Series of exponentials in the space of functions defined on curves (Q1824715)

Let \(\Lambda\) be a set of zeros of a function of sine type, \({\mathcal E}(\Lambda)=\{e^{i\lambda_ nt}\}^{\infty}_{n=-\infty}\), \(\Lambda =\{\lambda_ n\}^{\infty}_{-\infty}\); and let \(\Gamma\) be a piecewise smooth curve which connects the points \(\pm \pi\). Under some hypotheses the author proves that \({\mathcal E}(\Lambda)\) is complete in \(L^ 2(\Gamma)\) and receives a necessary and sufficient condition for \({\mathcal E}(\Lambda)\) to be minimal in \(L^ 2(\Gamma)\).