ABSTRACT
In this paper we give a survey of recent work by the authors and others on pure and mixed exponential sums of the type https://www.w3.org/1998/Math/MathML"> ∑ x = 1 p m e p m ( f ( x ) ) , ∑ x = 1 p m χ ( g ( x ) ) e p m ( f ( x ) ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429258978/3c59d1b3-c997-442a-81c4-7652a0f9e6a5/content/eq890.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
