Abstract:
Scientific computing is routinely assisting in the design of systems or components, which have potentially very complex shapes. In these situations, it is often underestimated that the mesh generation process takes the overwhelming portion of the overall analysis and design cycle. If high order discretizations are sought, the situation is even more critical. Methods that could ease these limitations are of great importance, since they could more effectively interface with meta-algorithms from Optimization, Uncertainty Quantification, Reduced Order Modeling, Machine Learning, and Artificial Neural Networks, in large-scale applications.Recently, immersed/embedded/unfitted boundary finite element methods (cutFEM, Finite Cell Method, Immerso-Geometric Analysis, etc.) have been proposed for this purpose, since they obviate the burden of body-fitted meshing. Unfortunately, most unfitted finite element methods are also difficult to implement due to: (a) the need to perform complex cell cutting operations at boundaries, (b) the necessity of specialized quadrature formulas on cut elements, and (c) the consequences that these operations may have on the overall conditioning/stability of the ensuing algebraic problems. This talk introduces a simple, stable, and accurate unfitted boundary method, named “Shifted Boundary Method” (SBM), which eliminates the need to perform cell cutting operations. Boundary conditions are imposed on the boundary of a “surrogate” discrete computational domain, specifically constructed to avoid cut elements. Appropriate field extension operators are then constructed by way of Taylor expansions (or similar operators), with the purpose of preserving accuracy when imposing boundary conditions. An extension of the SBM to higher order discretizations will also be presented, together with a summary of the numerical analysis results.The SBM belongs to the broader class of Approximate Boundary Methods, a less explored or somewhat forgotten class of algorithms, which however might have an important role in the future of scientific computing. The performance of the SBM is tested on large-scale problems selected from linear and nonlinear elasticity, fluid mechanics, shallow water flows, thermos-mechanics, porous media flow, and fracture mechanics.

16:30 • ETH Zentrum, Rämistrasse 101, Zürich, Building HG, Room E 1.2

Thursday, April 25

EPF Lausanne

Talks in Actuarial Mathematics

Simone Padoan (Bocconi University, Milan)

Some advances on likelihood-based inference arising from the Peaks Over Threshold method abstract

14:00 • EPF Lausanne, Anthropole 2102

EPF Lausanne

Groups, Arithmetic and Algebraic Geometry Seminar

Anna Medvekovsky (MPI Bonn)

Modular forms mod 3 of level one abstract

14:15 • EPF Lausanne, CM 1 517

Université de Genève

Séminaire de Topologie et Géométrie

Nicolas Orantin (UniGe)

From Catalan numbers to knot invariants: a short introduction to topological recursion abstract

14:15 • Université de Genève, Conseil Général 7-9, Room 1-15

Universität Zürich

PDE and Mathematical Physics

Dr. Louise Gassot (CNRS IRMAR)

Zero-dispersion limit for the Benjamin-Ono Equation abstract

16:15 • UZH Irchel, Winterthurerstrasse 190, Zürich, Building Y27, Room H 46

ETH Zürich

Talks in Financial and Insurance Mathematics

Dr. Xinwei Shen (ETH Zürich)

Causality-oriented robustness: exploiting general additive interventions abstract

17:15 • ETH Zentrum, Rämistrasse 101, Zürich, Building HG, Room G 43

Friday, April 26

Université de Genève

Séminaire de Mathématique Physique

Paul Norbury (Melbourne)

Volumes of moduli spaces of super hyperbolic surfaces abstract

10:30 • Université de Genève, Conseil Général 7-9, Room 1-05

Universität Basel

Seminar in Numerical Analysis

Malte Peter (University of Augsburg)

Identification of microstructural information from macroscopic boundary measurements in linear elasticity abstract

11:00 • Universität Basel

ETH Zürich

Number Theory Seminar

Dr. Julian Demeio (University of Bath)

The Grunwald Problem for solvable groups abstract

14:15 • ETH Zentrum, Rämistrasse 101, Zürich, Building HG, Room G 43

EPF Lausanne

Seminar of Analysis

Eric Séré (University Paris-Dauphine)

The ground state of the Dirac-Fock energy abstract

15:15 • EPF Lausanne, MA A1 10

ETH Zürich

Research Seminar in Statistics

Richard De Veaux (Williams College)

The Seven Deadly Sins of Data Science abstract

15:15 • ETH Zentrum, Rämistrasse 101, Zürich, Building HG, Room G 19.1

EPF Lausanne

Statistics Seminar

Linbo Wang (University of Toronto)

Sparse Causal Learning abstract

16:00 • EPF Lausanne, CM 1 517

ETH Zürich

Algebraic Geometry and Moduli Seminar

Aitor Iribar Lopez (ETH Zürich)

Morphisms between Hermitian domains and applications to enumerative geometry abstract

16:00 • ETH Zentrum, Rämistrasse 101, Zürich, Building HG, Room G 43

address: Alessandra Naldi Windler, Departement Mathematik, HG G 51.4, ETH Zurich, Raemistrasse 101, CH-8092 Zurich
email: bulletin@math.ch | phone: +41 44 632 3684 | url: https://math.ch

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