  Using both the exact enumeration method (microcanonical transfer matrix) for
a small system (L = 9) and the Wang-Landau Monte Carlo algorithm for large
systems to L = 30, we obtain the exact and approximate densities of states
g(M,E), as a function of magnetization M and exchange energy E, for the
triangular-lattice Ising model. Based on the density of states g(M,E), we
investigate the phase transition properties of Yang-Lee zeros for the
triangular Ising antiferromagnets and obtain the magnetic exponents at various
temperatures.
