2011/01/22 by Hong, Hoon, Lee, Eunjeong, Lee, Hyang-Sook +1 · 1 citation
#FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.1101.4255
Let g(f) denote the maximum of the differences (gaps) between two consecutive exponents occurring in a polynomial f. Let Φn denote the n-th cyclotomic polynomial and let Ψn denote the n-th inverse cyclotomic polynomial. In this note, we study g(Φn) and g(Ψn) where n is a product of odd primes, say p1 < p2 < p3, etc. It is trivial to determine g(Φp1), g(Ψp1) and g(Ψp1p2). Hence the simplest non-trivial cases are g(Φp1p2) and g(Ψp1p2p3). We provide an exact expression for g(Φp1p2). We also provide an exact expression for g(Ψp1p2p3) under a mild condition. The condition is almost always satisfied (only finite exceptions for each p1). We also provide a lower bound and an upper bound for g(Ψp1p2p3).