nLab D=4 N=4 super Yang-Mills theory

Idea

The super Yang-Mills theory in dimension 4 with the maximum number $N = 4$ of supersymmetries.

$d$	$N$	superconformal super Lie algebra	R-symmetry	black brane worldvolume superconformal field theory via AdS-CFT
$\phantom{A}3\phantom{A}$	$\phantom{A}2k+1\phantom{A}$	$\phantom{A}B(k,2) \simeq$ osp$(2k+1 \vert 4)\phantom{A}$	$\phantom{A}SO(2k+1)\phantom{A}$
$\phantom{A}3\phantom{A}$	$\phantom{A}2k\phantom{A}$	$\phantom{A}D(k,2)\simeq$ osp$(2k \vert 4)\phantom{A}$	$\phantom{A}SO(2k)\phantom{A}$	M2-brane D=3 SYM BLG model ABJM model
$\phantom{A}4\phantom{A}$	$\phantom{A}k+1\phantom{A}$	$\phantom{A}A(3,k)\simeq \mathfrak{sl}(4 \vert k+1)\phantom{A}$	$\phantom{A}U(k+1)\phantom{A}$	D3-brane D=4 N=4 SYM D=4 N=2 SYM D=4 N=1 SYM
$\phantom{A}5\phantom{A}$	$\phantom{A}1\phantom{A}$	$\phantom{A}F(4)\phantom{A}$	$\phantom{A}SO(3)\phantom{A}$	D4-brane D=5 SYM
$\phantom{A}6\phantom{A}$	$\phantom{A}k\phantom{A}$	$\phantom{A}D(4,k) \simeq$ osp$(8 \vert 2k)\phantom{A}$	$\phantom{A}Sp(k)\phantom{A}$	M5-brane D=6 N=(2,0) SCFT D=6 N=(1,0) SCFT

(Shnider 88, also Nahm 78, see Minwalla 98, section 4.2)

Properties of 4d SYM

Conformal invariance

$N=4$ $D=4$ SYM is an SCFT.

Closed expressions for physical observables

Among all gauge theory Lagrangians that of $N=4$, $D = 4$ SYM is special in several ways, in particular of course in that it is conformally invariant and in that it has maximal supersymmetry; and ultimately by the fact that it is the KK-reduction of the very special 6d (2,0)-superconformal QFT and related by AdS7-CFT6 duality to the very special theory of 11-dimensional supergravity/M-theory.

Accordingly, it is to be expected that the quantum observables of $N=4$, $D = 4$ SYM satisfy special relations that make them more tractable than the observables of a generic gauge theory, in particular by having closed-form expressions. Indeed, such relations have been and are being uncovered in the last years, in particular in what is called the planar limit of the theory, where scattering amplitudes are dominated by Feynman diagrams that can be given the structure of planar graphs.

This includes notably the following phenomena:

1. The operator spectrum of the dilatation operator (the part of the stress-energy tensor which induces conformal transformations) can be expressed in closed form, indeed when regarded as a Hamiltonian it defines an integrable system equivalent to spin chain models. This has been used in particular to explicitly check aspects of the conjectured AdS-CFT duality of $N=4$, $D= 4$ SYM with type II string theory on anti de Sitter spacetimes. See the review (Beisert et al).

2. Certain scattering amplitudes called maximally helicity violating amplitudes (“MHV amplitudes”) simplify drastically as compared to the generic situation and in fact are controled by a certain twistor string theory whose target space is a twistor space. See (Monteiro) for a review.

3. Generally, the scattering amplitudes of the theory in the planar limit have certain closed-form combinatorial expressions. See (Arkani-Hamed et al).

Such “exact solutions” of the theory are of interest in that even though N=4, D=4 SYM is very different from phenomenologically viable models such that QCD in the standard model of particle physics in that it is highly (super-)symmetric and conformal, it is still similar enough (being a nonabelian gauge theory minimally coupled to fermions) that one can or can hope to deduce from these exact results approximate information about these less symmetric theories.

In other words, because understanding observables in QCD/Yang-Mills theory in general is difficult, going to special points in the space of all such theories – such as the point of N=4, D=4 SYM – may be hoped to yield a tractable approximation. For more on this way of studying QCD and other realistic theories by studying instead their highly symmetric but phenomenologically unrealistic siblings, see also at string theory results applied elsewhere.

