Definition 4.8 .

Let F 𝐹 F italic_F be the set of reference frame configurations. We assume that there is some fixed map ϵ : F C : italic-ϵ 𝐹 𝐶 \epsilon:F\to C italic_ϵ : italic_F → italic_C , , which allows one to choose a particular element of the reference frame channel corresponding to one’s own reference frame. 5 5 5 For instance, in Example 4.4 , one could choose the orientation such that the x 𝑥 x italic_x -, y 𝑦 y italic_y - and z 𝑧 z italic_z -axes of the object are lined up with those of one’s own Cartesian frame. We also assume that this map is natural under a change in reference frame:

g ϵ ( f ) = ϵ ( g f ) 𝑔 italic-ϵ 𝑓 italic-ϵ 𝑔 𝑓 g\cdot\epsilon(f)=\epsilon(g\cdot f) italic_g ⋅ italic_ϵ ( italic_f ) = italic_ϵ ( italic_g ⋅ italic_f ) (6)

Definition C.11 .

Let X 𝑋 X italic_X be a compact Kähler manifold, let φ 𝒟 1 , 1 ( X ) 𝜑 superscript 𝒟 1 1 𝑋 \varphi\in\mathcal{D}^{\prime 1,1}(X) italic_φ ∈ caligraphic_D start_POSTSUPERSCRIPT ′ 1 , 1 end_POSTSUPERSCRIPT ( italic_X ) , we say φ 𝜑 \varphi italic_φ has C α superscript 𝐶 𝛼 C^{\alpha} italic_C start_POSTSUPERSCRIPT italic_α end_POSTSUPERSCRIPT primitive if for some(hence any) smooth representative ψ 𝜓 \psi italic_ψ of the cohomology class of φ 𝜑 \varphi italic_φ , there is a C α superscript 𝐶 𝛼 C^{\alpha} italic_C start_POSTSUPERSCRIPT italic_α end_POSTSUPERSCRIPT function f 𝑓 f italic_f such that

φ = ψ + dd c f . 𝜑 𝜓 superscript dd c 𝑓 \varphi=\psi+\mathrm{d}\mathrm{d}^{\mathrm{c}}f. italic_φ = italic_ψ + roman_dd start_POSTSUPERSCRIPT roman_c end_POSTSUPERSCRIPT italic_f .

Definition 2.1 .

Let λ 𝜆 \lambda italic_λ be a positive real number and ρ : 𝖠𝗎𝗍 ( 𝖧 3 ) normal-: 𝜌 normal-→ 𝖠𝗎𝗍 subscript 𝖧 3 \rho:\mathds{R}\rightarrow\mathsf{Aut}(\mathsf{H}_{3}) italic_ρ : blackboard_R → sansserif_Aut ( sansserif_H start_POSTSUBSCRIPT 3 end_POSTSUBSCRIPT ) the Lie group homomorphism given by

ρ ( t ) ( s , z ) = ( s , e i t λ z ) . 𝜌 𝑡 𝑠 𝑧 𝑠 superscript 𝑒 𝑖 𝑡 𝜆 𝑧 \rho(t)(s,z)=(s,e^{it\lambda}z). italic_ρ ( italic_t ) ( italic_s , italic_z ) = ( italic_s , italic_e start_POSTSUPERSCRIPT italic_i italic_t italic_λ end_POSTSUPERSCRIPT italic_z ) .

The real λ 𝜆 \lambda italic_λ -oscillator group of dimension 4 4 4 4 , denoted by O λ subscript 𝑂 𝜆 O_{\lambda} italic_O start_POSTSUBSCRIPT italic_λ end_POSTSUBSCRIPT , is the semidirect product of Heisenberg Lie group 𝖧 3 subscript 𝖧 3 \mathsf{H}_{3} sansserif_H start_POSTSUBSCRIPT 3 end_POSTSUBSCRIPT for the group ( , + ) (\mathds{R},+) ( blackboard_R , + ) by the representation ρ . 𝜌 \rho. italic_ρ .


Definition 2.3 .

Given a combinatorial map ( σ , α ) 𝜎 𝛼 (\sigma,\alpha) ( italic_σ , italic_α ) acting on H 𝐻 H italic_H , we call γ 𝛾 \gamma italic_γ an automorphism if it is a permutation acting on H 𝐻 H italic_H such that γ | H = Id H evaluated-at 𝛾 superscript 𝐻 subscript Id superscript 𝐻 \left.\gamma\right|_{H^{\partial}}={\rm Id}_{H^{\partial}} italic_γ | start_POSTSUBSCRIPT italic_H start_POSTSUPERSCRIPT ∂ end_POSTSUPERSCRIPT end_POSTSUBSCRIPT = roman_Id start_POSTSUBSCRIPT italic_H start_POSTSUPERSCRIPT ∂ end_POSTSUPERSCRIPT end_POSTSUBSCRIPT and

σ = γ σ γ - 1 , α = γ α γ - 1 . formulae-sequence 𝜎 𝛾 𝜎 superscript 𝛾 1 𝛼 𝛾 𝛼 superscript 𝛾 1 \sigma=\gamma\sigma\gamma^{-1},\ \ \ \ \ \ \alpha=\gamma\alpha\gamma^{-1}. italic_σ = italic_γ italic_σ italic_γ start_POSTSUPERSCRIPT - 1 end_POSTSUPERSCRIPT , italic_α = italic_γ italic_α italic_γ start_POSTSUPERSCRIPT - 1 end_POSTSUPERSCRIPT .

Definition 6.13 .

Let k 𝑘 k italic_k be a commutative ring with unit and let A 𝐴 A italic_A be a commutative k 𝑘 k italic_k -algebra. The A 𝐴 A italic_A -module of Kähler differentials of A 𝐴 A italic_A over k 𝑘 k italic_k is the A 𝐴 A italic_A -module generated by elements d ( a ) 𝑑 𝑎 d(a) italic_d ( italic_a ) for a A 𝑎 𝐴 a\in A italic_a ∈ italic_A subject to the relations that d 𝑑 d italic_d is k 𝑘 k italic_k -linear and satisfies the Leibniz rule:

d ( a b ) = d ( a ) b + a d ( b ) . 𝑑 𝑎 𝑏 𝑑 𝑎 𝑏 𝑎 𝑑 𝑏 d(ab)=d(a)b+ad(b). italic_d ( italic_a italic_b ) = italic_d ( italic_a ) italic_b + italic_a italic_d ( italic_b ) .

This A 𝐴 A italic_A -module is denoted by Ω A | k 1 subscript superscript Ω 1 conditional 𝐴 𝑘 \Omega^{1}_{A|k} roman_Ω start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_A | italic_k end_POSTSUBSCRIPT .


Definition 1 (Hom-associative algebra) .

A hom-associative algebra over an associative, commutative, and unital ring R 𝑅 R italic_R , is a triple ( M , , α ) 𝑀 𝛼 (M,\cdot,\alpha) ( italic_M , ⋅ , italic_α ) consisting of an R 𝑅 R italic_R -module M 𝑀 M italic_M , a binary operation : M × M M fragments : M M M \cdot\colon M\times M\to M ⋅ : italic_M × italic_M → italic_M linear in both arguments, and a linear map α : M M : 𝛼 𝑀 𝑀 \alpha\colon M\to M italic_α : italic_M → italic_M satisfying, for all a , b , c M 𝑎 𝑏 𝑐 𝑀 a,b,c\in M italic_a , italic_b , italic_c ∈ italic_M ,

α ( a ) ( b c ) = ( a b ) α ( c ) . 𝛼 𝑎 𝑏 𝑐 𝑎 𝑏 𝛼 𝑐 \alpha(a)\cdot(b\cdot c)=(a\cdot b)\cdot\alpha(c). italic_α ( italic_a ) ⋅ ( italic_b ⋅ italic_c ) = ( italic_a ⋅ italic_b ) ⋅ italic_α ( italic_c ) .

Definition 1.3 .

Let ( 𝒜 , μ , α ) 𝒜 𝜇 𝛼 (\mathcal{A},\mu,\alpha) ( caligraphic_A , italic_μ , italic_α ) and ( 𝒜 , μ , α ) ( resp. ( , [ , ] , α ) 𝑎𝑛𝑑 ( , [ , ] , α ) ) superscript 𝒜 normal-′ superscript 𝜇 normal-′ superscript 𝛼 normal-′ resp. normal-⋅ normal-⋅ 𝛼 𝑎𝑛𝑑 superscript normal-′ superscript normal-⋅ normal-⋅ normal-′ superscript 𝛼 normal-′ (\mathcal{A}^{\prime},\mu^{\prime},\alpha^{\prime})~{}~{}(\hbox{resp.}~{}(% \mathcal{L},[\cdot,\cdot],\alpha)~{}\hbox{and}~{}(\mathcal{L}^{\prime},[\cdot,% \cdot]^{\prime},\alpha^{\prime})) ( caligraphic_A start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT , italic_μ start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT , italic_α start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT ) ( resp. ( caligraphic_L , [ ⋅ , ⋅ ] , italic_α ) and ( caligraphic_L start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT , [ ⋅ , ⋅ ] start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT , italic_α start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT ) ) be two Hom-associative ( resp.  Hom-Lie ) resp.  Hom-Lie (\hbox{resp. ~{}Hom-Lie }) ( resp. Hom-Lie ) algebras. A linear map ϕ : 𝒜 𝒜 normal-: italic-ϕ normal-→ 𝒜 superscript 𝒜 normal-′ \phi:\mathcal{A}\rightarrow\mathcal{A}^{\prime} italic_ϕ : caligraphic_A → caligraphic_A start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT (resp. ϕ : normal-: italic-ϕ normal-→ superscript normal-′ \phi:\mathcal{L}\rightarrow\mathcal{L}^{\prime} italic_ϕ : caligraphic_L → caligraphic_L start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT ) is a Hom-associative (resp. Hom-Lie) algebra morphism if

