1,855 research outputs found
Some heuristics about elliptic curves
We give some heuristics for counting elliptic curves with certain properties.
In particular, we re-derive the Brumer-McGuinness heuristic for the number of
curves with positive/negative discriminant up to , which is an application
of lattice-point counting. We then introduce heuristics (with refinements from
random matrix theory) that allow us to predict how often we expect an elliptic
curve with even parity to have . We find that we expect there to
be about curves with with even parity
and positive (analytic) rank; since Brumer and McGuinness predict
total curves, this implies that asymptotically almost all even parity curves
have rank 0. We then derive similar estimates for ordering by conductor, and
conclude by giving various data regarding our heuristics and related questions
Rank distribution in a family of cubic twists
In 1987, Zagier and Kramarz published a paper in which they presented
evidence that a positive proportion of the even-signed cubic twists of the
elliptic curve should have positive rank. We extend their data,
showing that it is more likely that the proportion goes to zero
Some remarks on Heegner point computations
We explain how to find a rational point on a rational elliptic curve of rank
1 using Heegner points. We give some examples, and list new algorithms that are
due to Cremona and Delaunay. These are notes from a short course given at the
Institut Henri Poincare in December 2004
Explicit lower bounds on the modular degree of an elliptic curve
We derive an explicit zero-free region for symmetric square L-functions of
elliptic curves, and use this to derive an explicit lower bound for the modular
degree of rational elliptic curves. The techniques are similar to those used in
the classical derivation of zero-free regions for Dirichlet L-functions, but
here, due to the work of Goldfield-Hoffstein-Lieman, we know that there are no
Siegel zeros, which leads to a strengthened result
Cross-middleware Interoperability in Distributed Concurrent Engineering
Secure, distributed collaboration between different organizations is a key challenge in Grid computing today. The GDCD project has produced a Grid-based demonstrator Virtual Collaborative Facility (VCF) for the European Space Agency. The purpose of this work is to show the potential of Grid technology to support fully distributed concurrent design, while addressing practical considerations including network security, interoperability, and integration of legacy applications. The VCF allows domain engineers to use the concurrent design methodology in a distributed fashion to perform studies for future space missions. To demonstrate the interoperability and integration capabilities of Grid computing in concurrent design, we developed prototype VCF components based on ESAâs current Excel-based Concurrent Design Facility (a non-distributed environment), using a STEP-compliant database that stores design parameters. The database was exposed as a secure GRIA 5.1 Grid service, whilst a .NET/WSE3.0-based library was developed to enable secure communication between the Excel client and STEP database
Secondary terms in the number of vanishings of quadratic twists of elliptic curve L-functions
We examine the number of vanishings of quadratic twists of the L-function
associated to an elliptic curve. Applying a conjecture for the full asymptotics
of the moments of critical L-values we obtain a conjecture for the first two
terms in the ratio of the number of vanishings of twists sorted according to
arithmetic progressions.Comment: 16 pages, many figure
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