nLab graviton

Contents

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

fields and particles in particle physics

and in the standard model of particle physics:

force field gauge bosons

scalar bosons

matter field fermions (spinors, Dirac fields)

flavors of fundamental fermions in the
standard model of particle physics:
generation of fermions1st generation2nd generation3d generation
quarks (qq)
up-typeup quark (uu)charm quark (cc)top quark (tt)
down-typedown quark (dd)strange quark (ss)bottom quark (bb)
leptons
chargedelectronmuontauon
neutralelectron neutrinomuon neutrinotau neutrino
bound states:
mesonslight mesons:
pion (udu d)
ρ-meson (udu d)
ω-meson (udu d)
f1-meson
a1-meson
strange-mesons:
ϕ-meson (ss¯s \bar s),
kaon, K*-meson (usu s, dsd s)
eta-meson (uu+dd+ssu u + d d + s s)

charmed heavy mesons:
D-meson (uc u c, dcd c, scs c)
J/ψ-meson (cc¯c \bar c)
bottom heavy mesons:
B-meson (qbq b)
ϒ-meson (bb¯b \bar b)
baryonsnucleons:
proton (uud)(u u d)
neutron (udd)(u d d)

(also: antiparticles)

effective particles

hadrons (bound states of the above quarks)

solitons

in grand unified theory

minimally extended supersymmetric standard model

superpartners

bosinos:

sfermions:

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,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.

References

General

See the references at quantum gravity – and an effective perturbative field theory

On potential experiments detecting gravitons:

  • Freeman Dyson, Is the graviton detectable?, International Journal of Modern Physics A 28 25 (2013) 1330041 [doi:10.1142/S0217751X1330041X]

  • Tony Rothman, Stephen Boughn, Can Gravitons be Detected?, Foundations of Physics 36 (2006) 1801–1825 [doi:10.1007/s10701-006-9081-9]

  • Tony Rothman, Stephen Boughn, Aspects of graviton detection: graviton emission and absorption by atomic hydrogen, Classical and Quantum Gravity 23 20 (2006) 5839 [doi:10.1088/0264-9381/23/20/006]

  • Daniel Carney, Valerie Domcke, Nicholas L. Rodd, Graviton detection and the quantization of gravity [arXiv:2308.12988]

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 August 28, 2023 at 07:11:28. See the history of this page for a list of all contributions to it.