μ ( ϕ ϕ ) = ϕ μ ( resp. [ , ] ( ϕ ϕ ) = ϕ [ , ] ) 𝑎𝑛𝑑 ϕ α = α ϕ . fragments superscript 𝜇 fragments ( ϕ tensor-product ϕ ) ϕ μ fragments ( resp. superscript fragments [ , ] fragments ( ϕ tensor-product ϕ ) ϕ fragments [ , ] ) italic- 𝑎𝑛𝑑 italic- ϕ α superscript 𝛼 ϕ . \mu^{\prime}\circ(\phi\otimes\phi)=\phi\circ\mu~{}~{}(\hbox{resp. }[\cdot,% \cdot]^{\prime}\circ(\phi\otimes\phi)=\phi\circ[\cdot,\cdot])\quad\hbox{and}% \quad\phi\circ\alpha=\alpha^{\prime}\circ\phi. italic_μ start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT ∘ ( italic_ϕ ⊗ italic_ϕ ) = italic_ϕ ∘ italic_μ ( resp. [ ⋅ , ⋅ ] start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT ∘ ( italic_ϕ ⊗ italic_ϕ ) = italic_ϕ ∘ [ ⋅ , ⋅ ] ) and italic_ϕ ∘ italic_α = italic_α start_POSTSUPERSCRIPT ′ end_POSTSUPERSCRIPT ∘ italic_ϕ .
Definition 1.5 .

Let ( 𝒜 , μ , α ) 𝒜 𝜇 𝛼 (\mathcal{A},\mu,\alpha) ( caligraphic_A , italic_μ , italic_α ) be a Hom-associative algebra. A (left) 𝒜 𝒜 \mathcal{A} caligraphic_A -module is a triple ( M , f , γ ) 𝑀 𝑓 𝛾 (M,f,\gamma) ( italic_M , italic_f , italic_γ ) where M 𝑀 M italic_M is 𝕂 𝕂 \mathbb{K} blackboard_K -vector space and f : M M normal-: 𝑓 normal-→ 𝑀 𝑀 f:M\rightarrow M italic_f : italic_M → italic_M , γ : 𝒜 M M normal-: 𝛾 normal-→ tensor-product 𝒜 𝑀 𝑀 \gamma:\mathcal{A}\otimes M\rightarrow M italic_γ : caligraphic_A ⊗ italic_M → italic_M , are 𝕂 𝕂 \mathbb{K} blackboard_K -linear maps, such that the following identity is satisfied

γ ( μ f ) = γ ( α γ ) . 𝛾 tensor-product 𝜇 𝑓 𝛾 tensor-product 𝛼 𝛾 \gamma\circ(\mu\otimes f)=\gamma\circ(\alpha\otimes\gamma). italic_γ ∘ ( italic_μ ⊗ italic_f ) = italic_γ ∘ ( italic_α ⊗ italic_γ ) .

Definition 10 (Satisfaction Indicator) .
[ x ϕ ] = def 1 if x ϕ else 0 fragments fragments [ x ϕ ] superscript def 1 if x ϕ else 0 [x\in\phi]\mathrel{\stackrel{{\scriptstyle\makebox[0.0pt]{\mbox{def}}}}{{=}}}1% \text{ if }x\in\phi\text{ else }0 [ italic_x ∈ italic_ϕ ] start_RELOP SUPERSCRIPTOP start_ARG = end_ARG start_ARG def end_ARG end_RELOP 1 if italic_x ∈ italic_ϕ else 0 (0.12)

Definition 6.9 .

(cf. [ CQ95 , Section 8] , [ Mes14 , Section 5] ) An Ω normal-Ω \Omega roman_Ω -connection on a right operator B 𝐵 B italic_B -module Z 𝑍 Z italic_Z is a completely bounded A 𝐴 A italic_A -linear map : Z Z B h Ω : 𝑍 subscript superscript tensor-product h 𝐵 𝑍 Ω \nabla:Z\to Z\otimes^{\mathrm{h}}_{B}\Omega ∇ : italic_Z → italic_Z ⊗ start_POSTSUPERSCRIPT roman_h end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_B end_POSTSUBSCRIPT roman_Ω satisfying

( z b ) = ( z ) b + z d ( b ) 𝑧 𝑏 𝑧 𝑏 tensor-product 𝑧 𝑑 𝑏 \nabla(zb)=\nabla(z)b+z\otimes d(b) ∇ ( italic_z italic_b ) = ∇ ( italic_z ) italic_b + italic_z ⊗ italic_d ( italic_b )

for all b B 𝑏 𝐵 b\in B italic_b ∈ italic_B and z Z 𝑧 𝑍 z\in Z italic_z ∈ italic_Z . The curvature of a connection \nabla is the composite map

Z Z B h Ω id Z d 1 - id Ω Z B h Ω B h Ω , 𝑍 subscript superscript tensor-product h 𝐵 𝑍 Ω tensor-product subscript id 𝑍 superscript 𝑑 1 tensor-product subscript id Ω subscript superscript tensor-product h 𝐵 subscript superscript tensor-product h 𝐵 𝑍 Ω Ω Z\xrightarrow{\nabla}Z\otimes^{\mathrm{h}}_{B}\Omega\xrightarrow{\mathrm{id}_{% Z}\otimes d^{1}-\nabla\otimes\mathrm{id}_{\Omega}}Z\otimes^{\mathrm{h}}_{B}% \Omega\otimes^{\mathrm{h}}_{B}\Omega, italic_Z start_ARROW ∇ → end_ARROW italic_Z ⊗ start_POSTSUPERSCRIPT roman_h end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_B end_POSTSUBSCRIPT roman_Ω start_ARROW start_OVERACCENT roman_id start_POSTSUBSCRIPT italic_Z end_POSTSUBSCRIPT ⊗ italic_d start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT - ∇ ⊗ roman_id start_POSTSUBSCRIPT roman_Ω end_POSTSUBSCRIPT end_OVERACCENT → end_ARROW italic_Z ⊗ start_POSTSUPERSCRIPT roman_h end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_B end_POSTSUBSCRIPT roman_Ω ⊗ start_POSTSUPERSCRIPT roman_h end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_B end_POSTSUBSCRIPT roman_Ω ,

and a flat connection is one whose curvature is zero. If Z 𝑍 Z italic_Z is a right Hilbert C * superscript 𝐶 C^{*} italic_C start_POSTSUPERSCRIPT * end_POSTSUPERSCRIPT -module over B 𝐵 B italic_B , then a connection : Z Z B h Ω : 𝑍 subscript superscript tensor-product h 𝐵 𝑍 Ω \nabla:Z\to Z\otimes^{\mathrm{h}}_{B}\Omega ∇ : italic_Z → italic_Z ⊗ start_POSTSUPERSCRIPT roman_h end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_B end_POSTSUBSCRIPT roman_Ω is called Hermitian if it satisfies

(6.10) z 1 | ( z 2 ) Ω - z 2 | ( z 1 ) Ω * = d ( z 1 | z 2 ) subscript inner-product subscript 𝑧 1 subscript 𝑧 2 Ω superscript subscript inner-product subscript 𝑧 2 subscript 𝑧 1 Ω 𝑑 inner-product subscript 𝑧 1 subscript 𝑧 2 \langle z_{1}|\nabla(z_{2})\rangle_{\Omega}-\langle z_{2}|\nabla(z_{1})\rangle% _{\Omega}^{*}=d(\langle z_{1}|z_{2}\rangle) ⟨ italic_z start_POSTSUBSCRIPT 1 end_POSTSUBSCRIPT | ∇ ( italic_z start_POSTSUBSCRIPT 2 end_POSTSUBSCRIPT ) ⟩ start_POSTSUBSCRIPT roman_Ω end_POSTSUBSCRIPT - ⟨ italic_z start_POSTSUBSCRIPT 2 end_POSTSUBSCRIPT | ∇ ( italic_z start_POSTSUBSCRIPT 1 end_POSTSUBSCRIPT ) ⟩ start_POSTSUBSCRIPT roman_Ω end_POSTSUBSCRIPT start_POSTSUPERSCRIPT * end_POSTSUPERSCRIPT = italic_d ( ⟨ italic_z start_POSTSUBSCRIPT 1 end_POSTSUBSCRIPT | italic_z start_POSTSUBSCRIPT 2 end_POSTSUBSCRIPT ⟩ )

for all z 1 , z 2 Z subscript 𝑧 1 subscript 𝑧 2 𝑍 z_{1},z_{2}\in Z italic_z start_POSTSUBSCRIPT 1 end_POSTSUBSCRIPT , italic_z start_POSTSUBSCRIPT 2 end_POSTSUBSCRIPT ∈ italic_Z , where we are using the pairing

| Ω : Z × ( Z B h Ω ) Ω , z 1 | z 2 ω Ω z 1 | z 2 ω . fragments subscript fragments | Ω : Z fragments ( Z subscript superscript tensor-product h 𝐵 Ω ) Ω , subscript fragments subscript 𝑧 1 | subscript 𝑧 2 tensor-product ω Ω fragments subscript 𝑧 1 | subscript 𝑧 2 ω . \langle\cdot|\cdot\rangle_{\Omega}:Z\times(Z\otimes^{\mathrm{h}}_{B}\Omega)\to% \Omega,\qquad\langle z_{1}|z_{2}\otimes\omega\rangle_{\Omega}\coloneqq\langle z% _{1}|z_{2}\rangle\omega. ⟨ ⋅ | ⋅ ⟩ start_POSTSUBSCRIPT roman_Ω end_POSTSUBSCRIPT : italic_Z × ( italic_Z ⊗ start_POSTSUPERSCRIPT roman_h end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_B end_POSTSUBSCRIPT roman_Ω ) → roman_Ω , ⟨ italic_z start_POSTSUBSCRIPT 1 end_POSTSUBSCRIPT | italic_z start_POSTSUBSCRIPT 2 end_POSTSUBSCRIPT ⊗ italic_ω ⟩ start_POSTSUBSCRIPT roman_Ω end_POSTSUBSCRIPT ≔ ⟨ italic_z start_POSTSUBSCRIPT 1 end_POSTSUBSCRIPT | italic_z start_POSTSUBSCRIPT 2 end_POSTSUBSCRIPT ⟩ italic_ω .

