Uniform boundedness conjecture for rational points explained

K

and a positive integer

g\geq2

, there exists a number

N(K,g)

depending only on

K

and

g

such that for any algebraic curve

C

defined over

K

having genus equal to

g

has at most

N(K,g)

K

-rational points. This is a refinement of Faltings's theorem, which asserts that the set of

K

-rational points

C(K)

is necessarily finite.

Progress

The first significant progress towards the conjecture was due to Caporaso, Harris, and Mazur.[1] They proved that the conjecture holds if one assumes the Bombieri–Lang conjecture.

Mazur's conjecture B

Mazur's conjecture B is a weaker variant of the uniform boundedness conjecture that asserts that there should be a number

N(K,g,r)

such that for any algebraic curve

C

defined over

K

having genus

g

and whose Jacobian variety

JC

has Mordell–Weil rank over

K

equal to

r

, the number of

K

-rational points of

C

is at most

N(K,g,r)

.

Michael Stoll proved that Mazur's conjecture B holds for hyperelliptic curves with the additional hypothesis that

r\leqg-3

.[2] Stoll's result was further refined by Katz, Rabinoff, and Zureick-Brown in 2015.[3] Both of these works rely on Chabauty's method.

Mazur's conjecture B was resolved by Dimitrov, Gao, and Habegger in 2021 using the earlier work of Gao and Habegger on the geometric Bogomolov conjecture instead of Chabauty's method.[4]

Notes and References

  1. Lucia . Caporaso . Joe . Harris . Barry . Mazur . Uniformity of rational points . . 10 . 1 . 1997 . 1–35 . 10.1090/S0894-0347-97-00195-1. free .
  2. Michael . Stoll . Uniform bounds for the number of rational points on hyperelliptic curves of small Mordell–Weil rank . . 21 . 3 . 2019 . 923–956 . 10.4171/JEMS/857 . free . 1307.1773 .
  3. Eric . Katz . Joseph . Rabinoff . David . Zureick-Brown . Uniform bounds for the number of rational points on curves of small Mordell–Weil rank . . 165 . 16 . 2016 . 3189–3240 . 10.1215/00127094-3673558 . 1504.00694 . 42267487 .
  4. Vessilin . Dimitrov . Ziyang . Gao . Philipp . Habegger. Uniformity in Mordell–Lang for curves . . 194 . 2021. 237–298 . 10.4007/annals.2021.194.1.4. 210932420 .