Holography, AdS-CFT

$N=4$ $d=4$ SYM is supposed to be related under the AdS/CFT correspondence to type II superstring theory compactified on a 5-sphere to an asymptotically anti de Sitter spacetime.

gauge theory induced via AdS-CFT correspondence

M-theory perspective via AdS7-CFT6	F-theory perspective
11d supergravity/M-theory
$\;\;\;\;\downarrow$ Kaluza-Klein compactification on $S^4$	compactificationon elliptic fibration followed by T-duality
7-dimensional supergravity
$\;\;\;\;\downarrow$ topological sector
7-dimensional Chern-Simons theory
$\;\;\;\;\downarrow$ AdS7-CFT6 holographic duality
6d (2,0)-superconformal QFT on the M5-brane with conformal invariance	M5-brane worldvolume theory
$\;\;\;\; \downarrow$ KK-compactification on Riemann surface	double dimensional reduction on M-theory/F-theory elliptic fibration
N=2 D=4 super Yang-Mills theory with Montonen-Olive S-duality invariance; AGT correspondence	D3-brane worldvolume theory with type IIB S-duality
$\;\;\;\;\; \downarrow$ topological twist
topologically twisted N=2 D=4 super Yang-Mills theory
$\;\;\;\; \downarrow$ KK-compactification on Riemann surface
A-model on $Bun_G$, Donaldson theory

$\,$

gauge theory induced via AdS5-CFT4
type II string theory
$\;\;\;\;\downarrow$ Kaluza-Klein compactification on $S^5$
$\;\;\;\; \downarrow$ topological sector
5-dimensional Chern-Simons theory
$\;\;\;\;\downarrow$ AdS5-CFT4 holographic duality
N=4 D=4 super Yang-Mills theory
$\;\;\;\;\; \downarrow$ topological twist
topologically twisted N=4 D=4 super Yang-Mills theory
$\;\;\;\; \downarrow$ KK-compactification on Riemann surface
A-model on $Bun_G$ and B-model on $Loc_G$, geometric Langlands correspondence

Twistor space formulation

There is a natural reformulation of the theory using twistor fields. See the references below. And see at twistor string theory.

Topological twists

There is a topological twist of 4d SYM to a TQFT – the Kapustin-Witten TQFT. Its S-duality is supposed to contain geometric Langlands duality as a special case.

See at topologically twisted D=4 super Yang-Mills theory.

Related concepts

• D=4 Yang-Mills theory

• super Yang-Mills theory

  • N=1 D=4 super Yang-Mills theory

  • N=2 D=4 super Yang-Mills theory

  • N=4 D=3 super Yang-Mills theory

  • D=5 super Yang-Mills theory

  • topologically twisted D=4 super Yang-Mills theory

Table of branes appearing in supergravity/string theory (for classification see at brane scan).

brane	in supergravity	charged under gauge field	has worldvolume theory
black brane	supergravity	higher gauge field	SCFT
D-brane	type II	RR-field	super Yang-Mills theory
$(D = 2n)$	type IIA	$\,$	$\,$
D(-2)-brane	$\,$	$\,$
D0-brane	$\,$	$\,$	BFSS matrix model
D2-brane	$\,$	$\,$	$\,$
D4-brane	$\,$	$\,$	D=5 super Yang-Mills theory with Khovanov homology observables
D6-brane	$\,$	$\,$	D=7 super Yang-Mills theory
D8-brane	$\,$	$\,$
$(D = 2n+1)$	type IIB	$\,$	$\,$
D(-1)-brane	$\,$	$\,$	$\,$
D1-brane	$\,$	$\,$	2d CFT with BH entropy
D3-brane	$\,$	$\,$	N=4 D=4 super Yang-Mills theory
D5-brane	$\,$	$\,$	$\,$
D7-brane	$\,$	$\,$	$\,$
D9-brane	$\,$	$\,$	$\,$
(p,q)-string	$\,$	$\,$	$\,$
(D25-brane)	(bosonic string theory)
NS-brane	type I, II, heterotic	circle n-connection	$\,$
string	$\,$	B2-field	2d SCFT
NS5-brane	$\,$	B6-field	little string theory
D-brane for topological string			$\,$
A-brane			$\,$
B-brane			$\,$
M-brane	11D SuGra/M-theory	circle n-connection	$\,$
M2-brane	$\,$	C3-field	ABJM theory, BLG model
M5-brane	$\,$	C6-field	6d (2,0)-superconformal QFT
M9-brane/O9-plane			heterotic string theory
M-wave
topological M2-brane	topological M-theory	C3-field on G₂-manifold
topological M5-brane	$\,$	C6-field on G₂-manifold
S-brane
SM2-brane, membrane instanton
M5-brane instanton
D3-brane instanton
solitons on M5-brane	6d (2,0)-superconformal QFT
self-dual string		self-dual B-field
3-brane in 6d

