PhyslibSearch

Physlib.Mathematics.InnerProductSpace.Submodule

7 declarations

definition

Reinterpretation of a submodule ME×FM \subseteq E \times F as a submodule of L2(E×F)L^2(E \times F)

#submoduleToLp

Let EE and FF be inner product spaces over C\mathbb{C}. Given a submodule ME×FM \subseteq E \times F, the definition `submoduleToLp M` is the submodule of E×FE \times F equipped with the L2L^2 norm (the Euclidean norm e2+f2\sqrt{\|e\|^2 + \|f\|^2}), consisting of the same underlying elements as MM. This reinterpretation allows the submodule to inherit the inner product structure of the L2L^2 product space rather than the default product space structure (which uses the supremum norm).

theorem

fM    fsubmoduleToLp Mf \in M \iff f \in \text{submoduleToLp } M

#mem_submodule_iff_mem_submoduleToLp

Let EE and FF be inner product spaces over C\mathbb{C}, and let ME×FM \subseteq E \times F be a submodule. For any element fE×Ff \in E \times F, ff belongs to MM if and only if its reinterpretation in the L2L^2 product space (the product space E×FE \times F equipped with the Euclidean norm e2+f2\sqrt{\|e\|^2 + \|f\|^2}), denoted by toLp2(f)\text{toLp}_2(f), belongs to the reinterpreted submodule submoduleToLp(M)\text{submoduleToLp}(M).

theorem

submoduleToLp(M)=submoduleToLp(M)\text{submoduleToLp}(\overline{M}) = \overline{\text{submoduleToLp}(M)}

#submoduleToLp_closure

Let EE and FF be inner product spaces over C\mathbb{C}, and let MM be a submodule of the product space E×FE \times F (equipped with the default supremum norm topology). Let submoduleToLp(M)\text{submoduleToLp}(M) denote the reinterpretation of MM as a submodule of the product space E×FE \times F equipped with the L2L^2 norm (the Euclidean norm (e,f)2=e2+f2\|(e, f)\|_2 = \sqrt{\|e\|^2 + \|f\|^2}). Then the reinterpretation of the topological closure of MM is equal to the topological closure of the reinterpreted submodule submoduleToLp(M)\text{submoduleToLp}(M).

theorem

fM    toLp2(f)submoduleToLp Mf \in \overline{M} \iff \text{toLp}_2(f) \in \overline{\text{submoduleToLp } M}

#mem_submodule_closure_iff_mem_submoduleToLp_closure

Let EE and FF be inner product spaces over C\mathbb{C}, and let ME×FM \subseteq E \times F be a submodule. For any element fE×Ff \in E \times F, ff belongs to the topological closure M\overline{M} (with respect to the default product topology) if and only if its reinterpretation in the L2L^2 product space E×FE \times F (equipped with the Euclidean norm (e,f)2=e2+f2\|(e, f)\|_2 = \sqrt{\|e\|^2 + \|f\|^2}), denoted by toLp2(f)\text{toLp}_2(f), belongs to the topological closure of the reinterpreted submodule submoduleToLp(M)\text{submoduleToLp}(M).

theorem

gM.adjoint    (g2,g1)(submoduleToLp M)g \in M.\text{adjoint} \iff (g_2, -g_1) \in (\text{submoduleToLp } M)^\perp

#mem_submodule_adjoint_iff_mem_submoduleToLp_orthogonal

Let EE and FF be inner product spaces over C\mathbb{C}, and let MM be a submodule of the product space E×FE \times F. For any element g=(g1,g2)F×Eg = (g_1, g_2) \in F \times E, gg belongs to the adjoint submodule M.adjointM.\text{adjoint} if and only if the transformed element (g2,g1)(g_2, -g_1), when viewed in the L2L^2 product space E×FE \times F (the product space equipped with the Euclidean norm e2+f2\sqrt{\|e\|^2 + \|f\|^2}), belongs to the orthogonal complement of the reinterpreted submodule submoduleToLp M\text{submoduleToLp } M.

theorem

fM.adjoint.adjoint    toLp2(f)(submoduleToLp M)f \in M.\text{adjoint.adjoint} \iff \text{toLp}_2(f) \in (\text{submoduleToLp } M)^{\perp \perp}

#mem_submodule_adjoint_adjoint_iff_mem_submoduleToLp_orthogonal_orthogonal

Let EE and FF be inner product spaces over C\mathbb{C}, and let ME×FM \subseteq E \times F be a submodule. For any element fE×Ff \in E \times F, ff belongs to the double adjoint of MM (denoted M.adjoint.adjointM.\text{adjoint.adjoint}) if and only if its reinterpretation in the L2L^2 product space E×FE \times F (equipped with the Euclidean norm e2+f2\sqrt{\|e\|^2 + \|f\|^2}), denoted by toLp2(f)\text{toLp}_2(f), belongs to the double orthogonal complement of the reinterpreted submodule, denoted by (submoduleToLp M)(\text{submoduleToLp } M)^{\perp \perp}.

theorem

gM.adjoint    (g2,g1)(submoduleToLp M)g \in \overline{M}.\text{adjoint} \iff (g_2, -g_1) \in (\overline{\text{submoduleToLp } M})^\perp

#mem_submodule_closure_adjoint_iff_mem_submoduleToLp_closure_orthogonal

Let EE and FF be inner product spaces over C\mathbb{C}, and let ME×FM \subseteq E \times F be a submodule. For any element g=(g1,g2)F×Eg = (g_1, g_2) \in F \times E, gg belongs to the adjoint of the topological closure of MM (denoted M.adjoint\overline{M}.\text{adjoint}) if and only if the transformed element (g2,g1)(g_2, -g_1), when viewed in the L2L^2 product space E×FE \times F (equipped with the Euclidean norm (e,f)2=e2+f2\|(e, f)\|_2 = \sqrt{\|e\|^2 + \|f\|^2}), belongs to the orthogonal complement of the topological closure of the reinterpreted submodule, denoted (submoduleToLp M)(\overline{\text{submoduleToLp } M})^\perp.