Cylindrical Carleman s formula of subharmonic functions and its application

Our aim in this paper is to prove the cylindrical Carleman’s formula for subharmonic functions in a truncated cylinder. As an application, we prove that if the positive part of a harmonic function in a cylinder satisfies a slowly growing condition, then its negative part can also be dominated by a similar slowly growing condition, which improves some classical results about harmonic functions in a cylinder.