scholarly journals Finite-Size Effects in the φ4 Field and Lattice Theory Above the Upper Critical Dimension

1998 ◽  
Vol 09 (07) ◽  
pp. 1007-1019 ◽  
Author(s):  
X. S. Chen ◽  
V. Dohm
Keyword(s):  
Size Effects ◽  
Lattice Theory ◽  
Finite Size ◽  
Periodic Boundary Conditions ◽  
Critical Dimension ◽  
Spin Systems ◽  
Finite Size Effects ◽  
Upper Critical Dimension ◽  
Universal Properties ◽  
Binder Cumulant

We demonstrate that the standard O(n) symmetric φ4 field theory does not correctly describe the leading finite-size effects near the critical point of spin systems with periodic boundary conditions on a d-dimensional lattice with d>4. We show that these finite-size effects require a description in terms of a lattice Hamiltonian. For n →∞ and n=1, explicit results are given for the susceptibility and for the Binder cumulant. They imply that these quantities do not have the universal properties predicted previously and that recent analyses of Monte Carlo results for the five-dimensional Ising model are not conclusive.

scholarly journals TESTING BOUNDARY CONDITIONS EFFICIENCY IN SIMULATIONS OF LONG-RANGE INTERACTING MAGNETIC MODELS

2004 ◽  
Vol 15 (01) ◽  
pp. 115-127 ◽  
Author(s):  
SERGIO A. CANNAS ◽  
CINTIA M. LAPILLI ◽  
DANIEL A. STARIOLO
Keyword(s):  
Low Temperature ◽  
Boundary Conditions ◽  
Size Effects ◽  
Periodic Boundary ◽  
Finite Size ◽  
Periodic Boundary Conditions ◽  
Ferromagnetic Phase ◽  
Temperature Phase ◽  
Finite Size Effects ◽  
Magnetic Systems

Periodic boundary conditions have no unique implementation in magnetic systems where all spins interact with each other through a power law decaying interaction of the form 1/rα, r being the distance between spins. In this work we present a comparative study of the finite size effects oberved in numerical simulations by using first image and infinite image periodic boundary conditions in one- and two-dimensional spin systems with those interactions, including the ferromagnetic, anti-ferromagnetic and competitive interaction cases. Our results show no significative differences between the finite size effects produced by both boundary conditions when the low temperature phase has zero global magnetization, and it depends on the ratio α/d for systems with a low temperature ferromagnetic phase. In the last case the first image convention gives more stronger finite size effects than the other when the system enters into the classical regime α/d≤3/2.

scholarly journals Lattice φ4 Theory of Finite-Size Effects Above the Upper Critical Dimension

1998 ◽  
Vol 09 (07) ◽  
pp. 1073-1105 ◽  
Author(s):  
X. S. Chen ◽  
V. Dohm
Keyword(s):  
Field Theory ◽  
Lattice Model ◽  
Size Effects ◽  
Lattice Theory ◽  
Finite Size ◽  
Model Parameters ◽  
Scaling Functions ◽  
Finite Size Scaling ◽  
Finite Size Effects ◽  
Size Scaling

We present a perturbative calculation of finite-size effects near Tc of the φ4 lattice model in a d-dimensional cubic geometry of size L with periodic boundary conditions for d>4. The structural differences between the φ4 lattice theory and the φ4 field theory found previously in the spherical limit are shown to exist also for a finite number of components of the order parameter. The two-variable finite-size scaling functions of the field theory are nonuniversal whereas those of the lattice theory are independent of the nonuniversal model parameters. One-loop results for finite-size scaling functions are derived. Their structure disagrees with the single-variable scaling form of the lowest-mode approximation for any finite ξ/L where ξ is the bulk correlation length. At Tc, the large-L behavior becomes lowest-mode like for the lattice model but not for the field-theoretic model. Characteristic temperatures close to Tc of the lattice model, such as T max (L) of the maximum of the susceptibility χ, are found to scale asymptotically as Tc-T max (L) ~L-d/2, in agreement with previous Monte Carlo (MC) data for the five-dimensional Ising model. We also predict χ max ~Ld/2 asymptotically. On a quantitative level, the asymptotic amplitudes of this large-L behavior close to Tc have not been observed in previous MC simulations at d=5 because of nonnegligible finite-size terms ~L(4-d)/2 caused by the inhomogeneous modes. These terms identify the possible origin of a significant discrepancy between the lowest-mode approximation and previous MC data. MC data of larger systems would be desirable for testing the magnitude of the L(4-d)/2 and L4-d terms predicted by our theory.

Finite-size effects in field theory. Scaling behaviour

2021 ◽  
pp. 760-785
Author(s):  
Jean Zinn-Justin
Keyword(s):  
Finite Volume ◽  
Size Effects ◽  
Short Range ◽  
Periodic Boundary ◽  
Finite Size ◽  
Periodic Boundary Conditions ◽  
Vector Model ◽  
Finite Size Effects ◽  
Infinite Systems ◽  
New Situation

A number of numerical calculations, like Monte Carlo or transfer matrix calculations, are performed with systems in which the size in several or all dimensions is finite. To extrapolate the results to the infinite system, it is thus necessary to understand how the infinite size limit is reached. In particular in a system in which the forces are short range, no phase transition can occur in a finite volume, or in a geometry in which the size is infinite only in one dimension. This indicates that the infinite-size extrapolation is somewhat non-trivial. In this chapter, the problem is analysed in the case of second-order phase transitions, in the framework of the N-vector model. The existence of a finite-size scaling is established, extending renormalization group (RG) arguments to this new situation. Then, finite volume geometry and cylindrical geometry, in which the size is finite in all dimensions except one, are distinguished. It is explained how to adapt the methods used in the case of infinite systems to calculate the new universal quantities appearing in finite-size effects, for example, in d = 4−ϵ or d = 2+ϵ dimensions. Special properties of the commonly used periodic boundary conditions are emphasized.

scholarly journals Transient hydrodynamic finite-size effects in simulations under periodic boundary conditions

2017 ◽  
Vol 95 (6) ◽  
Author(s):  
Adelchi J. Asta ◽  
Maximilien Levesque ◽  
Rodolphe Vuilleumier ◽  
Benjamin Rotenberg
Keyword(s):  
Boundary Conditions ◽  
Size Effects ◽  
Periodic Boundary ◽  
Finite Size ◽  
Periodic Boundary Conditions ◽  
Finite Size Effects
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