Cosine problem and antigravity in EPRL/FK spinfoam model
GFM seminar
	    
	      IIIUL, Sala B3-01
	    
	    
                        
                        
                            2013-11-15 14:00
                            2013-11-15 15:00
                            2013-11-15
                            14:00
                            ..
                            15:00
                        
            
	    
            
	    
        Marko Vojinovic (GFMUL)
We  calculate the classical limit effective action of the EPRL/FK  spinfoam  model of quantum gravity coupled to matter fields. By  employing the  standard QFT background field method adapted to the  spinfoam setting,  we find that the model has many different classical  effective actions.  Most notably, these include the ordinary  Einstein-Hilbert action  coupled to matter, but also an action which  describes antigravity. All  those multiple classical limits appear as a  consequence of the fact  that the EPRL/FK vertex amplitude has  cosine-like large spin  asymptotics. We discuss some possible ways to eliminate the unwanted  classical limits.
         
             
             
             
                
                
             
                
             Symmetries in Quantum Physics 2017
            Symmetries in Quantum Physics 2017
        