Projective-truncation-approximation study of the one-dimensional ϕ^{4} lattice model
| Autor: | Kou-Han Ma, Yan-Jiang Guo, Lei Wang, Ning-Hua Tong |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Physical review. E. 106(1-1) |
| ISSN: | 2470-0053 |
| Popis: | In this paper, we first develop the projective truncation approximation (PTA) in the Green's function equation of motion (EOM) formalism for classical statistical models. To implement PTA for a given Hamiltonian, we choose a set of basis variables and projectively truncate the hierarchical EOM. We apply PTA to the one-dimensional $\phi^4$ lattice model. Phonon dispersion and static correlation functions are studied in detail. Using one- and two-dimensional bases, we obtain results identical to and beyond the quadratic variational approximation, respectively. In particular, we analyze the power-law temperature dependence of the static averages in the low- and high-temperature limits, and we give exact exponents. Comment: 14 pages, 6 figures, published version |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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