A formal mathematical theory which introduces "components at infinity" by defining a new type of divisor class group of integers of a number field. The divisor class group is called an "arithmetic surface."
Arakelov Theory
See also
Arithmetic GeometryExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Arakelov Theory." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ArakelovTheory.html