Let Con f ( B , A ) superscript Con f 𝐵 𝐴 \operatorname{Con^{f}}(B,A) start_OPFUNCTION roman_Con start_POSTSUPERSCRIPT roman_f end_POSTSUPERSCRIPT end_OPFUNCTION ( italic_B , italic_A ) denote the category whose objects ( Z , Z ) 𝑍 subscript 𝑍 (Z,\nabla_{Z}) ( italic_Z , ∇ start_POSTSUBSCRIPT italic_Z end_POSTSUBSCRIPT ) are right Hilbert C * superscript 𝐶 C^{*} italic_C start_POSTSUPERSCRIPT * end_POSTSUPERSCRIPT -modules over B 𝐵 B italic_B equipped with flat, Hermitian Ω ( B , A ) Ω 𝐵 𝐴 \Omega(B,A) roman_Ω ( italic_B , italic_A ) -connections, with morphisms t : ( W , W ) ( Z , Z ) : 𝑡 𝑊 subscript 𝑊 𝑍 subscript 𝑍 t:(W,\nabla_{W})\to(Z,\nabla_{Z}) italic_t : ( italic_W , ∇ start_POSTSUBSCRIPT italic_W end_POSTSUBSCRIPT ) → ( italic_Z , ∇ start_POSTSUBSCRIPT italic_Z end_POSTSUBSCRIPT ) the adjointable maps of Hilbert C * superscript 𝐶 C^{*} italic_C start_POSTSUPERSCRIPT * end_POSTSUPERSCRIPT -modules satisfying Z t = ( t id Ω ) W subscript 𝑍 𝑡 tensor-product 𝑡 subscript id Ω subscript 𝑊 \nabla_{Z}\circ t=(t\otimes\mathrm{id}_{\Omega})\circ\nabla_{W} ∇ start_POSTSUBSCRIPT italic_Z end_POSTSUBSCRIPT ∘ italic_t = ( italic_t ⊗ roman_id start_POSTSUBSCRIPT roman_Ω end_POSTSUBSCRIPT ) ∘ ∇ start_POSTSUBSCRIPT italic_W end_POSTSUBSCRIPT .


Definition 2.6 .

Let 𝕏 𝕏 \mathbb{X} blackboard_X be a convex algebra. An element z X 𝑧 𝑋 z\in X italic_z ∈ italic_X is 𝕏 𝕏 \mathbb{X} blackboard_X - cancellable if

x , y X . p ( 0 , 1 ) . p x + p ¯ z = p y + p ¯ z x = y . formulae-sequence for-all 𝑥 𝑦 𝑋 for-all 𝑝 0 1 𝑝 𝑥 ¯ 𝑝 𝑧 𝑝 𝑦 ¯ 𝑝 𝑧 𝑥 𝑦 \forall x,y\in X.\,\,\forall p\in(0,1).\,\,px+\bar{p}z=py+\bar{p}z\Rightarrow x% =y. ∀ italic_x , italic_y ∈ italic_X . ∀ italic_p ∈ ( 0 , 1 ) . italic_p italic_x + ¯ start_ARG italic_p end_ARG italic_z = italic_p italic_y + ¯ start_ARG italic_p end_ARG italic_z ⇒ italic_x = italic_y .

The convex algebra 𝕏 𝕏 \mathbb{X} blackboard_X is cancellative if every element of X 𝑋 X italic_X is 𝕏 𝕏 \mathbb{X} blackboard_X -cancellable. \diamond


Definition 38 ( Inner derivations [ 11 ] ) .

Given an endomorphism σ : 𝔽 𝔽 : 𝜎 𝔽 𝔽 \sigma:\mathbb{F}\longrightarrow\mathbb{F} italic_σ : blackboard_F ⟶ blackboard_F , we say that δ : 𝔽 𝔽 : 𝛿 𝔽 𝔽 \delta:\mathbb{F}\longrightarrow\mathbb{F} italic_δ : blackboard_F ⟶ blackboard_F is an inner σ 𝜎 \sigma italic_σ -derivation if there exists γ 𝔽 𝛾 𝔽 \gamma\in\mathbb{F} italic_γ ∈ blackboard_F such that

δ ( b ) = γ ( b - σ ( b ) ) , 𝛿 𝑏 𝛾 𝑏 𝜎 𝑏 \delta(b)=\gamma(b-\sigma(b)), italic_δ ( italic_b ) = italic_γ ( italic_b - italic_σ ( italic_b ) ) ,

for all b 𝔽 𝑏 𝔽 b\in\mathbb{F} italic_b ∈ blackboard_F .


Definition 1.2 .

Let A 𝐴 A italic_A be an algebra and V 𝑉 V italic_V a vector space. Let : A V V fragments : A tensor-product V V \triangleright:A\otimes V\longrightarrow V ▷ : italic_A ⊗ italic_V ⟶ italic_V and : V A V fragments : V tensor-product A V \triangleleft:V\otimes A\longrightarrow V ◁ : italic_V ⊗ italic_A ⟶ italic_V be two linear maps. Then ( V , , ) 𝑉 (V,\triangleright,\triangleleft) ( italic_V , ▷ , ◁ ) is called an A 𝐴 A italic_A -bimodule if

a ( b x ) = ( a b ) x , ( x a ) b = x ( a b ) , ( a x ) b = a ( x b ) , formulae-sequence 𝑎 𝑏 𝑥 𝑎 𝑏 𝑥 formulae-sequence 𝑥 𝑎 𝑏 𝑥 𝑎 𝑏 𝑎 𝑥 𝑏 𝑎 𝑥 𝑏 a\triangleright(b\triangleright x)=(ab)\triangleright x,~{}~{}(x\triangleleft a% )\triangleleft b=x\triangleleft(ab),~{}~{}(a\triangleright x)\triangleleft b=a% \triangleright(x\triangleleft b), italic_a ▷ ( italic_b ▷ italic_x ) = ( italic_a italic_b ) ▷ italic_x , ( italic_x ◁ italic_a ) ◁ italic_b = italic_x ◁ ( italic_a italic_b ) , ( italic_a ▷ italic_x ) ◁ italic_b = italic_a ▷ ( italic_x ◁ italic_b ) , (1.2)

where a , b A 𝑎 𝑏 𝐴 a,b\in A italic_a , italic_b ∈ italic_A and x V 𝑥 𝑉 x\in V italic_x ∈ italic_V .

An A 𝐴 A italic_A -bimodule map f 𝑓 f italic_f from ( V , V , V ) fragments normal-( V normal-, subscript normal-▷ 𝑉 normal-, subscript normal-◁ 𝑉 normal-) (V,\triangleright_{V},{{}_{V}\triangleleft}) ( italic_V , ▷ start_POSTSUBSCRIPT italic_V end_POSTSUBSCRIPT , start_FLOATSUBSCRIPT italic_V end_FLOATSUBSCRIPT ◁ ) to ( W , W , W ) fragments normal-( W normal-, subscript normal-▷ 𝑊 normal-, subscript normal-◁ 𝑊 normal-) (W,\triangleright_{W},{{}_{W}\triangleleft}) ( italic_W , ▷ start_POSTSUBSCRIPT italic_W end_POSTSUBSCRIPT , start_FLOATSUBSCRIPT italic_W end_FLOATSUBSCRIPT ◁ ) is a linear map f : V W : 𝑓 𝑉 𝑊 f:V\longrightarrow W italic_f : italic_V ⟶ italic_W such that f 𝑓 f italic_f is a left A 𝐴 A italic_A -module map from ( V , V ) 𝑉 subscript 𝑉 (V,\triangleright_{V}) ( italic_V , ▷ start_POSTSUBSCRIPT italic_V end_POSTSUBSCRIPT ) to ( W , W ) 𝑊 subscript 𝑊 (W,\triangleright_{W}) ( italic_W , ▷ start_POSTSUBSCRIPT italic_W end_POSTSUBSCRIPT ) and at the same time f 𝑓 f italic_f is a right A 𝐴 A italic_A -module map ( V , V ) fragments ( V , subscript 𝑉 ) (V,{{}_{V}\triangleleft}) ( italic_V , start_FLOATSUBSCRIPT italic_V end_FLOATSUBSCRIPT ◁ ) to ( W , W ) fragments ( W , subscript 𝑊 ) (W,{{}_{W}\triangleleft}) ( italic_W , start_FLOATSUBSCRIPT italic_W end_FLOATSUBSCRIPT ◁ ) .

Definition 3.1 .

