Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Physical Sciences and Mathematics

Ill-Posed Boundary Value Problem For Operator-Differential Equation Of Fourth Order, Kudratillo Fayazov, Ikrom Khajiev, Z. Fayazova Sep 2018

Ill-Posed Boundary Value Problem For Operator-Differential Equation Of Fourth Order, Kudratillo Fayazov, Ikrom Khajiev, Z. Fayazova

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We prove the correctness of the conditional boundary value problem for an operator differential equation of the fourth order. A priori estimate is get. Uniqueness and conditional stability of solution are proved. The approximate solution is construct and get estimates of the norm of the difference between the exact and approximate solution.


Translation-Invariant Gibbs Measures Of A Model On Cayley Tree, Golibjon Botirov Sep 2018

Translation-Invariant Gibbs Measures Of A Model On Cayley Tree, Golibjon Botirov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We consider a model where the spin takes values in the set [0,1]d, and is assigned to the vertexes of the Cayley tree. We reduce the problem of describing the “splitting Gibbs measures” of the model to the description of the solutions of some non-linear integral equation. For a concrete form of the Kernel of the integral equation we show the uniqueness of solution.


Using An A Priori Estimate For Constructing Difference Schemes For Quasi-Linear Hyperbolic Systems, Rakhmatillo Aloev, Mirzoali Khudayberganov Mar 2018

Using An A Priori Estimate For Constructing Difference Schemes For Quasi-Linear Hyperbolic Systems, Rakhmatillo Aloev, Mirzoali Khudayberganov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper we consider a class of quasi-linear hyperbolic systems, which allows the construction of a dissipative energy integrals. In the basis of the design and investigation the stability of difference schemes for the numerical solution of the initial boundary value problems for the above class of quasi-linear hyperbolic systems, we put the existence of a discrete analogue of the dissipative energy integrals.


Some Cardinal And Topological Properties Of The $N$-Permutation Degree Of A Topological Spaces And Locally $\Tau$-Density Of Hyperspaces, Farkhod Mukhamadiev Mar 2018

Some Cardinal And Topological Properties Of The $N$-Permutation Degree Of A Topological Spaces And Locally $\Tau$-Density Of Hyperspaces, Farkhod Mukhamadiev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In the paper we investigate some cardinal and topological properties of the $n$-permutation degree of a topological spaces and locally $\tau$-density of hyperspaces. It is proved that the functors $\exp_n$ and $SP^n$ preserves locally $\tau$-density of any infinite $T_1$-spaces.


Using An A Priori Estimate For Constructing Difference Schemes For Quasi-Linear Hyperbolic Systems, Rakhmatillo Aloev, Mirzoali Khudayberganov Mar 2018

Using An A Priori Estimate For Constructing Difference Schemes For Quasi-Linear Hyperbolic Systems, Rakhmatillo Aloev, Mirzoali Khudayberganov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper we consider a class of quasi-linear hyperbolic systems, which allows the construction of a dissipative energy integrals. In the basis of the design and investigation the stability of difference schemes for the numerical solution of the initial boundary value problems for the above class of quasi-linear hyperbolic systems, we put the existence of a discrete analogue of the dissipative energy integrals.


On The Manifolds Of Positive Curvature, Jasurbek Aslonov Mar 2018

On The Manifolds Of Positive Curvature, Jasurbek Aslonov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper invariant metrics on Lie group $G=S^3\times R$ are studied and it is found lower and upper bounds for the sectional curvature's of the manifold $G=S^3\times R$.


Positive Fixed Points Of Lyapunov Integral Operators And Gibbs Measures, Farkhod Haydarov Mar 2018

Positive Fixed Points Of Lyapunov Integral Operators And Gibbs Measures, Farkhod Haydarov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper it is found fixed points of Lyapunov integral equation and considered the connections between Gibbs measures for four competing interactions of models with uncountable (i.e. $[0,1]$) set of spin values on the Cayley tree of order two.


Carleman’S Formula For The Matrix Upper Half-Plane, Gulmirza Khudayberganov, Zokirbek Matyakubov Mar 2018

Carleman’S Formula For The Matrix Upper Half-Plane, Gulmirza Khudayberganov, Zokirbek Matyakubov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this work the Carleman’s formula for the matrix upper half-plane is obtained.


Carleman's Formula For The Matrix Upper Half-Plane, Gulmirza Khudayberganov, Zokirbek Matyakubov Mar 2018

Carleman's Formula For The Matrix Upper Half-Plane, Gulmirza Khudayberganov, Zokirbek Matyakubov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this work the Carleman’s formula for the matrix upper half-plane is obtained.


Some Cardinal And Topological Properties Of The N-Permutation Degree Of A Topological Spaces And Locally Τ-Density Of Hyperspaces, Farkhod Mukhamadiev Mar 2018

Some Cardinal And Topological Properties Of The N-Permutation Degree Of A Topological Spaces And Locally Τ-Density Of Hyperspaces, Farkhod Mukhamadiev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In the paper we investigate some cardinal and topological properties of the n-permutation degree of a topological spaces and locally τ-density of hyperspaces. It is proved that the functors expn and SPn preserves locally τ-density of any infinite T1-spaces.