Unirationality of Cubic Hypersurfaces
نویسنده
چکیده
A remarkable result of [Segre43] says that a smooth cubic surface over Q is unirational iff it has a rational point. [Manin72, II.2] observed that similar arguments work for higher dimensional cubic hypersurfaces satisfying a certain genericity assumption over any infinite field. [CT-S-SD87, 2.3.1] extended the result of Segre to any normal cubic hypersurface (other than cones) over a field of characteristic zero. It is also clear that the result should hold for all sufficiently large finite fields, though the details were not worked out in general. [Manin72, IV.8] settles the cubic surface case for finite fields with at least 34 elements. The aim of this note is to observe that a variant of the Segre–Manin method works for all fields and for all cubics:
منابع مشابه
Degree of Unirationality for Del Pezzo Surfaces over Finite Fields
We address the question of the degree of unirational parameterizations of degree four and degree three del Pezzo surfaces. Specifically we show that degree four del Pezzo surfaces over finite fields admit degree two parameterizations and minimal cubic surfaces admit parameterizations of degree 6. It is an open question whether or not minimal cubic surfaces over finite fields can admit degree 3 ...
متن کاملWeak Approximation for Cubic Hypersurfaces
We prove weak approximation for smooth cubic hypersurfaces of dimension at least 2 defined over the function field of a complex curve.
متن کاملRATIONAL POINTS ON CUBIC HYPERSURFACES OVER Fq(t)
The Hasse principle and weak approximation is established for non-singular cubic hypersurfaces X over the function field Fq(t), provided that char(Fq) > 3 and X has dimension at least 6.
متن کاملLooking for Rational Curves on Cubic Hypersurfaces
The aim of these lectures is to study rational points and rational curves on varieties, mainly over finite fields Fq. We concentrate on hypersurfaces Xn of degree ≤ n+ 1 in Pn+1, especially on cubic hypersurfaces. The theorem of Chevalley–Warning (cf. Esnault’s lectures) guarantees rational points on low degree hypersurfaces over finite fields. That is, if X ⊂ Pn+1 is a hypersurface of degree ≤...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2000