Degree-Three Rational Sphere Maps: Sharp Denominator Region and Gram Normal Forms

Eden Danielsen-Jensen, Dusty Grundmeier, Abdullah Al Helal +4

We study degree-three rational sphere maps in two complex variables. After a standard normalization, the denominator of such a map takes the form \[ g_σ(z)=1+σ_1 z_1^2+σ_2 z_2^2, \…