The conditions for disk evaporation by electron thermal conduction are examined, using a simplified semi–analytical 1-D model. The model is based on the mechanism proposed by Meyer & Meyer–Hofmeister (1994) in which an advection dominated accretion flow evaporates the top layers from the underlying disk by thermal conduction. The evaporation rate is calculated as a function of the density of th...

The positive semidefinite Procrustes (PSDP) problem is the following: given rectangular matrices X and B, find the symmetric positive semidefinite matrix A that minimizes the Frobenius norm of AX − B. No general procedure is known that gives an exact solution. In this paper, we present a semi-analytical approach to solve the PSDP problem. First, we characterize completely the set of optimal sol...

This note is concerned with a semi-analytical method for the solution of 2-D Helmholtz equation in unit square. The method uses orthogonal functions to project the problem down to finite dimensional space. After the projection, the problem simplifies to that of obtaining solutions for second order constant coefficient differential equations which can be done analytically. Numerical results indi...

Fourier inversion is the computational method of choice for a fast and accurate calculation of plain vanilla option prices in models with an analytically available characteristic function. Shifting the contour of integration along the complex plane allows for different representations of the inverse Fourier integral. In this article, we present the optimal contour of the Fourier integral, takin...

We address the issue of computing the non-linear matter power spectrum on mildly nonlinear scales with efficient semi-analytic methods. We implemented M. Pietroni’s Time Renormalization Group (TRG) method and its Dynamical 1-Loop (D1L) limit in a numerical module for the new Boltzmann code CLASS. A careful comparison of the D1L, TRG and Standard 1-Loop approaches reveals that results depend cru...

Road traffic noise is becoming an increasingly big problem in densely populated areas. One of the main contributions comes from the tyre/road interaction. For the interior noise, to which the occupants of the vehicle are exposed, tyre/road noise is also an important source, especially at lower frequencies. The vibrations of the tyre up to 500 Hz are transmitted via structural transmission paths...

Shocks in astrophysical fluids can generate suprathermal particles by first order (or diffusive) Fermi acceleration. In the test particle regime there is a simple relation between the spectrum of the accelerated particles and the jump conditions at the shock. This simple picture becomes complicated when the pressure of the accelerated particles becomes comparable with the pressure of the shocke...

Semi-analytical models of galaxy formation based on hierarchical clustering now make a wide range of predictions for observable properties of galaxies at low and high redshift. This article concentrates on 2 aspects: (1) Self-consistent modelling of dust absorption predicts a mean UV extinction AUV ∼ 1 mag, depending only weakly on redshift, and similar to observational estimates. (2) The model...

A semi-analytical solution for the simulation of one-dimensional subsurface solute transport incorporating multiple nonequilibrium processes is presented. The solution is based on the theory Ž . w developed by Brusseau et al. 1992 Brusseau, M.L., Jessup, R.E., Rao, P.S.C., 1992. Modeling solute transport influenced by multiprocess nonequilibrium and transformation reactions. Water Ž . x Resourc...

Abstract We present an extended validation of semi-analytical, semi-empirical covariance matrices for the two-point correlation function (2PCF) on simulated catalogs representative Luminous Red Galaxies (LRG) data collected during initial two months operations Stage-IV ground-based Dark Energy Spectroscopic Instrument (DESI). run pipeline multiple Zel’dovich (EZ) mock galaxy with corresponding ...