160 research outputs found
Electron to selectron pair conversion in a SUSY bubble
In the standard model, energy release in dense stars is severely restricted
by the Pauli exclusion principle. However, if, in regions of space of high
fermion degeneracy, there is a phase transition to a state of exact
supersymmetry (SUSY), fermion to sfermion pair conversion followed by radiative
transitions to the Bose ground state could lead to a highly collimated gamma
ray burst. We calculate the cross section for electron to selectron pair
conversion in a SUSY bubble and construct a monte carlo for the resulting
sfermion amplification by stimulated emission.Comment: 13 pages, 4 figures, published version with "with jet production by
Bose enhancement" added to titl
The shock-acoustic waves generated by earthquakes
We investigate the form and dynamics of shock-acoustic waves generated by
earthquakes. We use the method for detecting and locating the sources of
ionospheric impulsive disturbances, based on using data from a global network
of receivers of the GPS navigation system and requiring no a priori information
about the place and time of associated effects. The practical implementation of
the method is illustrated by a case study of earthquake effects in Turkey
(August 17, and November 12, 1999), in Southern Sumatera (June 4, 2000), and
off the coast of Central America (January 13, 2001). It was found that in all
instances the time period of the ionospheric response is 180-390 s, and the
amplitude exceeds by a factor of two as a minimum the standard deviation of
background fluctuations in total electron content in this range of periods
under quiet and moderate geomagnetic conditions. The elevation of the wave
vector varies through a range of 20-44 degree, and the phase velocity
(1100-1300 m/s) approaches the sound velocity at the heights of the ionospheric
F-region maximum. The calculated (by neglecting refraction corrections)
location of the source roughly corresponds to the earthquake epicenter. Our
data are consistent with the present views that shock-acoustic waves are caused
by a piston-like movement of the Earth surface in the zone of an earthquake
epicenter.Comment: EmTeX-386, 30 pages, 4 figures, 3 tabl
Nuclear Physics in a Susy Universe
We refine a previous zeroth order analysis of the nuclear properties of a
supersymmetric (susy) universe with standard model particle content plus
degenerate susy partners. No assumptions are made concerning the Higgs
structure except we assume that the degenerate fermion/sfermion masses are
non-zero. This alternate universe has been dubbed Susyria and it has been
proposed that such a world may exist with zero vacuum energy in the string
landscape.Comment: 8 pages, 1 figur
Stochastic effects in the eco-epidemiological model with multirhythmicity
We consider the eco-epidemiological "predator-prey"model taking into account the Allee effect in the population of predators and dividing the prey population into infected and susceptible. Depending on the Allee parameter, bifurcation analysis with the identification of zones of bi- and multirhythmicity is carried out. Spatial basins of attraction for cycles are constructed. For the stochastic version of the model, probabilistic mechanisms of transitions between two different regular oscillatory regimes and between regular and chaotic ones are studied. The preferential modes that occur in the presence of random interference are determined. A phenomenon of noise-induced extinction of the predator population is discussed. © 2022 Author(s).Russian Science Foundation, RSF, (N 21-11-00062)The work was supported by Russian Science Foundation (N 21-11-00062)
Poder do Estado na sociedade moderna: os problemas de compreensão e investigação
The article analyzes the problems associated with the understanding of state power, as well as theoretical and methodological innovations and research tools used in the study of this political and legal phenomenon. The authors analyze various directions of the legal, political and sociocultural definition of state power, identify and discuss various dimensions and levels in the conceptualization of the latter. In the context of the paper, the government is as a complex political and legal phenomenon, considered as a specific type of general system of public authority, which is implemented by various political subjects, which have a rigid link to the socio-cultural and territorial space.El artículo analiza los problemas asociados con la comprensión del poder estatal, así como las innovaciones teóricas y metodológicas y las herramientas de investigación utilizadas en el estudio de este fenómeno político y legal. Los autores analizan varias direcciones de la definición legal, política y sociocultural del poder estatal, identifican y discuten varias dimensiones y niveles en la conceptualización de este último. En el contexto del documento, el gobierno es como un fenómeno político y legal complejo, considerado como un tipo específico de sistema general de autoridad pública, que es implementado por varios sujetos políticos, que tienen un vínculo rígido con el contexto sociocultural y territorial. espacio.O artigo analisa os problemas associados à compreensão do poder do Estado, bem como as inovações teóricas e metodológicas e ferramentas de pesquisa utilizadas no estudo desse fenômeno político e jurídico. Os autores analisam várias direções da definição jurídica, política e sociocultural do poder do Estado, identificam e discutem várias dimensões e níveis na conceituação do último. No contexto do trabalho, o governo é um fenômeno político e jurídico complexo, considerado como um tipo específico de sistema geral de autoridade pública, que é implementado por vários sujeitos políticos, que têm um vínculo rígido com as relações socioculturais e territoriais. espaço
