Manin conjecture
{{short description|Unsolved problem in number theory}}
File:Rational points of bounded height outside the 27 lines on Clebsch's diagonal cubic surface.png diagonal cubic surface.]]
In mathematics, the Manin conjecture describes the conjectural distribution of rational points on an algebraic variety relative to a suitable height function. It was proposed by Yuri I. Manin and his collaborators
{{cite journal
| last1=Franke | first1 = J. | last2 = Manin | first2 = Y. I. | author2-link = Yuri I. Manin | last3 = Tschinkel | first3 = Y.
| title = Rational points of bounded height on Fano varieties
| journal = Inventiones Mathematicae
| volume = 95
| year = 1989
| issue = 2
| pages = 421–435
| mr = 974910
| zbl = 0674.14012 | doi=10.1007/bf01393904| bibcode = 1989InMat..95..421F }}
in 1989 when they initiated a program with the aim of describing the distribution of rational points on suitable algebraic varieties.
Conjecture
Their main conjecture is as follows.
Let
be a Fano variety defined
over a number field ,
let
be a height function which is relative to the anticanonical divisor
and assume that
is Zariski dense in .
Then there exists
a non-empty Zariski open subset
such that the counting function
of -rational points of bounded height, defined by
:
for ,
satisfies
:
as
Here
is the rank of the Picard group of
and
is a positive constant which
later received a conjectural interpretation by Peyre.{{cite journal
| last = Peyre | first = E.
| title = Hauteurs et mesures de Tamagawa sur les variétés de Fano
| journal = Duke Mathematical Journal
| volume = 79
| year = 1995
| issue = 1
| pages = 101–218
| mr = 1340296
| doi = 10.1215/S0012-7094-95-07904-6
| zbl = 0901.14025}}
Manin's conjecture has been decided for special families of varieties,
{{cite book | editor1-last=Duke | editor1-first=William | title=Analytic number theory. A tribute to Gauss and Dirichlet. Proceedings of the Gauss-Dirichlet conference, Göttingen, Germany, June 20–24, 2005 | location=Providence, RI | publisher=American Mathematical Society | isbn=978-0-8218-4307-9 | series=Clay Mathematics Proceedings | volume=7
| last = Browning | first = T. D.
| chapter = An overview of Manin's conjecture for del Pezzo surfaces
| year = 2007
| pages = 39–55
| mr = 2362193
| zbl = 1134.14017}}
but is still open in general.