2,273 research outputs found
Geometric variational problems of statistical mechanics and of combinatorics
We present the geometric solutions of the various extremal problems of
statistical mechanics and combinatorics. Together with the Wulff construction,
which predicts the shape of the crystals, we discuss the construction which
exhibits the shape of a typical Young diagram and of a typical skyscraper.Comment: 10 page
Rigorous Non-Perturbative Ornstein-Zernike Theory for Ising Ferromagnets
We rigorously derive the Ornstein-Zernike asymptotics of the pair-correlation
functions for finite-range Ising ferromagnets in any dimensions and at any
temperature above critical
Pentaquark decay is suppressed by chirality conservation
It is shown, that if the pentaquark baryon can be
represented by the local quark current , its decay is forbidden in the limit of chirality conservation. The
decay width is proportional to , where , is quark condensate, and,
therefore, is strongly suppressed. Also the polarization operator of the
pentaquark current with isospin 1 is calculated using the operator product
expansion and estimation for it mass is obtained .Comment: 4 pages, 1 fig, typos correcte
Random path representation and sharp correlations asymptotics at high-temperatures
We recently introduced a robust approach to the derivation of sharp
asymptotic formula for correlation functions of statistical mechanics models in
the high-temperature regime. We describe its application to the nonperturbative
proof of Ornstein-Zernike asymptotics of 2-point functions for self-avoiding
walks, Bernoulli percolation and ferromagnetic Ising models. We then extend the
proof, in the Ising case, to arbitrary odd-odd correlation functions. We
discuss the fluctuations of connection paths (invariance principle), and relate
the variance of the limiting process to the geometry of the equidecay profiles.
Finally, we explain the relation between these results from Statistical
Mechanics and their counterparts in Quantum Field Theory
Ornstein-Zernike Theory for the finite range Ising models above T_c
We derive precise Ornstein-Zernike asymptotic formula for the decay of the
two-point function in the general context of finite range Ising type models on
Z^d. The proof relies in an essential way on the a-priori knowledge of the
strict exponential decay of the two-point function and, by the sharp
characterization of phase transition due to Aizenman, Barsky and Fernandez,
goes through in the whole of the high temperature region T > T_c. As a
byproduct we obtain that for every T > T_c, the inverse correlation length is
an analytic and strictly convex function of direction.Comment: 36 pages, 5 figure
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