nLab
graviton

Context

Gravity

Physics

physics, mathematical physics, philosophy of physics

Surveys, textbooks and lecture notes


theory (physics), model (physics)

experiment, measurement, computable physics

Fields and quanta

Contents

Idea

The graviton is the (hypothetical) quantum of the field of gravity, i.e., the quanta of the theory of quantum gravity.

Details

In first-order formulation of gravity a field configuration is locally a Lie algebra-valued form

(E,Ω):TX𝔦𝔰𝔬(d) (E, \Omega) : T X \to \mathfrak{iso}(d)

with values in the Poincare Lie algebra.

This is a vielbein EE and a spin connection Ω\Omega. This together is the graviton field.

A graviton has spin 22, and is massless. We can see that it has spin 22 from the fact that the source of gravity is TT, the energy-momentum tensor, which is a second-rank tensor. It can be shown that a massless spin-22 particle has to be a graviton. The basic concept behind this is that massless particles have to couple to conserved currents - the stress-energy tensor TT, the source of gravity.

In supergravity this is accompanied by the gravitino.

Revised on April 16, 2014 14:28:46 by Sanath Devalapurkar (108.184.54.10)