Estimates for Hardy-type integral operators in weighted Lebesgue spaces

Sammanfattning: This PhD thesis deals with the theory of Hardy-type inequalities in a new situation, namely when the classical Hardy operator is replaced by a more general operator with a kernel. The kernels we consider belong to the new classes $\mathcal{O}^+_n$ and $\mathcal{O}^-_n$, $n=0,1,...$, which are wider than co-called Oinarov class of kernels. This PhD thesis consists of four papers (papers A, B, C and D), two complementary appendixes (A$_1$, C$_1$) and an introduction, which put these publications into a more general frame. This introduction also serves as a basic overview of the field. In paper A some boundedness criteria for the Hardy-Volterra integral operators are proved and discussed. The case $1