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                To B or not to B: Primordial magnetic fields from Weyl anomaly
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        Europe/Rome
    
                
                
                    
                        
                            
    
    
        
            
                
                Auta Teorici (DIFA)
            
            
                
    
        
            
        
    
                        
                    
                
            Auta Teorici
DIFA
Via Irnerio, 46
            
        
        
    Description
            For more than twenty years, it has been argued that the Weyl anomaly of quantum electrodynamics sources cosmological magnetic fields in the early universe. If true, this would be a natural way to produce the seed magnetic fields of our universe within the Standard Model. In this talk, I will examine this long-standing claim and show that there is actually no production of coherent magnetic fields from the Weyl anomaly, irrespective of the number of massless charged particles in the early universe. I will also comment on other possibilities for magnetic field generation.