References

General

• Riccardo D'Auria, Pietro Fré, A. J. da Silva, Geometric structure of $N=1$, $D=10$ and $N=4$, $D=4$ super Yang-Mills theory, Nuclear Physics B 196 2 (1982) 205-239 [doi:10.1016/0550-3213(82)90036-0]

  (in D'Auria-Fré formulation)

Discussion of D=4 N=4 SYM with emphasis on multi-trace operators:

• P. J. Heslop, Paul Howe, Aspects of $\mathcal{N}$=4 SYM, JHEP 0401 (2004) 058 (arXiv:hep-th/0307210)

Superconformal invariance of $\mathcal{N}=4$, $D=4$ SYM can be shown with the result of

• Robert Leigh, Matthew Strassler, Exactly Marginal Operators and Duality in Four Dimensional $\mathcal{N}=1$ Supersymmetric Gauge Theory (arXiv:hep-th/9503121)

(after regarding it as $\mathcal{N}=1$ SYM with three adjoint chiral superfields).

Introductions in view of single trace operators as spin chain integrable systems in the AdS/CFT correspondence:

• Joseph A. Minahan Review of AdS/CFT Integrability, Chapter I.1: Spin Chains in $\mathcal{N}=4$ Super Yang-Mills (arXiv:1012.3983)

More recent results are in

• Simon Caron-Huot, Superconformal symmetry and two-loop amplitudes in planar N=4 super Yang-Mills (arXiv:1105.5606)

Matrix model description

On the BMN matrix model as a KK-compactification of D=4 N=4 super Yang-Mills theory on the 3-sphere:

• Nakwoo Kim, Thomas Klose, Jan Plefka, Plane-wave Matrix Theory from N=4 Super Yang-Mills on $\mathbb{R} \times S^3$, Nucl. Phys. B671:359-382, 2003 (arXiv:hep-th/0306054)

Using the KK-compactification of D=4 N=4 super Yang-Mills theory to the BMN matrix model for lattice gauge theory-computations in D=4 N=4 SYM and for numerical checks of the AdS-CFT correspondence:

• Masazumi Honda, Goro Ishiki, Sang-Woo Kim, Jun Nishimura, Asato Tsuchiya, Direct test of the AdS/CFT correspondence by Monte Carlo studies of N=4 super Yang-Mills theory, JHEP 1311 (2013) 200 [arXiv:1308.3525]

Planar sector, integrability, MHV amplitudes

A comprehensive discussion of the integrability related to anomalous dimension in the planar sector is in

• Niklas Beisert et al., Review of AdS/CFT Integrability, An Overview

  Lett. Math. Phys. vv, pp (2011), (arXiv:1012.3982).

A review of MHV amplitudes is in

• Gustavo Machado Monteiro, MHV Tree Amplitudes in Super-Yang-Mills and in Superstring Theory (2010) (pdf)

Discussion of special properties of scattering amplitudes in the planar sector is in

• Nima Arkani-Hamed, Jacob L. Bourjaily, Freddy Cachazo, Alexander B. Goncharov, Alexander Postnikov, Jaroslav Trnka, Scattering Amplitudes and the Positive Grassmannian (arXiv:1212.5605)

For mathematical background see

• Alexander Postnikov, Total positivity, Grassmannians, and networks (arXiv:math/0609764)

Twistor space formulation

The twistor space formulation of $N=4$ $D = 4$ SYM was originally found from the B-model string theory in

• Edward Witten, Perturbative Gauge Theory As A String Theory In Twistor Space, Commun. Math. Phys. 252:189-258,2004 (arXiv:hep-th/0312171/)

A comprehensive discussion is in

• Rutger Boels, Lionel Mason, David Skinner, Supersymmetric Gauge Theories in Twistor Space, JHEP 0702:014,2007 (arXiv:hep-th/0604040)

See also (Monteiro) below.

Scattering amplitudes

For the moment see at

• scattering amplitude

and also at

• motivic multiple zeta values.

Relation to number theory

Relating the abc conjecture to D=4 N=4 super Yang-Mills theory:

• Yang-Hui He, Zhi Hu, Malte Probst, James Read, Yang-Mills Theory and the ABC Conjecture, International Journal of Modern Physics A Vol. 33, No. 13, 1850053 (2018) (arXiv:1602.01780, doi:10.1142/S0217751X18500537)