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Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Problems Of Formation And Evolution Of Bulges Of Spiral Galaxies, Farkhodjon Botirov, Salakhutdin Nuritdinov Mar 2022

Problems Of Formation And Evolution Of Bulges Of Spiral Galaxies, Farkhodjon Botirov, Salakhutdin Nuritdinov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this work, we develop the theory of the origin of galactic bulges, and gravitational instability of the bending, as well as modes of perturbation based on the background of a nonlinear non-stationary model. As a result, here, we propose critical diagrams and determine increments of instabilities for such types of perturbations. In addition, we also consider relationships between the masses of the bulge and the central black hole, which is of great importance in studying the evolution of the bulges of spiral galaxies. Moreover, problems on the evolution of bulges in spiral galaxies, together with discussions of their main …

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Study Asymmetry Of Stellar Jets, Stanislav Melnikov, Karomat Mirtadjieva Sep 2021

Study Asymmetry Of Stellar Jets, Stanislav Melnikov, Karomat Mirtadjieva

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

This review article describes the diversity of astrophysical jets. The differences between relativistic and slower stellar jets are described briefly. The data on recent studies of stellar jets, which led to the discovery of the asymmetry of their emissions - a mismatch of their parameters in the opposite components. A review of the physical mechanisms that is proposed to explain the observed asymmetry is given.

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Problems Of Classification Of Globular Clusters And Their Systems, Nuritdinov Saloxutdin, Ikram Tadjibaev Jun 2021

Problems Of Classification Of Globular Clusters And Their Systems, Nuritdinov Saloxutdin, Ikram Tadjibaev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

A review is carried out mainly of the classification problems of globular clusters (GC) of our Galaxy. Classification of GC has a rich history, since it was first considered by Shapley and Sawyer [1] over 90 years ago. After them, a number of authors [2-8] tried to classify GC in various ways, but however, before our work no one was able to solve this problem to the desired level. We first studied the physical characteristics of the GC of our Galaxy by constructing diagrams of the relationship between these characteristics. Next, we decided to answer the question of whether it …

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Death Line For Radio Pulsars In Braneworlds, Djavlanbek Rayimbaev, Satimbay Palvanov, Maksud Umaraliyev, Malika Khudoyberdiyeva Apr 2020

Death Line For Radio Pulsars In Braneworlds, Djavlanbek Rayimbaev, Satimbay Palvanov, Maksud Umaraliyev, Malika Khudoyberdiyeva

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We investigate the effects of braneworlds on energetic processes in plasma. magnetosphere of neutron stars. Obtained that the presence of brane charge causes an increase in the size of the polar cap region. It has shown that the polar capsize of neutron stars with larger rotation period and compactness parameter is also larger. We have studied deathline of radio pulsar in braneworld. Obtained that the deathline shifted down and the pulsars which lying on the deathline become visible in radio band. Moreover, we have extended particle acceleration in polar cap of neutron stars in the presence of the brane charge, …

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Test Particle Motion Around Brany Black Hole Immersed In An External Asymptotically Uniform Magnetic Field, Djavlanbek Rayimbaev, Azamjon Rakhmatov, Satimbay Palvanov, Ahror Mamadjanov Jun 2019

Test Particle Motion Around Brany Black Hole Immersed In An External Asymptotically Uniform Magnetic Field, Djavlanbek Rayimbaev, Azamjon Rakhmatov, Satimbay Palvanov, Ahror Mamadjanov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We investigate circular motion of charged and neutral particles around non-rotating black hole immersed in an external asymptotically uniform magnetic field. The effects of braneworlds on innermost circular stable orbits have been considered. Shown that innermost circular orbits (ISCO) decreases in decreasence of both brane charge and particle charge. Moreover, we have investigated energy extraction from black holes in braneworld through collision of two particles. Obtained that the presence of the brane charge parameter causes to decrease of the value of center of mass energy of colliding two charged particles, it means the brane charge acts as an additional gravity.

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Thermal Evolution Modification Due To Radio-Wave Production Inside Rotating Magnetized Ns, Pulat Tadjimuratov Sep 2018

Thermal Evolution Modification Due To Radio-Wave Production Inside Rotating Magnetized Ns, Pulat Tadjimuratov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

We study effect of additional cooling mechanism on the thermal evolution of rotating magnetized neutron star (NS). The influence of general relativistic effects on charge distribution inside a NS leads to the qualitative distinction of space charge distribution inside the conducting crust from that inside the superconducting core which may play a source of a possible mechanism of radio-wave radiation production in the intermediate medium inside a rotating neutron star. This radiation may interact the matter of the neutron star and energy of the electromagnetic radiation can be transformed into the heating energy. The intensity of radio-wave radiation produced inside …

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