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In mathematics, **E _{6}** is the name of some closely related Lie groups, linear algebraic groups or their Lie algebras , all of which have dimension 78; the same notation E

- Real and complex forms
- E6 as an algebraic group
- Automorphisms of an Albert Algebra
- Algebra
- Dynkin diagram
- Roots of E6
- Weyl group
- Cartan matrix
- Important subalgebras and representations
- E6 polytope
- Chevalley and Steinberg groups of type E6 and 2E6
- Importance in physics
- See also
- References

The fundamental group of the complex form, compact real form, or any algebraic version of E_{6} is the cyclic group **Z**/3**Z**, and its outer automorphism group is the cyclic group **Z**/2**Z**. Its fundamental representation is 27-dimensional (complex), and a basis is given by the 27 lines on a cubic surface. The dual representation, which is inequivalent, is also 27-dimensional.

In particle physics, E_{6} plays a role in some grand unified theories.

There is a unique complex Lie algebra of type E_{6}, corresponding to a complex group of complex dimension 78. The complex adjoint Lie group E_{6} of complex dimension 78 can be considered as a simple real Lie group of real dimension 156. This has fundamental group **Z**/3**Z**, has maximal compact subgroup the compact form (see below) of E_{6}, and has an outer automorphism group non-cyclic of order 4 generated by complex conjugation and by the outer automorphism which already exists as a complex automorphism.

As well as the complex Lie group of type E_{6}, there are five real forms of the Lie algebra, and correspondingly five real forms of the group with trivial center (all of which have an algebraic double cover, and three of which have further non-algebraic covers, giving further real forms), all of real dimension 78, as follows:

- The compact form (which is usually the one meant if no other information is given), which has fundamental group
**Z**/3**Z**and outer automorphism group**Z**/2**Z**. - The split form, EI (or E
_{6(6)}), which has maximal compact subgroup Sp(4)/(±1), fundamental group of order 2 and outer automorphism group of order 2. - The quasi-split form EII (or E
_{6(2)}), which has maximal compact subgroup SU(2) × SU(6)/(center), fundamental group cyclic of order 6 and outer automorphism group of order 2. - EIII (or E
_{6(-14)}), which has maximal compact subgroup SO(2) × Spin(10)/(center), fundamental group**Z**and trivial outer automorphism group. - EIV (or E
_{6(-26)}), which has maximal compact subgroup F_{4}, trivial fundamental group cyclic and outer automorphism group of order 2.

The EIV form of E_{6} is the group of collineations (line-preserving transformations) of the octonionic projective plane **OP**^{2}.^{ [1] } It is also the group of determinant-preserving linear transformations of the exceptional Jordan algebra. The exceptional Jordan algebra is 27-dimensional, which explains why the compact real form of E_{6} has a 27-dimensional complex representation. The compact real form of E_{6} is the isometry group of a 32-dimensional Riemannian manifold known as the 'bioctonionic projective plane'; similar constructions for E_{7} and E_{8} are known as the Rosenfeld projective planes, and are part of the Freudenthal magic square.

By means of a Chevalley basis for the Lie algebra, one can define E_{6} as a linear algebraic group over the integers and, consequently, over any commutative ring and in particular over any field: this defines the so-called split (sometimes also known as "untwisted") adjoint form of E_{6}. Over an algebraically closed field, this and its triple cover are the only forms; however, over other fields, there are often many other forms, or "twists" of E_{6}, which are classified in the general framework of Galois cohomology (over a perfect field *k*) by the set *H*^{1}(*k*, Aut(E_{6})) which, because the Dynkin diagram of E_{6} (see below) has automorphism group **Z**/2**Z**, maps to *H*^{1}(*k*, **Z**/2**Z**) = Hom (Gal(*k*), **Z**/2**Z**) with kernel *H*^{1}(*k*, E_{6,ad}).^{ [2] }

