In the first part, we investigate the singular BVP $${\frac{d}{dt}}^c{D}^{\alpha }u+{(a/t)}^c{D}^{\alpha }u=\mathscr{H}u$$ , u(0) = A, u(1) = B, c D α u(t)|t=0 = 0, where $$\mathscr{H}$$ is a continuous operator, α ∈ (0, 1) and a < 0. Here, c D denotes the Caputo fractional derivative. The existence result is proved by the Leray-Schauder nonlinear alternative. The second part establishes the relations between solutions of the sequence of problems $${\frac{d}{dt}}^c{D}^{{\alpha }_n}u+{(a/t)}^c{D}^{{\alpha }_n}u=f(t,u{,}^c{D}^{{\beta }_n}u)$$ , u(0) = A, u(1) = B, $${\left.{}^c{D}^{{\alpha }_n}u\left(t\right)\right|}_{t=0}=0$$ where a < 0, 0 < β n ≤ α n < 1, limn→∞ β n = 1, and solutions of u″+(a/t)u′ = f(t, u, u′) satisfying...

A new class of fractional linear continuous-time linear systems described by state equations is introduced. The solution to the state equations is derived using the Laplace transform. Necessary and sufficient conditions are established for the internal and external positivity of fractional systems. Sufficient conditions are given for the reachability of fractional positive systems.

We introduce fractional-order Bessel functions (FBFs) to obtain an approximate solution for various kinds of differential equations. Our main aim is to consider the new functions based on Bessel polynomials to the fractional calculus. To calculate derivatives and integrals, we use Caputo fractional derivatives and Riemann-Liouville fractional integral definitions. Then, operational matrices of fractional-order derivatives and integration for FBFs are derived. Also, we discuss an error estimate between...

A sufficient condition for the nonexistence of blowing-up solutions to evolution functional-differential equations in Banach spaces with the Riemann-Liouville integrals in their right-hand sides is proved. The linear part of such type of equations is an infinitesimal generator of a strongly continuous semigroup of linear bounded operators. The proof of the main result is based on a desingularization method applied by the author in his papers on integral inequalities with weakly singular kernels....