The hyperelliptic curve defined by y2 = x(x + 1)(x − 3)(x + 2)(x − 2) has only finitely many rational points (such as the points (−2, 0) and (−1, 0)) by Faltings' theorem.
The structure of algebraic varieties defined over non-algebraically closed fields has become a central area of interest that arose with the modern abstract development of algebraic geometry. Over finite fields, étale cohomology provides topological invariants associated to algebraic varieties.[6]p-adic Hodge theory gives tools to examine when cohomological properties of varieties over the complex numbers extend to those over p-adic fields.[7]
In the 1850s, Leopold Kronecker formulated the Kronecker–Weber theorem, introduced the theory of divisors, and made numerous other connections between number theory and algebra. He then conjectured his "liebster Jugendtraum" ("dearest dream of youth"), a generalization that was later put forward by Hilbert in a modified form as his twelfth problem, which outlines a goal to have number theory operate only with rings that are quotients of polynomial rings over the integers.[9]
Early-to-mid 20th century: algebraic developments and the Weil conjectures
Modern foundations of algebraic geometry were developed based on contemporary commutative algebra, including valuation theory and the theory of ideals by Oscar Zariski and others in the 1930s and 1940s.[11]
In the 1960s, Goro Shimura introduced Shimura varieties as generalizations of modular curves.[20] Since the 1979, Shimura varieties have played a crucial role in the Langlands program as a natural realm of examples for testing conjectures.[21]
In papers in 1977 and 1978, Barry Mazur proved the torsion conjecture giving a complete list of the possible torsion subgroups of elliptic curves over the rational numbers. Mazur's first proof of this theorem depended upon a complete analysis of the rational points on certain modular curves.[22][23] In 1996, the proof of the torsion conjecture was extended to all number fields by Loïc Merel.[24]
In 1983, Gerd Faltings proved the Mordell conjecture, demonstrating that a curve of genus greater than 1 has only finitely many rational points (where the Mordell–Weil theorem only demonstrates finite generation of the set of rational points as opposed to finiteness).[25][26]
In the 2010s, Peter Scholze developed perfectoid spaces and new cohomology theories in arithmetic geometry over p-adic fields with application to Galois representations and certain cases of the weight-monodromy conjecture.[28][29]
↑Weil, A. (1929). "L'arithmétique sur les courbes algébriques". Acta Mathematica52: 281–315.. Reprinted in Volume 1 of his collected papers, ISBN 0-387-90330-5.
↑Taniyama, Yutaka (1956). "Problem 12" (in ja). Sugaku7: 269.
↑Shimura, Goro (1989). "Yutaka Taniyama and his time. Very personal recollections". The Bulletin of the London Mathematical Society21 (2): 186–196. doi:10.1112/blms/21.2.186. ISSN0024-6093.