  For a class of solutions of the fundamental difference equation of isotropic
loop quantum cosmology, the difference equation can be replaced by a
differential equation valid for {\em all} values of the triad variable. The
differential equation admits a `unique' non-singular continuation through
vanishing triad. A WKB approximation for the solutions leads to an effective
continuum Hamiltonian. The effective dynamics is also non-singular (no big bang
singularity) and approximates the classical dynamics for large volumes. The
effective evolution is thus a more reliable model for further phenomenological
implications of the small volume effects.

General Relativity and Quantum Cosmology;Astrophysics;High Energy Physics - Theory