Over the field of real numbers, the real component of the identity of these algebraically twisted forms of E_{6} coincide with the three real Lie groups mentioned above, but with a subtlety concerning the fundamental group: all adjoint forms of E_{6} have fundamental group **Z**/3**Z** in the sense of algebraic geometry, with Galois action as on the third roots of unity; this means that they admit exactly one triple cover (which may be trivial on the real points); the further non-compact real Lie group forms of E_{6} are therefore not algebraic and admit no faithful finite-dimensional representations. The compact real form of E_{6} as well as the noncompact forms EI=E_{6(6)} and EIV=E_{6(-26)} are said to be *inner* or of type ^{1}E_{6} meaning that their class lies in *H*^{1}(*k*, E_{6,ad}) or that complex conjugation induces the trivial automorphism on the Dynkin diagram, whereas the other two real forms are said to be *outer* or of type ^{2}E_{6}.

Over finite fields, the Lang–Steinberg theorem implies that *H*^{1}(*k*, E_{6}) = 0, meaning that E_{6} has exactly one twisted form, known as ^{2}E_{6}: see below.

Similar to how the algebraic group G_{2} is the automorphism group of the octonions and the algebraic group F_{4} is the automorphism group of an Albert algebra, an exceptional Jordan algebra, the algebraic group E_{6} is the group of linear automorphisms of an Albert algebra that preserve a certain cubic form, called the "determinant".^{ [3] }

The Dynkin diagram for E_{6} is given by , which may also be drawn as .

Although they span a six-dimensional space, it is much more symmetrical to consider them as vectors in a six-dimensional subspace of a nine-dimensional space. Then one can take the roots to be

- (1,−1,0;0,0,0;0,0,0), (−1,1,0;0,0,0;0,0,0),
- (−1,0,1;0,0,0;0,0,0), (1,0,−1;0,0,0;0,0,0),
- (0,1,−1;0,0,0;0,0,0), (0,−1,1;0,0,0;0,0,0),
- (0,0,0;1,−1,0;0,0,0), (0,0,0;−1,1,0;0,0,0),
- (0,0,0;−1,0,1;0,0,0), (0,0,0;1,0,−1;0,0,0),
- (0,0,0;0,1,−1;0,0,0), (0,0,0;0,−1,1;0,0,0),
- (0,0,0;0,0,0;1,−1,0), (0,0,0;0,0,0;−1,1,0),
- (0,0,0;0,0,0;−1,0,1), (0,0,0;0,0,0;1,0,−1),
- (0,0,0;0,0,0;0,1,−1), (0,0,0;0,0,0;0,−1,1),

plus all 27 combinations of where is one of plus all 27 combinations of where is one of

**Simple roots**

One possible selection for the simple roots of E6 is:

- (0,0,0;0,0,0;0,1,−1)

- (0,0,0;0,0,0;1,−1,0)

- (0,0,0;0,1,−1;0,0,0)

- (0,0,0;1,−1,0;0,0,0)

- (0,1,−1;0,0,0;0,0,0)

E_{6} is the subset of E_{8} where a consistent set of three coordinates are equal (e.g. first or last). This facilitates explicit definitions of E_{7} and E_{6} as:

- E
_{7}= {**α**∈**Z**^{7}∪ (**Z**+1/2)^{7}**:**Σ**α**_{i}^{2}+**α**_{1}^{2}= 2, Σ**α**_{i}+**α**_{1}∈ 2**Z**}, - E
_{6}= {**α**∈**Z**^{6}∪ (**Z**+1/2)^{6}**:**Σ**α**_{i}^{2}+ 2**α**_{1}^{2}= 2, Σ**α**_{i}+ 2**α**_{1}∈ 2**Z**}

The following 72 E6 roots are derived in this manner from the split real even E8 roots. Notice the last 3 dimensions being the same as required:

An alternative (6-dimensional) description of the root system, which is useful in considering E_{6} × SU(3) as a subgroup of E_{8}, is the following:

All permutations of

- preserving the zero at the last entry,

and all of the following roots with an odd number of plus signs

Thus the 78 generators consist of the following subalgebras:

- A 45-dimensional SO(10) subalgebra, including the above generators plus the five Cartan generators corresponding to the first five entries.
- Two 16-dimensional subalgebras that transform as a Weyl spinor of and its complex conjugate. These have a non-zero last entry.
- 1 generator which is their chirality generator, and is the sixth Cartan generator.

