Congruences between modular forms modulo prime powers

Given a prime p ≥ 5 and an abstract odd representation pn with coefficients modulo pn (for some n ≥ 1) and big image, we prove the existence of a lift of pn to characteristic 0 whenever local lifts exist (under minor technical conditions). Moreover, our results allow to chose the lift's inertia...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Camporino, M., Pacetti, A.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_16089057_v_n6_p1609_Camporino
Aporte de:
id todo:paper_16089057_v_n6_p1609_Camporino
record_format dspace
spelling todo:paper_16089057_v_n6_p1609_Camporino2023-10-03T16:27:52Z Congruences between modular forms modulo prime powers Camporino, M. Pacetti, A. Galois representations Modular forms Given a prime p ≥ 5 and an abstract odd representation pn with coefficients modulo pn (for some n ≥ 1) and big image, we prove the existence of a lift of pn to characteristic 0 whenever local lifts exist (under minor technical conditions). Moreover, our results allow to chose the lift's inertial type at all primes but finitely many (where the lift is of Steinberg type). We apply this result to the realm of modular forms, proving a level lowering theorem modulo prime powers and providing examples of level raising. An easy application of our main result proves that given a modular eigenform f whose Galois representation is not induced from a character (i.e., f has no inner twists), for all primes p but finitely many, and for all positive integers n, there exists an eigenform g = f, which is congruent to f modulo pn. © European Mathematical Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_16089057_v_n6_p1609_Camporino
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Galois representations
Modular forms
spellingShingle Galois representations
Modular forms
Camporino, M.
Pacetti, A.
Congruences between modular forms modulo prime powers
topic_facet Galois representations
Modular forms
description Given a prime p ≥ 5 and an abstract odd representation pn with coefficients modulo pn (for some n ≥ 1) and big image, we prove the existence of a lift of pn to characteristic 0 whenever local lifts exist (under minor technical conditions). Moreover, our results allow to chose the lift's inertial type at all primes but finitely many (where the lift is of Steinberg type). We apply this result to the realm of modular forms, proving a level lowering theorem modulo prime powers and providing examples of level raising. An easy application of our main result proves that given a modular eigenform f whose Galois representation is not induced from a character (i.e., f has no inner twists), for all primes p but finitely many, and for all positive integers n, there exists an eigenform g = f, which is congruent to f modulo pn. © European Mathematical Society.
format JOUR
author Camporino, M.
Pacetti, A.
author_facet Camporino, M.
Pacetti, A.
author_sort Camporino, M.
title Congruences between modular forms modulo prime powers
title_short Congruences between modular forms modulo prime powers
title_full Congruences between modular forms modulo prime powers
title_fullStr Congruences between modular forms modulo prime powers
title_full_unstemmed Congruences between modular forms modulo prime powers
title_sort congruences between modular forms modulo prime powers
url http://hdl.handle.net/20.500.12110/paper_16089057_v_n6_p1609_Camporino
work_keys_str_mv AT camporinom congruencesbetweenmodularformsmoduloprimepowers
AT pacettia congruencesbetweenmodularformsmoduloprimepowers
_version_ 1807314793304948736