Simons cone

In geometry and geometric measure theory, the Simons cone refers to a specific minimal hypersurface in \mathbb R^8 that plays a crucial role in resolving Bernstein's problem in higher dimensions. It is named after American mathematician Jim Simons.

Definition

The Simons cone is defined as the hypersurface given by the equation

:S = \{x \in \mathbb R^8 | x_1^2 + x_2^2 + x_3^2 + x_4^2 = x_5^2 + x_6^2 + x_7^2 + x_8^2 \} \subset \mathbb R^8.

This 7-dimensional cone has the distinctive property that its mean curvature vanishes at every point except at the origin, where the cone has a singularity.Bombieri, E., De Giorgi, E., and Giusti, E. (1969). "Minimal cones and the Bernstein problem". Inventiones Mathematicae, 7: 243-268.G. De Philippis, E. Paolini (2009). "A short proof of the minimality of Simons cone". Rendiconti del Seminario Matematico della Università di Padova, 121. pp. 233-241

Applications

{{See also|Bernstein's problem}}

The classical Bernstein theorem states that any minimal graph in \mathbb R^3 must be a plane. This was extended to \mathbb R^4 by Wendell Fleming in 1962 and Ennio De Giorgi in 1965, and to dimensions up to \mathbb R^5 by Frederick J. Almgren Jr. in 1966 and to \mathbb R^8 by Jim Simons in 1968. The existence of the Simons cone as a minimizing cone in \mathbb R^8 demonstrated that the Bernstein theorem could not be extended to \mathbb R^9 and higher dimensions. Bombieri, De Giorgi, and Enrico Giusti proved in 1969 that the Simons cone is indeed area-minimizing, thus providing a negative answer to the Bernstein problem in higher dimensions.

See also

Original source