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Elliptic Curve Rank


The elliptic curve rank, also called the Mordell-Weil rank, of an elliptic curve E over Q is the group rank of its group of rational points. By the Mordell-Weil theorem,

 E(Q)=E(Q)_(tors) direct sum Z^r,
(1)

where E(Q)_(tors) is the finite subgroup of torsion points and the nonnegative integer r is the rank (Silverman 1986). Equivalently, r is the maximal number of linearly independent rational points of infinite order.

It is not known whether the ranks of elliptic curves over Q are bounded. A traditional conjecture says that they are unbounded. On the other hand, the heuristic of Park et al. (2019) predicts that they are bounded and that only finitely many elliptic curves over Q have rank greater than 21.

As of Aug. 29, 2026, the largest known lower bound for the rank of an elliptic curve over Q is 31. The record elliptic curve, submitted to the ICARM Elliptic Curve Rank Leaderboard on Aug. 23, 2026 and attributed there to Claude, L. Alpöge, and A. Howell, is

y^2+xy+y=x^3+x^2-1284727764113567728281797636015784768866707681415849262157224232063x
(2)
560368321454261339256859338901915312332769858684945406858043869199456710681989058863306170127006181.
(3)

Thirty-one linearly independent rational points prove unconditionally that its rank is at least 31. The rank is reported to be exactly 31 assuming both the generalized Riemann hypothesis and the Swinnerton-Dyer conjecture (ICARM, curve 302).

Earlier records were rank at least 28, found by N. D. Elkies in 2006, and rank at least 29, found by Elkies and Z. Klagsbrun in 2024 (Dujella). On Aug. 20, 2026, the elliptic curve

y^2+xy=x^3-201769035260418549083594900060734240952308696994802735114305555x
(4)
1151107939141058565733479426024323225135665982951300586808823640527729578307228357301072889377,
(5)

together with thirty linearly independent rational points, was submitted under the name "ranksunbounded" and subsequently attributed to Claude working with Alpöge and Howell (ICARM, curve 273).

Applying the analytic method of Bober (2013) gives an upper bound of 31 under the generalized Riemann hypothesis for the multiplicity of s=1 as a zero of the elliptic curve's Hasse-Weil L-function. The sign in its functional equation is 1, so this multiplicity is an even number. Consequently, assuming both the generalized Riemann hypothesis and the Swinnerton-Dyer conjecture, the rank of this elliptic curve is exactly 30. Without these assumptions, only the lower bound of 30 is known for this example.

Elkies and Klagsbrun independently found another elliptic curve of rank at least 30 in Sept. 2025, announced in Aug. 2026 (Elkies 2026; ICARM, curve 398),

y^2+xy=x^3-12892599774455576272301592959047823530919513428112484011550x
(6)
560755046348395412977088824999503890617558856687636981223935662848386484980312656296132.
(7)

Its elliptic curve conductor N and elliptic discriminant Delta satisfy lnN approx 304.984 and ln|Delta| approx 400.921, both smaller than those of the Aug. 20 example, for which lnN approx 339.348 and ln|Delta| approx 432.125. Elkies (2026) reports that its rank is exactly 30 under the generalized Riemann hypothesis for number fields, without assuming the Swinnerton-Dyer conjecture. The thirty linearly independent rational points give the unconditional lower bound of 30.

The same announcement gives further examples with small elliptic curve conductors or small elliptic discriminants and reported ranks 27, 28, and 29. In particular, the example of rank at least 28 cataloged as ICARM curve 400 has lnN approx 274.493 and ln|Delta| approx 354.248. Updated records and their rational points are maintained by ICARM.

The largest rank of an elliptic curve whose exact rank is known unconditionally is 20 (Elkies and Klagsbrun 2020, Dujella).


See also

Class Group, Elliptic Curve, Elliptic Curve Conductor, Elliptic Discriminant, Generalized Riemann Hypothesis, Group Rank, Hasse-Weil L-Function, Mordell-Weil Theorem, Swinnerton-Dyer Conjecture

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References

Bober, J. W. "Conditionally Bounding Analytic Ranks of Elliptic Curves." Open Book Ser. 1, 135-145, 2013. https://doi.org/10.2140/obs.2013.1.135.Dujella, A. "History of Elliptic Curves Rank Records." https://web.math.pmf.unizg.hr/~duje/tors/rankhist.html.Elkies, N. D. "N and |D| Records for Elliptic Curves E/Q of Ranks 27-30; Record 2-Ranks 25 (Real) and 26 (Complex) for Class Groups of Cubic Fields." Number Theory List, Aug. 29, 2026. https://listserv.nodak.edu/cgi-bin/wa.exe?A2=NMBRTHRY;e3f6d76d.2608&S=.Elkies, N. D. and Klagsbrun, Z. "New Rank Records for Elliptic Curves Having Rational Torsion." Open Book Ser. 4, 233-250, 2020. https://doi.org/10.2140/obs.2020.4.233.ICARM. "Curve 273." Elliptic Curve Rank Leaderboard. https://elliptic-rank.icarm.cloud/curve/273.ICARM. "Curve 302." Elliptic Curve Rank Leaderboard. https://elliptic-rank.icarm.cloud/curve/302.ICARM. "Curve 398." Elliptic Curve Rank Leaderboard. https://elliptic-rank.icarm.cloud/curve/398.ICARM. "Curve 400." Elliptic Curve Rank Leaderboard. https://elliptic-rank.icarm.cloud/curve/400.Park, J.; Poonen, B.; Voight, J.; and Wood, M. M. "A Heuristic for Boundedness of Ranks of Elliptic Curves." J. Eur. Math. Soc. 21, 2859-2903, 2019. https://doi.org/10.4171/JEMS/893. Pegg, E. Jr. "New Record in Elliptic Curves by Elkies-Klagsbrun: Rank 29 (and Now 30)." Wolfram Community, Aug. 20, 2026. https://community.wolfram.com/groups/-/m/t/3785084.Silverman, J. H. The Arithmetic of Elliptic Curves. New York: Springer-Verlag, 1986.

Cite this as:

Weisstein, Eric W. "Elliptic Curve Rank." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/EllipticCurveRank.html

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