Magnetic condensation, Abelian dominance, and instability of Savvidy vacuum in Yang-Mills theory

We propose a novel type of color magnetic condensation originating from magnetic monopoles so that it provides the mass of off-diagonal gluons in the Yang-Mills theory. This dynamical mass generation enables us to explain the infrared Abelian dominance and monopole dominance by way of a non-Abelian Stokes theorem, which supports the dual superconductivity picture of quark confinement. Moreover, we show that the instability of Savvidy vacuum disappears by sufficiently large color magnetic condensation.