Details

Autor(en) / Beteiligte

• Wei, Fu-Tsun
• Yamazaki, Takao

Titel

Rational torsion of generalized Jacobians of modular and Drinfeld modular curves

Ist Teil von

• Forum mathematicum, 2019-05, Vol.31 (3), p.647-659

Ort / Verlag

Berlin: De Gruyter

Erscheinungsjahr

2019

Quelle

De Gruyter journals

Beschreibungen/Notizen

• We consider the generalized Jacobian of the modular curve of level with respect to a reduced divisor consisting of all cusps. Supposing is square free, we explicitly determine the structure of the -rational torsion points on up to 6-primary torsion. The result depicts a fuller picture than [ ] where the case of prime power level was studied. We also obtain an analogous result for Drinfeld modular curves. Our proof relies on similar results for classical Jacobians due to Ohta, Papikian and the first author. We also discuss the Hecke action on and its Eisenstein property.