deemed of great importance in dealing with several situations that impact our daily lives, and it is applied in many areas such as finance and economics. In this article, we expand on some previous blow-up results for the explicit values and numerical simulation of finite-time blow-up solutions for a semilinear fractional partial differential problem involving a positive power of the solution. We show the behavior solution of the fractional problem, and the numerical solution of the finite-time blow-up solution is also considered. Finally, some illustrative examples and comparisons with the classical problem with integer order are presented, and the validity of the results is demonstrated. [ABSTRACT FROM AUTHOR]

Multivariate rational control functions r (x) of high degree d can be expressed in the Bernstein form defined over k -dimensional simplices (triangles). The range of rational functions can be optimized by the enclosure bound (minimum and maximum) of Bernstein coefficients. In this paper, linear and quadratic rate of convergence for the maximum error bound between the enclosure and range bounds are investigated. Furthermore, minimization and numerical identities for certifying the positivity of any given rational function over simplices are given. In order to provide global and local positivity certificates for r , the degree of Bernstein functions and number of simplex subdivision steps are estimated. Subsequently, we establish a bound for the maximum degree of Bernstein polynomials. • Numerical bound for rational polynomials. • Global optimization. • Positivity of rational control functions. [ABSTRACT FROM AUTHOR]

We consider degenerate identification problems with smoothing overdetermination in abstract spaces. We establish an identifiability result using a projection method and suitable hypotheses on the operators involved and develop an identification method by reformulating the problem into a nondegenerate problem. Then we use perturbation results for linear operators to solve the regular problem. The introduced identification method permits one to solve the problems under the minimum restrictions on the input data. Finally, we provide applications to degenerate differential equations that appear in mathematical physics to support the theoretical results. [ABSTRACT FROM AUTHOR]