In the hierarchical structure formation model cosmic halos are supposed to form by accretion of smaller units along anisotropic direction , defined by large-scale filamentary structures .
After the epoch of mass aggregation ( which depend on the cosmological model ) , violent relaxation processes will tend to alter the halo phase-space configuration producing quasi-spherical halos with a relatively smooth density profiles .

Here we attempt to investigate the relation between halos shapes , their environment and their dynamical state .
To this end we have run a large ( L = 500 h ^ { -1 } Mpc , N _ { p } = 512 ^ { 3 } particles ) N-body simulation of a flat low-density cold dark matter model with a matter density \Omega _ { m } = 1 - \Omega _ { \Lambda } = 0.3 , Hubble constant H _ { \circ } = 70 km s ^ { -1 } Mpc ^ { -1 } and a normalization parameter of \sigma _ { 8 } = 0.9 .
The particle mass is m _ { p } \geq 7.7 \times 10 ^ { 10 } h ^ { -1 } M _ { \odot } comparable to the mass of one single galaxy .
The halos are defined using a friends-of-friend algorithm with a linking length given by l = 0.17 \bar { \nu } where \bar { \nu } is the mean density .
This linking length corresponds to an overdensity \rho / \rho _ { mean } \simeq 200 at the present epoch ( z = 0 ) and the total number of halos with more than 130 particles ( M > 3 \times 10 ^ { 13 } h ^ { -1 } M _ { \odot } ) is 57524 .