Therefore in terms of the affine plane its equation is
An integer solution to the Fermat equation would correspond to a nonzero rational number solution to the affine equation, and vice versa. But by Fermat's last theorem it is now known that (for n ≥ 3) there are no nontrivial integer solutions to the Fermat equation; therefore, the Fermat curve has no nontrivial rational points.
This means genus 0 for the case n = 2 (a conic) and genus 1 only for n = 3 (an elliptic curve). The Jacobian variety of the Fermat curve has been studied in depth. It is isogenous to a product of simple abelian varieties with complex multiplication.
Fermat-style equations in more variables define as projective varieties the Fermat varieties.
- Gross, Benedict H.; Rohrlich, David E. (1978), Some Results on the Mordell-Weil Group of the Jacobian of the Fermat Curve, Inventiones Mathematicae 44 (3): 201–224, doi:10.1007/BF01403161.