Relativistic Tidal Acceleration of Astrophysical Jets
Within the framework of general relativity, we investigate the tidal acceleration of astrophysical jets relative to the central collapsed configuration ("Kerr source"). To simplify matters, we neglect electromagnetic forces throughout; however, these must be included in a complete analysis. The rest frame of the Kerr source is locally defined via the set of hypothetical static observers in the spacetime exterior to the source.
Comparison results for nonlinear anisotropic parabolic problems
Comparison results for solutions to the Dirichlet problems for a class of nonlinear, anisotropic parabolic equations are established. These results are obtained through a semidiscretization method in time after providing estimates for solutions to anisotropic elliptic problems with zero-order terms.
Some error bounds for Gauss-Jacobi quadrature rules
We estimate the error of Gauss-Jacobi quadrature rule applied to a function f, which is supposed locally absolutely continuous in some Besov type spaces, or of bounded variation on [-1,1]. In the first case the error bound concerns the weighted main part phi-modulus of smoothness of f introduced by Z. Ditzian and V. Totik, while in the second case we deal with a Stieltjes integral with respect to f.
Stringent error estimates for one-dimensional, space-dependent 2 x 2 relaxation systems
Sharp and local L-1 a posteriori error estimates are established for so-called "well-balanced" BV (hence possibly discontinuous) numerical approximations of 2 x 2 space-dependent Jin-Xin relaxation systems under sub-characteristic condition.
Limits of fractional Orlicz-Sobolev spaces
Extended versions of the Bourgain-Brezis-Mironescu theorems on the limit as
s->1^- of the Gagliardo-Slobodeckij fractional seminorm are established in the
Orlicz space setting. The results hold for fractional Orlicz-Sobolev spaces built upon
general Young functions, as well. The case of Young functions with an asymptotic
linear growth is also considered in connection with the space of functions of bounded
variation.
An extended version of the Maz'ya-Shaposhnikova theorem on the limit as s->0^+
of the Gagliardo-Slobodeckij fractional seminorm is established in the Orlicz
space setting.
Local membrane length conservation in two-dimensional vesicle simulation using a multicomponent lattice Boltzmann equation method
We present a method for applying a class of velocity-dependent forces within a multicomponent lattice Boltzmann equation simulation that is designed to recover continuum regime incompressible hydrodynamics. This method is applied to the problem, in two dimensions, of constraining to uniformity the tangential velocity of a vesicle membrane implemented within a recent multicomponent lattice Boltzmann simulation method, which avoids the use of Lagrangian boundary tracers.
Quiet ionospheric d-region (Qiondr) model based on vlf/lf observations
The ionospheric D-region affects propagation of electromagnetic waves including ground-based signals and satellite signals during its intensive disturbances. Consequently, the modeling of electromagnetic propagation in the D-region is important in many technological domains. One of sources of uncertainty in the modeling of the disturbed D-region is the poor knowledge of its parameters in the quiet state at the considered location and time period.
A game-theoretic multi-stakeholder model for cost allocation in urban consolidation centres
Recently, many European local authorities have set up Urban Consolidation Centres (UCC) for dealing with challenges arising from the environmental and social impacts of logistical activities in urban contexts through shipment synchronisation and carrier coordination policies. However, the number of successful UCC projects led by local authorities in Europe is low, with most of the UCCs failing to achieve financial sustainability after the initial experimental phase, which is often heavily supported by public funds.