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arXiv · hep-th/9808145

Variational Resummation of $ε$-Expansions of Critical Exponents of Nonlinear O(N)-Symmetric $σ$-Model in $2+ε$ Dimensions

Hagen Kleinert
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Abstract

We develop a method for extracting accurate critical exponents from perturbation expansions of the O(n)-symmetric nonlinear sigma-model in D=2+ epsilon dimensions. This is possible by considering the epsilon-expansions in this model as strong-coupling expansions of functions of the variable tildevarepsilon = 2(4-D)/(D-2), whose first five weak-coupling expansion coefficients of powers of tildevarepsilon are known from varepsilon-expansions of critical exponents in O(n)-symmetric phi^4-theory in D=4-epsilon dimensions.

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Hagen Kleinert. 1999-11-28. Variational Resummation of $ε$-Expansions of Critical Exponents of Nonlinear O(N)-Symmetric $σ$-Model in $2+ε$ Dimensions. https://doi.org/10.1016/s0375-9601(99)00833-6

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