Analysis of Noise-Induced Transitions in a Thermo-Kinetic Model of the Autocatalytic Trigger
Motivated by the increasingly important role of mathematical modeling and computer-aided analysis in engineering applications, we consider the problem of the mathematical modeling and computer-aided analysis of complex stochastic processes in thermo-kinetics. We study a mathematical model of the dynamic interaction of reagent concentration and temperature in autocatalysis. For the deterministic variant of this model, mono- and bistability parameter zones as well as local and global bifurcations are revealed, and we show how random multiplicative disturbances can deform coexisting equilibrium regimes. In a study of noise-induced transitions, we apply direct numerical simulation and an analytical approach based on the stochastic sensitivity technique. Two variants of bistability with different scenarios of stochastic transformations are studied and compared. © 2023 by the authors.Ministry of Education and Science of the Russian Federation, MinobrnaukaThis research was funded by the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority-2030 Program)
Parity and Time Reversal in J/Psi Decay
With the prospect of large numbers of decay events becoming
available in the near future, it is interesting to search for symmetry
violating effects as probes of new physics and tests of the standard model.
decay events could provide the first observation of weak effects in
otherwise strongly decaying particles. We calculate a T odd asymmetry in the
decay into photon plus lepton pair due to Z boson exchange. Extensions
to hadronic final states are also discussed.Comment: 9 pages, 3 eps figures revised to include additional relevant
reference
Stochastic sensitivity analysis of dynamic transformations in the “two prey – predator” model
This work is devoted to the study of the problem of modeling and analyzing complex oscillatory modes, both regular and chaotic, in systems of interacting populations in the presence of random perturbations. As an initial conceptual deterministic model, a Volterra system of three differential equations is considered, which describes the dynamics of prey populations of two competing species and a predator. This model takes into account the following key biological factors: the natural increase in prey, their intraspecific and interspecific competition, the extinction of predators in the absence of prey, the rate of predation by predators, the growth of the predator population due to predation, and the intensity of intraspecific competition in the predator population. The growth rate of the second prey population is used as a bifurcation parameter. At a certain interval of variation of this parameter, the system demonstrates a wide variety of dynamic modes: equilibrium, oscillatory, and chaotic. An important feature of this model is multistability. In this paper, we focus on the study of the parametric zone of tristability, when a stable equilibrium and two limit cycles coexist in the system. Such birhythmicity in the presence of random perturbations generates new dynamic modes that have no analogues in the deterministic case. The aim of the paper is a detailed study of stochastic phenomena caused by random fluctuations in the growth rate of the second population of prey. As a mathematical model of such fluctuations, we consider white Gaussian noise. Using methods of direct numerical modeling of solutions of the corresponding system of stochastic differential equations, the following phenomena have been identified and described: unidirectional stochastic transitions from one cycle to another, trigger mode caused by transitions between cycles, noise-induced transitions from cycles to the equilibrium, corresponding to the extinction of the predator and the second prey population. The paper presents the results of the analysis of these phenomena using the Lyapunov exponents, and identifies the parametric conditions for transitions from order to chaos and from chaos to order. For the analytical study of such noise-induced multi-stage transitions, the technique of stochastic sensitivity functions and the method of confidence regions were applied. The paper shows how this mathematical apparatus allows predicting the intensity of noise, leading to qualitative transformations of the modes of stochastic population dynamics. © 2022 Irina A. Bashkirtseva, Tatyana V. Perevalova, Lev B. Ryashko.Russian Science Foundation, RSF, (21-11-00062)This work was supported Russian Science Foundation (No. 21-11-00062)
Правове регулювання господарської діяльності в Україні
The textbook discusses the concept, legal status of business entities, the order of their formation and operation, lending, legal regulation of leasing and renting, exchange activities. After each topic, tests, practical tasks and topics for abstracts are provided. For students, graduate students and teachers of economics, philology and technical specialties.У навчальному посібнику розглядається поняття, правовий статус суб’єктів підприємницької діяльності, порядок їх утворення та діяльності, кредитування, правове регулювання лізингу та оренди, біржова діяльність. Після кожної теми надаються тести, практичні завдання та теми для рефератів. Для студентів, аспірантів та викладачів економічних, філологічних та технічних спеціальностей
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