Lie submodules of a Lie algebra #
In this file we define Lie submodules, we construct the lattice structure on Lie submodules and we use it to define various important operations, notably the Lie span of a subset of a Lie module.
Main definitions #
LieSubmodule
LieSubmodule.wellFounded_of_noetherian
LieSubmodule.lieSpan
LieSubmodule.map
LieSubmodule.comap
Tags #
lie algebra, lie submodule, lie ideal, lattice structure
A Lie submodule of a Lie module is a submodule that is closed under the Lie bracket. This is a sufficient condition for the subset itself to form a Lie module.
Instances For
Equations
- LieSubmodule.instSetLike = { coe := fun (s : LieSubmodule R L M) => (↑s).carrier, coe_injective' := ⋯ }
The zero module is a Lie submodule of any Lie module.
Equations
- LieSubmodule.instZero = { zero := let __src := 0; { toSubmodule := __src, lie_mem := ⋯ } }
Equations
- LieSubmodule.instInhabited = { default := 0 }
Equations
- LieSubmodule.coeSort = { coe := fun (N : LieSubmodule R L M) => ↥N }
Equations
- LieSubmodule.coeSubmodule = { coe := LieSubmodule.toSubmodule }
Alias of LieSubmodule.mem_toSubmodule
.
Alias of LieSubmodule.toSubmodule_mk
.
Alias of LieSubmodule.toSubmodule_injective
.
Alias of LieSubmodule.toSubmodule_inj
.
Alias of LieSubmodule.toSubmodule_inj
.
Copy of a LieSubmodule
with a new carrier
equal to the old one. Useful to fix definitional
equalities.
Equations
Instances For
Equations
- N.instLieRingModuleSubtypeMem = { bracket := fun (x : L) (m : ↥N) => ⟨⁅x, ↑m⁆, ⋯⟩, add_lie := ⋯, lie_add := ⋯, leibniz_lie := ⋯ }
Equations
- LieSubmodule.instUniqueOfSubsingleton = { default := 0, uniq := ⋯ }
Given a Lie subalgebra K ⊆ L
, if we view L
as a K
-module by restriction, it contains
a distinguished Lie submodule for the action of K
, namely K
itself.
Equations
- K.toLieSubmodule = { toSubmodule := K.toSubmodule, lie_mem := ⋯ }
Instances For
Alias of LieSubmodule.toSubmodule_le_toSubmodule
.
Equations
- LieSubmodule.instBot = { bot := 0 }
Equations
Alias of LieSubmodule.bot_toSubmodule
.
Alias of LieSubmodule.toSubmodule_eq_bot
.
Equations
- LieSubmodule.instTop = { top := let __src := ⊤; { toSubmodule := __src, lie_mem := ⋯ } }
Alias of LieSubmodule.top_toSubmodule
.
Alias of LieSubmodule.toSubmodule_eq_top
.
Equations
- LieSubmodule.instMin = { min := fun (N N' : LieSubmodule R L M) => let __src := ↑N ⊓ ↑N'; { toSubmodule := __src, lie_mem := ⋯ } }
Equations
- One or more equations did not get rendered due to their size.
Alias of LieSubmodule.inf_toSubmodule
.
Alias of LieSubmodule.sInf_toSubmodule
.
Alias of LieSubmodule.sInf_toSubmodule_eq_iInf
.
Alias of LieSubmodule.iInf_toSubmodule
.
Equations
- LieSubmodule.instMax = { max := fun (N N' : LieSubmodule R L M) => let __Submodule := ↑N ⊔ ↑N'; { toSubmodule := __Submodule, lie_mem := ⋯ } }
Equations
- One or more equations did not get rendered due to their size.
Alias of LieSubmodule.sup_toSubmodule
.
Alias of LieSubmodule.sSup_toSubmodule
.
Alias of LieSubmodule.sSup_toSubmodule_eq_iSup
.
Alias of LieSubmodule.iSup_toSubmodule
.
The set of Lie submodules of a Lie module form a complete lattice.
Equations
- One or more equations did not get rendered due to their size.
Alias of LieSubmodule.disjoint_iff_toSubmodule
.
Alias of LieSubmodule.codisjoint_iff_toSubmodule
.
Alias of LieSubmodule.isCompl_iff_toSubmodule
.
Alias of LieSubmodule.iSupIndep_iff_toSubmodule
.
Alias of LieSubmodule.iSupIndep_iff_toSubmodule
.
Alias of LieSubmodule.iSupIndep_iff_toSubmodule
.
Alias of LieSubmodule.iSupIndep_iff_toSubmodule
.
Alias of LieSubmodule.iSup_eq_top_iff_toSubmodule
.
