Infrared Problems in Quantum Field Theories.

It is envisaged that he will work on new symmetries in quantum field theory. These symmetries are the large gauge transformations in electromagnetism and their generalisations to Yang-Mills theories and to BMS transformations in gravitational theories. They are also related to the soft theorems in these theories. Recent work has shown that they are more widely applicable than just symmetries at infinity and can be related to black hole hair and to cosmological horizons and quite possibly to the past null cone of any observer. They also can be extended to supersymmetric situations and to the conformal transformations. He will explore some of the avenues brought to light by recent research.