Zobrazeno 1 - 10
of 6 559
pro vyhledávání: '"A. Führer"'
Autor:
Führer, Thomas, Gantner, Gregor
We develop Aubin--Nitsche-type estimates for recently proposed first-order system least-squares finite element methods (FOSLS) for the heat equation. Under certain assumptions, which are satisfied if the spatial domain is convex and the heat source a
Externí odkaz:
http://arxiv.org/abs/2412.04651
We develop couplings of a recent space-time first-order system least-squares (FOSLS) method for parabolic problems and space-time boundary element methods (BEM) for the heat equation to numerically solve a parabolic transmission problem on the full s
Externí odkaz:
http://arxiv.org/abs/2409.14449
Autor:
Führer, Thomas, Fuica, Francisco
Mixed variational formulations for the first-order system of the elastic membrane obstacle problem and the second-order system of the Kirchhoff--Love plate obstacle problem are proposed. The force exerted by the rigid obstacle is included as a new un
Externí odkaz:
http://arxiv.org/abs/2406.09605
Autor:
Conlon, David, Führer, Jakob
We show that for every non-spherical set $X$ in $\mathbb{E}^d$, there exists a natural number $m$ and a red/blue-colouring of $\mathbb{E}^n$ for every $n$ such that there is no red copy of X and no blue progression of length $m$ with each consecutive
Externí odkaz:
http://arxiv.org/abs/2406.07718
Autor:
Führer, Jakob, Solymosi, Jozsef
Let $H_n^{(3)}$ be a 3-uniform linear hypergraph, i.e. any two edges have at most one vertex common. A special hypergraph, {\em wicket}, is formed by three rows and two columns of a $3 \times 3$ point matrix. In this note, we give a new lower bound o
Externí odkaz:
http://arxiv.org/abs/2405.00923
Autor:
Führer, Thomas, Sánchez, Manuel A.
We design quasi-interpolation operators based on piecewise polynomial weight functions of degree less than or equal to $p$ that map into the space of continuous piecewise polynomials of degree less than or equal to $p+1$. We show that the operators h
Externí odkaz:
http://arxiv.org/abs/2404.13183
Autor:
Führer, Thomas, Paredes, Diego
For a reaction-dominated diffusion problem we study a primal and a dual hybrid finite element method where weak continuity conditions are enforced by Lagrange multipliers. Uniform robustness of the discrete methods is achieved by enriching the local
Externí odkaz:
http://arxiv.org/abs/2404.12956
Autor:
Führer, Jakob
For a prime $p$ we construct a subset of $\mathbb{F}_p^{(k^2-k)/2}$ of size $p^{(k^2-k)/2-1}$ that does not contain progressions of length $k$. More generally, we show that for any prime power $q$ there is a subset of $\mathbb{F}_q^{(k^2-k)/2}$ of si
Externí odkaz:
http://arxiv.org/abs/2403.18611
Autor:
Führer, Jakob, Tóth, Géza
Publikováno v:
European Journal of Combinatorics, Volume 125, 2025, 104105
Conlon and Wu showed that there is a red/blue-coloring of $\mathbb{E}^n$ that does not contain $3$ red collinear points separated by unit distance and $m=10^{50}$ blue collinear points separated by unit distance. We prove that the statement holds wit
Externí odkaz:
http://arxiv.org/abs/2402.12567
We study a first-order system formulation of the (acoustic) wave equation and prove that the operator of this system is an isomorphsim from an appropriately defined graph space to L^2. The results rely on well-posedness and stability of the weak and
Externí odkaz:
http://arxiv.org/abs/2311.10536