A note on the standard zero-free region for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e22" altimg="si3.svg"><mml:mi>L</mml:mi></mml:math>-functions

In this short note, we establish a standard zero-free region for a general class of L -functions for which their logarithms have coefficients with nonnegative real parts, including the Rankin–Selberg L -functions for unitary cuspidal automorphic representations.