Kinetic coefficients in the Hubbard model

The properties of the electron system with the strongest electron-electron coupling are studied. The kinetic equation in the Keldysh-Mills representation has been obtained. A new term has been discovered in the collision integral; this term is due to the relaxation of end multipliers and vanishes in the low-temperature limit as T ²/|t|, where |t| is the quantity on the order of the nearest-neighbor hopping integral and T is the temperature. The speed of sound has been calculated and the temperature behavior of the kinetic coefficients has been estimated.