One choice of simple roots for E_{6} is given by the rows of the following matrix, indexed in the order :

The Weyl group of E_{6} is of order 51840: it is the automorphism group of the unique simple group of order 25920 (which can be described as any of: PSU_{4}(2), PSΩ_{6}^{−}(2), PSp_{4}(3) or PSΩ_{5}(3)).^{ [4] }

The Lie algebra E_{6} has an F_{4} subalgebra, which is the fixed subalgebra of an outer automorphism, and an SU(3) × SU(3) × SU(3) subalgebra. Other maximal subalgebras which have an importance in physics (see below) and can be read off the Dynkin diagram, are the algebras of SO(10) × U(1) and SU(6) × SU(2).

In addition to the 78-dimensional adjoint representation, there are two dual 27-dimensional "vector" representations.

The characters of finite dimensional representations of the real and complex Lie algebras and Lie groups are all given by the Weyl character formula. The dimensions of the smallest irreducible representations are (sequence A121737 in the OEIS ):

__1__, 27 (twice),__78__, 351 (four times),__650__, 1728 (twice),__2430__,__2925__,__3003 (twice)__,__5824 (twice)__, 7371 (twice), 7722 (twice), 17550 (twice), 19305 (four times), 34398 (twice),__34749__,__43758__, 46332 (twice), 51975 (twice), 54054 (twice), 61425 (twice),__70070__,__78975 (twice)__,__85293__, 100386 (twice),__105600__, 112320 (twice),__146432 (twice)__,__252252 (twice)__, 314496 (twice), 359424 (four times),__371800 (twice)__, 386100 (twice), 393822 (twice), 412776 (twice),__442442 (twice)__...

The underlined terms in the sequence above are the dimensions of those irreducible representations possessed by the adjoint form of E_{6} (equivalently, those whose weights belong to the root lattice of E_{6}), whereas the full sequence gives the dimensions of the irreducible representations of the simply connected form of E_{6}.

The symmetry of the Dynkin diagram of E_{6} explains why many dimensions occur twice, the corresponding representations being related by the non-trivial outer automorphism; however, there are sometimes even more representations than this, such as four of dimension 351, two of which are fundamental and two of which are not.

The fundamental representations have dimensions 27, 351, 2925, 351, 27 and 78 (corresponding to the six nodes in the Dynkin diagram in the order chosen for the Cartan matrix above, i.e., the nodes are read in the five-node chain first, with the last node being connected to the middle one).

The ** E _{6} polytope ** is the convex hull of the roots of E

The groups of type *E*_{6} over arbitrary fields (in particular finite fields) were introduced by Dickson ( 1901 , 1908 ).

The points over a finite field with *q* elements of the (split) algebraic group E_{6} (see above), whether of the adjoint (centerless) or simply connected form (its algebraic universal cover), give a finite Chevalley group. This is closely connected to the group written E_{6}(*q*), however there is ambiguity in this notation, which can stand for several things:

- the finite group consisting of the points over
**F**_{q}of the simply connected form of E_{6}(for clarity, this can be written E_{6,sc}(*q*) or more rarely and is known as the "universal" Chevalley group of type E_{6}over**F**_{q}), - (rarely) the finite group consisting of the points over
**F**_{q}of the adjoint form of E_{6}(for clarity, this can be written E_{6,ad}(*q*), and is known as the "adjoint" Chevalley group of type E_{6}over**F**_{q}), or - the finite group which is the image of the natural map from the former to the latter: this is what will be denoted by E
_{6}(*q*) in the following, as is most common in texts dealing with finite groups.

