Marian Apostol - Academia.edu (original) (raw)
Papers by Marian Apostol
The book comprises a series of author's personal texts on various subjects in Theoretical Phy... more The book comprises a series of author's personal texts on various subjects in Theoretical Physics. Some are easy writings, like those on our world's numbers, main physical principles, numerical computation, probabilities, general laws of motion. Others deal with old subjects, like celestial mechanics, particles' scattering, fluids, many-body dynamics, the Thomas-Fermi atom, superfluidity, liquids. New insights are obtained from old problems, included in these Lectures, like the relation between quantization and the non-inertial motion, or the curved spaces, the connection between teleportation and the chemical reactivity, the theory of the laser, the van der Waals isotherms and condensation of matter. Modern issues like the quanta of electrical conductance or the hadronization of the quark-gluon plasma could be described by "elementary" Physics; or we can arrive at unexpected, strange things, like densitons in classical fluids, all included here. The book aims at conveying a certain, particularly attractive, worthiness of Physics.
Annals of Mathematics and Physics
The drag force in a gas (previously derived by Stokes and Rayleigh) is derived by means of the mo... more The drag force in a gas (previously derived by Stokes and Rayleigh) is derived by means of the molecular kinetics (transport equation of the momentum). Two regimes of resistance to motion are identified, governed by the relation of the velocity to the thermal (molecular) velocity. They correspond to the molecular movement, for small velocities, or to the hydrodynamic motion for high velocities. In the former case sound waves are not excited, and energy is dissipated by viscosity (friction), while in the latter case the energy is dissipated by the excitation of the sound waves. Also, the treatment is applied to the plasma. It is shown that in usual plasmas it is unlikely that the body motion excites plasmons.
Rev.Roum.Phys. {\bf 32}, 1987
arXiv: Atomic Physics, 2019
Binding energy of heavy atoms is estimated by means of the Thomas-Fermi model, giant dipole oscil... more Binding energy of heavy atoms is estimated by means of the Thomas-Fermi model, giant dipole oscillation are highlighted and ionization is discussed.
Open Access Journal of Mathematical and Theoretical Physics, 2018
Rev. Roum. Phys., v. 20, no. 6, pp. 645-651, 1975
... Publication Date, 1975 Jan 01. OSTI Identifier, OSTI ID: 4090834. Other Number(s), Journal ID... more ... Publication Date, 1975 Jan 01. OSTI Identifier, OSTI ID: 4090834. Other Number(s), Journal ID: RRPQA. Resource Type, Journal Article. Resource Relation, Journal Name: Rev. Roum. Phys., v. 20, no. 6, pp. 645-651; Other Information: Orig. Receipt Date: 30-JUN-76. ...
Solid State Communications, 1996
Physics and Chemistry of Liquids
arXiv (Cornell University), Dec 14, 2015
Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to... more Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to an external time-dependent electric field, are discussed in a few particular conditions which can be of some experimental interest. First, the spherical-pendulum molecular model is reviewed, with the aim of introducing an approximate method which consists in the separation of the azimuthal and zenithal motions. Second, rotation spectra are considered in the presence of a static electric field. Two particular cases are analyzed, corresponding to strong and weak fields. In both cases the dipoles perform rotations and vibrations about equilibrium positions, which may exhibit parametric resonances. For strong fields a large macroscopic electric polarization may appear. This situation may be relevant for polar matter (like pyroelectrics, ferroelectrics), or for heavy impurities embedded in a polar solid. The dipolar interaction is analyzed in polar condensed matter, where it is shown that new polarization modes appear for a spontaneous macroscopic electric polarization (these modes are tentatively called "dipolons"); one of the polarization modes is related to parametric resonances. The extension of these considerations to magnetic dipoles is briefly discussed. The treatment is extended to strong electric fields which oscillate with a high frequency, as those provided by high-power lasers. It is shown that the effect of such fields on molecular dynamics is governed by a much weaker, effective, renormalized, static electric field.
