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V. Celebonovic

Publications and source records attributed to V. Celebonovic.

At least 19 recordsLinked to original sources
arXiv2019

Material Science and Impact Crater Formation

The surfaces of solid objects in our planetary system are dappled with craters. Some of them are due to impacts of various solid projectiles into the surfaces of the objects. A smaller part of these craters is of volcanic origin. %Some of these are of volcanic origin, but others are consequences of impacts of various projectiles into the objects concerned On the Earth,two most often mentioned such events are the "Tunguska event" of 1908. and the impact which led to the formation of the Barringer crater in Arizona. Impact craters are frequently analyzed within the "scaling theory", which is founded on dimensional analysis. The same problem can be treated by using standard laws of material science and condensed matter physics. In this chapter the two approaches will be compared and possibilities for future work indicated to some extent. Some preliminary conclusions concerning an impact into a granular target will be presented.

astro-ph.EP↗
arXiv2016

A simple example of pressure excitation:the 3D square well potential

High pressure experiments in diamond anvil cells as well as in geophysics show that at certain discrete values of pressure abrupt changes of the mass density and changes of the material structure occur. The aim of this paper is to discuss the influence of high external pressure on atoms and molecules using the $3D$ square well potential as a simple solvable quantum mechanical example. Values of external pressure needed for a transition between energy levels with different values of the main quantum number $n$, as well as the pressure needed to expel the particle from this system are calculated. In both cases discrete values of pressure are obtained.

quant-ph↗
arXiv2014

A condensed matter analogy of impact crater formation

Impact craters exist on various solid objects in the planetary system. A simplified analogy of the process of their formation is here analyzed by standard solid state physics and the so called dynamic quantized fracture mechanics. An expression which links the crater volume to the parameters of the impactor and the target is obtained within the two approaches. For low impactor energy, this expression is of the same mathematical form as the one resulting from recent experiments.It is shown that the formation of an impact crater is possible even without heating of the target, if the critical stress in the target satisfies certain conditions. The critical value of the stress needed for the occurence of a fracture is calculated for three craters: two terrestrial and one lunar crater. The approach presented here uses only measurable material parameters, and is therefore more realistic than the treatement of the same problem using the cohesive energy of materials.

astro-ph.EP↗
arXiv2013

Solid state physics of impact crater formation: further considerations

Impact craters exist on solid surface planets, their satellites and many asteroids.The aim of this paper is to propose a theoretical expression for the product $ρr^{3} v_{1}^{2}$,where the three symbols denote the mass density,radius and speed of the impactor. The expression is derived using well known results of solid state physics,and it can be used in estimating parameters of impactors which have led to formation of craters on various solid bodies in the Solar System.

astro-ph.EP↗
arXiv2013

Solid state physics of impact crater formation: a detail

Impact craters exist on solid surface planets, their satellites and many asteroids.The aim of this paper is to propose a theoretical expression for the product $ρr^{3} v_{1}^{2}$,where the three symbols denote the mass density,radius and speed of the impactor. The expression is derived using well known results of solid state physics,and it can be used in estimating parameters of impactors which have led to formation of craters on various solid bodies in the Solar System.

astro-ph.EP↗
arXiv2012

Heating in collisions of solids:possible application to impact craters

Due to the importance of collisions and impacts in early phases of the evolution of the planetary system, it is interesting to estimate the heating of a solid target due to an impact in it . A physically simple calculation of the temperature to which a solid target heats up after the impact of a projectile with mass $m$ and speed $v$ is performed,and possibilities for the application of this result in planetology are pointed out.

astro-ph.EP↗
arXiv2011

The chemical potential of a Lennard Jones fluid

The aim of this paper is to present an analytical calculation of the chemical potential of a Lennard Jones fluid. The integration range is divided into two regions. In the small distance region,which is $r\leqσ$ in the usual notation,the integration range had to be cut off in order to avoid the occurence of divergences.In the large distance region,the calculation is technically simpler. The calculation reported here will be useful in all kinds of studies concerning phase equilibrium in a $LJ$ fluid. Interesting kinds of such systems are the giant planets and the icy satellites in various planetary systems,but also the (so far) hypothetical quark stars.

