Gyroresonant Surfing Acceleration

We discuss a new acceleration or energization mechanism of charged particles in space and astrophysical plasmas. In the presence of an electrostatic potential gradient and a circularly polarized electromagnetic monochromatic wave, particles are accelerated efficiently by keeping cyclotron resonance with the wave due to the electrostatic dragging force. In addition, particles can propagate against the electrostatic potential even if they have smaller parallel energy. This mechanism is potentially widely applicable, in terms of particle acceleration and transport, to various space and astrophysical phenomena, such as shock environment and short-large amplitude magnetic structures. We introduce the basic physical process of the acceleration or energization mechanism theoretically and numerically.