Spectrality and non-spectrality of the Riesz product measures with three elements in digit sets (Q2416594)

Let $\mu$ be a compactly supported Borel probability measure on $\mathbb{R}$. Such a measure is called spectral, Riesz spectral, or frame spectral if there exists a set $\Lambda\subset \mathbb{R}$ such that the family of exponential functions $E_\Lambda := \{\exp (2\pi i \lambda (\cdot)) : \lambda\in \Lambda\}$ forms an orthonormal, Riesz basis, or frame, respectively, for $L^2(\mu)$. The authors study the spectrality and non-spectrality of Riesz product measures with three element digit sets.