The interaction of rarefaction waves of the two-dimensional Euler equations Xinfu ChenYuxi Zheng 35L6535J7035R3535J652-D Riemann problemcompressiblecharacteristic decompositiongas dynamicshodograph transformationinclination angles of characteristicssimple waves We construct classical self-similar solutions to the interaction of two arbitrary planar rarefaction waves for the Euler equations in two space dimensions via the characteristics analysis without the hodograph transformations. We succeed in the case that the interaction (half) angle is between $\pi/6$ and $\pi/2$ for gas constant gamma between one and two. Indiana University Mathematics Journal 2010 text pdf 10.1512/iumj.2010.59.3752 10.1512/iumj.2010.59.3752 en Indiana Univ. Math. J. 59 (2010) 231 - 256 state-of-the-art mathematics http://iumj.org/access/