From the finite group perspective, the relation between these three groups, which is quite analogous to that between SL(*n,q*), PGL(*n,q*) and PSL(*n,q*), can be summarized as follows: E_{6}(*q*) is simple for any *q*, E_{6,sc}(*q*) is its Schur cover, and E_{6,ad}(*q*) lies in its automorphism group; furthermore, when *q*−1 is not divisible by 3, all three coincide, and otherwise (when *q* is congruent to 1 mod 3), the Schur multiplier of E_{6}(*q*) is 3 and E_{6}(*q*) is of index 3 in E_{6,ad}(*q*), which explains why E_{6,sc}(*q*) and E_{6,ad}(*q*) are often written as 3·E_{6}(*q*) and E_{6}(*q*)·3. From the algebraic group perspective, it is less common for E_{6}(*q*) to refer to the finite simple group, because the latter is not in a natural way the set of points of an algebraic group over **F**_{q} unlike E_{6,sc}(*q*) and E_{6,ad}(*q*).

Beyond this "split" (or "untwisted") form of E_{6}, there is also one other form of E_{6} over the finite field **F**_{q}, known as ^{2}E_{6}, which is obtained by twisting by the non-trivial automorphism of the Dynkin diagram of E_{6}. Concretely, ^{2}E_{6}(*q*), which is known as a Steinberg group, can be seen as the subgroup of E_{6}(*q*^{2}) fixed by the composition of the non-trivial diagram automorphism and the non-trivial field automorphism of **F**_{q2}. Twisting does not change the fact that the algebraic fundamental group of ^{2}E_{6,ad} is **Z**/3**Z**, but it does change those *q* for which the covering of ^{2}E_{6,ad} by ^{2}E_{6,sc} is non-trivial on the **F**_{q}-points. Precisely: ^{2}E_{6,sc}(*q*) is a covering of ^{2}E_{6}(*q*), and ^{2}E_{6,ad}(*q*) lies in its automorphism group; when *q*+1 is not divisible by 3, all three coincide, and otherwise (when *q* is congruent to 2 mod 3), the degree of ^{2}E_{6,sc}(*q*) over ^{2}E_{6}(*q*) is 3 and ^{2}E_{6}(*q*) is of index 3 in ^{2}E_{6,ad}(*q*), which explains why ^{2}E_{6,sc}(*q*) and ^{2}E_{6,ad}(*q*) are often written as 3·^{2}E_{6}(*q*) and ^{2}E_{6}(*q*)·3.

Two notational issues should be raised concerning the groups ^{2}E_{6}(*q*). One is that this is sometimes written ^{2}E_{6}(*q*^{2}), a notation which has the advantage of transposing more easily to the Suzuki and Ree groups, but the disadvantage of deviating from the notation for the **F**_{q}-points of an algebraic group. Another is that whereas ^{2}E_{6,sc}(*q*) and ^{2}E_{6,ad}(*q*) are the **F**_{q}-points of an algebraic group, the group in question also depends on *q* (e.g., the points over **F**_{q2} of the same group are the untwisted E_{6,sc}(*q*^{2}) and E_{6,ad}(*q*^{2})).

The groups E_{6}(*q*) and ^{2}E_{6}(*q*) are simple for any *q*,^{ [5] }^{ [6] } and constitute two of the infinite families in the classification of finite simple groups. Their order is given by the following formula (sequence A008872 in the OEIS ):

(sequence A008916 in the OEIS ). The order of E_{6,sc}(*q*) or E_{6,ad}(*q*) (both are equal) can be obtained by removing the dividing factor gcd(3,*q*−1) from the first formula (sequence A008871 in the OEIS ), and the order of ^{2}E_{6,sc}(*q*) or ^{2}E_{6,ad}(*q*) (both are equal) can be obtained by removing the dividing factor gcd(3,*q*+1) from the second (sequence A008915 in the OEIS ).