Let V 𝑉 V italic_V be a vector space and μ , ν : V V V : 𝜇 𝜈 tensor-product 𝑉 𝑉 𝑉 \mu,\nu:V\otimes V\longrightarrow V italic_μ , italic_ν : italic_V ⊗ italic_V ⟶ italic_V two linear maps such that

μ ( μ i d ) = μ ( i d μ ) , ν ( ν i d ) = ν ( i d ν ) , formulae-sequence 𝜇 tensor-product 𝜇 𝑖 𝑑 𝜇 tensor-product 𝑖 𝑑 𝜇 𝜈 tensor-product 𝜈 𝑖 𝑑 𝜈 tensor-product 𝑖 𝑑 𝜈 \mu(\mu\otimes id)=\mu(id\otimes\mu),~{}\nu(\nu\otimes id)=\nu(id\otimes\nu), italic_μ ( italic_μ ⊗ italic_i italic_d ) = italic_μ ( italic_i italic_d ⊗ italic_μ ) , italic_ν ( italic_ν ⊗ italic_i italic_d ) = italic_ν ( italic_i italic_d ⊗ italic_ν ) ,
ν ( μ i d ) = μ ( i d ν ) = μ ( ν i d ) = ν ( i d μ ) . 𝜈 tensor-product 𝜇 𝑖 𝑑 𝜇 tensor-product 𝑖 𝑑 𝜈 𝜇 tensor-product 𝜈 𝑖 𝑑 𝜈 tensor-product 𝑖 𝑑 𝜇 \nu(\mu\otimes id)=\mu(id\otimes\nu)=\mu(\nu\otimes id)=\nu(id\otimes\mu). italic_ν ( italic_μ ⊗ italic_i italic_d ) = italic_μ ( italic_i italic_d ⊗ italic_ν ) = italic_μ ( italic_ν ⊗ italic_i italic_d ) = italic_ν ( italic_i italic_d ⊗ italic_μ ) .

Then we call ( μ , ν ) 𝜇 𝜈 (\mu,\nu) ( italic_μ , italic_ν ) an associative compatible pair on V 𝑉 V italic_V .


Definition 2.1 .

Let ( A , ) 𝐴 (A,\diamond) ( italic_A , ⋄ ) be a group and let \circ be an associative operation on A 𝐴 A italic_A , for which there exists a function σ : A A : 𝜎 𝐴 𝐴 \sigma:A\to A italic_σ : italic_A → italic_A such that, for all a , b , c A 𝑎 𝑏 𝑐 𝐴 a,b,c\in A italic_a , italic_b , italic_c ∈ italic_A ,

a ( b c ) = ( a b ) σ ( a ) ( a c ) . 𝑎 𝑏 𝑐 𝑎 𝑏 𝜎 superscript 𝑎 𝑎 𝑐 a\circ(b\diamond c)=(a\circ b)\diamond\sigma(a)^{\diamond}\diamond(a\circ c). italic_a ∘ ( italic_b ⋄ italic_c ) = ( italic_a ∘ italic_b ) ⋄ italic_σ ( italic_a ) start_POSTSUPERSCRIPT ⋄ end_POSTSUPERSCRIPT ⋄ ( italic_a ∘ italic_c ) . (2.1)

A quadruple ( A , , , σ ) 𝐴 𝜎 (A,\diamond,\circ,\sigma) ( italic_A , ⋄ , ∘ , italic_σ ) , is called a skew left truss , and the function σ 𝜎 \sigma italic_σ is called a cocycle .

In a symmetric way, a skew right truss is a quadruple ( A , , , σ ) 𝐴 𝜎 (A,\diamond,\circ,\sigma) ( italic_A , ⋄ , ∘ , italic_σ ) with operations \diamond , \circ making A 𝐴 A italic_A into a group and a semigroup respectively, and σ : A A : 𝜎 𝐴 𝐴 \sigma:A\to A italic_σ : italic_A → italic_A such that

( a b ) c = ( a c ) σ ( c ) ( b c ) , 𝑎 𝑏 𝑐 𝑎 𝑐 𝜎 superscript 𝑐 𝑏 𝑐 (a\diamond b)\circ c=(a\circ c)\diamond\sigma(c)^{\diamond}\diamond(b\circ c), ( italic_a ⋄ italic_b ) ∘ italic_c = ( italic_a ∘ italic_c ) ⋄ italic_σ ( italic_c ) start_POSTSUPERSCRIPT ⋄ end_POSTSUPERSCRIPT ⋄ ( italic_b ∘ italic_c ) , (2.2)

for all a , b , c A 𝑎 𝑏 𝑐 𝐴 a,b,c\in A italic_a , italic_b , italic_c ∈ italic_A .

The adjective skew is dropped if the group ( A , ) 𝐴 (A,\diamond) ( italic_A , ⋄ ) is abelian.

The identities ( 2.1 ) and ( 2.2 ) are refered to as left and right truss dristributive laws , respectively.


Definition 2.8 .

Take any segment region I k , l [ 2 k , 2 k + 1 , 2 ( k + 1 ) , , 2 ( l - 1 ) , 2 l - 1 , 2 l ] subscript I 𝑘 𝑙 2 𝑘 2 𝑘 1 2 𝑘 1 2 𝑙 1 2 𝑙 1 2 𝑙 {\rm{I}}_{k,l}\equiv[2k,\;2k+1,\;2(k+1),\cdots,2(l-1),\;2l-1,\;2l] roman_I start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT ≡ [ 2 italic_k , 2 italic_k + 1 , 2 ( italic_k + 1 ) , ⋯ , 2 ( italic_l - 1 ) , 2 italic_l - 1 , 2 italic_l ] with k , l 𝑘 𝑙 k,l\in{\mathbb{Z}} italic_k , italic_l ∈ blackboard_Z k < l 𝑘 𝑙 k<l italic_k < italic_l . Assume that g ( n ) Υ k , l Υ I k , l 𝑔 𝑛 subscript Υ 𝑘 𝑙 subscript Υ subscript I 𝑘 𝑙 g(n)\in\Upsilon_{k,l}\equiv{\Upsilon_{{\rm{I}}_{k,l}}} italic_g ( italic_n ) ∈ roman_Υ start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT ≡ roman_Υ start_POSTSUBSCRIPT roman_I start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT end_POSTSUBSCRIPT should be constant on each of the two-site edges:

g ( 2 k ) = g ( 2 k + 1 ) and g ( 2 l - 1 ) = g ( 2 l ) . 𝑔 2 𝑘 𝑔 2 𝑘 1 and 𝑔 2 𝑙 1 𝑔 2 𝑙 g(2k)=g(2k+1)\ \text{and}\ g(2l-1)=g(2l). italic_g ( 2 italic_k ) = italic_g ( 2 italic_k + 1 ) and italic_g ( 2 italic_l - 1 ) = italic_g ( 2 italic_l ) . (2.14)

The above requirements will be called the open SUSY boundary condition. The set of all g ( n ) Υ k , l 𝑔 𝑛 subscript Υ 𝑘 𝑙 g(n)\in\Upsilon_{k,l} italic_g ( italic_n ) ∈ roman_Υ start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT satisfying the open SUSY boundary condition is denoted by Υ ^ k , l subscript ^ Υ 𝑘 𝑙 \widehat{\Upsilon}_{k,l} ^ start_ARG roman_Υ end_ARG start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT .

Definition 3.1 .

Take any k , l 𝑘 𝑙 k,l\in{\mathbb{Z}} italic_k , italic_l ∈ blackboard_Z such that k < l 𝑘 𝑙 k<l italic_k < italic_l and the finite interval I k , l subscript I 𝑘 𝑙 {\rm{I}}_{k,l} roman_I start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT defined in ( 2.8 ). Let f 𝑓 f italic_f be a { - 1 , + 1 } 1 1 \{-1,+1\} { - 1 , + 1 } -valued sequence on the finite interval I k , l subscript I 𝑘 𝑙 {\rm{I}}_{k,l} roman_I start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT . For any consequent triplet { 2 i - 1 , 2 i , 2 i + 1 } I k , l 2 𝑖 1 2 𝑖 2 𝑖 1 subscript I 𝑘 𝑙 \{2i-1,\;2i,\;2i+1\}\subset{\rm{I}}_{k,l} { 2 italic_i - 1 , 2 italic_i , 2 italic_i + 1 } ⊂ roman_I start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT ( i 𝑖 i\in{\mathbb{Z}} italic_i ∈ blackboard_Z ) assume that neither

f ( 2 i - 1 ) = - 1 , f ( 2 i ) = + 1 , f ( 2 i + 1 ) = - 1 , formulae-sequence 𝑓 2 𝑖 1 1 formulae-sequence 𝑓 2 𝑖 1 𝑓 2 𝑖 1 1 \displaystyle f(2i-1)=-1,\ \ f(2i)=+1,\ \ f(2i+1)=-1, italic_f ( 2 italic_i - 1 ) = - 1 , italic_f ( 2 italic_i ) = + 1 , italic_f ( 2 italic_i + 1 ) = - 1 , (3.1)

nor

f ( 2 i - 1 ) = + 1 , f ( 2 i ) = - 1 , f ( 2 i + 1 ) = + 1 , formulae-sequence 𝑓 2 𝑖 1 1 formulae-sequence 𝑓 2 𝑖 1 𝑓 2 𝑖 1 1 \displaystyle f(2i-1)=+1,\ \ f(2i)=-1,\ \ f(2i+1)=+1, italic_f ( 2 italic_i - 1 ) = + 1 , italic_f ( 2 italic_i ) = - 1 , italic_f ( 2 italic_i + 1 ) = + 1 , (3.2)

