Constructor for spaces of modular forms for Hecke triangle groups based on a type¶
AUTHORS:
Jonas Jermann (2013): initial version
- sage.modular.modform_hecketriangle.constructor.FormsRing(analytic_type, group=3, base_ring=Integer Ring, red_hom=False)¶
Return the FormsRing with the given
analytic_type,groupbase_ringand variablered_hom.INPUT:
analytic_type– An element ofAnalyticType()describingthe analytic type of the space.
group– The index of the (Hecke triangle) group of the space(default: 3`).
base_ring– The base ring of the space(default:
ZZ).
red_hom– The (boolean= variablered_homof the space(default:
False).
For the variables
group,base_ring,red_homthe same arguments as for the classFormsRing_abstractcan be used. The variables will then be put in canonical form.OUTPUT:
The FormsRing with the given properties.
EXAMPLES:
sage: from sage.modular.modform_hecketriangle.constructor import FormsRing sage: FormsRing("cusp", group=5, base_ring=CC) CuspFormsRing(n=5) over Complex Field with 53 bits of precision sage: FormsRing("holo") ModularFormsRing(n=3) over Integer Ring sage: FormsRing("weak", group=6, base_ring=ZZ, red_hom=True) WeakModularFormsRing(n=6) over Integer Ring sage: FormsRing("mero", group=7, base_ring=ZZ) MeromorphicModularFormsRing(n=7) over Integer Ring sage: FormsRing(["quasi", "cusp"], group=5, base_ring=CC) QuasiCuspFormsRing(n=5) over Complex Field with 53 bits of precision sage: FormsRing(["quasi", "holo"]) QuasiModularFormsRing(n=3) over Integer Ring sage: FormsRing(["quasi", "weak"], group=6, base_ring=ZZ, red_hom=True) QuasiWeakModularFormsRing(n=6) over Integer Ring sage: FormsRing(["quasi", "mero"], group=7, base_ring=ZZ, red_hom=True) QuasiMeromorphicModularFormsRing(n=7) over Integer Ring sage: FormsRing(["quasi", "cusp"], group=infinity) QuasiCuspFormsRing(n=+Infinity) over Integer Ring
- sage.modular.modform_hecketriangle.constructor.FormsSpace(analytic_type, group=3, base_ring=Integer Ring, k=0, ep=None)¶
Return the FormsSpace with the given
analytic_type,groupbase_ringand degree (k,ep).INPUT:
analytic_type– An element ofAnalyticType()describingthe analytic type of the space.
group– The index of the (Hecke triangle) group of thespace (default: \(3\)).
base_ring– The base ring of the space(default:
ZZ).
k– The weight of the space, a rational number(default:
0).
ep– The multiplier of the space, \(1\), \(-1\)or
None(in caseepshould be determined fromk). Default:None.
For the variables
group,base_ring,k,epthe same arguments as for the classFormsSpace_abstractcan be used. The variables will then be put in canonical form. In particular the multiplierepis calculated as usual fromkifep == None.OUTPUT:
The FormsSpace with the given properties.