It is shown that the construction introduced recently by Setlur and Chang (see, for instance, Phy... more It is shown that the construction introduced recently by Setlur and Chang (see, for instance, Phys. Rev. B57 15 144 (1998)) for generalized Fermi sea-displacement operators contains undefined, ambiguous, and superfluous elements, which may lead to divergencies, and, in fact, these are not bosonic operators. As such, it is hard to see (and to accept) the claim made by these authors of solving the interaction problem in Fermi systems by means of these operators.
The quasi-classical theory of matter aggregation is briefly reviewed and the guiding principles o... more The quasi-classical theory of matter aggregation is briefly reviewed and the guiding principles of formation of the atomic clusters are discussed. The interaction potential of a metallic ion with a semi-infinite solid exhibiting a free plane surface is derived and atomic clusters deposited on surfaces are constructed. Binding energies, ground-states, magic geometries, isomers, interatomic distances, vibration spectra and monolayers are thus obtained, and further developments are outlined.
At least four major misconceptions gravely affect science and technology today, and the progress ... more At least four major misconceptions gravely affect science and technology today, and the progress of scientific and technological research. These misconceptions are related to a utilitarian view of science, whereby large-scale collaborations and institutions of higher learning are conceived of as the only means for developing science and technology, where scientific publication is the sole aim of scientific research, within a commercial view of the nature of these human endeavours and activities. It is revealed herein just how abusive and destructive these misconceptions are, and to what great extent they now plague society. In complementing D. Rabounski’s recent Declaration of the Academic Freedom, scientific and technological research should reaffirm its free, universal and critical nature, as a source of human dignity and honour, honesty and lucidity. Unfortunately, a despicable vulgarization of science and technology has led nowadays to a widely held relativism and uncertainty, w...
The quasi-classical theoretical description of matter aggregation and solid-state cohesion at ato... more The quasi-classical theoretical description of matter aggregation and solid-state cohesion at atomic level is briefly presented in connection with its multiple applications to atomic clusters and nanostructures. The formation of isolated atomic clusters of up to 160 atoms is presented and characterized with respect to geometric forms, atomic positions, inter-atomic distances, ground-states and isomers, binding energies, magic numbers, vibration spectra, and the derivation of single-particle properties is outlined, within the point-like ions approximation. The surface of a semi-infinite solid is characterized within the same approach, and the formation of clusters deposited on surfaces is described, with regard to similar physical and chemical information. Peculiar nanostructures are also presented, as resulted from computation processes, as an indication of the large variety of possible nanostructured forms. The extension of the theoretical tools to more complex situations, in parti...
arXiv: High Energy Physics - Phenomenology, 2015
It is suggested that the hadronization of the quark-gluon plasma is a first-order phase transitio... more It is suggested that the hadronization of the quark-gluon plasma is a first-order phase transition described by a critical curve in the temperature-(quark) density plane which terminates in a critical point. Such a critical curve is derived from the van der Waals equation and its parameters are estimated. The main assumption is that quark-gluon plasma created by high-energy nucleus-nucleus collisions is a gas of ultrarelativistic quarks in equilibrium with gluons (vanishing chemical potential, indef- inite number of quarks). This plasma expands, gets cool and dilute and hadronizes at a certain transition temperature and transition density. The transition density is very close to the saturation density of the nuclear matter and, it is suggested that both these points are very close to the critical point n ' 1fm 3 (quark density) and T ' 200MeV (temperature).
Open Access Journal of Mathematical and Theoretical Physics, 2018
It is shown that the usual derivations of the van der Waals equation are inconsistent. The van de... more It is shown that the usual derivations of the van der Waals equation are inconsistent. The van der Waals equation is derived here in a more general framework, which employs the mean-field approximation.
The Journal of Physical Chemistry, 1996
The thermodynamical potential for dilute solutions is rederived, generalized and applied to defec... more The thermodynamical potential for dilute solutions is rederived, generalized and applied to defects in solids. It is shown that there are always defects in solids, i.e. there is no perfect solid at any finite temperature. Apart from the temperature-dependent concentration of defects, another case is presented, where the defect concentration does not depend on temperature.
