Moving mirrors and event horizons in asymptotically non-flat spacetimes

Moving mirrors have been used for a long time as simple models for studying various properties of black hole radiation, such as the thermal spectrum and entanglement entropy. These models are typically constructed to mimic the collapse of a spherically symmetric distribution of matter in the asymptotically Minkowski background. We generalize this correspondence to the case of non-trivial background geometry (e.g. a black hole in the AdS spacetime) and somewhat relax the assumption of spherical symmetry.Comment: 12 pages, 4 figure

Parisian ruin with power-asymmetric variance near the optimal point with application to many-inputs proportional reinsurance

This paper investigates the Parisian ruin probability for processes with power-asymmetric behavior of the variance near the unique optimal point. We derive the exact asymptotics as the ruin boundary tends to infinity and extend the previous result arXiv:1504.07061 to the case when the length of Parisian interval is of Pickands scale. As a primary application, we extend the recent result arXiv:2010.00222 on the many inputs proportional reinsurance fractional Brownian motion risk model to the Parisian ruin

Extremes of vector-valued locally additive Gaussian fields with application to double crossing probabilities

The asymptotic analysis of high exceedance probabilities for Gaussian processes and fields has been a blooming research area since J. Pickands introduced the now-standard techniques in the late 60's. The \textit{vector-valued} processes, however, have long remained out of reach due to the lack of some key tools including Slepian's lemma, Borell-TIS and Piterbarg inequalities. In a 2020 paper by K. Debicki, E. Hashorva and L. Wang, the authors extended the double-sum method to a large class of vector-valued processes, both stationary and non-stationary. In this contribution we make one step forward, extending these results to a simple yet rich class of non-homogenous vector-valued Gaussian \textit{fields}. As an application of our findings, we present an exact asymptotic result for the probability that a real-valued process first hits a high positive barrier and then a low negative barrier within a finite time horizon

On the temperature of lowest order inner bremsstrahlung

The relativistic thermodynamics of classical radiation from a single accelerating electron is investigated. The temperature characterizing the system highlights the dependence on acceleration. As the electron moves along a particular accelerated trajectory a deep infrared analysis of the soft radiation emitted is corroborated by experimental observation of lowest order inner bremsstrahlung during beta decay. In the context of acceleration radiation, the dynamic Casimir effect with Planck-distributed photons, and thermal black hole evaporation, we provide supporting analytic consistency for equilibrium thermal radiation. The motion is ultra-relativistic with a specific time-dependent Lorentz-invariant proper acceleration possessing long-lasting constant local acceleration.Comment: 6 pages, 4 figure

Non-thermal photons and a Fermi-Dirac spectral distribution

Although non-intuitive, an accelerated electron along a particular trajectory can be shown to emit classical electromagnetic radiation in the form of a Fermi-Dirac spectral distribution when observed in a particular angular regime. We investigate the relationship between the distribution, spectrum, and particle count. The result for the moving point charge is classical, as it accelerates along an exactly known trajectory. We map to the semi-classical regime of the moving mirror model with a quantized spin-0 field. The scalars also possess a $\beta$ Bogoliubov coefficient distribution with Fermi-Dirac form in the respective frequency regime.Comment: 4 pages, 3 figure

Humidity effects on tip-induced polarization switching in lithium niobate

Interest to ferroelectric materials has been increased significantly in last decades due to development of new generation of nonlinear optical and data storage devices. Scanning probe microscopy (SPM) can be used both for study of domain structures with nanoscale spatial resolution and for writing the isolated nanodomains by local application of the electric field. Tip-induced switching in the ambient still needs experimental investigations and theoretical explorations. Here we studied influence of the value of relative humidity in the SPM chamber on the process of tip-induced polarization switching. This phenomenon was attributed to existing of the water meniscus between tip and the sample surface in humid atmosphere. Presented results are important for further complex investigations of the ferroelectric materials and their applications.Comment: 15 pages, 5 figures, Submitted to Applied Physics Letter

Large-NN Solution and Effective Action of "Twisted-Mass'' Deformed CP(N−1)\mathbb{CP}(N-1) Model

We study effective dynamics of the non-supersymmetric two-dimensional $\mathbb{CP}(N-1)$ model in the large $N$ limit. This model is deformed by a mass term $m$ preserving $\mathbb{Z}_N$ symmetry of the Lagrangian. At small $m$ the theory is strongly coupled and resembles the undeformed $\mathbb{CP}(N-1)$ model, while at large $m$ it is in a weakly coupled Higgs phase with spontaneously broken $\mathbb{Z}_N$. We find the phase transition point and discuss the fate of the kink-antikink ``mesons'' at strong coupling. We also resolve an issue of instability that arose in previous studies of this model.Comment: 21 pages, 3 figure

OPTIMIZATION OF INVESTMENT RESOURCES DURING REPAIR OF POWER ENTERPRISE'S EQUIPMENT

The author presents an author's approach to the organization of the process of modeling equipment repair at enterprises of the power complex. The approach is based on the use of a modern network planning tool. It seems that the approach will increase the efficiency of using limited resources of energy companies

MODELING OF PROCESSES OF REPAIR OF ENERGY EQUIPMENT

In the article the correlation analysis by means of which the author establishes qualitative extent of influence of eleven factors on value of net profit of the enterprise of a power complex is submitted. Use of the modern device of network planning is the cornerstone of approach. The constructed model of network planning allows to choose optimum working hours of the power enterprise at repair and reconstruction of the equipment that in turn will allow to increase efficiency of adoption of administrative decisions