  This study presents a solution to the Yakubovsky equations for four-body
bound states in momentum space, bypassing the common use of two-body
$t-$matrices. Typically, such solutions are dependent on the fully-off-shell
two-body $t-$matrices, which are obtained from the Lippmann-Schwinger integral
equation for two-body subsystem energies controlled by the second and third
Jacobi momenta. Instead, we use a version of the Yakubovsky equations that
doesn't require $t-$matrices, facilitating the direct use of two-body
interactions. This approach streamlines the programming and reduces
computational time. Numerically, we found that this direct approach to the
Yakubovsky equations, using 2B interactions, produces four-body binding energy
results consistent with those obtained from the conventional $t-$matrix
dependent Yakubovsky equations, for both separable (Yamaguchi and Gaussian) and
non-separable (Malfliet-Tjon) interactions.

Nuclear Theory;Computational Physics;Quantum Physics