Equations
- LieSubmodule.instAdd = { add := max }
Equations
- LieSubmodule.instZero_1 = { zero := ⊥ }
Equations
- One or more equations did not get rendered due to their size.
The natural functor that forgets the action of L
as an order embedding.
Equations
- LieSubmodule.toSubmodule_orderEmbedding R L M = { toFun := LieSubmodule.toSubmodule, inj' := ⋯, map_rel_iff' := ⋯ }
Instances For
The inclusion of a Lie submodule into its ambient space is a morphism of Lie modules.
Instances For
Given two nested Lie submodules N ⊆ N'
,
the inclusion N ↪ N'
is a morphism of Lie modules.
Equations
- LieSubmodule.inclusion h = { toLinearMap := Submodule.inclusion ⋯, map_lie' := ⋯ }
Instances For
The lieSpan
of a set s ⊆ M
is the smallest Lie submodule of M
that contains s
.
Equations
- LieSubmodule.lieSpan R L s = sInf {N : LieSubmodule R L M | s ⊆ ↑N}
Instances For
lieSpan
forms a Galois insertion with the coercion from LieSubmodule
to Set
.
Equations
- LieSubmodule.gi R L M = { choice := fun (s : Set M) (x : ↑(LieSubmodule.lieSpan R L s) ≤ s) => LieSubmodule.lieSpan R L s, gc := ⋯, le_l_u := ⋯, choice_eq := ⋯ }
Instances For
An induction principle for span membership. If p
holds for 0 and all elements of s
, and is
preserved under addition, scalar multiplication and the Lie bracket, then p
holds for all
elements of the Lie submodule spanned by s
.
A morphism of Lie modules f : M → M'
pushes forward Lie submodules of M
to Lie submodules
of M'
.
Equations
- LieSubmodule.map f N = { toSubmodule := Submodule.map ↑f ↑N, lie_mem := ⋯ }
Instances For
Alias of LieSubmodule.toSubmodule_map
.
A morphism of Lie modules f : M → M'
pulls back Lie submodules of M'
to Lie submodules of
M
.
Equations
- LieSubmodule.comap f N' = { toSubmodule := Submodule.comap ↑f ↑N', lie_mem := ⋯ }
Instances For
Alias of LieSubmodule.toSubmodule_comap
.
An injective morphism of Lie modules embeds the lattice of submodules of the domain into that of the target.
Equations
- LieSubmodule.mapOrderEmbedding hf = { toFun := LieSubmodule.map f, inj' := ⋯, map_rel_iff' := ⋯ }
Instances For
For an injective morphism of Lie modules, any Lie submodule is equivalent to its image.
Equations
- One or more equations did not get rendered due to their size.
Instances For
An equivalence of Lie modules yields an order-preserving equivalence of their lattices of Lie Submodules.
Equations
- LieSubmodule.orderIsoMapComap e = { toFun := LieSubmodule.map e.toLieModuleHom, invFun := LieSubmodule.comap e.toLieModuleHom, left_inv := ⋯, right_inv := ⋯, map_rel_iff' := ⋯ }
Instances For
The kernel of a morphism of Lie algebras, as an ideal in the domain.
Equations
- f.ker = LieSubmodule.comap f ⊥
Instances For
Alias of LieModuleHom.ker_toSubmodule
.
The range of a morphism of Lie modules f : M → N
is a Lie submodule of N
.
See Note [range copy pattern].
Instances For
Alias of LieModuleHom.toSubmodule_range
.
A morphism of Lie modules f : M → N
whose values lie in a Lie submodule P ⊆ N
can be
restricted to a morphism of Lie modules M → P
.
Equations
- LieModuleHom.codRestrict P f h = { toFun := ⇑(LinearMap.codRestrict (↑P) (↑f) h), map_add' := ⋯, map_smul' := ⋯, map_lie' := ⋯ }
Instances For
The natural equivalence between the 'top' Lie submodule and the enclosing Lie module.
Equations
- LieModuleEquiv.ofTop R L M = { toLinearMap := ↑(LinearEquiv.ofTop ⊤ ⋯), map_lie' := ⋯, invFun := (LinearEquiv.ofTop ⊤ ⋯).invFun, left_inv := ⋯, right_inv := ⋯ }
Instances For
The natural equivalence between the 'top' Lie subalgebra and the enclosing Lie algebra.
This is the Lie subalgebra version of Submodule.topEquiv
.
Equations
- LieSubalgebra.topEquiv = { toLieHom := ⊤.incl, invFun := fun (x : L) => ⟨x, ⋯⟩, left_inv := ⋯, right_inv := ⋯ }