The accumulation of ice on an airplane in flight is one of the leading contributing factors to general aviation accidents, and to date only relatively sophisticated methods based on detailed empirical data and flight data exist for its analysis. This paper develops a methodology and simulation tool for a preliminary yet accurate evaluation of airplane dynamical response and stability and contro...

Two experiments compared 6-month-old infants as they reach for an object. All were proficient reachers but with different levels of sitting ability. The object was presented at various distances, within and beyond reach of the infant. In the first experiment, the scaling of perceived reachability in infants with different postural abilities (i.e. non-sitter, near-sitter, and sitter infants) was...

In these lectures we give a review of recent attempts to understand quantum gravity on de Sitter spaces. In particular, we discuss the holographic correspondence between de Sitter gravity and conformal field theories proposed by Hull and by Strominger, and how this may be reconciled with the finite-dimensional Hilbert space proposal by Banks and Fischler. Furthermore we review the no-go theorem...

The stability of de Sitter metric in spacetimes where inflaton fields are non-minimally coupled to propagating torsion is investigated. It is shown that the de Sitter background metric is unstable against small perturbations. Axionic torsion is generated by inflaton fluctuations and the analysis of cosmological perturbations in Einstein-Cartan-Klein-Gordon (ECKG) equations is undertaken. Instab...

These lectures present an elementary discussion of some background material relevant to the problem of de Sitter quantum gravity. The first two lectures discuss the classical geometry of de Sitter space and properties of quantum field theory on de Sitter space, especially the temperature and entropy of de Sitter space. The final lecture contains a pedagogical discussion of the appearance of the...

These lectures present an elementary discussion of some background material relevant to the problem of de Sitter quantum gravity. The first two lectures discuss the classical geometry of de Sitter space and properties of quantum field theory on de Sitter space, especially the temperature and entropy of de Sitter space. The final lecture contains a pedagogical discussion of the appearance of the...

Abstract The method for determining the main parameters of tail cargo doors transport category aircrafts is developed. A methodology ascertainment these has been described. An example based on an existing aircraft considered. Gathered were information pertaining to necessary design, operational and regulatory requirements international organisations Federal Aviation Regulations (FAR), Certifica...

It is well known that in de Sitter space the (free) minimally coupled massless scalar field theory does not admit any de Sitter-invariant Hadamard state. Related to this is the fact that the prop-agator for the massive scalar field corresponding to the de Sitter-invariant vacuum state diverges in the massless limit, with the infrared-divergent term being a constant. Since the Faddeev-Popov ghos...

The group theoretical approach to relativistic wave equations for spin 0,1/2 and 1 massless particles in the real reducible spaces and in the de Sitter and Anti-de Sitter spaces for spin 0 and 1/2 massive particles are considered. The invariant wave equations which determines the appropriate irreducible representations are constructed. The explicit solutions of these equations possessing a simp...