  We demonstrate the fractional Talbot effect of nonpraxial accelerating beams,
theoretically and numerically. It is based on the interference of nonparaxial
accelerating solutions of the Helmholtz equation in two dimensions. The effect
originates from the interfering lobes of a superposition of the solutions that
accelerate along concentric semicircular trajectories with different radii.
Talbot images form along certain central angles, which are referred to as the
Talbot angles. The fractional nonparaxial Talbot effect is obtained by choosing
the coefficients of beam components properly. A single nonparaxial accelerating
beam possesses duality --- it can be viewed as a Talbot effect of itself with
an infinite or zero Talbot angle. These results improve the understanding of
nonparaxial accelerating beams and the Talbot effect among them.
