On the Number of Perfect Binary Quadratic Forms
Aicardi, Francesca
Experiment. Math., Tome 13 (2004) no. 1, p. 451-457 / Harvested from Project Euclid
A perfect form is a form {\small $f=mx^2+ny^2+kxy$} with integral coefficients {\small $(m,n,k)$} such that {\small $f(\mathbb{Z}^2)$} is a multiplicative semigroup. The growth rate of the number of perfect forms in cubes of increasing side {\small $L$} in the space of the coefficients is known for small cubes, where all perfect forms are known. A form is perfect if its coefficients belong to the image of a map, {\small $Q$}, from {\small $\mathbb{Z}^4$} to {\small $\mathbb{Z}^3$}. This property of perfect forms allows us to estimate from below the growth rate of their number for larger values of {\small $L$}. The conjecture that all perfect forms are generated by {\small $Q$} allows us to reformulate results and conjectures on the numbers of the images {\small $Q(\mathbb{Z}^4)$} in cubes of side {\small $L$} in terms of the numbers of perfect forms. In particular, the proportion of perfect elliptic forms in a ball of radius {\small $R$} should decrease faster than {\small $R^{-3/4}$} and the proportion of all perfect forms in a ball of radius {\small $R$} should decrease faster than {\small $2/\sqrt{R}$}.
Publié le : 2004-05-14
Classification:  Quadratic forms,  multiplicative semigroups,  11E12,  11N99
@article{1109106437,
     author = {Aicardi, Francesca},
     title = {On the Number of Perfect Binary Quadratic Forms},
     journal = {Experiment. Math.},
     volume = {13},
     number = {1},
     year = {2004},
     pages = { 451-457},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1109106437}
}
Aicardi, Francesca. On the Number of Perfect Binary Quadratic Forms. Experiment. Math., Tome 13 (2004) no. 1, pp.  451-457. http://gdmltest.u-ga.fr/item/1109106437/