  Even- and odd-frequency superconductivity coexist due to broken time-reversal
symmetry under magnetic field. In order to describe this mixing, we extend the
linearized Eliashberg equation for the spin and charge fluctuation mechanism in
strongly correlated electron systems. We apply this extended Eliashberg
equation to the odd-frequency superconductivity on a quasi-one-dimensional
isosceles triangular lattice under in-plane magnetic field and examine the
effect of the even-frequency component.