The Schur multiplier of E_{6}(*q*) is always gcd(3,*q*−1) (i.e., E_{6,sc}(*q*) is its Schur cover). The Schur multiplier of ^{2}E_{6}(*q*) is gcd(3,*q*+1) (i.e., ^{2}E_{6,sc}(*q*) is its Schur cover) outside of the exceptional case *q*=2 where it is 2^{2}·3 (i.e., there is an additional 2^{2}-fold cover). The outer automorphism group of E_{6}(*q*) is the product of the diagonal automorphism group **Z**/gcd(3,*q*−1)**Z** (given by the action of E_{6,ad}(*q*)), the group **Z**/2**Z** of diagram automorphisms, and the group of field automorphisms (i.e., cyclic of order *f* if *q*=*p ^{f}* where

*N* = 8 supergravity in five dimensions, which is a dimensional reduction from 11 dimensional supergravity, admits an E_{6} bosonic global symmetry and an Sp(8) bosonic local symmetry. The fermions are in representations of Sp(8), the gauge fields are in a representation of E_{6}, and the scalars are in a representation of both (Gravitons are singlets with respect to both). Physical states are in representations of the coset E_{6}/Sp(8).

In grand unification theories, E_{6} appears as a possible gauge group which, after its breaking, gives rise to the SU(3) × SU(2) × U(1) gauge group of the standard model. One way of achieving this is through breaking to SO(10) × U(1). The adjoint **78** representation breaks, as explained above, into an adjoint **45**, spinor **16** and **16** as well as a singlet of the SO(10) subalgebra. Including the U(1) charge we have

Where the subscript denotes the U(1) charge.

Likewise, the fundamental representation **27** and its conjugate **27** break into a scalar **1**, a vector **10** and a spinor, either **16** or **16**:

Thus, one can get the Standard Model's elementary fermions and Higgs boson.

In mathematics, a **Lie algebra** is a vector space together with an operation called the **Lie bracket**, an alternating bilinear map , that satisfies the Jacobi identity. The vector space together with this operation is a non-associative algebra, meaning that the Lie bracket is not necessarily associative.

In mathematics, the **unitary group** of degree *n*, denoted U(*n*), is the group of *n* × *n* unitary matrices, with the group operation of matrix multiplication. The unitary group is a subgroup of the general linear group GL(*n*, **C**). **Hyperorthogonal group** is an archaic name for the unitary group, especially over finite fields. For the group of unitary matrices with determinant 1, see Special unitary group.

In mathematics, **G _{2}** is the name of three simple Lie groups (a complex form, a compact real form and a split real form), their Lie algebras as well as some algebraic groups. They are the smallest of the five exceptional simple Lie groups. G

In mathematics, **F _{4}** is the name of a Lie group and also its Lie algebra

In mathematics, in particular the theory of Lie algebras, the **Weyl group** of a root system Φ is a subgroup of the isometry group of that root system. Specifically, it is the subgroup which is generated by reflections through the hyperplanes orthogonal to the roots, and as such is a finite reflection group. In fact it turns out that *most* finite reflection groups are Weyl groups. Abstractly, Weyl groups are finite Coxeter groups, and are important examples of these.

In mathematics, the **adjoint representation** of a Lie group *G* is a way of representing the elements of the group as linear transformations of the group's Lie algebra, considered as a vector space. For example, if *G* is , the Lie group of real *n*-by-*n* invertible matrices, then the adjoint representation is the group homomorphism that sends an invertible *n*-by-*n* matrix to an endomorphism of the vector space of all linear transformations of defined by: .

In mathematics, **E _{8}** is any of several closely related exceptional simple Lie groups, linear algebraic groups or Lie algebras of dimension 248; the same notation is used for the corresponding root lattice, which has rank 8. The designation E

In mathematics, **E _{7}** is the name of several closely related Lie groups, linear algebraic groups or their Lie algebras

In abstract algebra, a **Jordan algebra** is a nonassociative algebra over a field whose multiplication satisfies the following axioms:

- .

