Scalar multi-wormholes

In 1921 Bach and Weyl derived the method of superposition to construct new axially symmetric vacuum solutions of General Relativity. In this paper we extend the Bach-Weyl approach to non-vacuum configurations with massless scalar fields. Considering a phantom scalar field with the negative kinetic energy, we construct a multi-wormhole solution describing an axially symmetric superposition of $N$ wormholes. The solution found is static, everywhere regular and has no event horizons. These features drastically tell the multi-wormhole configuration from other axially symmetric vacuum solutions which inevitably contain gravitationally inert singular structures, such as `struts' and `membranes', that keep the two bodies apart making a stable configuration. However, the multi-wormholes are static without any singular struts. Instead, the stationarity of the multi-wormhole configuration is provided by the phantom scalar field with the negative kinetic energy. Anther unusual property is that the multi-wormhole spacetime has a complicated topological structure. Namely, in the spacetime there exist $2^N$ asymptotically flat regions connected by throats.Comment: 11 pages, 13 figure

Analysis of emergency situations on the process of thermal power plants using mathematical apparatus of Petri nets

Article is dedicated to the issues of accident scenarios analysis on the process of thermal power plants. The theoretical foundations of the graphical and analytical representation of Petri nets are shown. The article describes the steam cycle process and listing of its technology protections. A state model for power unit equipment and technological protections under the influence of changes in critical process parameters (steam’s temperature, pressure, level) is presented. Conclusions about the plans for further work in this direction are proposed. 

Spherical and Hyperbolic Toric Topology-Based Codes On Graph Embedding for Ising MRF Models: Classical and Quantum Topology Machine Learning

The paper introduces the application of information geometry to describe the ground states of Ising models by utilizing parity-check matrices of cyclic and quasi-cyclic codes on toric and spherical topologies. The approach establishes a connection between machine learning and error-correcting coding. This proposed approach has implications for the development of new embedding methods based on trapping sets. Statistical physics and number geometry applied for optimize error-correcting codes, leading to these embedding and sparse factorization methods. The paper establishes a direct connection between DNN architecture and error-correcting coding by demonstrating how state-of-the-art architectures (ChordMixer, Mega, Mega-chunk, CDIL, ...) from the long-range arena can be equivalent to of block and convolutional LDPC codes (Cage-graph, Repeat Accumulate). QC codes correspond to certain types of chemical elements, with the carbon element being represented by the mixed automorphism Shu-Lin-Fossorier QC-LDPC code. The connections between Belief Propagation and the Permanent, Bethe-Permanent, Nishimori Temperature, and Bethe-Hessian Matrix are elaborated upon in detail. The Quantum Approximate Optimization Algorithm (QAOA) used in the Sherrington-Kirkpatrick Ising model can be seen as analogous to the back-propagation loss function landscape in training DNNs. This similarity creates a comparable problem with TS pseudo-codeword, resembling the belief propagation method. Additionally, the layer depth in QAOA correlates to the number of decoding belief propagation iterations in the Wiberg decoding tree. Overall, this work has the potential to advance multiple fields, from Information Theory, DNN architecture design (sparse and structured prior graph topology), efficient hardware design for Quantum and Classical DPU/TPU (graph, quantize and shift register architect.) to Materials Science and beyond.Comment: 71 pages, 42 Figures, 1 Table, 1 Appendix. arXiv admin note: text overlap with arXiv:2109.08184 by other author

Ignition of the Soaring Droplet Sets of Waste-Derived Coal-Water Slurry With Petrochemicals

We have analyzed the ignition of droplet sets of waste-derived coal-water slurry with petrochemicals for the case of their soaring inside special combustion chamber. The fuel composition consists of filter cake of bituminous coal type G, waste turbine oil, water and plasticizer. Features of the ignition process were emphasized for groups of three soaring droplets in comparison with single droplet ignition. The ignition delay times were registered for particles that were deformed or segregated due to the interaction of initial fuel droplets with walls of the combustion chamber

Local artistic style formation in urban environment design

The article presents the corporate style as the leading project method in design in XXth century and its use in the design of the urban environment in the form of a local architectural and artistic style of the ensemble. It has become widespread in the organization of pedestrian streets in urban centers as a means of stylistic harmonization of diverse buildings and increasing the artistic expressiveness of the spatial ensemble. The striking example is the reconstruction of the Nikolayviertel in Berlin and his development into a territorial brand. At the same time, the graphic, artistic and stylistic accompaniment of the territorial brand became a logical continuation and development of its local architectural and artistic style, embedded in the architectural context, enhancing its imaginative component and the general artistic «positive». The modern post-industrial society brings with it changes that have affected the artistic and aesthetic qualities of the environment. Instead of an «open-air museum» with a clearly organized historical and architectural exposition, the visitor is offered a «settled» and a little shabby in the «shabby chic» style urban environment with picturesque green corners of cafes and restaurants

Application of RGB-synthesis for complex interpretation of geophysical data in the study of areas contaminated by oil products

The information on geological structure as well as on the degree of contamination and geometrical parameters of a pollutant in oil-contaminated areas is necessary for risk assessment, planning of oil products recovery and territory remediation. Geophysical methods are actively used for solving such problems. The work considers the site on the Volga River bank, where soils are contaminated with petroleum products. The aim of the work is to delineate the distribution area of petroleum products. In order to achieve the goal, the set of near-surface geophysical methods (vertical electric sounding, seismic survey) and gas geochemistry were implemented. The results of a new approach to characterization of contaminated sites by RGB-data synthesis have been demonstrated as one of the ways of data interpretation. The method is based on the generalization of the available materials by optically mixing of the data of three spatially distributed characteristics presented in the form of three channels – red, green, and blue – for the purpose of localizing the lenses of gravity-mobile and immobilized oil products. According to the results of the qualitative interpretation of geophysical information, the authors have built a scheme with the proposed contour of oil products distribution in the studied territory. The proposed method can be used for the delineation of oil spills along with the sufficient information obtained by geophysical or other methods (at least three) at the stage of determining the spread of contamination for the sites. This approach can speed up the interpretation process, as such maps overlaying sets the color distribution of different petrophysical characteristics of the soils for the selected depth level, and also eases the task of determination of coordinates when correlating various anomalies, identified by different methods

Distribution of species from the genus Panorpa (Mecoptera, Panorpidae) in European Russia except the Caucasus

The study of the insect distribution in geographical areas is relevant since it is important in terms of understanding the global trend of biodiversity decline. The paper presents the results of a study on the distribution of six species of Panorpidae (Mecoptera), carried out in 2008, 2009, 2011, 2015, 2017–2020. One part of data was collected by the authors. Other material was provided by colleagues from 11 regions in Russia. In European Russia, six species of Panorpa are reliably known, namely Panorpa alpina, P. cognata, P. communis, P. germanica, P. hybrida, and P. vulgaris. The most common and frequently encountered species are P. communis (in 21 regions), P. hybrida (in 12 regions), P. vulgaris (in 11 regions), and P. cognata (in 11 regions). It is assumed that all studied species can be found in other regions of European Russia as a result of further investigations. Among the studied species, P. alpina and P. germanica are the rarest species, recorded from two and one regions, respectively. Panorpa vulgaris was found for the first time in Russia