Radiation of a massive classical scalar field from a point source is studied in the mass zero limit and compared with the radiation emitted in a mass zero theory. The total radiated energy momentum is the same in both theories, but the rate cannot be got in the massive theory. The massive theory adm
Generating functional and Green's function hierarchy of the Ising model
β Scribed by F Schwabl
- Publisher
- Elsevier Science
- Year
- 1969
- Tongue
- English
- Weight
- 738 KB
- Volume
- 54
- Category
- Article
- ISSN
- 0003-4916
No coin nor oath required. For personal study only.
β¦ Synopsis
The generating functional of the lsing model is studied. Equations of motion for the generating functional and the hierarchy of Green's functions are derived. These equations resemble a scalar field theory with nonlinear derivative coupling. Such a formulation bridges the gap between the Ising model as a configurational problem and field theoretic models of phase transitions. Only for the one dimensional lattice one can solve the equations exactly. In two and three dimensions several decoupling schemes are investigated: lowest order Hartree, Hartree approximation and a truncation, which includes also the four point function. The results are compared with graphical summations and other approximate theories.
π SIMILAR VOLUMES
The non-equilibrium Green's function (NEGF) formalism provides a sound conceptual basis for the devlopment of atomic-level quantum mechanical simulators that will be needed for nanoscale devices of the future. However, this formalism is based on concepts that are unfamiliar to most device physicists