scholarly journals A many-particle approach to the gyro-kinetic theory

2007 ◽  
Vol 73 (5) ◽  
pp. 757-772 ◽  
Author(s):  
ALEXEY MISHCHENKO ◽  
AXEL KÖNIES
Keyword(s):  
Kinetic Equation ◽  
Kinetic Theory ◽  
First Principles ◽  
Conventional Approach ◽  
The Self ◽  
Collision Term ◽  
Lie Transform ◽  
Self Consistent ◽  
The Many ◽  
Particle Approach

AbstractA systematic first-principles approach to the many-particle formulation of the gyro-kinetic theory is suggested. The gyro-kinetic many-particle Hamiltonian is derived using the Lie transform technique. The generalized gyro-kinetic equation is obtained following the Born–Bogoliubov–Green–Kirkwood–Yvon approach. The microscopic expression for the self-consistent potential and the polarization density is obtained. It is shown that new terms appear in the gyro-kinetic polarization that can not be derived in the conventional approach. An expression for the collision term is obtained in the Landau approximation.

scholarly journals Long-time discrete particle effects versus kinetic theory in the self-consistent single-wave model

2001 ◽  
Vol 64 (2) ◽  
Author(s):  
M-C. Firpo ◽  
F. Doveil ◽  
Y. Elskens ◽  
P. Bertrand ◽  
M. Poleni ◽  
...  
Keyword(s):  
Kinetic Theory ◽  
Wave Model ◽  
The Self ◽  
Single Wave ◽  
Discrete Particle ◽  
Self Consistent ◽  
Long Time

Electric Field Gradient Calculations of Various Borides

1996 ◽  
Vol 51 (5-6) ◽  
pp. 527-533 ◽  
Author(s):  
K. Schwarz ◽  
H. Ripplinger ◽  
P. Blaha
Keyword(s):  
Electric Field ◽  
First Principles ◽  
Density Functional ◽  
The Self ◽  
Full Potential ◽  
Electric Field Gradients ◽  
Charge Density Distribution ◽  
Functional Theory ◽  
Field Gradients ◽  
Self Consistent

Abstract A first-principles method for the computation of electric field gradients (EFG) is illustrated for various borides. It is based on energy band calculations using the full-potential linearized aug-mented plane wave (LAPW) method within density functional theory. From the self-consistent charge density distribution the EFG is obtained without further approximations by numerically solving Poisson's equation. The dependence of the EFG on structure, chemical composition or substitution is demonstrated for the diborides MB2 (with M = Ti, V, Cr, Zr, Nb, Mo, and Ta), the hexaborides (CaB6, SrB6 and BaB6) and boron carbide which is closely related to α-boron.

scholarly journals TO WHAT EXTENT DOES THE SELF-CONSISTENT MEAN-FIELD EXIST?

2006 ◽  
Vol 15 (05) ◽  
pp. 1141-1148 ◽  
Author(s):  
LU GUO ◽  
FUMIHIKO SAKATA ◽  
EN-GUANG ZHAO ◽  
J. A. MARUHN
Keyword(s):  
Mean Field Theory ◽  
Mean Field ◽  
Energy Difference ◽  
The Self ◽  
Fermion System ◽  
Avoided Crossing ◽  
Self Consistent ◽  
The Mean ◽  
The Many ◽  
First Time

A non-convergent difficulty near level-repulsive region is discussed within the self-consistent mean-field theory. It is shown by numerical and analytic studies that the mean-field is not realized in the many-fermion system when quantum fluctuations coming from two-body residual interaction and quadrupole deformation are larger than an energy difference between two avoided crossing orbits. An analytic condition indicating a limitation of the mean-field concept is derived for the first time.

scholarly journals Formation of the Planetary Sequence in a Highly Flattened Disk of Frequently Colliding Planetesimals

2004 ◽  
Vol 202 ◽  
pp. 181-183
Author(s):  
Evgeny Griv ◽  
Michael Gedalin ◽  
David Eichler ◽  
Chi Yuan
Keyword(s):  
Kinetic Equation ◽  
Kinetic Theory ◽  
Boltzmann Kinetic Equation ◽  
The Self ◽  
Gravity Disturbances ◽  
Dissipative Instability

The kinetic theory is used to study the evolution of the self-gravitating disk of planetesimals. The effects of frequent collisions between planetesimals are taken into account by using a Krook integral in the Boltzmann kinetic equation. It is shown that as a result of an aperiodic collision-dissipative instability of small gravity disturbances the disk is subdivided into numerous dense fragments. These can eventually condense into the planetary sequence.

