The 18th GAMM ANLA Workshop was held from October 10 to 12, 2018, at the Backagårdens Kurs & Konferenscenter, Höör, Sweden. The scientific organizers were Philipp Birken (Lund University) and Elias Jarlebring (KTH Stockholm), and the local organizing committee from Lund University consisted of Philipp Birken, Claus Führer, and Lea Versbach. The workshop was well attended, with 42 participants from 9 countries.
The special emphasis of the workshop on linear algebra challenges in optimization was reflected in the three plenary talks of the invited speakers. Anders Forsgren (KTH Stockholm) gave a survey of how to solve symmetric systems of linear equations arising in optimization. In particular, he discussed how to deal with ill-conditioning that is inherent in augmented systems that occur in interior point methods. He also presented a recent application of interior point methods for optimization problems in intensity-modulated radiation therapy. Maya Neytcheva (Uppsala University) focussed on the deflation of small eigenvalues and corresponding eigenvectors in Krylov subspace methods. She showed how to compute all eigenvalues of Toeplitz matrices (up to machine accuracy) based on sampling the matrix symbol, and discussed approaches for computing the eigenvectors. Pontus Giselsson (Lund University) presented a general framework for analyzing the convergence of various optimization algorithms for large-scale convex optimization.
In addition to the three plenary talks there were 26 talks on a wide variety of topics in applied and numerical linear algebra given by participants. For example, Ion Victor Gosea (MPI Magdeburg) presented the application of several numerical linear algebra tools to improve the algorithmic cost of Loewner interpolation in model order reduction. Lana Perisa (EPFL) talked about techniques to low-rank recompression techniques for Hadamard products arising in iterative methods, such as the Lanczos method and randomized algorithms. Lea Versbach (Lund University) presented work on multigrid preconditioners for discontinuous Galerkin methods, using optimized Runge-Kutta and W-smoothers. Many talks were devoted to numerical software, with Python and Julia featuring prominently as popular programming languages. The workshop schedule is available here: Lund2018.
During the business meeting, Jörg Liesen and Stefan Güttel were re-elected as chair and vice-chair, respectively, of the GAMM ANLA activity group for a new 3-year term starting January 1, 2019. The GAMM ANLA Workshop 2019 is planned to take place at TU Chemnitz.