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An elliptic surface of Mordell-Weil rank 8 over the rational numbers

Charles F. Schwartz (1994)

Journal de théorie des nombres de Bordeaux

Néron showed that an elliptic surface with rank 8 , and with base B = P 1 , and geometric genus = 0 , may be obtained by blowing up 9 points in the plane. In this paper, we obtain parameterizations of the coefficients of the Weierstrass equations of such elliptic surfaces, in terms of the 9 points. Manin also describes bases of the Mordell-Weil groups of these elliptic surfaces, in terms of the 9 points ; we observe that, relative to the Weierstrass form of the equation, Y 2 = X 3 + A X 2 + B X + C (with deg ( A ) 2 , deg ( B ) 4 , and deg ( C ) 6 ) a basis ( X 1 , Y 1 ) , , ( X 8 , Y 8 ) can be found...

An example of an asymptotically Chow unstable manifold with constant scalar curvature

Hajime Ono, Yuji Sano, Naoto Yotsutani (2012)

Annales de l’institut Fourier

Donaldson proved that if a polarized manifold ( V , L ) has constant scalar curvature Kähler metrics in c 1 ( L ) and its automorphism group Aut ( V , L ) is discrete, ( V , L ) is asymptotically Chow stable. In this paper, we shall show an example which implies that the above result does not hold in the case where Aut ( V , L ) is not discrete.

An explicit algebraic family of genus-one curves violating the Hasse principle

Bjorn Poonen (2001)

Journal de théorie des nombres de Bordeaux

We prove that for any t 𝐐 , the curve 5 x 3 + 9 y 3 + 10 z 3 + 12 t 2 + 82 t 2 + 22 3 ( x + y + z ) 3 = 0 in 𝐏 2 is a genus 1 curve violating the Hasse principle. An explicit Weierstrass model for its jacobian E t is given. The Shafarevich-Tate group of each E t contains a subgroup isomorphic to 𝐙 / 3 × 𝐙 / 3 .

An explicit formula for period determinant

Alexey A. Glutsyuk (2006)

Annales de l’institut Fourier

We consider a generic complex polynomial in two variables and a basis in the first homology group of a nonsingular level curve. We take an arbitrary tuple of homogeneous polynomial 1-forms of appropriate degrees so that their integrals over the basic cycles form a square matrix (of multivalued analytic functions of the level value). We give an explicit formula for the determinant of this matrix.

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