Topics in soft collinear effective theory for gravity: The diffeomorphism invariant Wilson lines and reparametrization invariance
Sabyasachi Chakraborty (Department of Physics, Florida State University, Tallahassee, Florida 32306, USA); Takemichi Okui (Theory Center, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan, Department of Physics, Florida State University, Tallahassee, Florida 32306, USA); Arash Yunesi (Department of Physics, Florida State University, Tallahassee, Florida 32306, USA, Department of Statics and Probability, Michigan State University, East Lansing, Michigan 48824, USA)
Two topics in soft collinear effective theory (SCET) for gravitational interactions are explored. First, the collinear Wilson lines—necessary building blocks for maintaining multiple copies of diffeomorphism invariance in gravity SCET—are extended to all orders in the SCET expansion parameter , where it has only been known to in the literature. Second, implications of reparametrization invariance (RPI) for the structure of gravity SCET Lagrangians are studied. The utility of RPI is illustrated by an explicit example in which hard interactions of a collinear graviton are completely predicted by RPI from its hard interactions. It is also pointed out that the multiple diffeomorphism invariances and RPI together require certain relations among terms, thereby reducing the number of terms that need to be fixed by matching onto the full theory in the first place.
