Exact inflationary solutions
  We present a new class of exact inflationary solutions for the evolution of a universe with spatial curvature, filled with a perfect fluid, a scalar field with potential $V_{\pm}(\phi)=\lambda(\phi^2\pm\delta^2)^2$ and a cosmological constant $\Lambda$. With the $V_+(\phi)$ potential and a negative cosmological constant, the scale factor experiments a graceful exit.   We give a brief discussion about the physical meaning of the solutions. 
Gabriella Piccinelli, Tonatiuh Matos and Merced Montesinos