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Full-Text Articles in Physical Sciences and Mathematics

Investigating Bremsstrahlung Radiation In Tungsten Targets: A Geant4 Simulation Study, Sindor Ashurov, Satimboy Palvanov, Abror Tuymuradov, Dilmurod Tuymurodov Dec 2023

Investigating Bremsstrahlung Radiation In Tungsten Targets: A Geant4 Simulation Study, Sindor Ashurov, Satimboy Palvanov, Abror Tuymuradov, Dilmurod Tuymurodov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Bremsstrahlung radiation, a pivotal phenomenon in high-energy physics, presents numerous applications and implications in both theoretical studies and practical scenarios. This article explores the Bremsstrahlung radiation of electrons in tungsten (W) targets of varying widths subjected to different energy beams using GEANT4 simulations. By systematically altering the target widths and electron beam energies, we assess the corresponding effects on radiation yield and spectrum. The findings contribute to a deeper understanding of Bremsstrahlung processes in high-$Z$ materials and offer valuable insights for applications ranging from radiation therapy to materials analysis.


Holomorphic Motion Of Julia Sets Of Polynomial-Like Maps, And Continuity Of Compact Sets And Their Green Functions, Bazarbaev Sardor, Sobir Boymurodov Dec 2023

Holomorphic Motion Of Julia Sets Of Polynomial-Like Maps, And Continuity Of Compact Sets And Their Green Functions, Bazarbaev Sardor, Sobir Boymurodov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper, we study holomorphic motion of Julia sets of polynomial-like maps. In particular, we prove that in the stable family of polynomial-like maps if all the continuos functions move continuously by parameter then the Julia sets move holomorphically. Moreover, we also study the relation between continuity of regular compact sets and their Green functions.


Translation-Invariant Gibbs Measures For Potts Model With Competing Interactions With A Countable Set Of Spin Values On Cayley Tree, Zarinabonu Mustafoyeva Dec 2023

Translation-Invariant Gibbs Measures For Potts Model With Competing Interactions With A Countable Set Of Spin Values On Cayley Tree, Zarinabonu Mustafoyeva

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In the present paper we consider of an infinite system of functional equations for the Potts model with competing interactions and countable spin values Φ = {0, 1, ..., } on a Cayley tree of order k. We study translation-invariant Gibbs measures that gives the description of the solutions of some infinite system of equations. For any k ≥ 1 and any fixed probability measure ν we show that the set of translation-invariant splitting Gibbs measures contains one and two points for odd k and even k, respectively, independently on parameters of the Potts model with a countable …


An Analogue Of Hartogs Lemma For Separately Harmonic Functions With Variable Radius Of Harmonicity, Sevdiyor Imomkulov, Sultanbay Abdikadirov Dec 2023

An Analogue Of Hartogs Lemma For Separately Harmonic Functions With Variable Radius Of Harmonicity, Sevdiyor Imomkulov, Sultanbay Abdikadirov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this note we prove that if a function u(x,y) is separately harmonic in a domain D × Vr = D × {y∈ℝ2:|y|<r,  r>1} ⊂ ℝn × ℝ2 and for each fixed point x0 ∈ D the function u(x0,y) of variable y continues harmonically into the great circle {y∈ℝ2:|y|<R(x0),  R(x0)>r}, then it continues harmonically into a domain {(x …


Cyclically Compact Operators In Banach Modules Over L0(B), Jasurbek Karimov Dec 2023

Cyclically Compact Operators In Banach Modules Over L0(B), Jasurbek Karimov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper the properties of linear cyclically compact operators in Banach modules over space L0(B) are given.


Laterally Complete Regular Modules, Jasurbek Karimov Dec 2023

Laterally Complete Regular Modules, Jasurbek Karimov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper we introduce the notion laterally complete regular modules and study some properties of theese modules.


A New Capacity In The Class Of ShM Functions Defined By Laplace Operator, Nurali Akramov, Khakimboy Egamberganov Sep 2023

A New Capacity In The Class Of ShM Functions Defined By Laplace Operator, Nurali Akramov, Khakimboy Egamberganov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper, we define a new capacity Δm on the class of shm functions, which is defined by Laplace operator. We prove that Δm-capacity satisfies Choquet’s axioms of measurability. Moreover, we compare our capacity with Sadullaev-Abdullaev capacities. In particular, it implies that Δm-capacity of a set E is zero if and only if E is a m-polar set.