is satisfied. Furthermore assume that f 𝑓 f italic_f is constant on the left-end pair sites { 2 k , 2 k + 1 } 2 𝑘 2 𝑘 1 \{2k,\;2k+1\} { 2 italic_k , 2 italic_k + 1 } and on the right-end pair sites { 2 l - 1 , 2 l } 2 𝑙 1 2 𝑙 \{2l-1,\;2l\} { 2 italic_l - 1 , 2 italic_l } . Namely, on the left-end pair

f ( 2 k ) = f ( 2 k + 1 ) = + 1 or f ( 2 k ) = f ( 2 k + 1 ) = - 1 formulae-sequence 𝑓 2 𝑘 𝑓 2 𝑘 1 1 or 𝑓 2 𝑘 𝑓 2 𝑘 1 1 \displaystyle f(2k)=f(2k+1)=+1\quad\text{or}\quad f(2k)=f(2k+1)=-1 italic_f ( 2 italic_k ) = italic_f ( 2 italic_k + 1 ) = + 1 or italic_f ( 2 italic_k ) = italic_f ( 2 italic_k + 1 ) = - 1 (3.3)

and on the right-end pair

f ( 2 l - 1 ) = f ( 2 l ) = + 1 or f ( 2 l - 1 ) = f ( 2 l ) = - 1 . formulae-sequence 𝑓 2 𝑙 1 𝑓 2 𝑙 1 or 𝑓 2 𝑙 1 𝑓 2 𝑙 1 \displaystyle f(2l-1)=f(2l)=+1\quad\text{or}\quad f(2l-1)=f(2l)=-1. italic_f ( 2 italic_l - 1 ) = italic_f ( 2 italic_l ) = + 1 or italic_f ( 2 italic_l - 1 ) = italic_f ( 2 italic_l ) = - 1 . (3.4)

The set of all { - 1 , + 1 } 1 1 \{-1,+1\} { - 1 , + 1 } -valued sequences on I k , l subscript I 𝑘 𝑙 {\rm{I}}_{k,l} roman_I start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT satisfying all the above conditions is denoted by Ξ ^ k , l subscript ^ Ξ 𝑘 𝑙 \hat{\Xi}_{k,l} ^ start_ARG roman_Ξ end_ARG start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT . The union of Ξ ^ k , l subscript ^ Ξ 𝑘 𝑙 \hat{\Xi}_{k,l} ^ start_ARG roman_Ξ end_ARG start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT over all k , l 𝑘 𝑙 k,l\in{\mathbb{Z}} italic_k , italic_l ∈ blackboard_Z ( k < l 𝑘 𝑙 k<l italic_k < italic_l ) is denoted by Ξ ^ ^ Ξ \hat{\Xi} ^ start_ARG roman_Ξ end_ARG :

Ξ ^ := k , l ( k < l ) Ξ ^ k , l . assign ^ Ξ subscript fragments k , l Z fragments ( k l ) subscript ^ Ξ 𝑘 𝑙 \displaystyle\hat{\Xi}:=\bigcup_{k,l\in{\mathbb{Z}}\;(k<l)}\hat{\Xi}_{k,l}. ^ start_ARG roman_Ξ end_ARG := ⋃ start_POSTSUBSCRIPT italic_k , italic_l ∈ blackboard_Z ( italic_k < italic_l ) end_POSTSUBSCRIPT ^ start_ARG roman_Ξ end_ARG start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT . (3.5)

Take any p , q 𝑝 𝑞 p,q\in{\mathbb{Z}} italic_p , italic_q ∈ blackboard_Z ( p < q ) 𝑝 𝑞 (p<q) ( italic_p < italic_q ) . Let

Ξ ^ ( p , q ) := k , l ; p k < l q Ξ ^ k , l . assign ^ Ξ 𝑝 𝑞 subscript formulae-sequence 𝑘 𝑙 𝑝 𝑘 𝑙 𝑞 subscript ^ Ξ 𝑘 𝑙 \displaystyle\hat{\Xi}(p,q):=\bigcup_{k,l\in{\mathbb{Z}};\;p\leq k<l\leq q}% \hat{\Xi}_{k,\;l}. ^ start_ARG roman_Ξ end_ARG ( italic_p , italic_q ) := ⋃ start_POSTSUBSCRIPT italic_k , italic_l ∈ blackboard_Z ; italic_p ≤ italic_k < italic_l ≤ italic_q end_POSTSUBSCRIPT ^ start_ARG roman_Ξ end_ARG start_POSTSUBSCRIPT italic_k , italic_l end_POSTSUBSCRIPT . (3.6)

Each f Ξ ^ 𝑓 ^ Ξ f\in\hat{\Xi} italic_f ∈ ^ start_ARG roman_Ξ end_ARG is called a local { - 1 , + 1 } 1 1 \{-1,+1\} { - 1 , + 1 } -sequence of conservation for the Nicolai model.


Definition 2.2 .

Let 𝒜 𝒜 \mathcal{A} caligraphic_A and 𝒜 ~ normal-~ 𝒜 \tilde{\mathcal{A}} ~ start_ARG caligraphic_A end_ARG be 𝕂 𝕂 \mathbb{K} blackboard_K -evolution algebras and S = { e i : i V } 𝑆 conditional-set subscript 𝑒 𝑖 𝑖 𝑉 S=\{e_{i}:i\in V\} italic_S = { italic_e start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT : italic_i ∈ italic_V } a natural basis for 𝒜 𝒜 \mathcal{A} caligraphic_A . We say that a triple ( f , g , h ) 𝑓 𝑔 (f,g,h) ( italic_f , italic_g , italic_h ) , where f , g , h 𝑓 𝑔 f,g,h italic_f , italic_g , italic_h are three non-singular linear transformations from 𝒜 𝒜 \mathcal{A} caligraphic_A into 𝒜 ~ normal-~ 𝒜 \tilde{\mathcal{A}} ~ start_ARG caligraphic_A end_ARG is an isotopism if

f ( u ) g ( v ) = h ( u v ) , for all u , v 𝒜 . formulae-sequence 𝑓 𝑢 𝑔 𝑣 𝑢 𝑣 for all 𝑢 𝑣 𝒜 f(u)\cdot g(v)=h(u\cdot v),\;\;\;\text{ for all }u,v\in\mathcal{A}. italic_f ( italic_u ) ⋅ italic_g ( italic_v ) = italic_h ( italic_u ⋅ italic_v ) , for all italic_u , italic_v ∈ caligraphic_A .

In this case we say that 𝒜 𝒜 \mathcal{A} caligraphic_A and 𝒜 ~ normal-~ 𝒜 \tilde{\mathcal{A}} ~ start_ARG caligraphic_A end_ARG are isotopic. In addition, the triple is called:

  1. (i)

    a strong isotopism if f = g 𝑓 𝑔 f=g italic_f = italic_g and we say that the algebras are strongly isotopic;

  2. (ii)

    an isomorphism if f = g = h 𝑓 𝑔 f=g=h italic_f = italic_g = italic_h and we say that the algebras are isomorphic.


Definition 19 .

The category FS of fusing strings is the strict monoidal category freely generated by one object, denoted by * * * , and the following four morphisms:

μ = μ - 1 = γ = v = formulae-sequence 𝜇 formulae-sequence superscript 𝜇 1 formulae-sequence 𝛾 𝑣 \mu=\raisebox{-20.0pt}{\includegraphics[height=43.362pt]{cat-mu}}\hskip 28.452% 756pt\mu^{-1}=\raisebox{25.0pt}{\includegraphics[height=43.362pt, angle=180]{% cat-mu}}\hskip 28.452756pt\gamma=\raisebox{-20.0pt}{\includegraphics[height=43% .362pt]{cat-gamma}}\hskip 28.452756ptv=\raisebox{-20.0pt}{\includegraphics[hei% ght=43.362pt]{cat-v}} italic_μ = italic_μ start_POSTSUPERSCRIPT - 1 end_POSTSUPERSCRIPT = italic_γ = italic_v =

where μ , μ - 1 , γ 𝜇 superscript 𝜇 1 𝛾 \mu,\mu^{-1},\gamma italic_μ , italic_μ start_POSTSUPERSCRIPT - 1 end_POSTSUPERSCRIPT , italic_γ and v : * * * * fragments v : tensor-product tensor-product v:*\otimes*\longrightarrow*\otimes* italic_v : * ⊗ * ⟶ * ⊗ * .


Definition 2.1 .

An operational tangent vector at point m M 𝑚 𝑀 m\in M italic_m ∈ italic_M is a linear map δ : C m ( M ) : 𝛿 subscript superscript 𝐶 𝑚 𝑀 \delta:C^{\infty}_{m}(M)\to\mathbb{R} italic_δ : italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT start_POSTSUBSCRIPT italic_m end_POSTSUBSCRIPT ( italic_M ) → blackboard_R satisfying Leibniz rule :

δ ( f g ) ( m ) = δ f g ( m ) + f ( m ) δ g . 𝛿 𝑓 𝑔 𝑚 𝛿 𝑓 𝑔 𝑚 𝑓 𝑚 𝛿 𝑔 \delta(fg)(m)=\delta f\;g(m)+f(m)\;\delta g. italic_δ ( italic_f italic_g ) ( italic_m ) = italic_δ italic_f italic_g ( italic_m ) + italic_f ( italic_m ) italic_δ italic_g . (2.1)

An operational vector field on M 𝑀 M italic_M is a collection of maps δ U : C ( U ) C ( U ) : subscript 𝛿 𝑈 superscript 𝐶 𝑈 superscript 𝐶 𝑈 \delta_{U}:C^{\infty}(U)\to C^{\infty}(U) italic_δ start_POSTSUBSCRIPT italic_U end_POSTSUBSCRIPT : italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_U ) → italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_U ) for each open set U M 𝑈 𝑀 U\subset M italic_U ⊂ italic_M , compatible with restrictions to open subsets and defining an operational tangent vector at every m M 𝑚 𝑀 m\in M italic_m ∈ italic_M .


