Özet:
We discuss the existence of positive solutions for the coupled system of multiterm singular fractional integrodifferential boundary value problems D-0+(alpha) + f(1)(t), u(t), v(t), (phi(1)u)(t), (psi(1)v)(t), D(0+)(p)u(t), D(0+)(mu 1)v(t), D(0+)(mu 2)v(t), ... , D(0+)(mu m)v(t)) = 0, D(0+)(beta)v(t) + f(2)(t, u(t), v(t), (phi(2)u)(t), (psi(2)v)(t), D(0+)(q)v(t), D(0+)(v1)v(t), D(0+)(v2)v(t), ... , D(0+)(vm)v(t) = 0, u((1))(0) = 0 and v((i))(0) = 0 for all 0 <= i <= n - 2, [D(0+)(delta 1)u(t)](t=1) - 0 for 2 < delta(1) < n - 1 and alpha - delta(1) >= 1, [D(0+)(delta 2)u(t)](t=1) - 0 for 2 < delta(2) < n - 1 and beta - delta(1) >= 1 where n >= 4 n - 1 < alpha, beta < n, 0 < 1, 1 < mu(i,) nu(i) < 2 (i = 1, 2, ... , m), gamma(j,) lambda(j) : [0, 1] x [0, 1] -> (0, infinity) are continuous functions (j = 1, 2) and (phi(j)u)(t) = integral(t)(0) gamma(j)(t, s)u(s)ds, (psi(j)v)(t) = integral(t)(0) gamma(j)(t, s)v(s)ds. Here D is the standard Riemann-Liouville fractional derivative, f(j) (j = 1, 2) is a Caratheodory function, and f(j)(t, x, y, z, w, v, u(1), u(2), ... , u(m)) is singular at the value 0 of its variables.