Gibbs Measures Of Models With Uncountable Set Of Spin Values On Lattice Systems, Farhod Haydarov Sep 2023

Gibbs Measures Of Models With Uncountable Set Of Spin Values On Lattice Systems, Farhod Haydarov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper, we shall discuss the construction of Gibbs measures for models with uncountable set of spin values on Cayley trees. It is known that "translation-invariant Gibbs measures" of the model with an uncountable set of spin values can be described by positive fixed points of a nonlinear integral operator of Hammerstein type. The problem of constructing a kernel with non-uniqueness of the integral operator is sufficient in Gibbs measure theory. In this paper, we construct a degenerate kernel in which the number of solutions does not exceed 3, and in turn, it only gives us a chance to …


Local And 2-Local Derivations On Small Dimensional Zinbiel Algebras, Bakhtiyor Yusupov, Sabohat Rozimova Jun 2023

Local And 2-Local Derivations On Small Dimensional Zinbiel Algebras, Bakhtiyor Yusupov, Sabohat Rozimova

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In the present paper we investigate local and 2-local derivations on small dimensional Zinbiel algebras. We give a description of derivations and local derivations on all three and four-dimensional Zinbiel algebras. Moreover, similar problem concerning 2-local derivations on all three and four-dimensional Zinbiel algebras are investigated.


Weighted M-Subharmonic Measure And (M, 𝜓)-Regularity Of Compacts, Kobiljon Kuldoshev, Nurbek Narzillaev Jun 2023

Weighted M-Subharmonic Measure And (M, 𝜓)-Regularity Of Compacts, Kobiljon Kuldoshev, Nurbek Narzillaev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

It is known that, the m−subharmonic measure of a set E ⊂ D,  related to a domain D ⊂ ℂn, is defined by m−subharmonic functions in D. In this article we define a generalization of the m−subharmonic measures and prove some of their properties.


On Specifications Of Positive Data Models With Effectively Separable Kernels Of Algorithmic Representations, Nodira R. Karimova May 2023

On Specifications Of Positive Data Models With Effectively Separable Kernels Of Algorithmic Representations, Nodira R. Karimova

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

It is established that any effectively separable multi-sorted positively representable model with an effectively separable representation kernel has an enrichment that is the only (up to isomorphism) model constructed from constants for a suitable computably enumerable set of sentences.


On The Negative Order Loaded Modified Korteweg–De Vries Equation, Praveen Agarwal, Bakhrom Abdullaev, Iroda Baltaeva, Shoira Atanazarova Mar 2023

On The Negative Order Loaded Modified Korteweg–De Vries Equation, Praveen Agarwal, Bakhrom Abdullaev, Iroda Baltaeva, Shoira Atanazarova

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this study, we establish the integration of the negative order loaded modified Korteweg-de Vries equation using the inverse scattering transform method. The main result is included in deriving the evolution equations for scattering data of the Dirac operator which is associated with the considered problem. Moreover, it was described the process of the construction of one-soliton solution of the negative order loaded modified Korteweg-de Vries equation.


On Generalizations Of The Upper Half Plane In A Multidimensional Complex Space, Bukharbay Kurbanov Mar 2023

On Generalizations Of The Upper Half Plane In A Multidimensional Complex Space, Bukharbay Kurbanov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

The paper considers an unbounded realization of a polydisk and a unit ball: the group of holomorphic automorphisms is described, and the Cauchy-Szego and Poisson kernels are calculated explicitly.


A Characterization Of Approximately Inner Automorphisms Of Aw*-Factor Of Type Ii1, Dmitriy Kim Mar 2023

A Characterization Of Approximately Inner Automorphisms Of Aw*-Factor Of Type Ii1, Dmitriy Kim

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Approximately inner *-automorphisms of AW*-algebra of type II1 are considered. Faithful normalized quasitraces of AW*-algebras are studied and the inequality connecting ||.||1 and ||.||2 norms generated by quasitrace is obtained. It is showed the characterization of approximately inner *-automorphisms of AW*-algebra of type II1.


