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Nonuniversal critical quantities from variational perturbation theory and their application to the Bose-Einstein condensation temperature shift

Kastening, Boris (2004):
Nonuniversal critical quantities from variational perturbation theory and their application to the Bose-Einstein condensation temperature shift.
In: Physical Review A, American Physical Society, pp. 043621-1-043621-20, 70, (4), ISSN 1050-2947, [Online-Edition: http://dx.doi.org/10.1103/PhysRevA.70.043621],
[Article]

Abstract

For an OsNd-symmetric scalar field theory with Euclidean action ed3 xf 12 u ¹fu2+ 12 rf2+ 14!uf4g, where f=sf1 , . . . ,fNd is a vector of N real-field components, variational perturbation theory through seven loops is employed for N=0,1,2,3,4 to compute the renormalized value of r / sN+2du2 at the phase transition. Its exact large-N limit is determined as well. We also extend an earlier computation of the interaction-induced shift Dkf2l /Nu from N=1,2,4 to N=0,3. For N=2, the results for the two quantities are used to compute the second-order shift of the condensation temperature of a dilute Bose gas, both in the homogenous case and for the wide limit of a harmonic trap. Our results are in agreement with earlier Monte Carlo simulations for N =1,2,4. The Appendix contains previously unpublished numerical seven-loop data.

Item Type: Article
Erschienen: 2004
Creators: Kastening, Boris
Title: Nonuniversal critical quantities from variational perturbation theory and their application to the Bose-Einstein condensation temperature shift
Language: English
Abstract:

For an OsNd-symmetric scalar field theory with Euclidean action ed3 xf 12 u ¹fu2+ 12 rf2+ 14!uf4g, where f=sf1 , . . . ,fNd is a vector of N real-field components, variational perturbation theory through seven loops is employed for N=0,1,2,3,4 to compute the renormalized value of r / sN+2du2 at the phase transition. Its exact large-N limit is determined as well. We also extend an earlier computation of the interaction-induced shift Dkf2l /Nu from N=1,2,4 to N=0,3. For N=2, the results for the two quantities are used to compute the second-order shift of the condensation temperature of a dilute Bose gas, both in the homogenous case and for the wide limit of a harmonic trap. Our results are in agreement with earlier Monte Carlo simulations for N =1,2,4. The Appendix contains previously unpublished numerical seven-loop data.

Journal or Publication Title: Physical Review A
Volume: 70
Number: 4
Publisher: American Physical Society
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Advanced Thin Film Technology
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
Date Deposited: 09 Jan 2013 08:52
Official URL: http://dx.doi.org/10.1103/PhysRevA.70.043621
Identification Number: doi:10.1103/PhysRevA.70.043621
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