On finite groups isospectral to $PSp_4(q)$
    
    
  
  
  
      
      
      
        
Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 29 (2023) no. 4, pp. 64-69
    
  
  
  
  
  
    
      
      
        
      
      
      
    Voir la notice de l'article provenant de la source Math-Net.Ru
            
              			The spectrum of a finite group is the set of its element orders. Let $q$ be a power of a prime $p$, with $p \geqslant 5$. It is known that any finite group having the same spectrum as the simple symplectic group $PSp_4(q)$ either is isomorphic to an almost simple group with socle $PSp_4(q)$ or can be homomorphically mapped onto an almost simple group $H$ with socle $PSL_2(q^2)$. We prove that the group $H$ cannot coincide with $PSL_2(q^2)$, i.e., $H$ must contain outer automorphisms of its socle.
			
            
            
            
          
        
      
                  
                    
                    
                    
                    
                    
                      
Keywords: 
finite group, element order.
                    
                  
                
                
                @article{TIMM_2023_29_4_a5,
     author = {M. A. Grechkoseeva and V. M. Rodionov},
     title = {On finite groups isospectral to $PSp_4(q)$},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {64--69},
     publisher = {mathdoc},
     volume = {29},
     number = {4},
     year = {2023},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2023_29_4_a5/}
}
                      
                      
                    M. A. Grechkoseeva; V. M. Rodionov. On finite groups isospectral to $PSp_4(q)$. Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 29 (2023) no. 4, pp. 64-69. http://geodesic.mathdoc.fr/item/TIMM_2023_29_4_a5/