In mathematics, a **reductive group** is a type of linear algebraic group over a field. One definition is that a connected linear algebraic group *G* over a perfect field is reductive if it has a representation with finite kernel which is a direct sum of irreducible representations. Reductive groups include some of the most important groups in mathematics, such as the general linear group *GL*(*n*) of invertible matrices, the special orthogonal group *SO*(*n*), and the symplectic group *Sp*(2*n*). **Simple algebraic groups** and **semisimple algebraic groups** are reductive.

In mathematics, a **vertex operator algebra** (**VOA**) is an algebraic structure that plays an important role in two-dimensional conformal field theory and string theory. In addition to physical applications, vertex operator algebras have proven useful in purely mathematical contexts such as monstrous moonshine and the geometric Langlands correspondence.

In mathematics, a **Cartan subalgebra**, often abbreviated as **CSA**, is a nilpotent subalgebra of a Lie algebra that is self-normalising. They were introduced by Élie Cartan in his doctoral thesis. It controls the representation theory of a semi-simple Lie algebra over a field of characteristic .

In mathematics, a Lie algebra is **semisimple** if it is a direct sum of simple Lie algebras.

In mathematics, a Lie algebra is **nilpotent** if its lower central series terminates in the zero subalgebra. The *lower central series* is the sequence of subalgebras

In mathematics, a **regular element** of a Lie algebra or Lie group is an element whose centralizer has dimension as small as possible. For example, in a complex semisimple Lie algebra, an element is regular if its centralizer in has dimension equal to the rank of , which in turn equals the dimension of some Cartan subalgebra . An element a Lie group is regular if its centralizer has dimension equal to the rank of .

In mathematics, **Borel–de Siebenthal theory** describes the closed connected subgroups of a compact Lie group that have *maximal rank*, i.e. contain a maximal torus. It is named after the Swiss mathematicians Armand Borel and Jean de Siebenthal who developed the theory in 1949. Each such subgroup is the identity component of the centralizer of its center. They can be described recursively in terms of the associated root system of the group. The subgroups for which the corresponding homogeneous space has an invariant complex structure correspond to parabolic subgroups in the complexification of the compact Lie group, a reductive algebraic group.

In mathematics, **symmetric cones**, sometimes called **domains of positivity**, are open convex self-dual cones in Euclidean space which have a transitive group of symmetries, i.e. invertible operators that take the cone onto itself. By the Koecher–Vinberg theorem these correspond to the cone of squares in finite-dimensional real Euclidean Jordan algebras, originally studied and classified by Jordan, von Neumann & Wigner (1934). The tube domain associated with a symmetric cone is a noncompact Hermitian symmetric space of **tube type**. All the algebraic and geometric structures associated with the symmetric space can be expressed naturally in terms of the Jordan algebra. The other irreducible Hermitian symmetric spaces of noncompact type correspond to Siegel domains of the second kind. These can be described in terms of more complicated structures called Jordan triple systems, which generalize Jordan algebras without identity.

In mathematics, a **mutation**, also called a **homotope**, of a unital Jordan algebra is a new Jordan algebra defined by a given element of the Jordan algebra. The mutation has a unit if and only if the given element is invertible, in which case the mutation is called a **proper mutation** or an **isotope**. Mutations were first introduced by Max Koecher in his Jordan algebraic approach to Hermitian symmetric spaces and bounded symmetric domains of tube type. Their functorial properties allow an explicit construction of the corresponding Hermitian symmetric space of compact type as a compactification of a finite-dimensional complex semisimple Jordan algebra. The automorphism group of the compactification becomes a complex subgroup, the complexification of its maximal compact subgroup. Both groups act transitively on the compactification. The theory has been extended to cover all Hermitian symmetric spaces using the theory of Jordan pairs or Jordan triple systems. Koecher obtained the results in the more general case directly from the Jordan algebra case using the fact that only Jordan pairs associated with period two automorphisms of Jordan algebras are required.

