activity
20132026
collaborators

10 papers

math.NA2026

Physics-Informed Neural Network for Diffusion-Reaction Problems with Dead-Core Formation in Catalyst Slabs

Piotr Skrzypacz, Kaisar Tangirbergen, Jan Valdman

This work investigates a nonlinear two-point boundary value problem arising in diffusion--reaction processes in catalyst slabs with power-law kinetics and fractional reaction order…

math.NA2026

Geometry-induced formation and merging of multiple dead zones in diffusion-reaction problems

Piotr Skrzypacz, Boris Golman, Jan Valdman

This study focuses on dead-core solutions for a two-dimensional isothermal reaction-diffusion problem involving a single chemical reaction described by power-law kinetics within a…

math.AP2026

Sharp mean Hadamard inequalities and polyconvex integrands that give rise to convex functionals

Jonathan Bevan, Martin Kružík, Jan Valdman

We investigate several instances of the Hadamard inequality in the mean in two dimensions. As a consequence, we prove the uniqueness of minimizers of an integral functional with a…

math.NA2026

Numerical Algorithms for Partially Segregated Elliptic Systems

Farid Bozorgnia, Avetik Arakelyan, Vyacheslav Kungurtsev +1

We develop numerical methods for elliptic systems governed by a ternary partial-segregation constraint, in which three nonnegative components are required to have a vanishing point…

math.NA2025

On Josephy-Halley method for generalized equations

Tomáš Roubal, Jan Valdman

We extend the classical third-order Halley iteration to the setting of generalized equations of the form \[ 0 \in f(x) + F(x), \] where \(f\colon X\longrightarrow Y\) is twice cont…

math.AP2024

New applications of Hadamard-in-the-mean inequalities to incompressible variational problems

Jonathan Bevan, Martin Kružík, Jan Valdman

Let be the Dirichlet energy of a map belonging to the Sobolev space and let be a subclass of whose m…

math.OC2024

On semismooth path-following method and uniformity of strong metric subregularity at/around the reference point

Tomáš Roubal, Jan Valdman

This paper investigates a path-following method inspired by the semismooth approach for solving algebraic inclusions, with a primary emphasis on the role of uniform subregulari…

cs.MS2024

Minimization of Nonlinear Energies in Python Using FEM and Automatic Differentiation Tools

Michal Béreš, Jan Valdman

This contribution examines the capabilities of the Python ecosystem to solve nonlinear energy minimization problems, with a particular focus on transitioning from traditional MATLA…

math.AP2023

Hadamard's inequality in the mean

Jonathan Bevan, Martin Kružík, Jan Valdman

Let be a Lipschitz domain in and let . We investigate conditions under which the functional $$I_n(φ)=\int_Q |\nabla φ|^n+ f(x)\,\mathrm{det}…

math.NA2013

Verification of functional a posteriori error estimates for obstacle problem in 1D

Petr Harasim, Jan Valdman

We verify functional a posteriori error estimate for obstacle problem proposed by Repin. Simplification into 1D allows for the construction of a nonlinear benchmark for which an ex…