Matrix algebra preconditioners for multilevel Toeplitz systems do not insure optimal convergence rate D Noutsos, SS Capizzano, P Vassalos Theoretical Computer Science 315 (2-3), 557-579, 2004 | 57 | 2004 |

New band Toeplitz preconditioners for ill-conditioned symmetric positive definite Toeplitz systems D Noutsos, P Vassalos SIAM journal on matrix analysis and applications 23 (3), 728-743, 2002 | 33 | 2002 |

Preconditioners for fractional diffusion equations based on the spectral symbol N Barakitis, SE Ekström, P Vassalos Numerical Linear Algebra with Applications 29 (5), e2441, 2022 | 23 | 2022 |

A general tool for determining the asymptotic spectral distribution of Hermitian matrix-sequences C Garoni, S Serra-Capizzano, P Vassalos Oper. Matrices 9 (3), 549-561, 2015 | 23 | 2015 |

Spectral equivalence and matrix algebra preconditioners for multilevel Toeplitz systems: a negative result D Noutsos, SS Capizzano, P Vassalos Contemporary Mathematics 323, 313-322, 2003 | 23 | 2003 |

Essential spectral equivalence via multiple step preconditioning and applications to ill conditioned Toeplitz matrices D Noutsos, S Serra-Capizzano, P Vassalos Linear Algebra and its Applications 491, 276-291, 2016 | 17 | 2016 |

Superlinear convergence for PCG using band plus algebra preconditioners for Toeplitz systems D Noutsos, P Vassalos Computers & Mathematics with Applications 56 (5), 1255-1270, 2008 | 14 | 2008 |

A preconditioning proposal for ill‐conditioned Hermitian two‐level Toeplitz systems D Noutsos, SS Capizzano, P Vassalos Numerical linear algebra with applications 12 (2‐3), 231-239, 2005 | 13 | 2005 |

The conditioning of FD matrix sequences coming from semi-elliptic differential equations D Noutsos, SS Capizzano, P Vassalos Linear algebra and its applications 428 (2-3), 600-624, 2008 | 12 | 2008 |

Block band Toeplitz preconditioners derived from generating function approximations: analysis and applications D Noutsos, SS Capizzano, P Vassalos Numerische Mathematik 104 (3), 339-376, 2006 | 12 | 2006 |

Two-level Toeplitz preconditioning: approximation results for matrices and functions D Noutsos, SS Capizzano, P Vassalos SIAM Journal on Scientific Computing 28 (2), 439-458, 2006 | 12 | 2006 |

A matrix-less method to approximate the spectrum and the spectral function of Toeplitz matrices with real eigenvalues SE Ekström, P Vassalos Numerical Algorithms 89 (2), 701-720, 2022 | 8 | 2022 |

A policy iteration algorithm for the American put option and free boundary control problems EF Magirou, P Vassalos, N Barakitis Journal of Computational and Applied Mathematics 373, 112544, 2020 | 8 | 2020 |

Band plus algebra preconditioners for two-level Toeplitz systems D Noutsos, P Vassalos BIT Numerical Mathematics 51, 695-719, 2011 | 6 | 2011 |

A Matrix-Less Method to Approximate the spectrum and the spectral function of Toeplitz matrices with complex eigenvalues SE Ekström, P Vassalos arXiv preprint arXiv:1910.13810, 2019 | 5 | 2019 |

Asymptotic results on the condition number of FD matrices approximating semi-elliptic PDEs P Vassalos The Electronic Journal of Linear Algebra 34, 566-581, 2018 | 3 | 2018 |

Asymptotic behavior of the condition number of two-level Toeplitz matrix sequences D Noutsos, SS Capizzano, P Vassalos Linear algebra and its applications 395, 121-140, 2005 | 3 | 2005 |

Fast Toeplitz eigenvalue computations, joining interpolation-extrapolation matrix-less algorithms and simple-loop theory: The preconditioned setting M Bogoya, S Serra-Capizzano, P Vassalos Applied Mathematics and Computation 466, 128483, 2024 | 2 | 2024 |

From asymptotic distribution and vague convergence to uniform convergence, with numerical applications G Barbarino, SE Ekström, C Garoni, D Meadon, S Serra-Capizzano, ... arXiv preprint arXiv:2309.03662, 2023 | 2 | 2023 |

Matrix‐less methods for the spectral approximation of large non‐Hermitian Toeplitz matrices: A concise theoretical analysis and a numerical study M Bogoya, SE Ekström, S Serra‐Capizzano, P Vassalos Numerical Linear Algebra with Applications, e2545, 2024 | | 2024 |