  A one-parameter deformation of Einstein?Hilbert gravity with an inverse
Riemann curvature term is derived as the classical limit of quantum gravity
compatible with an accelerating universe. This result is based on the
investigation of semi-classical theories with sectional curvature bounds which
are shown not to admit static spherically symmetric black holes if otherwise of
phenomenological interest. We discuss the impact on the canonical quantization
of gravity, and observe that worldsheet string theory is not affected.
