Published online by Cambridge University Press: 06 March 2015
Let ${\it\mu}_{1},\ldots ,{\it\mu}_{s}$ be real numbers, with
${\it\mu}_{1}$ irrational. We investigate sums of shifted
$k$th powers
$\mathfrak{F}(x_{1},\ldots ,x_{s})=(x_{1}-{\it\mu}_{1})^{k}+\cdots +(x_{s}-{\it\mu}_{s})^{k}$. For
$k\geqslant 4$, we bound the number of variables needed to ensure that if
${\it\eta}$ is real and
${\it\tau}>0$ is sufficiently large then there exist integers
$x_{1}>{\it\mu}_{1},\ldots ,x_{s}>{\it\mu}_{s}$ such that
$|\mathfrak{F}(\mathbf{x})-{\it\tau}|<{\it\eta}$. This is a real analogue to Waring’s problem. When
$s\geqslant 2k^{2}-2k+3$, we provide an asymptotic formula. We prove similar results for sums of general univariate degree-
$k$ polynomials.