TY - JOUR

T1 - Strong-coupling-expansion analysis of the false-vacuum decay rate of the lattice φ4 model in 1 + 1 dimensions

AU - Nishiyama, Yoshihiro

N1 - Copyright:
Copyright 2005 Elsevier Science B.V., Amsterdam. All rights reserved.

PY - 2001/12/21

Y1 - 2001/12/21

N2 - Strong-coupling expansion is performed for the lattice φ4 model in 1 + 1 dimensions. Because the strong-coupling limit itself is not solvable, we employed numerical calculations so as to set up unperturbed eigensystems. Restricting the number of Hilbert-space bases, we performed linked-cluster expansion up to 11th order. We carried out an alternative simulation by means of the density-matrix renormalization group. Thereby, we confirmed that our series-expansion data with a convergence-acceleration trick are in good agreement with the simulation result. Through the analytic continuation to the domain of negative biquadratic interaction, we obtain the false-vacuum decay rate. Contrary to common belief that the tunnelling phenomenon lies out of perturbative treatments, our series expansion reproduces the instanton-theory behaviour for a high potential barrier. For a shallow barrier, in contrast, our result tells us that the relaxation is no longer described by an instanton, but the decay rate acquires notable enhancement.

AB - Strong-coupling expansion is performed for the lattice φ4 model in 1 + 1 dimensions. Because the strong-coupling limit itself is not solvable, we employed numerical calculations so as to set up unperturbed eigensystems. Restricting the number of Hilbert-space bases, we performed linked-cluster expansion up to 11th order. We carried out an alternative simulation by means of the density-matrix renormalization group. Thereby, we confirmed that our series-expansion data with a convergence-acceleration trick are in good agreement with the simulation result. Through the analytic continuation to the domain of negative biquadratic interaction, we obtain the false-vacuum decay rate. Contrary to common belief that the tunnelling phenomenon lies out of perturbative treatments, our series expansion reproduces the instanton-theory behaviour for a high potential barrier. For a shallow barrier, in contrast, our result tells us that the relaxation is no longer described by an instanton, but the decay rate acquires notable enhancement.

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U2 - 10.1088/0305-4470/34/50/304

DO - 10.1088/0305-4470/34/50/304

M3 - Article

AN - SCOPUS:0035931050

VL - 34

SP - 11215

EP - 11223

JO - Journal of Physics A: Mathematical and Theoretical

JF - Journal of Physics A: Mathematical and Theoretical

SN - 1751-8113

IS - 50

ER -