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supergravity Lie 3-algebra

Context

\infty-Lie theory

∞-Lie theory

Background

Smooth structure

Higher groupoids

Lie theory

∞-Lie groupoids

∞-Lie algebroids

Formal Lie groupoids

Cohomology

Homotopy

Examples

\infty-Lie groupoids

\infty-Lie groups

\infty-Lie algebroids

\infty-Lie algebras

Super-Geometry

Contents

Definition

The supergravity Lie 3-algebra 𝔰𝔲𝔤𝔯𝔞(10,1)\mathfrak{sugra}(10,1) or M2-brane extension 𝔪2𝔟𝔯𝔞𝔫𝔢\mathfrak{m}2\mathfrak{brane} is a super L-∞ algebra that is a shifted extension

0b 2𝔰𝔲𝔤𝔯𝔞(10,1)𝔰𝔦𝔰𝔬(10,1)0 0 \to b^2 \mathbb{R} \to \mathfrak{sugra}(10,1) \to \mathfrak{siso}(10,1) \to 0

of the super Poincare Lie algebra 𝔰𝔦𝔰𝔬(10,1)\mathfrak{siso}(10,1) in 10+1 dimensions induced by the exceptional degree 4-super Lie algebra cocycle

μ=ψ¯Γ abψe ae bCE(𝔰𝔦𝔰𝔬(10,1)). \mu = \bar \psi \wedge \Gamma^{a b} \psi \wedge e_a \wedge e_b \;\; \in CE(\mathfrak{siso}(10,1)) \,.

This is the same mechanism by which the String Lie 2-algebra is a shifted central extensiono of 𝔰𝔬(n)\mathfrak{so}(n).

Properties

The Chevalley-Eilenberg algebra

Proposition

The Chevalley-Eilenberg algebra CE(𝔰𝔲𝔤𝔯𝔞(10,1))CE(\mathfrak{sugra}(10,1)) is generated on

  • elements {e a}\{e^a\} and {ω ab}\{\omega^{ a b}\} of degree (1,even)(1,even)

  • a single element cc of degree (3,even)(3,even)

  • and elements {ψ α}\{\psi^\alpha\} of degree (1,odd)(1,odd)

with the differential defined by

d CEω ab=ω a bω bc d_{CE} \omega^{a b} = \omega^a{}_b \wedge \omega^{b c}
d CEe a=ω a be b+i2ψ¯Γ aψ d_{CE} e^{a } = \omega^a{}_b \wedge e^b + \frac{i}{2}\bar \psi \Gamma^a \psi
d CEψ=14ω abΓ abψ d_{CE} \psi = \frac{1}{4} \omega^{ a b} \Gamma_{a b} \psi
d CEc=12ψ¯Γ abψe ae b. d_{CE} c = \frac{1}{2}\bar \psi \Gamma^{a b} \wedge \psi \wedge e_a \wedge e_b \,.

(fill in details)

Relation to M5-brane action functional

The supergravity Lie 3-algebra carries a 7-cocycle (the one that induces the supergravity Lie 6-algebra-extension of it). The corresponding WZW term is that of the M5-brane in its Green-Schwarz action functional-like formulation.

The brane scan.

The Green-Schwarz type super pp-brane sigma-models (see at table of branes for further links and see at The brane bouquet for the full classification):

=D\stackrel{D}{=}p=p =123456789
11M2M5
10D0F1, D1D2D3D4NS5, D5D6D7D8D9
9*\ast
8*\ast
7M2 top{}_{top}
6F1 little{}_{little}, S1 sd{}_{sd}S3
5*\ast
4*\ast*\ast
3*\ast

(The first colums follow the exceptional spinors table.)

The corresponding exceptional super L-∞ algebra cocycles (schematically, without prefactors):

=D\stackrel{D}{=}p=p =123456789
11Ψ 2E 2\Psi^2 E^2 on sIso(10,1)Ψ 2E 5+Ψ 2E 2C 3\Psi^2 E^5 + \Psi^2 E^2 C_3 on m2brane
10Ψ 2E 1\Psi^2 E^1 on sIso(9,1)B 2 2+B 2Ψ 2+Ψ 2E 2B_2^2 + B_2 \Psi^2 + \Psi^2 E^2 on StringIIA\cdots on StringIIBB 2 3+B 2 2Ψ 2+B 2Ψ 2E 2+Ψ 2E 4B_2^3 + B_2^2 \Psi^2 + B_2 \Psi^2 E^2 + \Psi^2 E^4 on StringIIAΨ 2E 5\Psi^2 E^5 on sIso(9,1)B 2 4++Ψ 2E 6B_2^4 + \cdots + \Psi^2 E^6 on StringIIA\cdots on StringIIBB 2 5++Ψ 2E 8B_2^5 + \cdots + \Psi^2 E^8 in StringIIA\cdots on StringIIB
9Ψ 2E 4\Psi^2 E^4 on sIso(8,1)
8Ψ 2E 3\Psi^2 E^3 on sIso(7,1)
7Ψ 2E 2\Psi^2 E^2 on sIso(6,1)
6Ψ 2E 1\Psi^2 E^1 on sIso(5,1)Ψ 2E 3\Psi^2 E^3 on sIso(5,1)
5Ψ 2E 2\Psi^2 E^2 on sIso(4,1)
4Ψ 2E 1\Psi^2 E^1 on sIso(3,1)Ψ 2E 2\Psi^2 E^2 on sIso(3,1)
3Ψ 2E 1\Psi^2 E^1 on sIso(2,1)

