Green s functions

In Fig. 3a,b are shown respectively the modulus of the measured magnetic induction and the computed one. In Fig. 3c,d we compare the modulus and the Lissajous curves on a line j/ = 0. The results show a good agreement between simulated data and experimental data for the modulus. We can see a difference between the two curves in Fig. 3d this one can issue from the Born approximation. These results would be improved if we take into account the angle of inclination of the sensor. This work, which is one of our future developpements, makes necessary to calculate the radial component of the magnetic field due to the presence of flaw. This implies the calculation of a new Green s function. 

Due to its importance the impulse-pulse response function could be named. .contrast function". A similar function called Green s function is well known from the linear boundary value problems. The signal theory, applied for LLI-systems, gives a strong possibility for the comparison of different magnet field sensor systems and for solutions of inverse 2D- and 3D-eddy-current problems. 

By using the method of the dyadic Green s function [4] and the adequate boundary conditions [5], the expressions of the electric field in the zone where the transducer is placed can be written as [2]... 

Stuchebrukhov A A 1991 Green s functions in quantum transition state theory J. Chem. Phys. 95 4258... 

Cederbaum L S and Domcke W 1977 Theoretical aspects of ionization potentials and photoelectron spectroscopy a Green s function approach Adv. Chem. Phys. 36 205-344 Oddershede J 1987 Propagator methods Adv. Chem. Phys. 69 201-39... 

Hedin L 1965 New method for calculating the one-particle Green s function with application to the electron-gas problem Pbys. Rev. 139 A796... 

Williams A R, Feibelman P J and Lang N D 1982 Green s-function methods for electronic-structure calculations Phys. Rev. B 26 5433... 

Mandelshtam V A and Taylor H S 1995 A simple recursion polynomial expansion of the Green s function with absorbing boundary conditions. Application to the reactive scattering J. Chem. Phys. 102... 

In the further manipulations the site representation will be used for convenience. The Fourier transform with respect to time of a single-exciton retarded Green s function (t) of a system under the Hamiltonian in the site representation for exciton coordinates and Fock s representation for phonon coordinates is written as... 

To verify effectiveness of NDCPA we carried out the calculations of absorption spectra for a system of excitons locally and linearly coupled to Einstein phonons at zero temperature in cubic crystal with one molecule per unit cell (probably the simplest model of exciton-phonon system of organic crystals). Absorption spectrum is defined as an imaginary part of one-exciton Green s function taken at zero value of exciton momentum vector... 

Dilfusion and Green s function QMC calculations are often done using a fixed-node approximation. Within this scheme, the nodal surfaces used define the state that is obtained as well as ensuring an antisymmetric wave function. 

Green s function method of Korringa, Kohn, and Rostoker (sometimes denoted KKR)... 

Any orbital-based scheme can be used for crystal-structure calculations. The trend is toward more accurate methods. Some APW and Green s function methods use empirical parameters, thus edging them toward a semiempirical classification. In order of preference, the commonly used methods are ... 

The photoelectron spectra of pyridazine have been interpreted on the basis of many-body Green s function calculations both for the outer and the inner valence region. The calculations confirm that ionization of the first n-electron occurs at lower energy than of the first TT-electron (79MI21201). A large number of bands in the photoelectron spectrum of 3,6-diphenylpyridazine in stretched polymer sheets have been assigned to transitions predicted... 

Stakgold, I. Green s Functions and Boundary Value Problems. Interscience, New York (1979). 

In the derivation of (5.38) we have extracted the <5-function term from the phonon Green s function which, in turn, renormalized the bare potential V to the adiabatic one An expression similar to (5.37) can be obtained for an arbitrary bath whenever the coupling is suflSciently weak and the functional Z[Q(t)] can be expanded into the series... 

However, the Green s function of the bath Gb(t, t ) = 5 Z/5Q(t)5Q(t ) may have a form quite different from a single-phonon Green s function and may exhibit a strong temperature dependence. It would be interesting, for example, to see explicitly how this kernel, say, for a liquid, reduces to the phonon Green s function but with temperature-dependent parameters so that the friction coeflScient rj depends on temperature. To the authors knowledge this has not been done as yet. 

Other quantum simulations involve simulations with effective Hamiltonians [261-263] or the simulation of ground state wave properties by Green s function Monte Carlo or diffusion Monte Carlo for reviews and further references on these methods see Refs. 162, 264-268. 

TOTAL ENERGY CALCULATIONS OF ALLOYS LOCALLY SELF-CONSISTENT GREEN S FUNCTION METHOD... 

To improve the latter a number of 0 N) methods have been recently proposed but practically all of them exploit Hamiltonian formalism. However, in Refs. 4,5 the locally self-consistent multiple scattering (LSMS) method based on the real space multiple scattering theory has been outlined, and in Ref. 6 its central idea in the form of the local interaction zone (LIZ) was incorporated into the Green s function technique, leading to the locally self-consistent Green s function method (LSGF). 

As a matter of fact there is an infinite number of possible choices for the effective medium. But if one deals with an alloy problem, it is well-known that the best single-site effective medium is given by the CPA. In fact, it fulfills all the criteria mentioned above. That is, the Green s function for the CPA effective medium decays, apart from an oscillating factor, exponentially as, where I is the mean free... 

Here R, R LIZ, and the effective medium Green s function for the LIZ gnni is calculated only once for the entire system... 

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