| 
      This article is available for purchase or by subscription. See below.
     
          
            | Abstract |  
            | A projective property of an embeddable polar space
 
 is a property of the family of its projective embeddings, such as
 the existence of an embedding of vector dimension twice the rank of
 
 or the fact that
 all embeddings of 
 have the same dimension, while properties such as the fact that all pairs of opposite
 points are regular or all triads of points are centric, are synthetic properties.
 We prove that all pairs of opposite points of an embeddable polar space
 
 of rank
 
 are regular if and
 only if 
 admits
 a 
-dimensional
 embedding; we also prove that all embeddings of
 
 have the
 same dimension if and only if the subspace spanned by two opposite singular subspaces is
 closed under taking hyperbolic lines. Moreover, we characterize the fact that all triads of
 points of 
 are centric by means of suitable properties of the universal embedding of
 
.
  |  
          
            | Dedicated to the memory of Jacques
              Tits |  
    
      PDF Access Denied
    
	      We have not been able to recognize your IP address
      216.73.216.116
      as that of a subscriber to this journal.Online access to the content of recent issues is by
      
          subscription, or purchase of single articles.
 
      Please contact your institution's librarian suggesting a subscription, for example by using our
      journal-recommendation form.
      Or, visit our
      subscription page
      for instructions on purchasing a subscription.
       
      You may also contact us at
      contact@msp.orgor by using our
      contact form.
 
      Or, you may purchase this single article for
      USD 40.00:
      
 
          
            | Keywords
                polar spaces, embeddings, regularity, centric triads
               |  
          
            | Mathematical Subject Classification
                Primary: 51A50
               |  
          
            | Milestones
                Received: 31 May 2022
               
                Revised: 1 December 2022
               
                Accepted: 20 December 2022
               
                Published: 13 September 2023
               |  
          
            | © 2023 MSP (Mathematical Sciences
            Publishers). |  |