A Sharp Form of the Discrete Hardy Inequality and the Keller–Pinchover–Pogorzelski Inequality

Abstract

We give a short proof of a recently established Hardy-type inequality due to Keller, Pinchover, and Pogorzelski together with its optimality. Moreover, we identify the remainder term which makes it into an identity.

MSC::

• Primary 26D15

Acknowledgment

The research of the authors was supported by the GAČR grant No. 20-17749X.

Additional information

Funding

The research of the authors was supported by the GAČR grant No. 20-17749X.