Theoretical and Computational Problems in Modeling Glow Discharges

1986 ◽  
Vol 68 ◽  
Author(s):  
David B. Graves ◽  
Klavs F. Jensen
Keyword(s):  
Plasma Reactor ◽  
Physical Structure ◽  
Plasma Sheath ◽  
The Self ◽  
Rf Discharge ◽  
Fluid Equation ◽  
Complex Interactions ◽  
Self Consistent ◽  
Self Consistent Field ◽  
The Many

AbstractIt is desirable to develop detailed models of glow discharge chemical reactors in order to understand the many complex interactions that govern reactor performance.One important part of an overall model of the plasma reactor is the description of the discharge physical structure including charged particle densities, energies and the self-consistent electric field.The continuum or fluid equation approach to this problem is presented in this paper and potential problems with this approach are discussed.Results from recent simulations of a 13.56 MHz rf discharge are presented.The behavior of the electrons in the quasineutral plasma and their interaction with the self-consistent field are highlighted.It is shown that the rf power dissipation peaks at the plasma-sheath boundary, and the implications of this for the validity of estimates of mean electron density from equivalent rf rcircuit models is discussed.

Note on the Interpretation of the Density Matrix in the Many-Electron Problem

1931 ◽  
Vol 27 (2) ◽  
pp. 240-243 ◽  
Author(s):  
P. A. M. Dirac
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Density Matrix ◽  
The Self ◽  
Transformation Theory ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
The Many

When we treat an atom containing a number n of electrons by the method of the self-consistent field, we assume that each electron has its own particular “orbit,” specified by a wave function (q|r) in four variables q. These four variables are usually taken to be the three coordinates of the electron together with a variable describing the spin, but according to the transformation theory of quantum mechanics, they may be any four independent commuting functions of the coordinates, momenta and spin variables.

A First Principles Approach for Partitioning Linear Response Properties into Additive and Cooperative Contributions

2018 ◽  
Author(s):  
Daniel Lambrecht ◽  
Eric Berquist
Keyword(s):  
First Principles ◽  
Linear Response ◽  
Building Blocks ◽  
Field Method ◽  
Response Property ◽  
Response Properties ◽  
Consistent Field ◽  
Molecular Building Blocks ◽  
Self Consistent ◽  
Self Consistent Field

We present a first principles approach for decomposing molecular linear response properties into orthogonal (additive) plus non-orthogonal/cooperative contributions. This approach enables one to 1) identify the contributions of molecular building blocks like functional groups or monomer units to a given response property and 2) quantify cooperativity between these contributions. In analogy to the self consistent field method for molecular interactions, SCF(MI), we term our approach LR(MI). The theory, implementation and pilot data are described in detail in the manuscript and supporting information.

Intrinsic doping limit and defect-assisted luminescence in Cs4PbBr6

2019 ◽  
Author(s):  
Young-Kwang Jung ◽  
Joaquin Calbo ◽  
Ji-Sang Park ◽  
Lucy D. Wahlley ◽  
Sunghyun Kim ◽  
...  
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Stokes Shift ◽  
Green Luminescence ◽  
Counter Ions ◽  
Self Consistent ◽  
Deep Ultraviolet ◽  
Halide Perovskite ◽  
Related Compounds ◽  
Level Analysis

Cs<sub>4</sub>PbBr<sub>6 </sub>is a member of the halide perovskite family that is built from isolated (zero-dimensional) PbBr<sub>6</sub><sup>4-</sup> octahedra with Cs<sup>+</sup> counter ions. The material exhibits anomalous optoelectronic properties: optical absorption and weak emission in the deep ultraviolet (310 - 375 nm) with efficient luminescence in the green region (~ 540 nm). Several hypotheses have been proposed to explain the giant Stokes shift including: (i) phase impurities; (ii) self-trapped exciton; (iii) defect emission. We explore, using first-principles theory and self-consistent Fermi level analysis, the unusual defect chemistry and physics of Cs<sub>4</sub>PbBr<sub>6</sub>. We find a heavily compensated system where the room-temperature carrier concentrations (< 10<sup>9</sup> cm<sup>-3</sup>) are more than one million times lower than the defect concentrations. We show that the low-energy Br-on-Cs antisite results in the formation of a polybromide (Br<sub>3</sub>) species that can exist in a range of charge states. We further demonstrate from excited-state calculations that tribromide moieties are photoresponsive and can contribute to the observed green luminescence. Photoactivity of polyhalide molecules is expected to be present in other halide perovskite-related compounds where they can influence light absorption and emission. <br>

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