KTH/Nordita/SU seminar in Theoretical Physics

Massive gravity and Bi-metric gravity as consistent theories of massive spin-2 fields

by Dr Fawad Hassan (Fysikum)

Europe/Stockholm
FA31 ()

FA31

Description
This talk will describe the recent construction of consistent (ghost free) theories of massive spin-2 fields and their interpretation as theories of massive gravity and bi-metric gravity.

While General Relativity is a theory of a massless spin-2 field, obtaining consistent non-linear theories of massive spin-2 fields has been a long standing problem since the original work of Pauli and Fierz in 1939. In fact, in 1972 and again in 2005, it was argued that such consistent theories may not even exist. This is puzzling since at least massive spin-2 mesons do exist in nature. However, over the past one year, theories of massive spin-2 fields have been constructed and shown to be consistent (ghost free). This has also been extended to theories of interacting massive and massless spin-2 fields. As a straightforward application, such theories can be regarded as theories of modified gravity, that is, massive gravity and bi-metric gravity. The talk will review recent progress in this field.