Finite adelic double cosets of orthogonal and Spin groups #
Let Q be a quadratic form over โ and let U be compatible compact-open reference data.
The finite adelic class sets attached to U are
G(โ) \ G(๐ธ_f) / โ_p U_p
for G = O, SO, and Spin. The left subgroup is the range of the corresponding rational
diagonal, rather than an unrelated copy of G(โ), and the right subgroup is the
everywhere-integral subgroup of the restricted product.
The comparisons for these types are deliberately the general double-coset constructions:
- the
finiteAdelic*DoubleCosetMapOfLEmaps are the surjections obtained by enlarging the right compact-open subgroup; - the
finiteAdelic*DoubleCosetConjequivalences compare a right compact-open subgroup with its conjugate by right translation; - the
finiteAdelic*DoubleCosetCongrequivalences compare the actual class sets attached to two compatible tuples when componentwise equivalences preserve every reference subgroup and the rational diagonals.
Keeping these maps separate matters. An eventual change of reference family canonically identifies the ambient restricted products, but need not carry one everywhere-integral subgroup to the other.
References #
- O. T. O'Meara, Introduction to Quadratic Forms (1963), ยง101.
- A. Weil, Adeles and Algebraic Groups (1982), Chapter I.
The finite adelic orthogonal double-coset set
O(V)(โ) \ O(V)(๐ธ_f) / โ_p U_p^O.
Instances For
The finite adelic Spin double-coset set
Spin(V)(โ) \ Spin(V)(๐ธ_f) / โ_p U_p^{Spin}.
Instances For
The finite adelic special-orthogonal double-coset set
SO(V)(โ) \ SO(V)(๐ธ_f) / โ_p U_p^{SO}.
Instances For
Enlargement and conjugation of the right subgroup #
Enlarging the right subgroup of the finite adelic orthogonal class set gives a surjection.
Instances For
Enlarging the orthogonal right subgroup preserves representatives.
The finite adelic orthogonal double-coset map obtained by enlarging the right subgroup is surjective.
Right translation identifies the finite adelic orthogonal class set with the quotient by the conjugate of its right compact-open subgroup.
Instances For
Orthogonal right translation sends the class of x to the class of x * g.
Not a simp lemma: the codomain contains a coerced mapped subgroup, which simp rewrites to a
set image in the dependent type.
The inverse orthogonal right translation sends the class of y to the class of y * gโปยน.
Not a simp lemma, for the same dependent-type reason as
finiteAdelicOrthogonalDoubleCosetConj_apply_mk.
Enlarging the right subgroup of the finite adelic Spin class set gives a surjection.
Instances For
Enlarging the Spin right subgroup preserves representatives.
The finite adelic Spin double-coset map obtained by enlarging the right subgroup is surjective.
Right translation identifies the finite adelic Spin class set with the quotient by the conjugate of its right compact-open subgroup.
Instances For
Spin right translation sends the class of x to the class of x * g.
Not a simp lemma: the codomain contains a coerced mapped subgroup, which simp rewrites to a
set image in the dependent type.
The inverse Spin right translation sends the class of y to the class of y * gโปยน.
Not a simp lemma, for the same dependent-type reason as
finiteAdelicSpinDoubleCosetConj_apply_mk.
Enlarging the right subgroup of the finite adelic special-orthogonal class set gives a surjection.
Instances For
Enlarging the special-orthogonal right subgroup preserves representatives.
The finite adelic special-orthogonal double-coset map obtained by enlarging the right subgroup is surjective.
Right translation identifies the finite adelic special-orthogonal class set with the quotient by the conjugate of its right compact-open subgroup.
Instances For
Special-orthogonal right translation sends the class of x to the class of x * g.
Not a simp lemma: the codomain contains a coerced mapped subgroup, which simp rewrites to a
set image in the dependent type.
The inverse special-orthogonal right translation sends the class of y to the class of
y * gโปยน.
Not a simp lemma, for the same dependent-type reason as
finiteAdelicSpecialOrthogonalDoubleCosetConj_apply_mk.
Change of quadratic space and compatible tuple #
Componentwise equivalences which preserve every orthogonal reference subgroup and carry the rational diagonal subgroup onto the target diagonal subgroup identify the finite adelic class sets.
Instances For
Change of orthogonal tuple applies the componentwise equivalence to representatives.
The inverse change of orthogonal tuple applies the inverse componentwise equivalence to representatives.
Componentwise equivalences which preserve every Spin reference subgroup and carry the rational diagonal subgroup onto the target diagonal subgroup identify the finite adelic class sets.
Instances For
Change of Spin tuple applies the componentwise equivalence to representatives.
The inverse change of Spin tuple applies the inverse componentwise equivalence to representatives.
Componentwise equivalences which preserve every special-orthogonal reference subgroup and carry the rational diagonal subgroup onto the target diagonal subgroup identify the finite adelic class sets.
Instances For
Change of special-orthogonal tuple applies the componentwise equivalence to representatives.
The inverse change of special-orthogonal tuple applies the inverse componentwise equivalence to representatives.