Different radio emission processes also exist for certain pre-main-sequence stars, along with post-main sequence stars such as neutron stars. These objects have very high rotation rates, which leads to very intense magnetic fields that are capable of accelerating large amounts of particles to highly- relativistic speeds. Of particular interest is the fact that there is no consensus yet on the coherent radio emission mechanism responsible for pulsars, which cannot be explained by the two well-established coherent mechanisms discussed here, plasma emission and electron cyclotron maser emission. Proposed mechanisms for pulsar radio emission include coherent curvature emission, relativistic plasma emission, anomalous Doppler emission, and linear acceleration emission or free-electron maser emission. All of these processes still involve the transfer of energy from moving electrons into radiation. However, in this case the electrons are moving at nearly the speed of light, and the debate revolves around what process accelerates these electrons and how their energy is converted into radiation.