Definition 2.4 .

Given the rule list d 𝑑 d italic_d of Equation ( 1 ) (or the prefix e 𝑒 e italic_e of Equation ( 3 )), we say that an input 𝐱 𝒳 𝐱 𝒳 \mathbf{x}\in\mathcal{X} bold_x ∈ caligraphic_X is captured by the j 𝑗 j italic_j -th antecedent in d 𝑑 d italic_d (or e 𝑒 e italic_e ) if 𝐱 𝐱 \mathbf{x} bold_x satisfies a j ( d ) superscript subscript 𝑎 𝑗 𝑑 a_{j}^{(d)} italic_a start_POSTSUBSCRIPT italic_j end_POSTSUBSCRIPT start_POSTSUPERSCRIPT ( italic_d ) end_POSTSUPERSCRIPT (or a j ( e ) superscript subscript 𝑎 𝑗 𝑒 a_{j}^{(e)} italic_a start_POSTSUBSCRIPT italic_j end_POSTSUBSCRIPT start_POSTSUPERSCRIPT ( italic_e ) end_POSTSUPERSCRIPT , respectively), and for all k { 0 , 1 , , | d | } 𝑘 0 1 𝑑 k\in\{0,1,...,|d|\} italic_k ∈ { 0 , 1 , … , | italic_d | } (or k { 0 , 1 , , | e | - 1 } 𝑘 0 1 𝑒 1 k\in\{0,1,...,|e|-1\} italic_k ∈ { 0 , 1 , … , | italic_e | - 1 } , respectively) such that 𝐱 𝐱 \mathbf{x} bold_x satisfies a k ( d ) superscript subscript 𝑎 𝑘 𝑑 a_{k}^{(d)} italic_a start_POSTSUBSCRIPT italic_k end_POSTSUBSCRIPT start_POSTSUPERSCRIPT ( italic_d ) end_POSTSUPERSCRIPT (or a k ( e ) superscript subscript 𝑎 𝑘 𝑒 a_{k}^{(e)} italic_a start_POSTSUBSCRIPT italic_k end_POSTSUBSCRIPT start_POSTSUPERSCRIPT ( italic_e ) end_POSTSUPERSCRIPT , respectively), j k 𝑗 𝑘 j\leq k italic_j ≤ italic_k holds – in other words, a j ( d ) superscript subscript 𝑎 𝑗 𝑑 a_{j}^{(d)} italic_a start_POSTSUBSCRIPT italic_j end_POSTSUBSCRIPT start_POSTSUPERSCRIPT ( italic_d ) end_POSTSUPERSCRIPT (or a j ( e ) superscript subscript 𝑎 𝑗 𝑒 a_{j}^{(e)} italic_a start_POSTSUBSCRIPT italic_j end_POSTSUBSCRIPT start_POSTSUPERSCRIPT ( italic_e ) end_POSTSUPERSCRIPT , respectively) is the first antecedent that 𝐱 𝐱 \mathbf{x} bold_x satisfies. We define the function capt by

capt ( 𝐱 , d ) = j (or capt ( 𝐱 , e ) = j , respectively) capt 𝐱 𝑑 𝑗 (or capt 𝐱 𝑒 𝑗 , respectively) \text{capt}(\mathbf{x},d)=j\text{ (or }\text{capt}(\mathbf{x},e)=j\text{, % respectively)} capt ( bold_x , italic_d ) = italic_j (or roman_capt ( bold_x , italic_e ) = italic_j , respectively)

if 𝐱 𝐱 \mathbf{x} bold_x is captured by the j 𝑗 j italic_j -th antecedent in d 𝑑 d italic_d (or e 𝑒 e italic_e ). Moreover, given the prefix e 𝑒 e italic_e of Equation ( 3 ), we say that an input 𝐱 𝒳 𝐱 𝒳 \mathbf{x}\in\mathcal{X} bold_x ∈ caligraphic_X is captured by the prefix e 𝑒 e italic_e if 𝐱 𝐱 \mathbf{x} bold_x is captured by some antecedent in e 𝑒 e italic_e , and we define capt ( 𝐱 , e ) = | e | capt 𝐱 𝑒 𝑒 \text{capt}(\mathbf{x},e)=|e| capt ( bold_x , italic_e ) = | italic_e | if 𝐱 𝐱 \mathbf{x} bold_x is not captured by the prefix e 𝑒 e italic_e .


Definition 3.1 .

The (commutative) operations with ? ? ? ? are defined as

0 * ? = 0 , x * ? = ? , y + ? = ? , and ? + ? = ? = ? * ? formulae-sequence 0 ? 0 formulae-sequence 𝑥 ? ? formulae-sequence 𝑦 ? ? and ? ? ? ? ? 0*?=0,\quad x*?=?,\quad\quad y+?=?,\quad\textnormal{and }?+?=?=?*? 0 * ? = 0 , italic_x * ? = ? , italic_y + ? = ? , and ? + ? = ? = ? * ? (3.1)

for x 𝔽 q * 𝑥 superscript subscript 𝔽 𝑞 x\in\mathbb{F}_{q}^{*} italic_x ∈ blackboard_F start_POSTSUBSCRIPT italic_q end_POSTSUBSCRIPT start_POSTSUPERSCRIPT * end_POSTSUPERSCRIPT and y 𝔽 q 𝑦 subscript 𝔽 𝑞 y\in\mathbb{F}_{q} italic_y ∈ blackboard_F start_POSTSUBSCRIPT italic_q end_POSTSUBSCRIPT .


Definition 1

A vector space 𝔸 𝔸 \mathbb{A} blackboard_A over 𝔽 𝔽 \mathbb{F} blackboard_F with multiplication : 𝔸 𝔸 𝔸 fragments normal-⋅ normal-: A tensor-product A normal-→ A \cdot:\mathbb{A}\otimes\mathbb{A}\rightarrow\mathbb{A} ⋅ : blackboard_A ⊗ blackboard_A → blackboard_A given by ( 𝐮 , 𝐯 ) 𝐮 𝐯 maps-to 𝐮 𝐯 normal-⋅ 𝐮 𝐯 (\mathbf{u},\mathbf{v})\mapsto\mathbf{u}\cdot\mathbf{v} ( bold_u , bold_v ) ↦ bold_u ⋅ bold_v such that

( α 𝐮 + β 𝐯 ) 𝐰 = α ( 𝐮 𝐰 ) + β ( 𝐯 𝐰 ) , 𝐰 ( α 𝐮 + β 𝐯 ) = α ( 𝐰 𝐮 ) + β ( 𝐰 𝐯 ) formulae-sequence 𝛼 𝐮 𝛽 𝐯 𝐰 𝛼 𝐮 𝐰 𝛽 𝐯 𝐰 𝐰 𝛼 𝐮 𝛽 𝐯 𝛼 𝐰 𝐮 𝛽 𝐰 𝐯 (\alpha\mathbf{u}+\beta\mathbf{v})\cdot\mathbf{w}=\alpha(\mathbf{u}\cdot% \mathbf{w})+\beta(\mathbf{v}\cdot\mathbf{w}),\ \ \mathbf{w}\cdot(\alpha\mathbf% {u}+\beta\mathbf{v})=\alpha(\mathbf{w}\cdot\mathbf{u})+\beta(\mathbf{w}\cdot% \mathbf{v}) ( italic_α bold_u + italic_β bold_v ) ⋅ bold_w = italic_α ( bold_u ⋅ bold_w ) + italic_β ( bold_v ⋅ bold_w ) , bold_w ⋅ ( italic_α bold_u + italic_β bold_v ) = italic_α ( bold_w ⋅ bold_u ) + italic_β ( bold_w ⋅ bold_v )

whenever 𝐮 , 𝐯 , 𝐰 𝔸 𝐮 𝐯 𝐰 𝔸 \mathbf{u},\mathbf{v},\mathbf{w}\in\mathbb{A} bold_u , bold_v , bold_w ∈ blackboard_A and α , β 𝔽 𝛼 𝛽 𝔽 \alpha,\beta\in\mathbb{F} italic_α , italic_β ∈ blackboard_F , is said to be an algebra.


Definition 10 (Assert) .

Let p Σ ω 𝖡𝗈𝗈𝗅 𝑝 superscript normal-Σ 𝜔 normal-→ 𝖡𝗈𝗈𝗅 p\in\Sigma^{\omega}\rightarrow\mathsf{Bool} italic_p ∈ roman_Σ start_POSTSUPERSCRIPT italic_ω end_POSTSUPERSCRIPT → sansserif_Bool be a property. The assert property transformer { p } : ( Σ ω 𝖡𝗈𝗈𝗅 ) ( Σ ω 𝖡𝗈𝗈𝗅 ) fragments fragments normal-{ p normal-} normal-: fragments normal-( superscript normal-Σ 𝜔 normal-→ Bool normal-) normal-→ fragments normal-( superscript normal-Σ 𝜔 normal-→ Bool normal-) \{p\}:(\Sigma^{\omega}\rightarrow\mathsf{Bool})\rightarrow(\Sigma^{\omega}% \rightarrow\mathsf{Bool}) { italic_p } : ( roman_Σ start_POSTSUPERSCRIPT italic_ω end_POSTSUPERSCRIPT → sansserif_Bool ) → ( roman_Σ start_POSTSUPERSCRIPT italic_ω end_POSTSUPERSCRIPT → sansserif_Bool ) is defined by

{ p } ( q ) = p q . 𝑝 𝑞 𝑝 𝑞 \{p\}(q)=p\land q. { italic_p } ( italic_q ) = italic_p ∧ italic_q .