Some Properties Of The Quartic Numerical Range For 4x4 Operator Matrices, Hakimboy Latipov Mar 2023

Some Properties Of The Quartic Numerical Range For 4x4 Operator Matrices, Hakimboy Latipov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In the present paper we consider self-adjoint 4x4 operator matrices A. For some special cases the alternative formulas for the calculating the quartic numerical range of 4x4 operator matrices A are derived. Using the obtained alternative formula for the quartic numerical range of A we estimate the lower and upper bound of A.


Inverse Source Problem For The Heat Equation On A Metric Star Graph With Integral Over-Determination Condition, Zarif Sobirov, Ariuxan Turemuratova Mar 2023

Inverse Source Problem For The Heat Equation On A Metric Star Graph With Integral Over-Determination Condition, Zarif Sobirov, Ariuxan Turemuratova

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this work we investigated an initial boundary value problem for the heat equation on a metric star graph in Sobolev space. The existence and uniqueness of the generalized solution are proved with the classical functional method based on a priori estimates. Also, we considered the inverse source problem with the integral over-determination condition. We reduced the inverse problem to the operator-based equation and proved that the corresponding resolvent operator is well-defined.


Integration Of The Negative Order Korteweg-De Vries Equation With Self-Consistent Source, Michal Fečkan, Gayrat Urazboev, Iroda Baltaeva, Oxunjon Ismoilov Mar 2023

Integration Of The Negative Order Korteweg-De Vries Equation With Self-Consistent Source, Michal Fečkan, Gayrat Urazboev, Iroda Baltaeva, Oxunjon Ismoilov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper, we show that the negative-order Korteweg-de Vries equation with a self-consistent source can be solved by the inverse scattering method. The evolution of the spectral data of the Sturm-Liouville operator with the potential associated with the solution of the negative order Korteweg-de Vries equation with a self-consistent source is determined. The results obtained make it possible to apply the method of the inverse scattering problem to solve the problem under consideration.


Cyclically Compact Sets In Banach Modules Over Algebra L0, Jasurbek Karimov Dec 2022

Cyclically Compact Sets In Banach Modules Over Algebra L0, Jasurbek Karimov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper some properties of cyclic compact sets in Banach modules over the algebra of measurable functions are given. The convergence of the cyclic subnet of any convergent sequence, and to the same limit is proved. It is also shown that if we multiply the cyclic compact set to any measurable function it will be cyclic compact set too.


Strongly M-Subharmonic Functions On Complex Manifolds, Sukrotbek Kurbonboyev Jun 2022

Strongly M-Subharmonic Functions On Complex Manifolds, Sukrotbek Kurbonboyev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

This article is devoted to the definition and study of strongly m-subharmonic (shm) functions on complex manifolds. A definition of strongly m-subharmonic functions on a Stein manifold is introduced and some basic properties are proven.


Analogue Of The Mittag-Leffler Theorem For A(Z)-Analytic Functions, Muhayyo Ne'matillayeva Jun 2022

Analogue Of The Mittag-Leffler Theorem For A(Z)-Analytic Functions, Muhayyo Ne'matillayeva

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We consider A(z)-analytic functions in case when A(z) is antiholomorphic function. For A(z)-analytic functions analog of the Mittag-Leffler theorem is proved.


Existence Of Boundary Values Of Hardy Class Functions H1A, Nasridin Zhabborov, Shokhruh Khursanov, Behzod Husenov Jun 2022

Existence Of Boundary Values Of Hardy Class Functions H1A, Nasridin Zhabborov, Shokhruh Khursanov, Behzod Husenov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We consider A(z)-analytic functions in case when A(z) is antianalytic function. In this paper, the Hardy class for A(z)-analytic functions are introduced and for these classes, the boundary values of the function are investigated. For the Hardy class of functions H1A, an analogue of Fatou's theorem was proved about that the bounded functions have the boundary values. As the main result, the boundary uniqueness theorem for Hardy classes of functions H1A is proven.


Algorithmic Criterion Of Locally Finite Separability Of Algebras Represented Over Equivalence Α2 ∪ Id Ω, Sarvar Zhavliev Jun 2022

Algorithmic Criterion Of Locally Finite Separability Of Algebras Represented Over Equivalence Α2 ∪ Id Ω, Sarvar Zhavliev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

It has been established that for equivalences of the form α2 ∪ id ω, the locally finite separability of any universal algebra represented over it is equivalent to the immune of the complement α. It is shown that for finitely separable algebras this criterion does not meet.


