Convergence proof for optimized Delta expansion: The Anharmonic oscillator

Jul, 1992
40 pages
Published in:
  • Phys.Rev.D 47 (1993) 2560-2572
Report number:
  • IMPERIAL-TP-91-92-29

Citations per year

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Abstract: (APS)
A recent proof of the convergence of the optimized δ expansion for one-dimensional non-Gaussian integrals is extended to the finite-temperature partition function of the quantum anharmonic oscillator. The convergence is exponentially fast, with the remainder falling as e−cN23 at order N in the expansion, independently of the size of the coupling or the sign of the mass term. In particular, the approach gives a convergent resummation procedure for the double-well (non-Borel-summable) case.
  • delta expansion
  • model: oscillator
  • finite temperature
  • partition function
  • scaling
  • numerical calculations