The purpose of this paper is to perform the feasibility and performance evaluation of the High-altitude launch technique using high altitude atmospheric Properties to near earth orbits. The current propulsion transportation system from Earth to space has been deemed by many to be expensive, unreliable, and an unnecessarily dangerous means of travel to space. It is suggested in this paper to ana...

The spectral characteristics of combustion noise is dictated by the temporal correlation of the heat release rate fluctuation. This paper investigates the two-point space-time correlation of heat release rate fluctuations by analysing recent direct numerical simulation (DNS) data of turbulent premixed flames. The results show that this correlation decays rapidly in both space and time due to th...

Sign type spectra are an important tool in the investigation of spectral properties of selfadjoint operators in Krein spaces. It is our aim to show that also sign type spectra for normal operators in Krein spaces provide insight in the spectral nature of the operator: If the real part and the imaginary part of a normal operator in a Krein space have real spectra only and if the growth of the re...

With the example of the spherically symmetric scalar wave equation on Minkowski space-time we demonstrate that a fully pseudospectral scheme (i.e. spectral with respect to both spatial and time directions) can be applied for solving hyperbolic equations. The calculations are carried out within the framework of conformally compactified space-times. In our formulation, the equation becomes singul...

With the example of the spherically symmetric scalar wave equation on Minkowski space-time we demonstrate that a fully pseudospectral scheme (i.e. spectral with respect to both spatial and time directions) can be applied for solving hyperbolic equations. The calculations are carried out within the framework of conformally compactified space-times. In our formulation, the equation becomes singul...

This paper solved the problem of the scattering of radiation from a material half-space by the transient spectral domain method. The transient spectral domain method is a general theoretical approach for the exact solution to the time-dependent source radiation in the presence of media. It is located in the air region in the vicinity of lossy half-space. The apply of the integral transform to t...

Spacetime, understood as a globally hyperbolic manifold, may be characterized by spectral data using a 3+1 splitting into space and time, a description of space by spectral triples and by employing causal relationships, as proposed earlier. Here, it is proposed to use the Hadamard condition of quantum field theory as a smoothness principle.

We solve the inverse spectral problem for rotationally symmetric manifolds, which include the class of surfaces of revolution, by giving an analytic isomorphism from the space of spectral data onto the space of functions describing the radius of rotation. An analogue of the Minkowski problem is also solved.

We report on a simple method allowing one to decompose the duration of arbitrary ultrashort light pulses, potentially distorted by space-time coupling, into four elementary durations. Such a decomposition shows that, in linear optics, a spatio-temporal pulse can be stretched with respect to its Fourier limit by only three independent phenomena: nonlinear frequency dependence of the spectral pha...

We consider the scattering from and transmission through a one-dimensional periodic surface. For this problem, the electromagnetic cases of TE and TMpolarization reduce to the scalar acoustic examples. Three different theoretical and computational methods are described, all involving the solution of integral equations and their resulting discrete matrix system of equations for the boundary unkn...