@article{Kanevsky:190461,
      title = {Idempotent filtering in spectral and spectral element  methods},
      author = {Kanevsky, Alex and Carpenter, Mark H. and Hesthaven, Jan  S.},
      publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE},
      journal = {Journal of Computational Physics},
      number = {1},
      volume = {220},
      pages = {41-58},
      year = {2006},
      abstract = {The comparison of numerical results for implicit-explicit  and fully explicit Runge-Kutta time integration methods for  a nozzle flow problem shows that filtering can  significantly degrade the accuracy of the numerical  solution for long-time integration problems. We demonstrate  analytically and numerically that filtering-in-time errors  become additive for parallel to u(N)(x, t + k Delta t) -  u(N)(x, t)parallel to << parallel to u(N)(x, t)parallel to  when nonidempotent filters are used, and suggest the  development and implementation of idempotent filters. (c)  2006 Elsevier Inc. All rights reserved.},
}