On The Hartogs Theorem For A-Analytic Functions In ℂN, Tolib Otaboev Mar 2022

On The Hartogs Theorem For A-Analytic Functions In ℂN, Tolib Otaboev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper, we define a separately A-analytic and an A-analytic function of several variables as a solution of system of equations of Beltrami in the space ℂn. It is proved an analogue of the Cauchy integral formula for an A-analytic function of several variables. It is proved a theorem on the expansion of an A-analytic function of several variables into a multiple series. When the function is bounded, it is proved an analogue of the Hartogs’ theorem for A-analytic functions of several variables.


M-Subharmonic Functions On The Projective Space PN, Gokhan Gogus, Azimbay Sadullaev Dec 2021

M-Subharmonic Functions On The Projective Space PN, Gokhan Gogus, Azimbay Sadullaev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We consider a class of quasi m-subharmonic functions in the projective space ℙn. Similarly to the m-subharmonic functions, we will show a number of potential properties of quasi m-subharmonic functions. We introduce the concepts of Green’s function Vqm*(z,K,ℙn), ��m-measure ωqm*(z,E,D) and study m-regularities of compact sets K ⊂ ℙn. In contrast to the complex space ℂn, we will prove that in the projective space ℙn the locally …


Interpretation Of De Sitter Space Of Second Kind, Abdulaziz Artikbaev, Botirjon Mamadaliyev Dec 2021

Interpretation Of De Sitter Space Of Second Kind, Abdulaziz Artikbaev, Botirjon Mamadaliyev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In a five-dimensional pseudo-Euclidean space of index two, the geometry on its sphere is studied. The equivalence of the geometry on a sphere of imaginary radius on de Sitter space is shown. The interpretation of the geometry on a sphere of imaginary radius, inside the sphere of imaginary radius of the Minkowski four-dimensional space, is implemented. We study a curve in a five-dimensional pseudo-Euclidean space of index two and determine the membership condition of the curve to a sphere of imaginary radius.


Dirichlet Problem In The Class Of A(Z)-Harmonic Functions, Shohruh Khursanov Dec 2021

Dirichlet Problem In The Class Of A(Z)-Harmonic Functions, Shohruh Khursanov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

This paper work is devoted to the study of the Dirichlet problem in the class of A(z)-harmonic functions.


On Extensions And Restrictions Of Τ-Smooth And Τ-Maxitive Idempotent Measures, Muzaffar Eshimbetov Sep 2021

On Extensions And Restrictions Of Τ-Smooth And Τ-Maxitive Idempotent Measures, Muzaffar Eshimbetov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In the paper we investigate maps between idempotent measures spaces, τ-maxitive idempotent measures and their extensions and restrictions. For an idempotent measure we prove that its extension is τ-maxitive if and only if its restriction is τ-maxitive.


Duality For L1-Spaces Associated With The Maharam Measure, Botir Zakirov, Khabibulla Umarov Sep 2021

Duality For L1-Spaces Associated With The Maharam Measure, Botir Zakirov, Khabibulla Umarov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Dual space for the Banach-Kantorovich space L1(m) of all functions integrable with respect to a Maharam measure m is described and its pre-dual space is constructed.


Weighted (M, Δ)-Green Functions In CN, Nurbek Narzillaev Sep 2021

Weighted (M, Δ)-Green Functions In CN, Nurbek Narzillaev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this work some extremal function and its properties are studied for the class of m-subharmonic functions. We study weighted (m,δ)-Green function Vm*(z,K,ψ,δ), defined by the class ℒmδ = {u(z)∈shm(ℂn): u(z)≤δ, z∈ℂn}, δ > 0. We see that the regularity of the points with respect to different numbers δ differ from each other. Nevertheless, we will prove that if the compact K ⊂ ℂn …


Negative Representability Degree Structures Of Linear Orders With Endomorphisms, Nadimulla Kasymov, Sarvar Javliyev Jun 2021

Negative Representability Degree Structures Of Linear Orders With Endomorphisms, Nadimulla Kasymov, Sarvar Javliyev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

The structure of partially ordered sets of degrees of negative representability of linear orders with endomorphisms is studied. For these structures, the existence of incomparable, maximum and minimum degrees, infinite chains and antichains is established,and also considered connections with the concepts of reducibility of enumerations, splittable degrees and positive representetions.