The book comprises a series of author's personal texts on various subjects in Theoretical Phy... more The book comprises a series of author's personal texts on various subjects in Theoretical Physics. Some are easy writings, like those on our world's numbers, main physical principles, numerical computation, probabilities, general laws of motion. Others deal with old subjects, like celestial mechanics, particles' scattering, fluids, many-body dynamics, the Thomas-Fermi atom, superfluidity, liquids. New insights are obtained from old problems, included in these Lectures, like the relation between quantization and the non-inertial motion, or the curved spaces, the connection between teleportation and the chemical reactivity, the theory of the laser, the van der Waals isotherms and condensation of matter. Modern issues like the quanta of electrical conductance or the hadronization of the quark-gluon plasma could be described by "elementary" Physics; or we can arrive at unexpected, strange things, like densitons in classical fluids, all included here. The book aims at conveying a certain, particularly attractive, worthiness of Physics.
Annals of Mathematics and Physics
The drag force in a gas (previously derived by Stokes and Rayleigh) is derived by means of the mo... more The drag force in a gas (previously derived by Stokes and Rayleigh) is derived by means of the molecular kinetics (transport equation of the momentum). Two regimes of resistance to motion are identified, governed by the relation of the velocity to the thermal (molecular) velocity. They correspond to the molecular movement, for small velocities, or to the hydrodynamic motion for high velocities. In the former case sound waves are not excited, and energy is dissipated by viscosity (friction), while in the latter case the energy is dissipated by the excitation of the sound waves. Also, the treatment is applied to the plasma. It is shown that in usual plasmas it is unlikely that the body motion excites plasmons.
Rev.Roum.Phys. {\bf 32}, 1987
arXiv: Atomic Physics, 2019
Binding energy of heavy atoms is estimated by means of the Thomas-Fermi model, giant dipole oscil... more Binding energy of heavy atoms is estimated by means of the Thomas-Fermi model, giant dipole oscillation are highlighted and ionization is discussed.
Open Access Journal of Mathematical and Theoretical Physics, 2018
Rev. Roum. Phys., v. 20, no. 6, pp. 645-651, 1975
... Publication Date, 1975 Jan 01. OSTI Identifier, OSTI ID: 4090834. Other Number(s), Journal ID... more ... Publication Date, 1975 Jan 01. OSTI Identifier, OSTI ID: 4090834. Other Number(s), Journal ID: RRPQA. Resource Type, Journal Article. Resource Relation, Journal Name: Rev. Roum. Phys., v. 20, no. 6, pp. 645-651; Other Information: Orig. Receipt Date: 30-JUN-76. ...
Solid State Communications, 1996
Physics and Chemistry of Liquids
arXiv (Cornell University), Dec 14, 2015
Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to... more Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to an external time-dependent electric field, are discussed in a few particular conditions which can be of some experimental interest. First, the spherical-pendulum molecular model is reviewed, with the aim of introducing an approximate method which consists in the separation of the azimuthal and zenithal motions. Second, rotation spectra are considered in the presence of a static electric field. Two particular cases are analyzed, corresponding to strong and weak fields. In both cases the dipoles perform rotations and vibrations about equilibrium positions, which may exhibit parametric resonances. For strong fields a large macroscopic electric polarization may appear. This situation may be relevant for polar matter (like pyroelectrics, ferroelectrics), or for heavy impurities embedded in a polar solid. The dipolar interaction is analyzed in polar condensed matter, where it is shown that new polarization modes appear for a spontaneous macroscopic electric polarization (these modes are tentatively called "dipolons"); one of the polarization modes is related to parametric resonances. The extension of these considerations to magnetic dipoles is briefly discussed. The treatment is extended to strong electric fields which oscillate with a high frequency, as those provided by high-power lasers. It is shown that the effect of such fields on molecular dynamics is governed by a much weaker, effective, renormalized, static electric field.
