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A universal property of C 0 -semigroups

Gerd Herzog, Christoph Schmoeger (2009)

Commentationes Mathematicae Universitatis Carolinae

Let T : [ 0 , ) L ( E ) be a C 0 -semigroup with unbounded generator A : D ( A ) E . We prove that ( T ( t ) x - x ) / t has generically a very irregular behaviour for x D ( A ) as t 0 + .

A useful algebra for functional calculus

Mohammed Hemdaoui (2019)

Mathematica Bohemica

We show that some unital complex commutative LF-algebra of 𝒞 ( ) -tempered functions on + (M. Hemdaoui, 2017) equipped with its natural convex vector bornology is useful for functional calculus.

A variational approach to bifurcation in reaction-diffusion systems with Signorini type boundary conditions

Jamol I. Baltaev, Milan Kučera, Martin Väth (2012)

Applications of Mathematics

We consider a simple reaction-diffusion system exhibiting Turing's diffusion driven instability if supplemented with classical homogeneous mixed boundary conditions. We consider the case when the Neumann boundary condition is replaced by a unilateral condition of Signorini type on a part of the boundary and show the existence and location of bifurcation of stationary spatially non-homogeneous solutions. The nonsymmetric problem is reformulated as a single variational inequality with a potential...

A variational approach to bifurcation points of a reaction-diffusion system with obstacles and Neumann boundary conditions

Jan Eisner, Milan Kučera, Martin Väth (2016)

Applications of Mathematics

Given a reaction-diffusion system which exhibits Turing's diffusion-driven instability, the influence of unilateral obstacles of opposite sign (source and sink) on bifurcation and critical points is studied. In particular, in some cases it is shown that spatially nonhomogeneous stationary solutions (spatial patterns) bifurcate from a basic spatially homogeneous steady state for an arbitrarily small ratio of diffusions of inhibitor and activator, while a sufficiently large ratio is necessary in the...

A viability result for nonconvex semilinear functional differential inclusions

Vasile Lupulescu, Mihai Necula (2005)

Discussiones Mathematicae, Differential Inclusions, Control and Optimization

We establish some sufficient conditions in order that a given locally closed subset of a separable Banach space be a viable domain for a semilinear functional differential inclusion, using a tangency condition involving a semigroup generated by a linear operator.

A Viscoelastic Frictionless Contact Problem with Adhesion

Arezki Touzaline (2015)

Bulletin of the Polish Academy of Sciences. Mathematics

We consider a mathematical model which describes the equilibrium between a viscoelastic body in frictionless contact with an obstacle. The contact is modelled with normal compliance, associated with Signorini's conditions and adhesion. The adhesion is modelled with a surface variable, the bonding field, whose evolution is described by a first-order differential equation. We establish a variational formulation of the mechanical problem and prove the existence and uniqueness of the weak solution....

A viscosity-proximal gradient method with inertial extrapolation for solving certain minimization problems in Hilbert space

L.O. Jolaoso, H.A. Abass, O.T. Mewomo (2019)

Archivum Mathematicum

In this paper, we study the strong convergence of the proximal gradient algorithm with inertial extrapolation term for solving classical minimization problem and finding the fixed points of δ -demimetric mapping in a real Hilbert space. Our algorithm is inspired by the inertial proximal point algorithm and the viscosity approximation method of Moudafi. A strong convergence result is achieved in our result without necessarily imposing the summation condition n = 1 β n x n - 1 - x n < + on the inertial term. Finally, we provide...

A way of estimating the convergence rate of the Fourier method for PDE of hyperbolic type

Evgenii Pustylnik (2001)

Czechoslovak Mathematical Journal

The Fourier expansion in eigenfunctions of a positive operator is studied with the help of abstract functions of this operator. The rate of convergence is estimated in terms of its eigenvalues, especially for uniform and absolute convergence. Some particular results are obtained for elliptic operators and hyperbolic equations.

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