The theory of gravitational lensing is reviewed from a spacetime perspective, without quasi-Newtonian approximations. More precisely, the review covers all aspects of gravitational lensing where light propagation is described in terms of lightlike geodesics of a metric of Lorentzian signature. It includes the basic equations and the relevant techniques for calculating the position, the shape, a...

An experimental set-up of the method of caustics was proposed for the accurate evaluation of stress intensity factor. The stress intensity factor evaluation was based on a new formula which was based on the caustic shape area. The new formula was based on the shape area of the caustics. The stress optical constants were evaluated according to the new formula of the stress intensity factor. The ...

Axion physics is briefly reviewed. Constraints from laboratory searches, astrophysics and cosmology require the axion mass to be in the range 10 . ma < 3 · 10eV. Near the lower end of this range, axions are all or a major component of the cold dark matter of the universe. The late infall of axions, and of any other cold dark matter particles, onto our galaxy produces streams and caustics in its...

OBJECTIVES To analyze and to compare clinical repercussions of accidents involving legally and illegally commercialized household sanitizers in children under 7 years of age. METHODS A descriptive cross-sectional design was used to collect data from electronic database of a regional Poison Control Center during one year. Data were analyzed by means of descriptive non-parametric statistics and...

The availability of a robust and efficient routine for calculating light curves of a finite source magnified due to bending its light by the gravitational field of an intervening binary lens is essential for determining the characteristics of planets in such microlensing events, as well as for modelling stellar lens binaries and resolving the brightness profile of the source star. However, the ...

Backward polygon beam tracing methods, that is beam tracing from the light source (L), are well suited to gather path coherency from specular (S) scattering surfaces. These methods are useful for modelling and efficiently simulating caustics on diffuse (D) surfaces; an effect due to LS+D transport paths. This paper generalizes backward polygon beam tracing to include a glossy (G) scattering sur...

We consider a timelike geodesic congruence in the presence of perturbative quantum fluctuations spacetime metric. calculate change volume bundle geodesics due to such and thereby obtain quantum-gravitationally modified Raychaudhuri equation. Quantum gravity generically increases convergence congruences production caustics.

In this work we establish a relationship between Cartan’s geometric approach to third order ODEs and the 3-dim Null Surface Formulation (NSF). We then generalize both constructions to allow for caustics and singularities that necessarily arise in these formalisms.