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A stochastic phase-field model determined from molecular dynamics

Erik von Schwerin, Anders Szepessy (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

The dynamics of dendritic growth of a crystal in an undercooled melt is determined by macroscopic diffusion-convection of heat and by capillary forces acting on the nanometer scale of the solid-liquid interface width. Its modelling is useful for instance in processing techniques based on casting. The phase-field method is widely used to study evolution of such microstructural phase transformations on a continuum level; it couples the energy equation to a phenomenological Allen-Cahn/Ginzburg-Landau equation...

Attractors of Strongly Dissipative Systems

A. G. Ramm (2009)

Bulletin of the Polish Academy of Sciences. Mathematics

A class of infinite-dimensional dissipative dynamical systems is defined for which there exists a unique equilibrium point, and the rate of convergence to this point of the trajectories of a dynamical system from the above class is exponential. All the trajectories of the system converge to this point as t → +∞, no matter what the initial conditions are. This class consists of strongly dissipative systems. An example of such systems is provided by passive systems in network theory (see, e.g., MR0601947...

Bulk superconductivity in Type II superconductors near the second critical field

Soren Fournais, Bernard Helffer (2010)

Journal of the European Mathematical Society

We consider superconductors of Type II near the transition from the ‘bulk superconducting’ to the ‘surface superconducting’ state. We prove a new L estimate on the order parameter in the bulk, i.e. away from the boundary. This solves an open problem posed by Aftalion and Serfaty [AS].

Cauchy problem for the complex Ginzburg-Landau type Equation with L p -initial data

Daisuke Shimotsuma, Tomomi Yokota, Kentarou Yoshii (2014)

Mathematica Bohemica

This paper gives the local existence of mild solutions to the Cauchy problem for the complex Ginzburg-Landau type equation u t - ( λ + i α ) Δ u + ( κ + i β ) | u | q - 1 u - γ u = 0 in N × ( 0 , ) with L p -initial data u 0 in the subcritical case ( 1 q < 1 + 2 p / N ), where u is a complex-valued unknown function, α , β , γ , κ , λ > 0 , p > 1 , i = - 1 and N . The proof is based on the L p - L q estimates of the linear semigroup { exp ( t ( λ + i α ) Δ ) } and usual fixed-point argument.

Dynamique des points vortex dans une équation de Ginzburg-Landau complexe

Evelyne Miot (2009/2010)

Séminaire Équations aux dérivées partielles

On considère une équation de Ginzburg-Landau complexe dans le plan. On étudie un régime asymptotique à petit paramètre dans lequel les solutions comportent des singularités ponctuelles, appelées points vortex, et on détermine un système d’équations différentielles ordinaires du premier ordre décrivant la dynamique de ces points jusqu’au premier temps de collision.

Global solution to a generalized nonisothermal Ginzburg-Landau system

Nesrine Fterich (2010)

Applications of Mathematics

The article deals with a nonlinear generalized Ginzburg-Landau (Allen-Cahn) system of PDEs accounting for nonisothermal phase transition phenomena which was recently derived by A. Miranville and G. Schimperna: Nonisothermal phase separation based on a microforce balance, Discrete Contin. Dyn. Syst., Ser. B, 5 (2005), 753–768. The existence of solutions to a related Neumann-Robin problem is established in an N 3 -dimensional space setting. A fixed point procedure guarantees the existence of solutions...

Landau-Ginzburg models in real mirror symmetry

Johannes Walcher (2011)

Annales de l’institut Fourier

In recent years, mirror symmetry for open strings has exhibited some new connections between symplectic and enumerative geometry (A-model) and complex algebraic geometry (B-model) that in a sense lie between classical and homological mirror symmetry. I review the rôle played in this story by matrix factorizations and the Calabi-Yau/Landau-Ginzburg correspondence.

Low-Dimensional Description of Pulses under the Action of Global Feedback Control

Y. Kanevsky, A. A. Nepomnyashchy (2012)

Mathematical Modelling of Natural Phenomena

The influence of a global delayed feedback control which acts on a system governed by a subcritical complex Ginzburg-Landau equation is considered. The method based on a variational principle is applied for the derivation of low-dimensional evolution models. In the framework of those models, one-pulse and two-pulse solutions are found, and their linear stability analysis is carried out. The application of the finite-dimensional model allows to reveal...

