Condensed matter electrodynamics: equations of state by partition function

2020 ◽  
Author(s):  
Sergey Leble
Keyword(s):  
Partition Function ◽  
Equations Of State ◽  
Condensed Matter

scholarly journals Condensed-matter equation of states covering a wide region of pressure studied experimentally

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Elijah E. Gordon ◽  
Jürgen Köhler ◽  
Myung-Hwan Whangbo
Keyword(s):  
Strain Energy ◽  
Equations Of State ◽  
Interatomic Potential ◽  
Condensed Matter ◽  
Mathematical Functions ◽  
Wide Region ◽  
Equation Of States ◽  
Cubic Polynomial ◽  
Temperature And Pressure ◽  
Fitting Parameters

Abstract The relationships among the pressure P, volume V, and temperature T of solid-state materials are described by their equations of state (EOSs), which are often derived from the consideration of the finite-strain energy or the interatomic potential. These EOSs consist of typically three parameters to determine from experimental P-V-T data by fitting analyses. In the empirical approach to EOSs, one either refines such fitting parameters or improves the mathematical functions to better simulate the experimental data. Despite over seven decades of studies on EOSs, none has been found to be accurate for all types of solids over the whole temperature and pressure ranges studied experimentally. Here we show that the simple empirical EOS, P = α 1 (PV) + α 2 (PV) 2  + α 3 (PV) 3 , in which the pressure P is indirectly related to the volume V through a cubic polynomial of the energy term PV with three fitting parameters α 1 –α 3 , provides accurate descriptions for the P-vs-V data of condensed matter in a wide region of pressure studied experimentally even in the presence of phase transitions.

scholarly journals Towards the Keplerian sequence: Realistic equations of state in rapidly rotating neutron stars

2020 ◽  
Vol 27 ◽  
pp. 85
Author(s):  
Polychronis Koliogiannis Koutmiridis ◽  
Charalampos Moustakidis
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Equations Of State ◽  
Condensed Matter ◽  
Rest Mass ◽  
Spin Parameter ◽  
Nuclear Models ◽  
The Moment ◽  
The Universe ◽  
Axisymmetric Instability

Neutron stars are among the densest known objects in the universe and an ideal laboratory for the strange physics of super-condensed matter. In the present work, we investigate the Keplerian (mass-shedding) sequence of rotating neutron stars by employing realistic equations of state based on various theoretical nuclear models. In particular, we compute the moment of inertia and angular momentum of neutron stars against mass-shedding and secular axisymmetric instability. We mainly focus on the dependence of these properties from the bulk properties of neutron stars. Another property that studied in detail, is the dimensionless spin parameter (kerr parameter) of rotating neutron stars at the mass-shedding limit. In addition, supramassive time evolutionary rest mass sequences, which have their origin in general relativity, are explored. Supramassive sequences have masses exceeding the maximum mass of a non-rotating neutron star and evolve toward catastrophic collapse to a black hole. Important information can be gained from the astrophysical meaning of the kerr parameter and the supramassive sequences in neutron stars. Finally, the effects of the Keplerian sequence, in connection with the latter, may provide us constraints on the high density part of the equation of state of cold neutron star matter.

scholarly journals Statistical Mechanics of Simple Dense Fluids Using Functional Integration

1969 ◽  
Vol 22 (6) ◽  
pp. 747 ◽  
Author(s):  
RG Storer
Keyword(s):  
Partition Function ◽  
Statistical Mechanics ◽  
Short Range ◽  
Equations Of State ◽  
Functional Integration ◽  
Functional Integral ◽  
Grand Partition Function ◽  
Dense Fluids ◽  
Approximate Equations

The use of functional integration in developing approximate equations of state for simple dense fluids is outlined. The repulsive (short range) and attraotive parts of the potential are treated separately and the grand partition function is expressed in terms of a functional integral which involves knowledge of the thermodynamio properties of the "short.range system". Two separate prooedures are outlined to obtain approximate equations of state for dense fluids from this exact functional integral.

scholarly journals COSMIC TACHYON BACKGROUND RADIATION

1999 ◽  
Vol 14 (27) ◽  
pp. 4275-4285 ◽  
Author(s):  
ROMAN TOMASCHITZ
Keyword(s):  
Wave Equation ◽  
Partition Function ◽  
Equations Of State ◽  
Background Radiation ◽  
Spectral Energy ◽  
Spectral Energy Density ◽  
Microwave Background ◽  
Negative Mass ◽  
Thermodynamic Variables ◽  
Ideal Bose Gas

The equilibrium statistical mechanics of a background radiation of superluminal particles is investigated, based on a vectorial wave equation for tachyons of the Proca type. The partition function, the spectral energy density, and the various thermodynamic variables of an ideal Bose gas of tachyons in an open Robertson–Walker cosmology are derived. The negative mass square in the wave equation changes the frequency scaling in the Rayleigh–Jeans law, and there are also significant changes in the low temperature regime as compared to the microwave background, in particular in the caloric and thermal equations of state.

scholarly journals Olbert’s Kappa Fermi and Bose Distributions

2021 ◽  
Vol 9 ◽  
Author(s):  
R. A. Treumann ◽  
Wolfgang Baumjohann
Keyword(s):  
Partition Function ◽  
Condensed Matter ◽  
Kappa Distribution ◽  
Microscopic Scale ◽  
Quantum Plasmas ◽  
Astrophysical Objects ◽  
Quantum Version ◽  
Statistical Mechanical ◽  
Energy And Momentum ◽  
Very Low Temperature

The quantum version of Olbert’s kappa distribution applicable to fermions is obtained. Its construction is straightforward but requires recognition of the differences in the nature of states separated by Fermi momenta. Its complement, the bosonic version of the kappa distribution is also given, as is the procedure of how to construct a hypothetical kappa-anyon distribution. At very low temperature the degenerate kappa Fermi distribution yields a kappa-modified version of the ordinary degenerate Fermi energy and momentum. We provide the Olbert-generalized expressions of the Olbert-Fermi partition function and entropy which may serve determining all relevant statistical mechanical quantities. Possible applications are envisaged to condensed matter physics, possibly quantum plasmas, and dense astrophysical objects like the interior state of terrestrial planets, neutron stars, magnetars where quantum effects come into play and dominate the microscopic scale but may have macroscopic consequences.

Inelastic scattering at surfaces and interfaces

1986 ◽  
Vol 44 ◽  
pp. 392-393
Author(s):  
R. H. Ritchie ◽  
A. Howie
Keyword(s):  
Inelastic Scattering ◽  
Surface Properties ◽  
Correlation Energy ◽  
Condensed Matter ◽  
Charged Particles ◽  
Condensed Matter Physics ◽  
Optical Phonons ◽  
Exchange Correlation ◽  
Surfaces And Interfaces ◽  
Inelastic Interactions

An important part of condensed matter physics in recent years has involved detailed study of inelastic interactions between swift electrons and condensed matter surfaces. Here we will review some aspects of such interactions.Surface excitations have long been recognized as dominant in determining the exchange-correlation energy of charged particles outside the surface. Properties of surface and bulk polaritons, plasmons and optical phonons in plane-bounded and spherical systems will be discussed from the viewpoint of semiclassical and quantal dielectric theory. Plasmons at interfaces between dissimilar dielectrics and in superlattice configurations will also be considered.

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