In mathematics, **Lie group–Lie algebra correspondence** allows one to correspond a Lie group to a Lie algebra or vice versa, and study the conditions for such a relationship. Lie groups that are isomorphic to each other have Lie algebras that are isomorphic to each other, but the converse is not necessarily true. One obvious counterexample is and which are non-isomorphic to each other as Lie groups but their Lie algebras are isomorphic to each other. However, by restricting our attention to the simply connected Lie groups, the Lie group-Lie algebra correspondence will be one-to-one.

This is a glossary for the terminology applied in the mathematical theories of Lie groups and Lie algebras. For the topics in the representation theory of Lie groups and Lie algebras, see Glossary of representation theory. Because of the lack of other options, the glossary also includes some generalizations such as quantum group.

- Adams, J. Frank (1996),
*Lectures on exceptional Lie groups*, Chicago Lectures in Mathematics, University of Chicago Press, ISBN 978-0-226-00526-3, MR 1428422 . - Baez, John (2002). "The Octonions, Section 4.4: E
_{6}".*Bull. Amer. Math. Soc*.**39**(2): 145–205. arXiv: math/0105155 . doi:10.1090/S0273-0979-01-00934-X. ISSN 0273-0979. S2CID 586512. Online HTML version at . - Cremmer, E.; J. Scherk; J. H. Schwarz (1979). "Spontaneously Broken N=8 Supergravity".
*Phys. Lett. B*.**84**(1): 83–86. Bibcode:1979PhLB...84...83C. doi:10.1016/0370-2693(79)90654-3. Online scanned version at^{[ }*permanent dead link*]. - Dickson, Leonard Eugene (1901), "A class of groups in an arbitrary realm connected with the configuration of the 27 lines on a cubic surface",
*The Quarterly Journal of Pure and Applied Mathematics*,**33**: 145–173, reprinted in volume V of his collected works - Dickson, Leonard Eugene (1908), "A class of groups in an arbitrary realm connected with the configuration of the 27 lines on a cubic surface (second paper)",
*The Quarterly Journal of Pure and Applied Mathematics*,**39**: 205–209, ISBN 9780828403061, reprinted in volume VI of his collected works - Ichiro, Yokota (2009). "Exceptional Lie groups". arXiv: 0902.0431 [math.DG].

- ↑ Rosenfeld, Boris (1997),
*Geometry of Lie Groups*(theorem 7.4 on page 335, and following paragraph). - ↑ Платонов, Владимир П.; Рапинчук, Андрей С. (1991).
*Алгебраические группы и теория чисел*. Наука. ISBN 5-02-014191-7. (English translation: Platonov, Vladimir P.; Rapinchuk, Andrei S. (1994).*Algebraic groups and number theory*. Academic Press. ISBN 0-12-558180-7.), §2.2.4 - ↑ Springer, Tonny A.; Veldkamp, Ferdinand D. (2000).
*Octonions, Jordan Algebras, and Exceptional Groups*. Springer. doi:10.1007/978-3-662-12622-6. ISBN 978-3-642-08563-5. MR 1763974., §7.3 - ↑ Conway, John Horton; Curtis, Robert Turner; Norton, Simon Phillips; Parker, Richard A; Wilson, Robert Arnott (1985).
*Atlas of Finite Groups: Maximal Subgroups and Ordinary Characters for Simple Groups*. Oxford University Press. p. 26. ISBN 0-19-853199-0. - ↑ Carter, Roger W. (1989).
*Simple Groups of Lie Type*. Wiley Classics Library. John Wiley & Sons. ISBN 0-471-50683-4. - ↑ Wilson, Robert A. (2009).
*The Finite Simple Groups*. Graduate Texts in Mathematics.**251**. Springer-Verlag. ISBN 978-1-84800-987-5.

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