Relation to the 11-dimensional polyvector super Poincaré-algebra

Proposition

Let 𝔡𝔢𝔯(𝔰𝔲𝔤𝔯𝔞(10,1))\mathfrak{der}(\mathfrak{sugra}(10,1)) be the automorphism ∞-Lie algebra of 𝔰𝔲𝔤𝔯𝔞(10,1)\mathfrak{sugra}(10,1). This is a dg-Lie algebra. Write 𝔡𝔢𝔯(𝔰𝔲𝔤𝔯𝔞(10,1)) 0\mathfrak{der}(\mathfrak{sugra}(10,1))_0 for the ordinary Lie algebra in degree 0.

This is isomorphic to the polyvector-extension of the super Poincaré Lie algebra (see there) in d=10+1d = 10+1 – the “M-theory super Lie algebra” – with “2-brane central charge”: the Lie algebra spanned by generators {P a,Q α,J ab,Z ab}\{P_a, Q_\alpha, J_{a b}, Z^{a b}\} and graded Lie brackets those of the super Poincaré Lie algebra as well as

[Q α,Q β]=i(CΓ a) αβP a+(CΓ ab)Z ab [Q_\alpha, Q_\beta] = i (C \Gamma^a)_{\alpha \beta} P_a + (C \Gamma_{a b})Z^{a b}
[Q α,Z ab]=2i(CΓ [a) αβQ b]β [Q_\alpha, Z^{a b}] = 2 i (C \Gamma^{[a})_{\alpha \beta}Q^{b]\beta}

etc.

This observation appears implicitly in (Castellani05, section 3.1), see (FSS 13).

Proof

With the presentation of the Chevalley-Eilenberg algebra CE(𝔰𝔲𝔤𝔯𝔞(10,1))CE(\mathfrak{sugra}(10,1)) as in prop. 1 above, the generators are identified with derivations on CE(𝔰𝔲𝔤𝔯𝔞(10,1))CE(\mathfrak{sugra}(10,1)) as

P a=[d CE,e a] P_a = [d_{CE}, \frac{\partial}{\partial e^a} ]

and

Q α=[d CE,ψ α] Q_\alpha = [d_{CE}, \frac{\partial}{\partial \psi^\alpha} ]

and

J ab=[d CE,ω ab] J_{a b} = [d_{CE}, \frac{\partial}{\partial \omega^{a b}} ]

and

Z ab=[d CE,e ae bc] Z^{a b} = [d_{CE}, e^a \wedge e^b \wedge \frac{\partial}{\partial c}]

etc. With this it is straightforward to compute the commutators. Notably the last term in

[Q α,Q β]=i(CΓ a) αβP a+(CΓ ab)Z ab [Q_\alpha, Q_\beta] = i (C \Gamma^a)_{\alpha \beta} P_a + (C \Gamma_{a b})Z^{a b}

arises from the contraction of the 4-cocycle ψ¯Γ abψe ae b\bar \psi \Gamma^{a b} \wedge \psi \wedge e_a \wedge e_b with ψ αψ β\frac{\partial}{\partial \psi^\alpha}\wedge \frac{\partial}{\partial \psi^\beta}.

Applications

The field configurations of 11-dimensional supergravity may be identified with ∞-Lie algebra-valued forms with values in 𝔰𝔲𝔤𝔯𝔞(10,1)\mathfrak{sugra}(10,1). See D'Auria-Fre formulation of supergravity.

supergravity Lie 6-algebra \to supergravity Lie 3-algebra \to super Poincaré Lie algebra

References

The Chevalley-Eilenberg algebra of 𝔰𝔲𝔤𝔯𝔞(10,1)\mathfrak{sugra}(10,1) first appears in (3.15) of

and later in the textbook

The manifest interpretation of this as a Lie 3-algebra and the supergravity field content as ∞-Lie algebra valued forms with values in this is mentioned in

A systematic study of the super-Lie algebra cohomology involved is in

See also division algebra and supersymmetry.

The computation of the automorphism Lie algebra of 𝔰𝔲𝔤𝔯𝔞(10,1)\mathfrak{sugra}(10,1) is in

A similar argument with more explicit use of the Lie 3-algebra as underlying the Green-Schwarz-like action functional for the M5-brane is in

Revised on September 12, 2013 00:51:33 by Urs Schreiber (145.116.131.249)