This question is a reposting of a comment I made on http://mathoverflow.net/questions/9731/polynomial-representing-all-nonnegative-integers. Let $f(x,y)\in \mathbb Q[x,y]$ such that $f(\mathbb Z\times \mathbb Z)$ is a subset of $\mathbb N$ (the nonnegative integers). Let $g(n)$ be the number of elements of $f(\mathbb Z\times \mathbb Z)\cap \lbrace 0,1,\dots, n\rbrace$. How fast can $g(n)$ grow? Is it always true that $g(n)=O(n/\sqrt{\log(n)})$? If true this is best possible since if $f(x,y)=x^2+y^2$ then $g(n)\sim cn/\sqrt{\log(n)})$cn/\sqrt{\log(n)}$.
|
2 | deleted 1 characters in body | ||
|
|
||||
|
|
1 |
|
||
Density of values of polynomials in two variablesThis question is a reposting of a comment I made on http://mathoverflow.net/questions/9731/polynomial-representing-all-nonnegative-integers. Let $f(x,y)\in \mathbb Q[x,y]$ such that $f(\mathbb Z\times \mathbb Z)$ is a subset of $\mathbb N$ (the nonnegative integers). Let $g(n)$ be the number of elements of $f(\mathbb Z\times \mathbb Z)\cap \lbrace 0,1,\dots, n\rbrace$. How fast can $g(n)$ grow? Is it always true that $g(n)=O(n/\sqrt{\log(n)})$? If true this is best possible since if $f(x,y)=x^2+y^2$ then $g(n)\sim cn/\sqrt{\log(n)})$.
|
||||
