@article{34886,
  abstract     = {{We give asymptotic upper and lower bounds for the number of squarefree d (0 < d ≤ X) such that the equation x² − dy²= −1 is solvable. These estimates, as usual, can equivalently be interpreted in terms of real quadratic fields with a fundamental unit with norm −1 and give strong evidence in the direction of a conjecture due to P. Stevenhagen.}},
  author       = {{Fouvry, Étienne and Klüners, Jürgen}},
  issn         = {{0003-486X}},
  journal      = {{Annals of Mathematics}},
  keywords     = {{Statistics, Probability and Uncertainty, Mathematics (miscellaneous)}},
  number       = {{3}},
  pages        = {{2035--2104}},
  publisher    = {{Annals of Mathematics}},
  title        = {{{On the negative Pell equation}}},
  doi          = {{10.4007/annals.2010.172.2035}},
  volume       = {{172}},
  year         = {{2010}},
}