5 research outputs found
Future soft singularities, Born-Infeld-like fields and particles
We consider different scenarios of the evolution of the universe, where the
singularities or some non-analyticities in the geometry of the spacetime are
present, trying to answer the following question: is it possible to conserve
some kind of notion of particle corresponding to a chosen quantum field present
in the universe when the latter approaches the singularity? We study scalar
fields with different types of Lagrangians, writing down the second-order
differential equations for the linear perturbations of these fields in the
vicinity of a singularity. If both independent solutions are regular, we
construct the vacuum state for quantum particles as a Gaussian function of the
corresponding variable. If at least one of two independent solutions has a
singular asymptotic behavior, then we cannot define the creation and the
annihilation operators and construct the vacuum. This means that the very
notion of particle loses sense. We show that at the approaching to the Big Rip
singularity, particles corresponding to the phantom scalar field driving the
evolution of the universe must vanish, while particles of other fields still
can be defined. In the case of the model of the universe described by the
tachyon field with a special trigonometric potential, where the Big Brake
singularity occurs, we see that the (pseudo) tachyon particles do not pass
through this singularity. Adding to this model some quantity of dust, we
slightly change the characteristics of this singularity and tachyon particles
survive. Finally, we consider a model with the scalar field with the cusped
potential, where the phantom divide line crossing occurs. Here the particles
are well defined in the vicinity of this crossing point.Comment: 13 pages, 1 figure. Final version to be published in PR
The Unruh effect under the de Broglie-Bohm perspective
We investigate the Minkowski ground state associated with a real massless
scalar field as seen by an accelerated observer under the perspective of the de
Broglie-Bohm quantum theory. We use the Schr\"odinger picture to obtain the
wave functional associated with the Minkowski vacuum in Rindler coordinates,
and we calculate the field trajectories through the Bohmian guidance equations.
The Unruh temperature naturally emerges from the calculus of the average
energy, but the Bohmian approach precisely distinguishes between its quantum
and classical components, showing that they periodically interchange their
roles as the dominant cause for the temperature effects, with abrupt jumps in
the infrared regime. We also compute the power spectra, and we exhibit a very
special Bohmian field configuration with remarkable physical properties.Comment: 32 pages, 6 figure
Controlling the Quality of Nanodrugs According to Their New Property—Radiothermal Emission
Previous studies have shown that complexly shaped nanoparticles (NPs) have their intrinsic radiothermal emission in the millimeter range. This article presents a method for controlling the quality of nanodrugs—immunobiological preparations (IBPs)—based on the detection of their intrinsic radiothermal emissions. The emissivity of interferon (IFN) medicals, determined without opening the primary package, is as follows (µW/m2): IFN-α2b—80 ± 9 (105 IU per package), IFN-β1a—40 ± 5 (24 × 106 IU per package), IFN-γ—30 ± 4 (105 IU per package). The emissivity of virus-like particles (VLP), determined using vaccines Gam-VLP-multivac (120 μg) in an injection bottle (crimp cap vials), was as follows: 12 ± 1 µW/m2, Gam-VLP—rota vaccines—9 ± 1 µW/m2. This study shows the reproducibility of emissivity over the course of a year, subject to the storage conditions of the immunobiological products. It has been shown that accelerated aging and a longer shelf life are accompanied by the coagulation of active NPs, and lead to a manyfold drop in emissivity. The dependence of radiothermal emission on temperature has a complex, non-monotonic nature. The emission intensity depends on the form of dosage, but remains within the order of magnitude for IFN-α2b for intranasal aqueous solution, ointments, and suppositories. The possibility of the remote quantitative control of the first phases of the immune response (increased synthesis of IFNs) to the intranasal administration of VLP vaccines has been demonstrated in experimental animals