  This is a numerical study of thermoelectric properties of ballistic bilayer
graphene in the presence of trigonal warping term in the effective Hamiltonian.
We find, in the mesoscopic samples of the length $L>10\,\mu{}$m at sub-Kelvin
temperatures, that both the Seebeck coefficient and the Lorentz number show
anomalies (the additional maximum and minimum, respectively) when the
electrochemical potential is close to the Lifshitz energy, which can be
attributed to the presence of the van Hove singularity in a bulk density of
states. At higher temperatures the anomalies vanish, but measurable quantities
characterizing remaining maximum of the Seebeck coefficient still unveil the
presence of massless Dirac fermions and make it possible to determine the
trigonal warping strength. Behavior of the thermoelectric figure of merit
($ZT$) is also discussed.
