# nLab graviton

Contents

### Context

#### Gravity

gravity, supergravity

## Surveys, textbooks and lecture notes

#### Fields and quanta

field (physics)

standard model of particle physics

force field gauge bosons

scalar bosons

flavors of fundamental fermions in the
standard model of particle physics:
generation of fermions1st generation2nd generation3d generation
quarks ($q$)
up-typeup quark ($u$)charm quark ($c$)top quark ($t$)
down-typedown quark ($d$)strange quark ($s$)bottom quark ($b$)
leptons
chargedelectronmuontauon
neutralelectron neutrinomuon neutrinotau neutrino
bound states:
mesonspion ($u d$)
rho-meson ($u d$)
omega-meson ($u d$)
kaon ($q_{u/d} s$)
eta-meson (u u + d d + s s)
B-meson ($q b$)
baryonsproton $(u u d)$
neutron $(u d d)$

(also: antiparticles)

effective particles

hadron (bound states of the above quarks)

solitons

minimally extended supersymmetric standard model

superpartners

bosinos:

dark matter candidates

Exotica

auxiliary fields

# 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

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

with values in the Poincare Lie algebra.

This is a vielbein $E$ and a spin connection $\Omega$. This together is the graviton field.

A graviton has spin $2$, and is massless. We can see that it has spin $2$ from the fact that the source of gravity is $T$, the energy-momentum tensor, which is a second-rank tensor. It can be shown that a massless spin-$2$ 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 $T$, the source of gravity.

In supergravity this is accompanied by the gravitino.

## References

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### Classification of long-range forces

Classification of possible long-range forces, hence of scattering processes of massless fields, by classification of suitably factorizing and decaying Poincaré-invariant S-matrices depending on particle spin, leading to uniqueness statements about Maxwell/photon-, Yang-Mills/gluon-, gravity/graviton- and supergravity/gravitino-interactions:

Review:

Last revised on January 30, 2020 at 07:03:37. See the history of this page for a list of all contributions to it.