I describe the treatment of gravity as a quantum effective field theory. This allows a natural separation of the (known) low energy quantum effects from the (unknown) high energy contributions. Within this framework, gravity is a well behaved quantum field theory at ordinary energies. In studying the class of quantum corrections at low energy , the dominant… (More)
This is a pedagogical introduction to the treatment of general rel-ativity as a quantum effective field theory. Gravity fits nicely into the effective field theory description and forms a good quantum theory at ordinary energies.
I argue that the leading quantum corrections, in powers of the energy or inverse powers of the distance, may be computed in quantum gravity through knowledge of only the low energy structure of the theory. As an example, I calculate the leading quantum corrections to the Newtonian gravitational potential.
In theories in which different regions of the universe can have different values of the the physical parameters, we would naturally find ourselves in a region which has parameters favorable for life. We explore the range of anthropically allowed values of the mass parameter in the Higgs potential, µ 2. For µ 2 < 0, the requirement that complex elements be… (More)
We treat general relativity as an effective field theory, obtaining the full nonanalytic component of the scattering matrix potential to one-loop order. The lowest order vertex rules for the resulting effective field theory are presented and the one-loop diagrams which yield the leading nonrelativistic post-Newtonian and quantum corrections to the… (More)
One of the puzzles of the Standard Model is why the mass parameter which determines the scale of the Weak interactions is closer to the scale of Quantum Chromodymanics (QCD) than to the Grand Unification or Planck scales. We discuss a novel approach to this problem which is possible in theories in which different regions of the universe can have different… (More)
We examine the corrections to the lowest order gravitational interactions of massive particles arising from gravitational radiative corrections. We show how the masslessness of the graviton and the gravitational self interactions imply the presence of nonanalytic pieces ∼ −q 2 , ∼ q 2 ln −q 2 , etc. in the form factors of the energy-momentum tensor and that… (More)
We use effective field theory techniques to examine the quantum corrections to the gravitational metrics of charged particles, with and without spin. In momentum space the masslessness of the photon implies the presence of nonanalytic pieces ∼ −q 2 , q 2 log −q 2 , etc. in the form factors of the energy-momentum tensor. We show how the former reproduces the… (More)
A class of loop diagrams in general relativity appears to have a behavior which would upset the utility of the energy expansion for quantum effects. We show through the study of specific diagrams that cancellations occur which restore the expected behaviour of the energy expansion. By considering the power counting in a physical gauge we show that the… (More)
We argue that there is a potential flaw in the standard treatment of weak decay amplitudes, including that of ǫ ′ /ǫ. We show that (contrary to conventional wisdom) dimension-eight operators do contribute to weak amplitudes, at order G F α s and without 1/M 2 W suppression. We demonstrate the existence of these operators through the use of a simple weak… (More)