2015/10/26 by B. A. Fayzullaev, Fayzullaev, B. A. · 1 citation
Computer Science · Economics, Econometrics and Finance · Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Quantum Computing Algorithms and Architecture #Quantum Mechanics and Applications #Stochastic processes and financial applications #advanced mathematical theories
paper · pdf · doi:10.48550/arxiv.1510.07367
openalex publication_date 2015/10/26 · openalex created_date 2024/04/10 · openalex updated_date 2026/07/28
The equations for effective action for nonlinear σ model are derived using DeWitt method in two forms - for generator of vertex parts Γ and for generator of weakly connected parts W. Loop-expansion solutions to these equations are found. It is shown that vacuum expectation values for various quantities including divergence of a Nöther current, trace of the energy-momentum tensor and so on, can be calculated by this method. Also it is shown that vacuum expectation to the sigma-field is determined by an explicit combination of tree Green function and classical solution. It is shown that the limit when coupling constant tends to zero is singular one.