Mass function of low-mass dark halos

The mass function of dark halos in a Lambda-dominated cold dark matter universe is investigated. We analyze 529 output files from five runs of N-body simulations using the friends-of-friends cluster finding algorithm. All the runs use 5123 particles in the box size of 35-140 h(-1) Mpc. Mass of particles for 35 h(-1) Mpc runs is 2: 67; 10(7) h(-1) M-circle dot. Because of the high-mass resolution of our simulations, the multiplicity function in the low-mass range, where the mass is well below the characteristic mass and v = delta(c)/sigma less than or similar to 1.0, is evaluated in the present work, and it is well fitted by the functional form (ST) proposed by Sheth & Tormen. However, the maximum value of the multiplicity function from our simulations at v similar to 1 is smaller, and its low-mass tail is shallower when compared with the ST multiplicity function.