Definition 2.24 (Suspension action) .

Let G 𝐺 G italic_G be a Lie group which acts on an Alexandrov space X 𝑋 X italic_X . The action of G 𝐺 G italic_G on Susp ( X ) Susp 𝑋 \operatorname{Susp}(X) roman_Susp ( italic_X ) is called suspension action , if G 𝐺 G italic_G acts on Susp ( X ) Susp 𝑋 \operatorname{Susp}(X) roman_Susp ( italic_X ) as follows:

g [ ( x , t ) ] = [ ( g x , t ) ] . 𝑔 delimited-[] 𝑥 𝑡 delimited-[] 𝑔 𝑥 𝑡 g\cdot[(x,t)]=[(gx,t)]. italic_g ⋅ [ ( italic_x , italic_t ) ] = [ ( italic_g italic_x , italic_t ) ] .

Definition 1 ( Matrix morphisms and vector derivations ) .

We call every ring morphism σ : 𝔽 𝔽 n × n : 𝜎 𝔽 superscript 𝔽 𝑛 𝑛 \sigma:\mathbb{F}\longrightarrow\mathbb{F}^{n\times n} italic_σ : blackboard_F ⟶ blackboard_F start_POSTSUPERSCRIPT italic_n × italic_n end_POSTSUPERSCRIPT a matrix morphism (over 𝔽 𝔽 \mathbb{F} blackboard_F ), and we say that a map δ : 𝔽 𝔽 n : 𝛿 𝔽 superscript 𝔽 𝑛 \delta:\mathbb{F}\longrightarrow\mathbb{F}^{n} italic_δ : blackboard_F ⟶ blackboard_F start_POSTSUPERSCRIPT italic_n end_POSTSUPERSCRIPT is a σ 𝜎 \sigma italic_σ -vector derivation (over 𝔽 𝔽 \mathbb{F} blackboard_F ) if it is additive and satisfies

δ ( a b ) = σ ( a ) δ ( b ) + δ ( a ) b , 𝛿 𝑎 𝑏 𝜎 𝑎 𝛿 𝑏 𝛿 𝑎 𝑏 \delta(ab)=\sigma(a)\delta(b)+\delta(a)b, italic_δ ( italic_a italic_b ) = italic_σ ( italic_a ) italic_δ ( italic_b ) + italic_δ ( italic_a ) italic_b ,

for all a , b 𝔽 𝑎 𝑏 𝔽 a,b\in\mathbb{F} italic_a , italic_b ∈ blackboard_F .


Definition 1.1 .

Let p 𝑝 p italic_p be a singular point of the metric d s 2 𝑑 superscript 𝑠 2 ds^{2} italic_d italic_s start_POSTSUPERSCRIPT 2 end_POSTSUPERSCRIPT on M 2 superscript 𝑀 2 M^{2} italic_M start_POSTSUPERSCRIPT 2 end_POSTSUPERSCRIPT . Then a non-zero tangent vector 𝒗 T p M 2 𝒗 subscript 𝑇 𝑝 superscript 𝑀 2 \boldsymbol{v}\in T_{p}M^{2} bold_italic_v ∈ italic_T start_POSTSUBSCRIPT italic_p end_POSTSUBSCRIPT italic_M start_POSTSUPERSCRIPT 2 end_POSTSUPERSCRIPT is called a null vector if

(1.1) d s 2 ( 𝒗 , 𝒗 ) = 0 . 𝑑 superscript 𝑠 2 𝒗 𝒗 0 ds^{2}(\boldsymbol{v},\boldsymbol{v})=0. italic_d italic_s start_POSTSUPERSCRIPT 2 end_POSTSUPERSCRIPT ( bold_italic_v , bold_italic_v ) = 0 .

Moreover, a local coordinate neighborhood ( U ; u , v ) 𝑈 𝑢 𝑣 (U;u,v) ( italic_U ; italic_u , italic_v ) is called adjusted at p U 𝑝 𝑈 p\in U italic_p ∈ italic_U if v := / v assign subscript 𝑣 𝑣 \partial_{v}:=\partial/\partial v ∂ start_POSTSUBSCRIPT italic_v end_POSTSUBSCRIPT := ∂ / ∂ italic_v gives a null vector of d s 2 𝑑 superscript 𝑠 2 ds^{2} italic_d italic_s start_POSTSUPERSCRIPT 2 end_POSTSUPERSCRIPT at p 𝑝 p italic_p .


Definition 2 .

An algebra 𝐋 = ( L , , \ , / , 0 ) 𝐋 𝐿 \ 0 \mathbf{L}=(L,\cdot,\backslash,/,0) bold_L = ( italic_L , ⋅ , \ , / , 0 ) is called a loop if for all x , y L 𝑥 𝑦 𝐿 x,y\in L italic_x , italic_y ∈ italic_L :

  1. (1)

    x \ ( x y ) = y \ 𝑥 𝑥 𝑦 𝑦 x\backslash(x\cdot y)=y italic_x \ ( italic_x ⋅ italic_y ) = italic_y and ( x y ) / x = y 𝑥 𝑦 𝑥 𝑦 (x\cdot y)/x=y ( italic_x ⋅ italic_y ) / italic_x = italic_y

  2. (2)

    x ( x \ y ) = y 𝑥 \ 𝑥 𝑦 𝑦 x\cdot(x\backslash y)=y italic_x ⋅ ( italic_x \ italic_y ) = italic_y and ( y / x ) x = y 𝑦 𝑥 𝑥 𝑦 (y/x)\cdot x=y ( italic_y / italic_x ) ⋅ italic_x = italic_y

  3. (3)

    0 x = x 0 = x 0 𝑥 𝑥 0 𝑥 0\cdot x=x\cdot 0=x 0 ⋅ italic_x = italic_x ⋅ 0 = italic_x


Definition 2.1 ( Γ Γ \Gamma roman_Γ -invariance) .

Let Γ normal-Γ \Gamma roman_Γ be an r 𝑟 r italic_r dimensional linear subspace of d superscript normal-ℝ 𝑑 {\mathbb{R}}^{d} roman_ℝ start_POSTSUPERSCRIPT italic_d end_POSTSUPERSCRIPT . A function f : d normal-: 𝑓 normal-→ superscript normal-ℝ 𝑑 normal-ℝ f:{\mathbb{R}}^{d}\rightarrow{\mathbb{R}} italic_f : roman_ℝ start_POSTSUPERSCRIPT italic_d end_POSTSUPERSCRIPT → roman_ℝ is said to be Γ normal-Γ \Gamma roman_Γ -invariant if for all x d 𝑥 superscript normal-ℝ 𝑑 x\in{\mathbb{R}}^{d} italic_x ∈ roman_ℝ start_POSTSUPERSCRIPT italic_d end_POSTSUPERSCRIPT and y 𝑦 y italic_y belonging to the subspace Γ superscript normal-Γ perpendicular-to \Gamma^{\perp} roman_Γ start_POSTSUPERSCRIPT ⟂ end_POSTSUPERSCRIPT , i.e. M Γ y = 0 subscript 𝑀 normal-Γ 𝑦 0 M_{\Gamma}y=0 italic_M start_POSTSUBSCRIPT roman_Γ end_POSTSUBSCRIPT italic_y = 0 we have that

f ( x ) = f ( x + y ) 𝑓 𝑥 𝑓 𝑥 𝑦 f(x)=f(x+y) italic_f ( italic_x ) = italic_f ( italic_x + italic_y )

Equivalently there exists a function g : r normal-: 𝑔 normal-→ superscript normal-ℝ 𝑟 normal-ℝ g:{\mathbb{R}}^{r}\rightarrow{\mathbb{R}} italic_g : roman_ℝ start_POSTSUPERSCRIPT italic_r end_POSTSUPERSCRIPT → roman_ℝ such that for all x 𝑥 x italic_x , f ( x ) = g ( M Γ x ) 𝑓 𝑥 𝑔 subscript 𝑀 normal-Γ 𝑥 f(x)=g(M_{\Gamma}x) italic_f ( italic_x ) = italic_g ( italic_M start_POSTSUBSCRIPT roman_Γ end_POSTSUBSCRIPT italic_x ) .


Definition 3 .

[ 17 ] A (right) Leibniz algebra is an non-associative algebra such that for all x , y , z L 𝑥 𝑦 𝑧 𝐿 x,y,z\in L italic_x , italic_y , italic_z ∈ italic_L , the following identity holds:

x ( y z ) = ( x y ) z - ( x z ) y . 𝑥 𝑦 𝑧 𝑥 𝑦 𝑧 𝑥 𝑧 𝑦 x(yz)=(xy)z-(xz)y. italic_x ( italic_y italic_z ) = ( italic_x italic_y ) italic_z - ( italic_x italic_z ) italic_y .

