Orders of torsion points of elliptic curves

We give a simple proof of the following proposition: if the elliptic curve contains a primitiveK -point of order 3 then theK -torsion of the curveT is uniformly bounded. We include application of the theorem.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 121, pp. 47–57, 1983.     

Examples of torsion points on genus two curves

We describe a method that sometimes determines all the torsion points lying on a curve of genus two defined over a number field and embedded in its Jacobian using a Weierstrass point as base point. We then apply this to the examples , , and .

     

Exact bounds on the order of torsion points of curves of genus 1

Let k be an algebraic number field of degree n on ₂; and , respectively, the curves on k; let, and _m, '_m be the bases of groups of all points of order m on and g, respectively. A proof of the following theorem is sketched: let p>3 be prime; if, then (p^t)6n; if k, then (p^t)4n. The resulting bounds are unimprovable.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 151, pp. 57–65, 1986.     

New orders of torsion points in Jacobians of curves of genus 2 over the rational number field

Doklady Mathematics -     

Pair correlation of torsion points on elliptic curves

We prove the existence of the pair correlation measure associated to torsion points on the real locus E(R) of an elliptic curve E and provide an explicit formula for the limiting pair correlation function.     

Gap sequences of 1-Weierstrass points on non-hyperelliptic curves of genus 10

In this paper, we compute the 1-gap sequences of 1-Weierstrass points of non-hyperelliptic smooth projective curves of genus 10. Furthermore, the geometry of such points is classified as flexes, sextactic and tentactic points. Also, upper bounds for their numbers are estimated.     

Finding rational points on bielliptic genus 2 curves

We discuss a technique for trying to find all rational points on curves of the form Y ²=f ₃ X ⁶+f ₂ X ⁴+f ₁ X ²+f ₀, where the sextic has nonzero discriminant. This is a bielliptic curve of genus 2. When the rank of the Jacobian is 0 or 1, Chabauty's Theorem may be applied. However, we shall concentrate on the situation when the rank is at least 2. In this case, we shall derive an associated family of elliptic curves, defined over a number field ℚα. If each of these elliptic curves has rank less than the degree of ℚα : ℚ, then we shall describe a Chabauty-like technique which may be applied to try to find all the points (x,y) defined over ℚα) on the elliptic curves, for which x∈ℚ. This in turn allows us to find all ℚ-rational points on the original genus 2 curve. We apply this to give a solution to a problem of Diophantus (where the sextic in X is irreducible over ℚ), which simplifies the recent solution of Wetherell. We also present two examples where the sextic in X is reducible over ℚ. Received: 27 November 1998 / Revised version: 4 June 1999     

Ray class fields generated by torsion points of certain elliptic curves

We first normalize the derivative Weierstrass ???-function appearing in the Weierstrass equations which give rise to analytic parametrizations of elliptic curves, by the Dedekind ??-function. And, by making use of this normalization of ???, we associate a certain elliptic curve to a given imaginary quadratic field K and then generate an infinite family of ray class fields over K by adjoining to K torsion points of such an elliptic curve. We further construct some ray class invariants of imaginary quadratic fields by utilizing singular values of the normalization of ???, as the y-coordinate in the Weierstrass equation of this elliptic curve, which would be a partial result towards the Lang?CSchertz conjecture of constructing ray class fields over K by means of the Siegel?CRamachandra invariant.     

Bounds for the size of integral points on curves of genus zero

Abstract. Let K be an algebraic number field and F(X, Y ) be an absolutelyirreducible polynomial of K[X, Y ] such that the curve defined by the equation F(X, Y ) = 0 is of genus 0 with at least threeinfinite valuations. In this paper we establish explicit upper bounds forthe size of integral solutions to the equation F(X, Y ) = 0 defined over K,improving significantly earlier estimates.     

The genus of curves over finite fields with many rational points

We prove the following result which was conjectured by Stichtenoth and Xing: letg be the genus of a projective, irreducible non-singular algebraic curve over the finite field and whose number of -rational points attains the Hasse-Weil bound; then either 4g≤(q−1)² or 2g=(q−1)q. Supported by a grant from the International Atomic Energy and UNESCOCorrespondence to: F. Torres This article was processed by the author using theLatex style file from Springer-Verlag.     

2-Weierstrass points of genus 3 hyperelliptic curves with extra involutions

We consider families of curves with extra automorphisms in ?₃, the moduli space of smooth hyperelliptic curves of genus g = 3. Such families of curves are explicitly determined in terms of the absolute invariants of binary octavics. For each family of positive dimension where |Aut (C)|>4, we determine the possible distributions of weights of 2-Weierstrass points.     

Relating decision and search algorithms for rational points on curves of higher genus

In the study of rational solutions to polynomial equations in two-variables, we show that an algorithmic solution to the decision problem (existence of solutions) enables one to construct a search algorithm for all solutions.