Language:   Search:   Contact
Zentralblatt MATH has released its new interface!
For an improved author identification, see the new author database of ZBMATH.

Query:
Fill in the form and click »Search«...
Format:
Display: entries per page entries
Zbl 1152.82305
Boukraa, S.; Guttmann, A.J.; Hassani, S.; Jensen, I.; Maillard, J-M; Nickel, B.; Zenine, N.
Experimental mathematics on the magnetic susceptibility of the square lattice Ising model.
(English)
[J] J. Phys. A, Math. Theor. 41, No. 45, Article ID 455202, 51 p. (2008). ISSN 1751-8113; ISSN 1751-8121/e

Summary: We calculate very long low- and high-temperature series for the susceptibility $\chi$ of the square lattice Ising model as well as very long series for the five-particle contribution $\chi^{(5)}$ and six-particle contribution $\chi^{(6)}$. These calculations have been made possible by the use of highly optimized polynomial time modular algorithms and a total of more than 150\,000 CPU hours on computer clusters. The series for $\chi$ (low- and high-temperature regimes), $\chi^{(5)}$ and $\chi^{(6)}$ are now extended to 2000 terms. In addition, for $\chi^{(5)}$, 10\,000 terms of the series are calculated modulo a single prime, and have been used to find the linear ODE satisfied by $\chi^{(5)}$ modulo a prime. A diff-Padé analysis of the 2000 terms series for $\chi^{(5)}$ and $\chi^{(6)}$ confirms to a very high degree of confidence previous conjectures about the location and strength of the singularities of the n-particle components of the susceptibility, up to a small set of additional' singularities. The exponents at all the singularities of the Fuchsian linear ODE of $\chi^{(5)}$ and the (as yet unknown) ODE of $\chi^{(6)}$ are given: they are all rational numbers. We find the presence of singularities at $w=1/2$ for the linear ODE of $\chi^{(5)}$, and $w^2=1/8$ for the ODE of $\chi^{(6)}$, which are not singularities of the physical' $\chi^{(5)}$ and $\chi^{(6)}$, that is to say the series solutions of the ODE's which are analytic at $w=0$. Furthermore, analysis of the long series for $\chi^{(5)}$ (and $\chi^{(6)}$) combined with the corresponding long series for the full susceptibility $\chi$ yields previously conjectured singularities in some $\chi^{(n)}$, $n\ge7$. The exponents at all these singularities are also seen to be rational numbers. We also present a mechanism of resummation of the logarithmic singularities of the $\chi^{(n)}$ leading to the known power-law critical behaviour occurring in the full $\chi$, and perform a power spectrum analysis giving strong arguments in favour of the existence of a natural boundary for the full susceptibility $\chi$.
MSC 2000:
*82B20 Lattice systems
34M55 Painlevé and other special equations
47E05 Ordinary differential operators
81Qxx General mathematical topics and methods in quantum theory
32G34 Moduli and deformations for ODE
82-05 Experimental papers (statistical mechanics)

Highlights
Master Server