Convergent perturbation theory for studying phase transitions
    
    
  
  
  
      
      
      
        
Teoretičeskaâ i matematičeskaâ fizika, Tome 204 (2020) no. 2, pp. 226-241
    
  
  
  
  
  
    
      
      
        
      
      
      
    Voir la notice de l'article provenant de la source Math-Net.Ru
            
              			We propose a method for constructing a perturbation theory with a finite radius of convergence for a rather wide class of quantum field models traditionally used to describe critical and near-critical behavior in problems in statistical physics. For the proposed convergent series, we use an instanton analysis to find the radius of convergence and also indicate a strategy for calculating their coefficients based on the diagrams in the standard (divergent) perturbation theory. We test the approach in the example of the standard stochastic dynamics $\mathrm A$-model and a matrix model of the phase transition in a system of nonrelativistic fermions, where its application allows explaining the previously observed quasiuniversal behavior of the trajectories of a first-order phase transition.
			
            
            
            
          
        
      
                  
                    
                    
                    
                    
                    
                      
Keywords: 
renormalization group, instanton analysis, convergent perturbation theory,
superconductivity, critical behavior.
                    
                  
                
                
                @article{TMF_2020_204_2_a4,
     author = {M. Yu. Nalimov and A. V. Ovsyannikov},
     title = {Convergent perturbation theory for studying phase transitions},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {226--241},
     publisher = {mathdoc},
     volume = {204},
     number = {2},
     year = {2020},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_2020_204_2_a4/}
}
                      
                      
                    TY - JOUR AU - M. Yu. Nalimov AU - A. V. Ovsyannikov TI - Convergent perturbation theory for studying phase transitions JO - Teoretičeskaâ i matematičeskaâ fizika PY - 2020 SP - 226 EP - 241 VL - 204 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TMF_2020_204_2_a4/ LA - ru ID - TMF_2020_204_2_a4 ER -
M. Yu. Nalimov; A. V. Ovsyannikov. Convergent perturbation theory for studying phase transitions. Teoretičeskaâ i matematičeskaâ fizika, Tome 204 (2020) no. 2, pp. 226-241. http://geodesic.mathdoc.fr/item/TMF_2020_204_2_a4/