Resonance spin filter

A design of the resonance spin finter is suggested in form of a quantum well with three quantum wires attached. Explicit formula is suggested for transmission coefficients accross the well in terms of the resonance eigenfunction of the Schredinger operator on the well with Rashba spin-orbital interaction.Comment: 6 page

Holographic variables for CFT2_2 conformal blocks with heavy operators

We consider large-$c$ $n$-point Virasoro blocks with $n-k$ background heavy operators and $k$ perturbative heavy operators. Conformal dimensions of heavy operators scale linearly with large $c$, while splitting into background/perturbative operators assumes an additional perturbative expansion. Such conformal blocks can be calculated within the monodromy method that basically reduces to solving auxiliary Fuchsian second-order equation and finding monodromy of solutions. We show that there exist particular variables that we call holographic, use of which drastically simplifies the whole analysis. In consequence, we formulate the uniformization property of the large-$c$ blocks which states that in the holographic variables their form depends only on the number of perturbative heavy operators. On the other hand, the holographic variables encode the metric in the bulk space so that the conformal blocks with the same number of perturbative operators are calculated by the same geodesic trees but on different geometries created by the background operators.Comment: 21 pages, v3: More comments and explanations, new Fig. 1, references added. Journal versio

Upper limits on the rapid cooling of the Central Compact Object in Cas A

The Central Compact Object (CCO) in the Cassiopeia A supernova remnant is most likely a very young ($\approx 300$ yr) neutron star. If a previously reported decrease of its surface temperature by 4% in 10 years could be confirmed, it would have profound theoretical implications for neutron star physics. However, the temperature decrease was inferred from Chandra ACIS data affected by instrumental effects which could cause time-dependent spectral distortions. Employing a different instrument setup which minimizes spectral distortions, our 2006 and 2012 Chandra spectra of the CCO did not show a statistically significant temperature decrease. Here, we present additional observations from 2015 taken in the same instrument mode. During the time span of 8.5 years, we detect no significant temperature decrease, using either carbon or hydrogen atmosphere models in the X-ray spectral fits. Our conservative $3\sigma$ upper limits correspond to $<3.3$% and $<2.4$% temperature decrease in 10 years for carbon atmosphere model fits with varying or constant values of the absorbing hydrogen column density, respectively. The recently revised model for the ACIS filter contaminant has a strong effect on the fit results, reducing the significance of the previously reported temperature and flux changes. We expect that a further improved contaminant model and longer time coverage can significantly lower the upper limits in the future.Comment: 9 pages, 9 figures, 3 tables; accepted for publication in Ap

A possible resonance mechanism of earthquakes

It had been observed by Linkov, Petrova and Osipov (1992) that there exist periodic 4-6 hours pulses of 200 microHz seismogravitational oscillations ( SGO ) before 95 % of powerful earthquakes. We explain this by beating between an oscillation eigenmode of a whole tectonic plate and a local eigenmode of an active zone. The beating transfers the oscillation energy from the remote zone of the tectonic plate to the active zone, triggering the earthquake. Oscillation frequencies of the plate and ones of the active zone are tuned to a resonance by an additional compression applied to the active zone due to collision of neighboring plates or the magma flow in the liquid underlay of the astenosphere ( the upper mantle). In the case when there are three or more SGO with incommensurable difference frequencies the SGO beating pattern looks quasi-random, thus masking the non-random nature of the beating process. Nevertheless, we are able to discuss a possibility of the short term earthquakes predictions based on an accurate monitoring of the beating dynamics.Comment: Journal of Seismology (JOSE) DOI 10.1007/s10950-015-9525-

Intrinsic Time in Geometrodynamics of Closed Manifolds

The global time in Geometrodynamics is defined in a covariant under diffeomorphisms form. An arbitrary static background metric is taken in the tangent space. The global intrinsic time is identified with the mean value of the logarithm of the square root of the ratio of the metric determinants. The procedures of the Hamiltonian reduction and deparametrization of dynamical systems are implemented. The explored Hamiltonian system appeared to be non-conservative. The Hamiltonian equations of motion of gravitational field in the global time are written. Relations between different time intervals (coordinate, intrinsic, proper) are obtained.Comment: 11 pages; format is changed; arXiv admin note: substantial text overlap with arXiv:1710.0152

Static Casimir Condensate of Conformal Scalar Field in Friedmann Universe

The quantum Casimir condensate of a conformal massive scalar field in a compact Friedmann universe is considered in the static approximation. The Abel-Plana formula is used for renormalization of divergent series in the condensate calculation. A differential relation between the static Casimir energy density and static Casimir condensate is derived.Comment: 7 pages, 1 figure, misprints correcte

Reduced Conformal Geometrodynamics of Closed Manifolds

The global time is defined in covariant form under the condition of a constant mean curvature slicing of spacetime. The background static metric is taken in the tangent space. The global intrinsic time is identified with the logarithmic function of the mean value of the ratio of the square root of the metric determinants. The procedures of the Hamiltonian reduction and deparametrization of dynamical systems are implemented. The Hamiltonian system appears to be non-conservative. The Hamiltonian equations of motion of gravitational field in the global time are written.Comment: 5 page

Regular frames and particle's rotation near a black hole

We consider a particle moving towards a rotating black hole. We are interested in the number of its revolution $n$ around a black hole. In our previous work (Pavlov and Zaslavskii in Gen Relativ Gravit 50: 14, 2018. arXiv:1707.02860) we considered this issue in the Boyer-Lindquist type of coordinates with a subsequent procedure of subtraction. Now, we reconsider this issue using from the very beginning the frames regular on the horizon. For a nonextremal black hole, regularity of a coordinate frame leads to the finiteness of a number of revolutions around a black hole without a subtraction procedure. Meanwhile, for extremal black holes comparison of $n$ calculated in the regular frame with some subtraction procedures used by us earlier shows that the results can be different.Comment: 11 pages, 1 figure. Misprints in eq. (27) corrected. Matches published versio

Quantum Electronic Devices Based on Metal-Dielectric Transition in Low-Dimensional Quantum Structures

Two types of optically manipulated quantum electronic devices are considered: a quantum dot and a finite periodic molecular chain, with the period doubled under resonance optical excitation. The stability of the working regimes of the devices in large scale of temperatures is discussed. Some motivation in favor of the molecular chain is suggested. A class of materials, which can be used for producing this device is discussed

Number of revolutions of a particle around a black hole: Is it infinite or finite?

We consider a particle falling into a rotating black hole. Such a particle makes an infinite number of revolutions $n$ from the viewpoint of a remote observer who uses the Boyer-Lindquist type of coordinates. We examine the behavior of $n$ when it is measured with respect to a local reference frame that also rotates due to dragging effect of spacetime. The crucial point consists here in the observation that for a nonextremal black hole, the leading contributions to $n$ from a particle itself and the reference frame have the same form being in fact universal, so that divergences mutually cancel. As a result, the relative number of revolutions turns out to be finite. For the extremal black hole this is not so, $n$ can be infinite. Different choices of the local reference frame are considered, the results turn out to be the same qualitatively. For illustration, we discuss two explicit examples - rotation in the flat spacetime and in the Kerr metric.Comment: 19 pages, 3 figure