Fast Algorithms with Applications to PDEs

*Correspondence: [email protected] Department of Applied Mechanics, Chalmers University of Technology, Hörsalsvägen 7, 412 96 Göteborg, Sweden Abstract Background: Seepage in porous media is modeled as a Stokes flow in an open pore system contained in a rigid, impermeable and spatially periodic matrix. By homogenization, the problem is turned into a two-scale problem consisting of a Da...

i dAj dt + γ|Aj |Aj + ε(Aj+1 + Aj−1) = 0, (1) where i = √−1, the index j ranges over the 1D lattice. The lattice may be infinite (j = 0,±1,±2, . . .) or finite (j = 1, 2, . . . , f). In the latter case one usually assumes periodic boundary conditions, Aj+f = Aj . The quantity Aj = Aj(t) is the complex mode amplitude of the oscillator at site j, and γ is a anharmonic parameter. The connection wi...

– We study in d = 3 dimensions the short-range Ising spin glass with Jij = ±1 couplings and periodic boundary conditions at T = 0. We show that the overlap distribution is non-trivial in the limit of large system size. Introduction. – There has been an upsurge of interest in the Edwards-Anderson model [1] of the short-range Ising spin glass with binary couplings,

The Casimir forces on two parallel plates in conformally flat domain wall background due to conformally coupled massless scalar field satisfying mixed boundary conditions on the plates is investigated. In the general case of mixed boundary conditions formulae are derived for the vacuum expectation values of the energy-momentum tensor and vacuum forces acting on boundaries.

In this article we study the exact controllability of a one-dimensional wave equation with mixed boundary conditions in a non-cylindrical domain. The fixed endpoint has a Dirichlet-type boundary condition, while the moving end has a Neumann-type condition. When the speed of the moving endpoint is less than the characteristic speed, the exact controllability of this equation is established by Hi...

We discuss solutions of the one-dimensional telegrapher’s equation in the presence of boundary conditions. We revisit the case of a radiation boundary condition and obtain an alternative expression for the already known Green’s function. Furthermore, we formulate a backreaction boundary condition, which has been widely used in the context of diffusion-controlled reversible reactions, for a one-...