Picard modular group

Not to be confused with Picard group.

In mathematics, a Picard modular group, studied by Picard (1881), is a group of the form SU(J,L), where L is a 3-dimensional lattice over the ring of integers of an imaginary quadratic field and J is a hermitian form on L of signature (2, 1). Picard modular groups act on the unit sphere in C² and the quotient is called a Picard modular surface.

See also

• Fuchsian group
• Kleinian group