Pair production in a constant electric field is closely analogous to bubble nucleation false vacuum. The classical trajectories of the pairs are Lorentz invariant, but this invariance should be broken by process. Garriga et al. used model detector, consisting other particles interacting with pairs, investigate how pair seen different Lorentzian observers. They found that (antiparticles) predomi...

We study perfect fluid cosmological models with a constant equation of state parameter γ in which there are two naturally defined time-like congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities, in the two frames. We study expanding ...

In this note we construct finite and infinite horizon minimax observers for a linear stationary DAE with deterministic, unknown, but bounded noise. By using generalized Kalman duality and geometric control we prove that the finite (infinite) horizon observer exists if and only if the DAE is observable (detectable). Remarkably, the regularity for the DAE is not required.

Introdouction: Canal length measurement is essential for proper endodontic treatment. Any error or miscalculation in working length determination, particularly in curved canals, can result in complications during or after root canal therapy. Digital radiography has enabled accurate measurement of curved canal length. In this study, we evaluated the accuracy of calibration of a complementary m...

Introduction: The image quality as well as film speed is influenced by the film processing conditions. Different combinations of films and processing methods affect the diagnostic accu-racy. Temperature and developer exhaustion result in different image quality. The purpose of this study was to evaluate the influence of film type and processing conditions on caries detec-tion.  Material a...

In this paper a family of homogeneity–based observers is proposed to estimate the state class multiple–outputs linear systems with some parametric uncertainties and unknown inputs. Such possesses robustness, finite– fixed–time convergence properties depending on considered The structure these simple since requires neither additional observers, for an priori stabilization, nor complex transforma...