Definition 1

The average treatment moderation effect (ATME) is defined as

δ = 𝛿 absent \delta= italic_δ =
E [ { Y i ( T i = 1 , S i = 1 ) - Y i ( T i = 0 , S i = 1 ) } - { Y i ( T i = 1 , S i = 0 ) - Y i ( T i = 0 , S i = 0 ) } ] = fragments E fragments [ fragments { subscript 𝑌 𝑖 fragments ( subscript 𝑇 𝑖 1 , subscript 𝑆 𝑖 1 ) subscript 𝑌 𝑖 fragments ( subscript 𝑇 𝑖 0 , subscript 𝑆 𝑖 1 ) } fragments { subscript 𝑌 𝑖 fragments ( subscript 𝑇 𝑖 1 , subscript 𝑆 𝑖 0 ) subscript 𝑌 𝑖 fragments ( subscript 𝑇 𝑖 0 , subscript 𝑆 𝑖 0 ) } ] E\left[\{Y_{i}(T_{i}=1,S_{i}=1)-Y_{i}(T_{i}=0,S_{i}=1)\}-\{Y_{i}(T_{i}=1,S_{i}% =0)-Y_{i}(T_{i}=0,S_{i}=0)\}\right]= italic_E [ { italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( italic_T start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 1 , italic_S start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 1 ) - italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( italic_T start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 0 , italic_S start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 1 ) } - { italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( italic_T start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 1 , italic_S start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 0 ) - italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( italic_T start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 0 , italic_S start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT = 0 ) } ] =
E [ { Y i ( 1 , 1 ) - Y i ( 0 , 1 ) } - { Y i ( 1 , 0 ) - Y i ( 0 , 0 ) } ] 𝐸 delimited-[] subscript 𝑌 𝑖 1 1 subscript 𝑌 𝑖 0 1 subscript 𝑌 𝑖 1 0 subscript 𝑌 𝑖 0 0 E\left[\{Y_{i}(1,1)-Y_{i}(0,1)\}-\{Y_{i}(1,0)-Y_{i}(0,0)\}\right] italic_E [ { italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( 1 , 1 ) - italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( 0 , 1 ) } - { italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( 1 , 0 ) - italic_Y start_POSTSUBSCRIPT italic_i end_POSTSUBSCRIPT ( 0 , 0 ) } ]

Definition 5 .

A 1-form ω , normal-ω \omega, italic_ω , on any manifold M 𝑀 M italic_M is a map from the set of vector fields on M 𝑀 M italic_M called Vect ( M ) Vect 𝑀 \textnormal{Vect}(M) Vect ( italic_M ) to C ( M ) superscript 𝐶 𝑀 C^{\infty}(M) italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_M ) that is linear over C ( M ) . superscript 𝐶 𝑀 C^{\infty}(M). italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_M ) . In other words, for any u , v Vect ( M ) 𝑢 𝑣 Vect 𝑀 u,v\in\textnormal{Vect}(M) italic_u , italic_v ∈ Vect ( italic_M ) and g C ( M ) 𝑔 superscript 𝐶 𝑀 g\in C^{\infty}(M) italic_g ∈ italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_M )

  1. (1)
    ω ( u + v ) = ω ( u ) + ω ( v ) 𝜔 𝑢 𝑣 𝜔 𝑢 𝜔 𝑣 \omega(u+v)=\omega(u)+\omega(v) italic_ω ( italic_u + italic_v ) = italic_ω ( italic_u ) + italic_ω ( italic_v )

  2. (2)
    ω ( g v ) = g ω ( v ) 𝜔 𝑔 𝑣 𝑔 𝜔 𝑣 \omega(gv)=g\omega(v) italic_ω ( italic_g italic_v ) = italic_g italic_ω ( italic_v )

The space of all 1 - limit-from 1 1- 1 - forms on a manifold M 𝑀 M italic_M will be denoted by Ω 1 ( M ) superscript normal-Ω 1 𝑀 \Omega^{1}(M) roman_Ω start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT ( italic_M ) [ 2 ] .

Definition 7 .

The exterior algebra over a vector space V 𝑉 V italic_V denoted Λ V normal-Λ 𝑉 \Lambda V roman_Λ italic_V is the algebra generated by V 𝑉 V italic_V with the relation

v u = - u v 𝑣 𝑢 𝑢 𝑣 v\wedge u=-u\wedge v italic_v ∧ italic_u = - italic_u ∧ italic_v

for vectors u , v V 𝑢 𝑣 𝑉 u,v\in V italic_u , italic_v ∈ italic_V where \wedge is known as the wedge product [ 2 ] .

Definition 8 .

We define the differential forms on M 𝑀 M italic_M , denoted Ω ( M ) normal-Ω 𝑀 \Omega(M) roman_Ω ( italic_M ) , to be the algebra generated by Ω 1 ( M ) superscript normal-Ω 1 𝑀 \Omega^{1}(M) roman_Ω start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT ( italic_M ) with the relations

ω μ = - μ ω 𝜔 𝜇 𝜇 𝜔 \omega\wedge\mu=-\mu\wedge\omega italic_ω ∧ italic_μ = - italic_μ ∧ italic_ω

for all ω , μ Ω 1 ( M ) . 𝜔 𝜇 superscript normal-Ω 1 𝑀 \omega,\mu\in\Omega^{1}(M). italic_ω , italic_μ ∈ roman_Ω start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT ( italic_M ) . Elements that are linear combinations of products of k 𝑘 k italic_k 1 - limit-from 1 1- 1 - forms are called k - limit-from 𝑘 k- italic_k - forms and the space is denoted by Ω k ( M ) superscript normal-Ω 𝑘 𝑀 \Omega^{k}(M) roman_Ω start_POSTSUPERSCRIPT italic_k end_POSTSUPERSCRIPT ( italic_M ) . Moreover,

Ω ( M ) = k Ω k ( M ) Ω 𝑀 subscript direct-sum 𝑘 superscript Ω 𝑘 𝑀 \Omega(M)=\oplus_{k}\Omega^{k}(M) roman_Ω ( italic_M ) = ⊕ start_POSTSUBSCRIPT italic_k end_POSTSUBSCRIPT roman_Ω start_POSTSUPERSCRIPT italic_k end_POSTSUPERSCRIPT ( italic_M )

[ 2 ] .

Definition 9 .

In particular when k = 2 𝑘 2 k=2 italic_k = 2 ω 𝜔 \omega italic_ω is a 2 - limit-from 2 2- 2 - form. If

d ω = 0 , 𝑑 𝜔 0 d\omega=0, italic_d italic_ω = 0 ,

then we say that ω 𝜔 \omega italic_ω is a closed 2 - limit-from 2 2- 2 - form. We say that ω 𝜔 \omega italic_ω is a nondegenerate 2 - limit-from 2 2- 2 - form if for any nonzero v 𝑣 v italic_v there exists u 𝑢 u italic_u such that

ω ( v , u ) 0 𝜔 𝑣 𝑢 0 \omega(v,u)\neq 0 italic_ω ( italic_v , italic_u ) ≠ 0

where u , v T x M 𝑢 𝑣 subscript 𝑇 𝑥 𝑀 u,v\in T_{x}M italic_u , italic_v ∈ italic_T start_POSTSUBSCRIPT italic_x end_POSTSUBSCRIPT italic_M [ 1 ] .

Definition 11 .

Given functions f , g , h C ( M ) 𝑓 𝑔 superscript 𝐶 𝑀 f,g,h\in C^{\infty}(M) italic_f , italic_g , italic_h ∈ italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_M ) and a , b , 𝑎 𝑏 a,b\in\mathbb{R}, italic_a , italic_b ∈ blackboard_R , a Poisson bracket on a manifold M 𝑀 M italic_M is a binary operation

C ( M ) × C ( M ) C ( M ) , superscript 𝐶 𝑀 superscript 𝐶 𝑀 superscript 𝐶 𝑀 C^{\infty}(M)\times C^{\infty}(M)\to C^{\infty}(M), italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_M ) × italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_M ) → italic_C start_POSTSUPERSCRIPT ∞ end_POSTSUPERSCRIPT ( italic_M ) ,
( f , g ) { f , g } , maps-to 𝑓 𝑔 𝑓 𝑔 (f,g)\mapsto\{f,g\}, ( italic_f , italic_g ) ↦ { italic_f , italic_g } ,

that satisfies the following:

  1. (1)

    Antisymmetry { f , g } = - { g , f } 𝑓 𝑔 𝑔 𝑓 \{f,g\}=-\{g,f\} { italic_f , italic_g } = - { italic_g , italic_f }

  2. (2)

    Bilinearity

    { f , a g + b h } = a { f , g } + b { f , h } 𝑓 𝑎 𝑔 𝑏 𝑎 𝑓 𝑔 𝑏 𝑓 \{f,ag+bh\}=a\{f,g\}+b\{f,h\} { italic_f , italic_a italic_g + italic_b italic_h } = italic_a { italic_f , italic_g } + italic_b { italic_f , italic_h }

  3. (3)

    Jacobi Identity

    { f , { g , h } } + { { g , h } , f } + { h , { f , g } } = 0 . 𝑓 𝑔 𝑔 𝑓 𝑓 𝑔 0 \{f,\{g,h\}\}+\{\{g,h\},f\}+\{h,\{f,g\}\}=0. { italic_f , { italic_g , italic_h } } + { { italic_g , italic_h } , italic_f } + { italic_h , { italic_f , italic_g } } = 0 .

  4. (4)

    Leibniz Law

    { f g , h } = { f , h } g + f { g , h } 𝑓 𝑔 𝑓 𝑔 𝑓 𝑔 \{fg,h\}=\{f,h\}g+f\{g,h\} { italic_f italic_g , italic_h } = { italic_f , italic_h } italic_g + italic_f { italic_g , italic_h }

[ 6 ] .