Quartic surface
In mathematics, especially in algebraic geometry, a quartic surface is a surface defined by an equation of degree 4.
More specifically there are two closely related types of quartic surface: affine and projective. An affine quartic surface is the solution set of an equation of the form
where Template:Mvar is a polynomial of degree 4, such as Template:Tmath. This is a surface in affine space Template:Math.
On the other hand, a projective quartic surface is a surface in projective space Template:Math of the same form, but now Template:Mvar is a homogeneous polynomial of 4 variables of degree 4, so for example Template:Tmath.
If the base field is Template:Tmath or Template:Tmath the surface is said to be real or complex respectively. One must be careful to distinguish between algebraic Riemann surfaces, which are in fact quartic curves over Template:Tmath, and quartic surfaces over Template:Tmath. For instance, the Klein quartic is a real surface given as a quartic curve over Template:Tmath. If on the other hand the base field is finite, then it is said to be an arithmetic quartic surface.
Special quartic surfaces
- Dupin cyclides
- The Fermat quartic, given by x4 + y4 + z4 + w4 =0 (an example of a K3 surface).
- More generally, certain K3 surfaces are examples of quartic surfaces.
- Kummer surface
- Plücker surface
- Weddle surface
See also
- Quadric surface (The union of two quadric surfaces is a special case of a quartic surface)
- Cubic surface (The union of a cubic surface and a plane is another particular type of quartic surface)