Magnetic vortices for a Ginzburg-Landau type energy with discontinuous constraint

Ayman Kachmar (2010)

ESAIM: Control, Optimisation and Calculus of Variations

This paper is devoted to an analysis of vortex-nucleation for a Ginzburg-Landau functional with discontinuous constraint. This functional has been proposed as a model for vortex-pinning, and usually accounts for the energy resulting from the interface of two superconductors. The critical applied magnetic field for vortex nucleation is estimated in the London singular limit, and as a by-product, results concerning vortex-pinning and boundary conditions on the interface are obtained.

On the Lawrence–Doniach model of superconductivity: magnetic fields parallel to the axes

Stan Alama, Lia Bronsard, Etienne Sandier (2012)

Journal of the European Mathematical Society

We consider periodic minimizers of the Lawrence–Doniach functional, which models highly anisotropic superconductors with layered structure, in the simultaneous limit as the layer thickness tends to zero and the Ginzburg–Landau parameter tends to infinity. In particular, we consider the properties of minimizers when the system is subjected to an external magnetic field applied either tangentially or normally to the superconducting planes. For normally applied fields, our results show that the resulting...

Patterns and Waves Generated by a Subcritical Instability in Systems with a Conservation Law under the Action of a Global Feedback Control

Y. Kanevsky, A.A. Nepomnyashchy (2010)

Mathematical Modelling of Natural Phenomena

A global feedback control of a system that exhibits a subcritical monotonic instability at a non-zero wavenumber (short-wave, or Turing instability) in the presence of a zero mode is investigated using a Ginzburg-Landau equation coupled to an equation for the zero mode. The method based on a variational principle is applied for the derivation of a low-dimensional evolution model. In the framework of this model the investigation of the system’s dynamics...

Solutions with vortices of a semi-stiff boundary value problem for the Ginzburg–Landau equation

Leonid Berlyand, Volodymyr Rybalko (2010)

Journal of the European Mathematical Society

We study solutions of the 2D Ginzburg–Landau equation - Δ u + ε - 2 u ( | u | 2 - 1 ) = 0 subject to “semi-stiff” boundary conditions: Dirichlet conditions for the modulus, | u | = 1 , and homogeneous Neumann conditions for the phase. The principal result of this work shows that there are stable solutions of this problem with zeros (vortices), which are located near the boundary and have bounded energy in the limit of small ε . For the Dirichlet boundary condition (“stiff” problem), the existence of stable solutions with vortices, whose energy...

Sur l'équation de Ginzburg-Landau avec champ magnétique

Sylvia Serfaty (1998)

Journées équations aux dérivées partielles

On étudie la fonctionnelle d’énergie de Ginzburg-Landau J ( u , A ) = 1 2 Ω | A u | 2 + | h - h e x | 2 + κ 2 2 ( 1 - | u | 2 ) 2 , qui modélise les supraconducteurs cylindriques soumis à un champ magnétique extérieur h e x , dans l’asymptotique κ . On trouve et on décrit des branches de solutions stables des équations associées. On a une estimation sur la valeur critique H c 1 ( κ ) de h e x correspondant à une «transition de phase» où des vortex (c.à.d. zéros de u ) deviennent énergétiquement favorables. On obtient également dans le cas d’un disque, que pour h e x H c 1 comme pour h e x H c 1 , il existe à la...

Symmetry of local minimizers for the three-dimensional Ginzburg–Landau functional

Vincent Millot, Adriano Pisante (2010)

Journal of the European Mathematical Society

We classify nonconstant entire local minimizers of the standard Ginzburg–Landau functional for maps in H loc 1 ( 3 ; 3 ) satisfying a natural energy bound. Up to translations and rotations,such solutions of the Ginzburg–Landau system are given by an explicit solution equivariant under the action of the orthogonal group.

Systems with Coulomb interactions

Sylvia Serfaty (2014)

Journées Équations aux dérivées partielles

Systems with Coulomb and logarithmic interactions arise in various settings: an instance is the classical Coulomb gas which in some cases happens to be a random matrix ensemble, another is vortices in the Ginzburg-Landau model of superconductivity, where one observes in certain regimes the emergence of densely packed point vortices forming perfect triangular lattice patterns named Abrikosov lattices, a third is the study of Fekete points which arise in approximation theory. In this review, we describe...

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