“…The unilateral obstacle problem has many applications, such as lubrication phenomena, fluid flow in porous media and option pricing, etc. [19,20]. In this paper, we propose a new ADMM [7,21] with an optimal parameter for the unilateral obstacle problem [22][23][24][25][26][27][28][29][30][31], which is based on the extreme eigenvalues of the matrix using the finite difference method (FDM) [6,22,26,32].…”