Approaching the critical region of two-dimensional phi/sup 4/ quantum field theory with post-Gaussian approximations

Journal Article · Thu Jan 15 00:00:00 EST 1987 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.35.621· OSTI ID:7018178

Funke, M; Kaulfuss, U; Kuemmel, H

We investigate the vacuum state of (1+1)-dimensional phi/sup 4/ quantum field theory utilizing a modification of the powerful coupled cluster method by the additional maximum-overlap condition. This permits us to construct the ground state of that field theory for nearly all values of the coupling strength. Only a small region has to be excluded where our method still fails. This is most probably due to critical behavior showing up in a change of the order parameter of the model. Our procedure predicts a behavior of the (phi/sup 4/)/sub 2/ model in complete agreement with some rigorous mathematical statements which is not possible in the case of a Gaussian approximation only. Perhaps somewhat unexpectedly, the symmetry-breaking Hamiltonian does not have any critical point.

• Research Organization: Institut fuer Theoretische Physik II, Ruhr-Universitat Bochum, 4630 Bochum 1, Federal Republic of Germany
• OSTI ID: 7018178
• Journal Information: Phys. Rev. D; (United States), Vol. 35:2
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
PHI4-FIELD THEORY
VACUUM STATES
DUALITY
HAMILTONIANS
MANY-BODY PROBLEM
NUMERICAL ANALYSIS
SYMMETRY BREAKING
TWO-DIMENSIONAL CALCULATIONS
FIELD THEORIES
MATHEMATICAL OPERATORS
MATHEMATICS
QUANTUM FIELD THEORY
QUANTUM OPERATORS
645400* - High Energy Physics- Field Theory