Abstract
The gyrokinetic theory is a basic framework for describing microinstabilities, turbulence, and resultant anomalous transport in magnetically confined plasmas. This article reviews basic governing equations of the gyrokinetic theory, namely, gyrokinetic equations for the gyrocenter distribution function, the electrostatic potential, and the magnetic vector potential, based on Lagrangian and Hamiltonian formulation. In this formulation, conservation laws for the magnetic moment, the phase space volume, and the total energy are rigorously treated.
