Intermediate-mass black holes as LISA sources

Intermediate-mass black holes (IMBHs), with masses in the range similar to 10(2-4)M(circle dot), would be unique sources of gravitational waves for LISA. Here we discuss their context as well as specific characteristics of IMBH-IMBH and IMBH-supermassive black hole mergers and how these would allow sensitive tests of the predictions of general relativity in strong gravity.