cond-mat.stat-mech↗
arXiv2011

The two dimensional Hubbard model:a theoretical tool for molecular electronics

When speaking about molecular electronics, the obvious question which occurs is how does one study it theoretically. The simplest theoretical model suitable for application in molecular electronics is the two dimensional Hubbard model. The aim of the present paper is to introduce this model, and give some examples of the systems which it can describe. After a short mathematically oriented discussion, it will be shown how to calculate the electrical conductivity of a particular planar system: a rectangular lattice with mutually independent conductivities along the two axes,but without using the 2D Hamiltonian. This system could find applications in high Tc studies. It will finally be shown that the electrical conductivity of graphene can be determined not by using the full formalism of the $2D$ Hubbard model, but by a slight reformulation of the Hamiltonian of the 1D Hubbard model

cond-mat.str-el↗
arXiv2010

Invisibility in one dimensional systems: a possible way to achieve it

The aim of this paper is to provide the mathematical framework for analyzing the possibility of rendering one dimensional objects visible with difficulty and ultimately invisible,by changing the experimental conditions to which they are subdued. The calculation was performed using the Hubbard model,and it will be based on a recent expression for a particular class of Q1D organic salts. Two sets of material parameters for which the reflectivity of a 1D object tends to zero have been determined.

cond-mat.str-el↗
arXiv2010

The reflection spectra of the Bechgaard salts:a theoretical determination

The aim of this contribution is to analyze to some extent the reflectivity of the family of organic salts known as the Bechgaard salts. The reflectivity will be calculated using a well known theoretical framework,and results for the electrical conductivity and susceptibility of these materials. The result obtained for the reflectivity is a non-linear expression depending on various material parameters within the Hubbard model. The position of the region where the reflectivity tends to zero will also be determined as a function of model parameters. A possibility of extending the results to 2D systems is briefly mentioned.

cond-mat.str-el↗
arXiv2010

The Hubbard model: basic notions and selected applications

The aim of this paper is to present a self contained introduction to the Hubbard model and some of its applications.The paper consists of two parts: the first will introduce the basic notions of the Hubbard model starting from the motivation for its development to the formulation of the Hamiltonian,and some methods of calculation within the model. The second part will discuss some applications of the model to 1D and 2D systems,based on a combination of the author's results with those from the literature.

cond-mat.mtrl-sci↗
arXiv2010

Impact crater formation: a simple application of solid state physics

This contribution is a first step aiming to address a general question: what can be concluded on impact craters which exist on various planetary system objects, by combining astronomical data and known theoretical results from solid state physics. Assuming that the material of the target body is of crystaline structure,it is shown that a simple calculation gives the possibility of estimating the speed of the impactor responsible for the creation of a crater.A test value,calculated using observed data on the composition of some asteroids,gives a value of the speed in good agreement with results of celestial mechanics.

astro-ph.EP↗
arXiv2010

Transport properties of the Hubbard model in low dimensions

The Hubbard model describes interacting electrons on a lattice,a situation which occurs in various solid state materials and devices. The aim of the present paper is to briefly discuss this model and its applications in the study of transport properties of Q1D and Q2D systems. Several examples are taken from materials and fields that have been intensively studied in recent years.

cond-mat.mtrl-sci↗
arXiv2009

On the coexistence of phases in a Lennard Jones liquid:first results

The aim of this paper is to investigate the conditions for the coexistence of phases in a Lennard Jones fluid. The calculation has been performed within the virial developement mathod and, as a result, a simple approximate relation has been obtained between the number densities of two coexisting densities and the interparticle potentials in them. The calculation is preliminary,in the sense that it does not take into account the equality of the chemical potentials. The results of this work may have implications for modelling of the giant planets. More than 300 exoplanets have been discovered, so this has become more important than ever.

astro-ph.EP↗
arXiv2008

A simple determination of some characteristics of the beta Pictoris system

The aim of this contribution is to determine the lower limit of the electron number density,the Debye temperature and the specific heat of solid grains present in the protoplanetary grains around beta Pictoris. The calculation has been performed using the Salpeter criterion,slightly modified a couple of years ago. The results obtained are physically reasonable and could be helpful in determining the chemical composition of solid particles in this system.

astro-ph↗
arXiv2007

The internal structure of the asteroids

This contribution has the aim to review the basics of existing knowledge on asteroid interiors and to explore the possibility of advancing the field by introducing into it some ideas from solid state physics.

astro-ph↗
arXiv2006

Basic notions of dense matter physics: applications to astronomy

The aim of this paper is to present basic notions of dense matter physics and some of its applications to geophysics and astronomy.Topics covered in the paper include:basic observational data,fun- damental ideas of static high pressure experiments, notions of theoretical dense matter physics, and finally some details about theoretical work on dense matter physics and its astronomical applications in Serbia.

astro-ph↗