The biharmonic operator, also known as the bilaplacian, is the differential operator defined by

where is the Laplacian.

In -dimensional space,

The biharmonic operator, also known as the bilaplacian, is the differential operator defined by

where is the Laplacian.

In -dimensional space,

Weisstein, Eric W. "Biharmonic Operator."
From *MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/BiharmonicOperator.html