X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2Feja_element.py;h=ee33e4ba89fcc3c47be1f9467042dae5e678c859;hb=08aba469c5f8d8947a543f8882fa676ed165e7ee;hp=e7dff7529026cf007056a5ecd66a8f9fba98562a;hpb=6b80adf4c1b41455d6e2afe003cdbc96452d0928;p=sage.d.git diff --git a/mjo/eja/eja_element.py b/mjo/eja/eja_element.py index e7dff75..ee33e4b 100644 --- a/mjo/eja/eja_element.py +++ b/mjo/eja/eja_element.py @@ -1046,6 +1046,13 @@ class FiniteDimensionalEuclideanJordanAlgebraElement(IndexedFreeModuleElement): Return the associative subalgebra of the parent EJA generated by this element. + Since our parent algebra is unital, we want "subalgebra" to mean + "unital subalgebra" as well; thus the subalgebra that an element + generates will itself be a Euclidean Jordan algebra after + restricting the algebra operations appropriately. This is the + subalgebra that Faraut and Korányi work with in section II.2, for + example. + SETUP:: sage: from mjo.eja.eja_algebra import random_eja @@ -1070,14 +1077,13 @@ class FiniteDimensionalEuclideanJordanAlgebraElement(IndexedFreeModuleElement): sage: A(x^2) == A(x)*A(x) True - The subalgebra generated by the zero element is trivial:: + By definition, the subalgebra generated by the zero element is the + one-dimensional algebra generated by the identity element:: sage: set_random_seed() sage: A = random_eja().zero().subalgebra_generated_by() - sage: A - Euclidean Jordan algebra of dimension 0 over... - sage: A.one() - 0 + sage: A.dimension() + 1 """ return FiniteDimensionalEuclideanJordanElementSubalgebra(self, orthonormalize_basis)