Liubomir Chiriac 
 


Liubomir Chiriac


 
 
 
 

Office: FMH 462N
Phone: 503-725-3652
Email: chiriac at pdx dot edu

I am an Assistant Professor at Portland State University in the Fariborz Maseeh Department of Mathematics and Statistics. Prior to PSU, I was a postdoc at UMass Amherst. I received my PhD from Caltech, under the direction of Dinakar Ramakrishnan. Before that, I was an undergraduate at Princeton University.


My research interests are in number theory, with a focus on automorphic forms and Galois representations. I am particularly interested in arithmetic and statistical properties of Fourier coefficients of modular forms. 



I am one of the organizers of Oregon Number Theory Days, a triannual number theory conference rotating between Portland State University, Oregon State University, and the University of Oregon. 





Papers


  •   The non-vanishing of the trace of T3
          (joint with PSU students Daphne Kurzenhauser and Eric Williams)
          to appear in Involve, a Journal of Mathematics (2023)
          ( pdf  ) 

  •   Summing Hecke eigenvalues over polynomials
          (joint with Liyang Yang)
          Mathematische Zeitschrift (2022)
          ( pdf  |  journal  |  view-only )
         
  •   The trace of T2 takes no repeated values
          (joint with Andrei Jorza)
          Indagationes Mathematicae (2022)
          ( pdf  |  journal )

  •   The average number of divisors in certain arithmetic sequences
          Mathematica Pannonica (2022)
          ( pdf  |  journal )

  •   Newton Polygons of Hecke operators
          (joint with Andrei Jorza)
          Annales mathématiques du Québec (2021)
          ( pdf  |  journal  |  view-only )
          Data on the 2-adic valuations of the trace of T2 is available here
  •   Comparing Hecke coefficients of automorphic representations
          (joint with Andrei Jorza)
          Transactions of the American Mathematical Society (2019)
          ( pdf  |  journal )
  • 
 

  •   On the equality case of the Ramanujan Conjecture for Hilbert modular forms
          International Journal of Number Theory (2019)
          ( pdf  |  journal )
  • 
 

  •   On the number of dominating Fourier coefficients of two newforms
          Proceedings of the American Mathematical Society (2018)
          ( pdf  |  journal )
  • 
 

  •   Comparing Hecke eigenvalues of newforms
          Archiv der Mathematik (2017)
          ( pdf  |  journal )

  •   Irreducible adjoint representations in prime power dimensions, with an application
          Journal of the Ramanujan Mathematical Society (2015)
          ( pdf  |  journal )