We study the evolution of the global stellar mass density in a Λ cold dark matter (CDM) universe using two different types of hydrodynamical simulations (Eulerian TVD and SPH) and the analytical model of Hernquist & Springel (2003). We find that the theoretical calculations all predict both a higher stellar mass density at z ∼ 3 than indicated by current observations, and that the peak of the c...

The Lax-Wendro↵ time discretization is an alternative method to the popular total variation diminishing Runge-Kutta time discretization of discontinuous Galerkin schemes for the numerical solution of hyperbolic conservation laws. The resulting fully discrete schemes are known as LWDG and RKDG methods, respectively. Although LWDG methods are in general more compact and e cient than RKDG methods ...

Acoustic wave propagation in a one-dimensional waveguide connected with Helmholtz resonators is studied numerically. Finite amplitude waves and viscous boundary layers are considered. The model consists of two coupled evolution equations: a nonlinear PDE describing nonlinear acoustic waves, and a linear ODE describing the oscillations in the Helmholtz resonators. The thermal and viscous losses ...

Aims. We have performed a comprehensive parameter study of the collapse of rotating, strongly magnetized stellar cores in axisymmetry to determine their gravitational wave signature based on the Einstein quadrupole formula. Methods. We use a Newtonian explicit magnetohydrodynamic Eulerian code based on the relaxing-TVD method for the solution of the ideal MHD equations, and apply the constraint...

Unsteady interfacial problems, considered in an Eulerian form, are studied. The phenomena are modeled using the incompressible viscous Navier–Stokes equations to get the velocity field and an advection equation to predict interface evolutions. The momentum equation is solved by means of an implicit hybrid augmented Lagrangian–Projection method, whereas an explicit characteristic method coupled ...

We address the fine-grained control of information flow between distributed applications to protect transactions. Confining transactions in distributed untrusted environments is crucial for Web services, distributed computing, and most e-commerce applications relying on those technologies. Applications must be protected from rogue peer applications but at the same time applications need to comm...

[1] Physics‐based global magnetosphere modeling requires large computational resources. It is still impractical to resolve the computational domain to the point where numerical errors become negligible. One possible way of reducing numerical diffusion is the “Boris correction”: the semirelativistic magnetohydrodynamics equations are solved with an artificially reduced speed of light. Here we in...

This paper presents a class of new second-order accurate (IK + 3)-point explicit schemes for the computation of weak solutions of hyperbolic conservation laws, that are total-variation-diminishing under a CFL restriction of K. These highly nonlinear schemes are obtained by applying a nonoscillatory first-order accurate (IK + l)-point scheme to a modified flux. The so-derived second-order accura...

Time varying parameter (TVP) models have enjoyed an increasing popularity in empirical macroeconomics. However, TVP models are parameter-rich and risk over-…tting unless the dimension of the model is small. Motivated by this worry, this paper proposes several Time Varying dimension (TVD) models where the dimension of the model can change over time, allowing for the model to automatically choose...

A vertex centred Finite Volume algorithm is presented for the numerical simulation of fast transient dynamics problems involving large deformations. A mixed formulation based upon the use of the linear momentum, the deformation gradient tensor and the total energy as conservation variables is discretised in space using linear triangles and tetrahedra in two-dimensional and three-dimensional com...