Around a black hole there is a mathematically defined surface called an event horizon that marks the point of no return.

A hyperbola can be defined mathematically in several equivalent ways.

These templates were mathematically defined outlines which sought to capture the position and shape of the feature.

Criteria can be defined mathematically, such that any voting system either passes or fails.

Now, any description of a benefit or weakness in a voting system is expected to be backed up by a mathematically defined criterion.

Significance is very well defined mathematically; there is no "transitivity".

The conditions under which regression toward the mean occurs depend on the way the term is mathematically defined.

Scholars of electoral systems often compare them using mathematically defined voting system criteria.

Key terms in theoretical physics like "field" are defined purely mathematically.

The ellipsoid is a mathematically defined regular surface with specific dimensions.