EXAMPLES:
sage: from sage.modular.modform_hecketriangle.constructor import FormsSpace sage: FormsSpace([]) ZeroForms(n=3, k=0, ep=1) over Integer Ring sage: FormsSpace(["quasi"]) # not implemented sage: FormsSpace("cusp", group=5, base_ring=CC, k=12, ep=1) CuspForms(n=5, k=12, ep=1) over Complex Field with 53 bits of precision sage: FormsSpace("holo") ModularForms(n=3, k=0, ep=1) over Integer Ring sage: FormsSpace("weak", group=6, base_ring=ZZ, k=0, ep=-1) WeakModularForms(n=6, k=0, ep=-1) over Integer Ring sage: FormsSpace("mero", group=7, base_ring=ZZ, k=2, ep=-1) MeromorphicModularForms(n=7, k=2, ep=-1) over Integer Ring sage: FormsSpace(["quasi", "cusp"], group=5, base_ring=CC, k=12, ep=1) QuasiCuspForms(n=5, k=12, ep=1) over Complex Field with 53 bits of precision sage: FormsSpace(["quasi", "holo"]) QuasiModularForms(n=3, k=0, ep=1) over Integer Ring sage: FormsSpace(["quasi", "weak"], group=6, base_ring=ZZ, k=0, ep=-1) QuasiWeakModularForms(n=6, k=0, ep=-1) over Integer Ring sage: FormsSpace(["quasi", "mero"], group=7, base_ring=ZZ, k=2, ep=-1) QuasiMeromorphicModularForms(n=7, k=2, ep=-1) over Integer Ring sage: FormsSpace(["quasi", "cusp"], group=infinity, base_ring=ZZ, k=2, ep=-1) QuasiCuspForms(n=+Infinity, k=2, ep=-1) over Integer Ring
- sage.modular.modform_hecketriangle.constructor.rational_type(f, n=3, base_ring=Integer Ring)¶
Return the basic analytic properties that can be determined directly from the specified rational function
fwhich is interpreted as a representation of an element of a FormsRing for the Hecke Triangle group with parameternand the specifiedbase_ring.In particular the following degree of the generators is assumed:
\(deg(1) := (0, 1)\) \(deg(x) := (4/(n-2), 1)\) \(deg(y) := (2n/(n-2), -1)\) \(deg(z) := (2, -1)\)
The meaning of homogeneous elements changes accordingly.
INPUT:
f– A rational function inx,y,z,doverbase_ring.n– An integer greater or equal to \(3\) correspondingto the
HeckeTriangleGroupwith that parameter (default: \(3\)).
base_ring– The base ring of the corresponding forms ring, resp.polynomial ring (default:
ZZ).
OUTPUT:
A tuple
(elem, homo, k, ep, analytic_type)describing the basic analytic properties of \(f\) (with the interpretation indicated above).elem–Trueif \(f\) has a homogeneous denominator.homo–Trueif \(f\) also has a homogeneous numerator.k–Noneif \(f\) is not homogeneous, otherwisethe weight of \(f\) (which is the first component of its degree).
ep–Noneif \(f\) is not homogeneous, otherwisethe multiplier of \(f\) (which is the second component of its degree)
analytic_type– TheAnalyticTypeof \(f\).
For the zero function the degree \((0, 1)\) is choosen.
This function is (heavily) used to determine the type of elements and to check if the element really is contained in its parent.
EXAMPLES:
sage: from sage.modular.modform_hecketriangle.constructor import rational_type sage: (x,y,z,d) = var("x,y,z,d") sage: rational_type(0, n=4) (True, True, 0, 1, zero) sage: rational_type(1, n=12) (True, True, 0, 1, modular) sage: rational_type(x^3 - y^2) (True, True, 12, 1, cuspidal) sage: rational_type(x * z, n=7) (True, True, 14/5, -1, quasi modular) sage: rational_type(1/(x^3 - y^2) + z/d) (True, False, None, None, quasi weakly holomorphic modular) sage: rational_type(x^3/(x^3 - y^2)) (True, True, 0, 1, weakly holomorphic modular) sage: rational_type(1/(x + z)) (False, False, None, None, None) sage: rational_type(1/x + 1/z) (True, False, None, None, quasi meromorphic modular) sage: rational_type(d/x, n=10) (True, True, -1/2, 1, meromorphic modular) sage: rational_type(1.1 * z * (x^8-y^2), n=8, base_ring=CC) (True, True, 22/3, -1, quasi cuspidal) sage: rational_type(x-y^2, n=infinity) (True, True, 4, 1, modular) sage: rational_type(x*(x-y^2), n=infinity) (True, True, 8, 1, cuspidal) sage: rational_type(1/x, n=infinity) (True, True, -4, 1, weakly holomorphic modular)