Eigenform product identities for Hilbert modular forms

Kirti N Joshi, Yichao Zhang

Research output: Contribution to journalArticle


We prove that amongst all real quadratic fields and all spaces of Hilbert modular forms of full level and of weight 2 or greater, the product of two Hecke eigenforms is not a Hecke eigenform except for finitely many real quadratic fields and finitely many weights. We show that for Q(5) there are exactly two such identities.

Original languageEnglish (US)
JournalMathematische Zeitschrift
Publication statusAccepted/In press - Jan 1 2018



  • Hecke eigenform
  • Hilbert modular form
  • Product identity

ASJC Scopus subject areas

  • Mathematics(all)

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