| 
      This article is available for purchase or by subscription. See below.
     
          
            | Abstract |  
            | We obtain sharp bounds for the quotient
 
, where
 
 are Bessel functions
 of the first kind and 
.
 These bounds are asymptotically correct close to the zeros of
 
,
 allowing us to derive sharp estimates for the zeros of the function
 
, with
 applications to eigenvalue problems associated with the Laplace and Dirac
 operators.
  |  
    
      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
                Bessel functions, eigenvalues, Mittag–Leffler expansion
               |  
          
            | Mathematical Subject Classification
                Primary: 33C10, 34B30
               
                Secondary: 35P15
               |  
          
            | Milestones
                Received: 4 September 2020
               
                Accepted: 11 October 2021
               
                Published: 13 December 2021
               |  |