Let E be an elliptic curve over Q. By Mordell's
theorem, E(Q) is a finitely generated abelian group.
This means that E(Q) =
E(Q)tors
× Zr.
By Mazur's theorem, we know that
E(Q)tors is one of the following 15 groups:
Z/nZ with 1 ≤ n ≤ 10 or
n = 12, Z/2Z × Z/2mZ with
1 ≤ m ≤ 4.
On the other hand, it is not known what values of rank r are
possible for elliptic curves over Q. The "folklore"
conjecture is that a rank can be arbitrary large.
However there are also recent heuristic arguments that suggest
the boundedness of the rank of elliptic curves.
The current
record is an example of elliptic curve with
rank ≥ 29,
found by Elkies and Klagsbrun in 2024 (the previous record was
rank ≥ 28,
found by Elkies in 2006).
The highest rank of an
elliptic curve which is (unconditionally) known exactly (not only a lower bound for rank)
is equal to 20,
and it is found by Elkies-Klagsbrun in 2020.
It improves previous records due to Kretschmer
(rank = 10),
Schneiders-Zimmer (rank = 11),
Fermigier (rank = 14),
Dujella (rank = 15) and Elkies (rank = 17,
rank = 18, rank = 19).
The following table contains some historical data on elliptic curve
rank records.
Concerning the first three entries in the table, let us note that, according to Buquet,
in 1921, Rignaux discovered the curve y2 = x4 - 4432x2 + 4190281,
which is equivalent to an elliptic curve with rank 6.
Click on rank r to see the corresponding
curve(s) and independent points
P1, P2, ... ,
Pr of infinite order.
References:
G. Billing, Beitrage zur arithmetischen Theorie der ebenen
kubishen Kurven vom Geschlecht Eins, Nova Acta Soc. Sci.
Upsal. (4) 11 (1938), Nr.1, Diss.165.
A. Wiman, Uber den Rang von Kurven y2 =
x(x+a)(x+b),
Acta Math. 76 (1945), 225-251.
A. Wiman, Uber rationale Punkte auf Kurven
y2 =
x(x2-c2),
Acta Math. 77 (1945), 281-320.
A. Buquet, Diophante 1 (1948), p. 32.
D.E. Penney and C. Pomerance, A search for elliptic curves
with large rank, Math. Comp. 28 (1974), 851-853.
D.E. Penney and C. Pomerance, Three elliptic curves with rank at least seven, Math. Comp. 29 (1975), 965-967.
F.J. Grunewald and R. Zimmert, Uber einige rationale elliptische
Kurven mit treiem Rang ≥ 8, J. Reine Angew. Math.
296 (1977), 100-107.
A. Brumer and K. Kramer, The rank of elliptic curves,
Duke Math. J. 44 (1977), 715-743.
J.-F. Mestre, Construction d'une courbe elliptique
de rang ≥ 12, C. R. Acad. Sci. Paris Ser I Math.
295 (1982), 643-644.
J.-F. Mestre, Courbes elliptiques et formules
explicites, Theorie des nombres, Semin. Delange-Pisot-Poitou,
Paris 1981/82, Prog. Math. 38, Birkhauser, Boston, 1983, pp. 179-187
J.-F. Mestre, Formules explicites et minorations de
conducteurs de varietes algebriques, Compositio Math. 58 (1986),
209-232.
J.-F. Mestre, Un exemple de courbe elliptique sur
Q de rang ≥ 15, C. R. Acad. Sci. Paris Ser I Math.
314 (1992), 453-455.
K. Nagao, Examples of elliptic curves over Q
with rank ≥ 17, Proc. Japan Acad. Ser. A Math. Sci. 68 (1992), 287-289.
S. Fermigier, Un exemple de courbe elliptique definie
sur Q(t) de rang ≥ 19, C. R. Acad.
Sci. Paris Ser. I 315 (1992), 719-722.
K. Nagao, An example of elliptic curve over Q
with rank ≥ 20, Proc. Japan Acad. Ser. A Math. Sci. 69 (1993), 291-293.
K. Nagao and T. Kouya, An example of elliptic curve over
Q with rank ≥ 21, Proc. Japan Acad. Ser. A Math. Sci. 70 (1994), 104-105.
K. Nagao, Construction of high-rank elliptic curves,
Kobe J. Math. 11 (1994), 211-219.
S. Fermigier, Une courbe elliptique definie
sur Q de rang ≥ 22, Acta Arith. (1997), 359-363.
R. Martin and W. McMillen, An elliptic curve over Q
with rank
at least 23, Number Theory Listserver, March 1998.
R. Martin and W. McMillen, An elliptic curve over Q
with rank
at least 24, Number Theory Listserver, May 2000.
N. D. Elkies, Z28 in E(Q), etc.,
Number Theory Listserver, May 2006.
N. D. Elkies, Three lectures on elliptic surfaces and curves of high rank,
Lecture notes, Oberwolfach, 2007, arXiv:0709.2908.
T.J. Kretschmer, Construction of elliptic curves with large
rank, Math. Comp. 46 (1986), 627-635.
U. Schneiders and H.G. Zimmer, The rank of elliptic curves
upon quadratic extensions, in: Computational Number Theory
(A. Petho, H.C. Williams, H.G. Zimmer, eds.), de Gruyter, Berlin,
1991, pp. 239-260.
S. Fermigier, Exemples de courbes elliptiques de grand rang
sur Q(t) et sur Q
possedant des points d'ordre 2, C. R. Acad.
Sci. Paris Ser. I 322 (1996), 949-952.
A. Dujella, An
example of elliptic curve over Q with rank equal to 15,
Proc. Japan Acad. Ser. A Math. Sci. 78 (2002), 109-111.
N. D. Elkies, E(Q) =
(Z/2Z) × Z17,
Number Theory Listserver, Jun 2005.
N. D. Elkies, Some more rank records: E(Q) = (Z/2Z) × Z18,
(Z/4Z) × Z12, (Z/8Z) × Z6,
(Z/2Z) × (Z/6Z) × Z6,
Number Theory Listserver, Jun 2006.
N. D. Elkies, Personal communication, 2009.
N. D. Elkies and Z. Klagsbrun, New rank records for elliptic curves faving rational torsion,
Proceedings of the Fourteenth Algorithmic Number Theory Symposium, Mathematical Sciences Publishers, Berkeley, 2020, pp. 233-250.
N. D. Elkies and Z. Klagsbrun, Z29 in E(Q),
Number Theory Listserver, Aug 2024.