• 제목/요약/키워드: unimodular roots

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SOME POLYNOMIALS WITH UNIMODULAR ROOTS

  • Dubickas, Arturas
    • 대한수학회보
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    • 제59권5호
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    • pp.1269-1277
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    • 2022
  • In this paper we consider a sequence of polynomials defined by some recurrence relation. They include, for instance, Poupard polynomials and Kreweras polynomials whose coefficients have some combinatorial interpretation and have been investigated before. Extending a recent result of Chapoton and Han we show that each polynomial of this sequence is a self-reciprocal polynomial with positive coefficients whose all roots are unimodular. Moreover, we prove that their arguments are uniformly distributed in the interval [0, 2𝜋).

UNIMODULAR ROOTS OF RECIPROCAL LITTLEWOOD POLYNOMIALS

  • Drungilas, Paulius
    • 대한수학회지
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    • 제45권3호
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    • pp.835-840
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    • 2008
  • The main result of this paper shows that every reciprocal Littlewood polynomial, one with {-1, 1} coefficients, of odd degree at least 7 has at least five unimodular roots, and every reciprocal Little-wood polynomial of even degree at least 14 has at least four unimodular roots, thus improving the result of Mukunda. We also give a sketch of alternative proof of the well-known theorem characterizing Pisot numbers whose minimal polynomials are in $$A_N=\{[{X^d+ \sum\limits^{d-1}_{k=0} a_k\;X^k{\in} \mathbb{Z}[X]\;:\;a_k={\pm}N,\;0{\leqslant}k{\leqslant}d-1}\}$$ for positive integer $N{\geqslant}2$.