On the pointwise convergence of a class of nonharmonic Fourier series
On the pointwise convergence of a class of nonharmonic Fourier series
Extending a classical theorem of Levinson [<bold>1</bold>, Theorem XVIII], we show that when the numbers <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="left-brace lamda Subscript n Baseline right-brace"> <mml:semantics> <mml:mrow> <mml:mo>{</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mi>λ<!-- λ --></mml:mi> <mml:mi>n</mml:mi> </mml:msub> </mml:mrow> </mml:mrow> <mml:mo>}</mml:mo> </mml:mrow> <mml:annotation encoding="application/x-tex">\left \{ {{\lambda _n}} \right \}</mml:annotation> </mml:semantics> …