It is shown that the construction introduced recently by Setlur and Chang (see, for instance, Phy... more It is shown that the construction introduced recently by Setlur and Chang (see, for instance, Phys. Rev. B57 15 144 (1998)) for generalized Fermi sea-displacement operators contains undefined, ambiguous, and superfluous elements, which may lead to divergencies, and, in fact, these are not bosonic operators. As such, it is hard to see (and to accept) the claim made by these authors of solving the interaction problem in Fermi systems by means of these operators.
The quasi-classical theory of matter aggregation is briefly reviewed and the guiding principles o... more The quasi-classical theory of matter aggregation is briefly reviewed and the guiding principles of formation of the atomic clusters are discussed. The interaction potential of a metallic ion with a semi-infinite solid exhibiting a free plane surface is derived and atomic clusters deposited on surfaces are constructed. Binding energies, ground-states, magic geometries, isomers, interatomic distances, vibration spectra and monolayers are thus obtained, and further developments are outlined.
At least four major misconceptions gravely affect science and technology today, and the progress ... more At least four major misconceptions gravely affect science and technology today, and the progress of scientific and technological research. These misconceptions are related to a utilitarian view of science, whereby large-scale collaborations and institutions of higher learning are conceived of as the only means for developing science and technology, where scientific publication is the sole aim of scientific research, within a commercial view of the nature of these human endeavours and activities. It is revealed herein just how abusive and destructive these misconceptions are, and to what great extent they now plague society. In complementing D. Rabounski’s recent Declaration of the Academic Freedom, scientific and technological research should reaffirm its free, universal and critical nature, as a source of human dignity and honour, honesty and lucidity. Unfortunately, a despicable vulgarization of science and technology has led nowadays to a widely held relativism and uncertainty, w...
The quasi-classical theoretical description of matter aggregation and solid-state cohesion at ato... more The quasi-classical theoretical description of matter aggregation and solid-state cohesion at atomic level is briefly presented in connection with its multiple applications to atomic clusters and nanostructures. The formation of isolated atomic clusters of up to 160 atoms is presented and characterized with respect to geometric forms, atomic positions, inter-atomic distances, ground-states and isomers, binding energies, magic numbers, vibration spectra, and the derivation of single-particle properties is outlined, within the point-like ions approximation. The surface of a semi-infinite solid is characterized within the same approach, and the formation of clusters deposited on surfaces is described, with regard to similar physical and chemical information. Peculiar nanostructures are also presented, as resulted from computation processes, as an indication of the large variety of possible nanostructured forms. The extension of the theoretical tools to more complex situations, in parti...
arXiv: High Energy Physics - Phenomenology, 2015
It is suggested that the hadronization of the quark-gluon plasma is a first-order phase transitio... more It is suggested that the hadronization of the quark-gluon plasma is a first-order phase transition described by a critical curve in the temperature-(quark) density plane which terminates in a critical point. Such a critical curve is derived from the van der Waals equation and its parameters are estimated. The main assumption is that quark-gluon plasma created by high-energy nucleus-nucleus collisions is a gas of ultrarelativistic quarks in equilibrium with gluons (vanishing chemical potential, indef- inite number of quarks). This plasma expands, gets cool and dilute and hadronizes at a certain transition temperature and transition density. The transition density is very close to the saturation density of the nuclear matter and, it is suggested that both these points are very close to the critical point n ' 1fm 3 (quark density) and T ' 200MeV (temperature).
Open Access Journal of Mathematical and Theoretical Physics, 2018
It is shown that the usual derivations of the van der Waals equation are inconsistent. The van de... more It is shown that the usual derivations of the van der Waals equation are inconsistent. The van der Waals equation is derived here in a more general framework, which employs the mean-field approximation.
The Journal of Physical Chemistry, 1996
The thermodynamical potential for dilute solutions is rederived, generalized and applied to defec... more The thermodynamical potential for dilute solutions is rederived, generalized and applied to defects in solids. It is shown that there are always defects in solids, i.e. there is no perfect solid at any finite temperature. Apart from the temperature-dependent concentration of defects, another case is presented, where the defect concentration does not depend on temperature.