Polyakov action in string theory
E724407
The Polyakov action in string theory is a reformulation of the string’s dynamics that treats the worldsheet metric as an independent field, providing a convenient starting point for quantizing strings and analyzing their conformal symmetry.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Polyakov action for path-integral quantization | 1 |
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
action functional in theoretical physics
ⓘ
string theory formalism ⓘ |
| afterGaugeFixingLeadsTo | free 2D scalar fields plus ghosts in flat background ⓘ |
| allows | gauge fixing to conformal gauge ⓘ |
| betaFunctionsCorrespondTo | target-space equations of motion ⓘ |
| canCoupleTo |
antisymmetric B-field background
ⓘ
dilaton background ⓘ |
| centralTo | modern covariant string perturbation theory ⓘ |
| couplesTo | target-space metric background ⓘ |
| dependsOn |
embedding coordinates of the string in target spacetime
ⓘ
string tension ⓘ worldsheet metric ⓘ |
| describes | dynamics of relativistic strings ⓘ |
| exhibits |
Weyl invariance at the classical level
ⓘ
two-dimensional diffeomorphism invariance ⓘ worldsheet conformal invariance ⓘ |
| field | string theory ⓘ |
| formulatedIn |
Euclidean worldsheet signature
ⓘ
Lorentzian worldsheet signature ⓘ |
| frameworkFor | deriving low-energy effective field equations from string theory ⓘ |
| generalizedBy | nonlinear sigma model with background fields ⓘ |
| hasDomain | two-dimensional worldsheet ⓘ |
| implies |
critical dimension 10 for superstring (with supersymmetric extension)
ⓘ
critical dimension 26 for bosonic string ⓘ |
| introducedIn | late 1970s ⓘ |
| involves |
pullback of target-space metric to the worldsheet
ⓘ
two-dimensional scalar curvature term (topological in 2D) ⓘ worldsheet area element ⓘ |
| isClassicallyEquivalentTo | Nambu–Goto action NERFINISHED ⓘ |
| isMoreConvenientThan | Nambu–Goto action for quantization ⓘ |
| leadsTo | conformal field theory on the worldsheet ⓘ |
| mathematicallyFormulatedAs | two-dimensional nonlinear sigma model ⓘ |
| namedAfter | Alexander Polyakov NERFINISHED ⓘ |
| quantizationRequires | cancellation of conformal (Weyl) anomaly ⓘ |
| reformulates | Nambu–Goto action NERFINISHED ⓘ |
| treatsAsIndependentField | worldsheet metric ⓘ |
| usedFor |
analysis of conformal symmetry on the worldsheet
ⓘ
covariant quantization of strings ⓘ derivation of Virasoro constraints ⓘ path integral quantization of strings ⓘ study of critical dimensions of string theory ⓘ |
| usedIn |
bosonic string theory
NERFINISHED
ⓘ
heterotic string theory NERFINISHED ⓘ superstring theory (with fermionic generalizations) ⓘ type I string theory NERFINISHED ⓘ type II string theories ⓘ |
| variationWithRespectTo |
embedding coordinates gives string equations of motion
ⓘ
worldsheet metric gives energy–momentum tensor constraints ⓘ |
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Polyakov action for path-integral quantization