# BETA-EXPANSIONS WITH PISOT BASES OVER Fq((x-1))

• Hbaib, Mohamed (Departement de Mathematiques Faculte des Sciences de Sfax)
• Published : 2012.01.31

#### Abstract

It is well known that if the ${\beta}$-expansion of any nonnegative integer is finite, then ${\beta}$ is a Pisot or Salem number. We prove here that $\mathbb{F}_q((x^{-1}))$, the ${\beta}$-expansion of the polynomial part of ${\beta}$ is finite if and only if ${\beta}$ is a Pisot series. Consequently we give an other proof of Scheiche theorem about finiteness property in $\mathbb{F}_q((x^{-1}))$. Finally we show that if the base ${\beta}$ is a Pisot series, then there is a bound of the length of the fractional part of ${\beta}$-expansion of any polynomial P in $\mathbb{F}_q[x]$.

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#### Cited by

1. Continued $$\beta$$ β -fractions with formal power series over finite fields vol.39, pp.1, 2016, https://doi.org/10.1007/s11139-015-9725-5