The hyperbolic polar sine is a function of an -dimensional simplex in hyperbolic space. It is analogous to
the polar sine of an
-dimensional simplex in elliptic or spherical space. If the
edges between vertices
and
have length
, the value of the hyperbolic polar sine of the
-dimensional hyperbolic simplex
in space with Gaussian curvature
is given by
The hyperbolic polar sine is used in the generalized law of sines for a hyperbolic simplex.
The limit of the hyperbolic polar sine of an -dimensional hyperbolic simplex as the curvature
of the space approaches zero is
, where
is the content of the Euclidean simplex with the same edge
lengths.